Plural Doping Steps Patents (Class 438/232)
  • Patent number: 6033949
    Abstract: The preferred embodiment of the present invention overcomes the limitations of the prior art and provides a device and method to increase the latch-up immunity of CMOS devices by forming implants at the well edges. The preferred method uses hybrid resist to form these implants at the edges of the N-wells and/or P-wells. The implants reduce the lifetime of minority carriers in the parasitic transistor, and hence reduce the gain of the parasitic transistor. This reduces the propensity of the CMOS device to latch-up. The preferred embodiment method allows these implants to be formed without requiring additional masking steps over prior art methods. Furthermore, the preferred method for forming the implants results in implants that are self aligned to the edges of the wells.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: March 7, 2000
    Assignee: International Business Machines Corporation
    Inventors: Faye D. Baker, Jeffrey S. Brown, Robert J. Gauthier, Jr., Steven J. Holmes, Robert K. Leidy, Edward J. Nowak, Steven H. Voldman
  • Patent number: 6030863
    Abstract: A method for forming salicide contacts and polycide conductive lines in integrated circuits is described which employs the ion implantation of both germanium and arsenic into polysilicon structures and into source/drain MOSFET elements is described. The method is particularly beneficial in the manufacture of sub-micron CMOS integrated circuits. Germanium is implanted into the polysilicon and into the source/drain surfaces forming a amorphized surface layer. Next a low dose, low energy arsenic implant is administered into the amorphized layer. The low dose shallow arsenic implant in concert with the amorphized layer initiates a balanced formation of titanium suicide over both NMOS and PMOS devices in CMOS integrated circuits without degradation of the PMOS devices with an accompanying reduction of gate-to-source/drain shorts. Amorphization by the electrically neutral germanium ions permits the use of a lower dose of arsenic than would be required if arsenic alone were implanted.
    Type: Grant
    Filed: September 11, 1998
    Date of Patent: February 29, 2000
    Assignee: Taiwan Semiconductor Manufacturing Company
    Inventors: Shou-Zen Chang, Chaochieh Tsai, Cheng Kun Lin, Chi Ming Yang
  • Patent number: 6030875
    Abstract: A semiconductor device having a nitrogen-rich active region-channel interface and process for fabrication thereof is provided. The nitrogen-rich interface can, for example, can reduce the electric field potential in this region and reduce hot carrier injection effects. Consistent with one embodiment of the invention, a semiconductor device is provided having a substrate, at least one gate electrode disposed over the substrate and an active region disposed adjacent to gate electrode. The semiconductor device further includes a channel region extending from the active region beneath the gate electrode and a nitrogen-rich region disposed at an interface between the channel region and the active region. The nitrogen-rich region may, for example, be disposed at least in part in the channel region. The nitrogen-rich region may, for example, also be disposed at least part of the active region. Further, the active region may be disposed, for example, within the nitrogen-rich region.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: February 29, 2000
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Charles E. May, Robert Dawson, Michael Duane
  • Patent number: 6025237
    Abstract: Methods of forming field effect transistors include the steps of implanting first conductivity type dopants at a first dose level into a first portion of a relatively lightly doped drift region of first conductivity type semiconductor and then oxidizing the first portion of the semiconductor drift region to form a relatively thick field oxide isolation region and simultaneously form a drain region extension of first conductivity type semiconductor (e.g., N.sup.0) underneath the field oxide isolation region by driving the dopants implanted at the first dose level into the drift region. A body region of second conductivity type semiconductor (e.g., P-type) is then formed in a second portion of the semiconductor drift region. A gate electrode is then formed on the drift region to extend opposite the body region and the field oxide isolation region. Source and drain regions of first conductivity type semiconductor (e.g.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: February 15, 2000
    Assignee: Fairchild Korea Semiconductor, Ltd.
    Inventor: Young-Suk Choi
  • Patent number: 6017787
    Abstract: A twin tub integrated circuit and method for its formation are disclosed. A portion of the substrate is covered by photoresist while an n region is formed, illustratively, by ion implantation. Then the n region is covered with a protective material, illustratively a spin on glass or another photoresist. The previously-formed photoresist is removed and a p-type implant is performed to create an p region. When all the protective layers are removed, both regions have upper surfaces which are co-planar. The co-planar surfaces, a departure from previous practice, make submicron lithography easier. The regions are annealed to form twin tubs.
    Type: Grant
    Filed: December 31, 1996
    Date of Patent: January 25, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Sailesh Chittipeddi, William Thomas Cochran, Stephen Knight
  • Patent number: 6013545
    Abstract: A method of manufacturing a high-voltage metal-oxide-semiconductor device that uses trenches instead of a field oxide layer as an isolating structure, and employs a vertical layout rather than a horizontal layout so that more area is available for forming devices and drift region is lengthened as well. Therefore, this invention is capable of fabricating a CMOS transistor even at the sub-micron level, and hence is able to increase the level of circuit integration for a given a wafer. Furthermore, localized atomic oxygen implant and epitaxial growth techniques are used in this invention. Consequently, an etching stop layer can be precisely established in the silicon substrate within an active area. Due to the presence of an oxide layer underneath the epitaxial layer, the oxide layer can serve as an etching stop layer when the active area of a silicon substrate is patterned.
    Type: Grant
    Filed: July 7, 1998
    Date of Patent: January 11, 2000
    Assignee: United Microelectronics Corp.
    Inventor: Jia-Sheng Lee
  • Patent number: 6010926
    Abstract: The present invention provide a method for forming a triple well. The triple well includes an n-well, a first p-well surrounded with the n-well and a second p-well apart from the first p-well and adjacent to the n-well. According to the present invention, only one conductivity type of impurities are implanted in each well. Therefore, it is possible to prevent the decrease of the carrier mobility and increase of the leakage current.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: January 4, 2000
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventors: Kwang Myoung Rho, Chan Kwang Park, Yo Hwan Koh
  • Patent number: 5994178
    Abstract: The present invention discloses a method of forming CMOS transistors with planar shallow trench isolations. Before a twin well being formed, a pad oxide film and a nitride film are sequentially deposited on a silicon substrate. When a photoresist film is patterned to define active regions, the silicon substrate is recessed by using the patterned photoresist film as a mask. A liquid-phase-deposition oxide (LPD) film is then grown on the recess structure for shallow trench isolations. Next, a high temperature annealing procedure is performed to densify the LPD oxide film. Finally, when the pad oxide and the nitride films are removed, processes for fabricating CMOS transistors can be continued on the silicon substrate.
    Type: Grant
    Filed: December 31, 1997
    Date of Patent: November 30, 1999
    Assignee: Texas Instruments - Acer Incorporated
    Inventor: Shye-Lin Wu
  • Patent number: 5985707
    Abstract: A semiconductor memory device and a fabrication method thereof include formation of surplus gates connected to a cell node of a gate edge region, located at a cell node side of a SRAM access transistor, and to the gate of a driving transistor located at the opposite side thereof. The present invention prevents silicon loss of the substrate caused by the formation of a buried contact in the conventional device, secures an operational stability of the memory cell by controlling differently the current flow of an access transistor in accordance with the condition of the cell node (for example, low level or high level), and facilitates an interconnection in the cell since the gate of a side transistor is used as a substitute for another interconnection (for example, a wiring) when realizing a SRAM.
    Type: Grant
    Filed: January 6, 1998
    Date of Patent: November 16, 1999
    Assignee: LG Semicon Co., Ltd.
    Inventor: Gyoung-Seon Gil
  • Patent number: 5979784
    Abstract: A method of forming local interconnection of a SRAM, including the following steps: First, an NMOS and a PMOS are formed on a P-well and an N-well on a substrate, respectively. An isolation oxide layer is formed and the isolation oxide layer on a node is removed. A thin polysilicon layer is formed and N+ shallow implantation and N+ deep implantation is performed by using a photolithography technique. Also, P+ shallow implantation and P+ deep implantation are performed by using a photolithography technique. After the formation of a low resistance material, the low resistance material and the thin polysilicon layer are together formed.
    Type: Grant
    Filed: April 17, 1997
    Date of Patent: November 9, 1999
    Assignee: Winbond Electronics Corp.
    Inventors: Kuei-Chang Liang, Yu-Hao Yang
  • Patent number: 5976923
    Abstract: A method for fabricating high-voltage semiconductor devices is disclosed, in which a P-well and a N-well are first formed over the substrate, where a plurality of P-wells and N-wells used as isolation regions and drift regions are further formed therein. More shallot P-type and N-type regions are subsequently formed in the drift regions and isolation regions, so as to increase the breakdown voltage and enhance the current-driving performance. In addition, a deepened isolation doping, can also increase the latch up capability, resulting in less area required for fabricating a device.
    Type: Grant
    Filed: December 8, 1998
    Date of Patent: November 2, 1999
    Assignee: United Microelectronics Corp.
    Inventor: Ming-Tsung Tung
  • Patent number: 5976937
    Abstract: Method of making transistors having ultrashallow source and drain junction with reduced gate overlap may comprise forming a first gate electrode (124) separated from a first active area (126) of a semiconductor layer (112) by a first gate insulator (130). A second gate electrode (140) may be formed substantially perpendicular to the first gate electrode (124) and separated from a second active area (142) of the semiconductor layer by a second gate insulator (146). A masking layer (160) may be formed over the semiconductor layer (112) and expose a source and a drain section (162 and 164) of the first active area (126) and a source and a drain section (166 and 168) of the second active area (142). Dopants may be implanted from a first direction substantially parallel to the first gate electrode (124) into the source and drain sections (166 and 168) of the first active area (126).
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: November 2, 1999
    Assignee: Texas Instruments Incorporated
    Inventors: Mark S. Rodder, Mahalingam Nandakumar
  • Patent number: 5976921
    Abstract: A semiconductor device having an electrostatic discharge protection device and at least one accompanying device selected from the group comprising of a N or P channel MOS transistor, CMOS, bipolar transistor and BiCMOS, in which the electrostatic discharge protection device comprises a vertical type bipolar transistor including; a semiconductor substrate; an epitaxial layer laminated on the semiconductor substrate; a buried collector of a first conductivity type which is formed of the semiconductor substrate or which is formed from the surface of the semiconductor substrate to the epitaxial layer; a base of a second conductivity type which is a lightly doped well and formed on the epitaxial layer; and an emitter of the first conductivity type and formed on the surface layer of the base of the second conductivity type; and in which the base is adapted to have impurity concentration and depth so that a punch-through is generated between the emitter and the collector of the electrostatic discharge protection dev
    Type: Grant
    Filed: December 23, 1997
    Date of Patent: November 2, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Hiroshi Maeda
  • Patent number: 5976922
    Abstract: A method for fabricating a high-bias device compatible with a low-bias device is provided. The method of the invention includes using a doped well as a drift region of the high-bias device so that the drift region can be formed simultaneously when a well for a low-bias device is formed. The method of the invention also fabricates the high-bias device and the low-bias device simultaneously, using a commonly used photomask. Several ion implantation processes are also performed simultaneously. There is no need of some extra fabrication of photomasks and ion implantation processes separately used for forming the high-bias device.
    Type: Grant
    Filed: November 27, 1998
    Date of Patent: November 2, 1999
    Assignee: United Microelectronics Corp.
    Inventor: Ming-Tsung Tung
  • Patent number: 5970335
    Abstract: A semiconductor processing method of forming complementary first conductivity type doped and second conductivity type doped active regions within a semiconductor substrate includes, a) providing a semiconductor substrate; b) masking a desired first conductivity type region of the substrate while conducting second conductivity type doping into a desired second conductivity type active region of the substrate; c) providing an insulating layer over the substrate over the desired first conductivity type region and the second conductivity type doped region; d) patterning the insulating layer to provide a void therethrough to the desired first conductivity type region; e) filling the void with a first conductivity type doped polysilicon plug, the plug having a first conductivity type dopant impurity concentration of at least 1.times.10.sup.20 ions/cm.sup.
    Type: Grant
    Filed: February 7, 1997
    Date of Patent: October 19, 1999
    Assignee: Micron Technology, Inc.
    Inventors: Mark Helm, Charles Dennison
  • Patent number: 5970353
    Abstract: A method of reducing an effective channel length of a lightly doped drain transistor (50), includes the steps of forming a gate electrode (52) and a gate oxide (54) over a semiconductor substrate (56) and implanting a drain region (58) of the substrate (56) with a sub-amorphous large tilt angle implant to thereby supply interstitials (62) at a location under the gate oxide (54). The method also includes forming a lightly doped drain extension region (66) in the drain region (58) of the substrate (56) and forming a drain (70) in the drain region (58) and forming a source extension region (67) and a source (72) in a source region (60) of the substrate (56).
    Type: Grant
    Filed: March 30, 1998
    Date of Patent: October 19, 1999
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Akif Sultan
  • Patent number: 5963801
    Abstract: A retrograde well in a CMOS device is formed by using a low energy ion implanter. Dopant atoms are implanted into a bare surface of the device's substrate, in a direction that is orthogonal to the surface of the substrate (for a substrate having a <100> orientation). The well implant can be performed at an energy below 220 keV. Chained implants for a punch-through barrier in the retrograde well can be performed after the well implant. When the substrate is annealed, the punch-through barrier is activated at the same time as the retrograde well.
    Type: Grant
    Filed: December 19, 1996
    Date of Patent: October 5, 1999
    Assignee: LSI Logic Corporation
    Inventors: Sheldon Aronowitz, Laique Khan, James Kimball
  • Patent number: 5956584
    Abstract: The present invention includes forming gate structures having a nitride cap on the substrate. An ion implantation is used to dope ions into the substrate to form the lightly doped drain (LDD) structures. An oxide layer is formed on the gate structures. Subsequently, the oxide layer is etched back to form oxide spacers on the side walls of the gate structures. Next, an ion implantation with a high dose is carried out to dope nitrogen ions into the oxide spacers, the cap silicon nitride and the silicon substrate. The cap silicon nitride layer is then removed. Then, a refractory or noble metal layer is sputtered on the substrate, nitride doped oxide spacers and the gates. A first step thermal process is performed to form SALICIDE and polycide. Next, an ion implantation is utilized to dope ions into the SALICIDE and polycide films. A second step thermal process is employed to form shallow source and drain junction.
    Type: Grant
    Filed: March 30, 1998
    Date of Patent: September 21, 1999
    Assignee: Texas Instruments - Acer Incorporated
    Inventor: Shye-Lin Wu
  • Patent number: 5956591
    Abstract: A method of making N-channel and P-channel devices using separate drive-in steps is disclosed. The method includes providing a semiconductor substrate with first and second active regions, introducing a first dopant into the first active region to provide all doping for a source and a drain in the first active region, driving-in the first dopant to form the source and the drain in the first active region, introducing a second dopant into the second active region to provide all doping for a source and a drain in the second active region after driving-in the first dopant, and driving-in the second dopant to form the source and the drain in the second active region. Preferably, the first dopant is arsenic or phosphorus, the second dopant is boron, and the first temperature exceeds the second temperature by at least 50.degree. C. In this manner, the boron need not be subjected to the higher first temperature, thereby reducing boron diffusion.
    Type: Grant
    Filed: February 25, 1997
    Date of Patent: September 21, 1999
    Assignee: Advanced Micro Devices, Inc.
    Inventor: H. Jim Fulford, Jr.
  • Patent number: 5946564
    Abstract: Integrated circuitry and methods of forming integrated circuitry are described. In one implementation, a common masking step is utilized to provide source/drain diffusion regions and halo ion implantation or dopant regions relative to the source/drain regions within one well region of a substrate; and well contact diffusion regions within another well region of the substrate. The common masking step preferably defines at least one mask opening over the substrate within which the well contact diffusion region is to be formed, and the mask opening is suitably dimensioned to reduce the amount of halo ion implantation dopant which ultimately reaches the substrate therebelow. According to one aspect, a plurality of mask openings are provided. According to another aspect, a suitably-dimensioned single mask opening is provided.
    Type: Grant
    Filed: August 4, 1997
    Date of Patent: August 31, 1999
    Assignee: Micron Technology, Inc.
    Inventors: Zhiqiang Wu, Luan C. Tran, Robert Kerr, Shubneesh Batra, Rongsheng Yang
  • Patent number: 5943565
    Abstract: N-channel and P-channel transistor performances are separately optimized by activating the source/drain regions of the N-channel transistor before forming the P-channel lightly doped implant. Separate sidewall spacers for the moderately or heavily doped implants of the N- and P-channel transistors are employed. Embodiments enable independent control of the junction depths and channel lengths of N- and P-channel transistors.
    Type: Grant
    Filed: September 5, 1997
    Date of Patent: August 24, 1999
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Dong-Hyuk Ju
  • Patent number: 5943595
    Abstract: A method of manufacturing a semiconductor device having a triple-well structure, includes the steps of: forming a first well layer of a second conductivity type by implanting, as a first ion implantation, impurity ions of the second conductivity type to a specific depth from the surface of a semiconductor substrate of a first conductivity type and then subjecting the semiconductor substrate to an annealing treatment; forming a second ion-implanted region by implanting, as a second ion implantation, impurity ions of the second conductivity type into an end portion of first well layer with a specific width and at a depth from the surface of the semiconductor substrate to the surface of the first well layer to surround the first well layer; forming a third ion-implanted region by implanting, as a third ion implantation, impurity ions of the first conductivity type into a portion of the semiconductor substrate surrounded by the first well layer and the second ion-implanted region and at depth from the surface of
    Type: Grant
    Filed: February 24, 1998
    Date of Patent: August 24, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yukiharu Akiyama, Toshiyuki Matsushima, Shinichi Sato
  • Patent number: 5932906
    Abstract: A semiconductor device is provided in which conjunction leakage current from a conductive layer to a semiconductor substrate is restrained and the electric field in the vicinity of a region immediately below a gate electrode is relieved. The device includes n.sup.+ and n.sup.++ impurity diffusion layers electrically connected with a columnar conductive layer at a contact portion. The distance L4 from contact portion to n.sup.+ impurity diffusion layer, the distance L5 from n.sup.++ impurity diffusion layer to a source/drain region, and the distance L6 from n.sup.+ impurity diffusion layer to the region immediately below the side surface of gate electrode are approximately the same, and columnar conductive layer and gate electrode are formed close to each other to such a degree that their distance L7 is almost the same as the distance L2 from the surface of semiconductor substrate to the top surface of gate electrode.
    Type: Grant
    Filed: June 27, 1996
    Date of Patent: August 3, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahiro Shimizu
  • Patent number: 5933721
    Abstract: A method of establishing a differential threshold voltage during the fabrication of first and second IGFETs having like conductivity type is disclosed. A dopant is introduced into the gate electrode of each transistor of the pair. The dopant is differentially diffused into respective channel regions to provide a differential dopant concentration therebetween, which results in a differential threshold voltage between the two transistors. One embodiment includes introducing a diffusion-retarding material, such as nitrogen, into the first gate electrode before the dopant is diffused into the respective channel regions, and without introducing a significant amount of the diffusion-retarding material into the second gate electrode. Advantageously, a single dopant implant can provide both threshold voltage values. The two threshold voltages may be chosen to provide various combinations of enhancement mode and depletion mode IGFETs.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: August 3, 1999
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Frederick N. Hause, Mark I. Gardner, Daniel Kadosh
  • Patent number: 5933722
    Abstract: A method for forming a well structure in an integrated circuit such that, without any additional masking steps, the well implantation can be performed before the definition of the active device area. Hence, besides being able to avoid problems caused by a low breakdown voltage, also can provide a self-alignment mark for subsequent mask alignment, thereby reducing misalignment errors.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: August 3, 1999
    Assignee: United Microelectronics Corp.
    Inventor: Gary Hong
  • Patent number: 5930616
    Abstract: A method of forming a field effect transistor includes, a) providing a gate over a semiconductor substrate, the gate having a thickness; b) providing an insulating dielectric layer over the gate, the insulating dielectric layer being provided to a thickness which is greater than the gate thickness to provide an outer dielectric layer surface which is above the gate; c) patterning and etching the insulating dielectric layer to provide openings therethrough to the substrate to define and expose active area adjacent the gate for formation of one of PMOS type or NMOS type diffusion regions; d) providing a layer of conductive material over the insulating dielectric layer and within the openings; e) providing the one of PMOS or NMOS type diffusion regions within the substrate relative to the first openings; and f) etching back the conductive layer to define electrically conductive projections which are isolated from one another within the openings.
    Type: Grant
    Filed: November 16, 1998
    Date of Patent: July 27, 1999
    Assignee: Micron Technology, Inc.
    Inventor: Charles H. Dennison
  • Patent number: 5930615
    Abstract: A semiconductor processing method of forming complementary NMOS and PMOS field effect transistors on a substrate comprises the following steps: (a) providing a first conductivity type region and a second conductivity type region of the semiconductor substrate, one of the first and second type regions being an n-type region and the other being a p-type region; (b) providing a first transistor gate over the first conductivity type region, the first transistor gate defining the gate of a second conductivity type field effect transistor; (c) providing a second transistor gate over the second conductivity type region, the second transistor gate defining the gate of a first conductivity type field effect transistor; (d) providing an implant masking layer over the first conductivity type region; and (e) ion implanting a second conductivity type dopant into the first conductivity type region through the implant masking layer to define graded junction regions for the second conductivity type field effect transistor an
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: July 27, 1999
    Assignee: Micron Technology, Inc.
    Inventor: Monte Manning
  • Patent number: 5926704
    Abstract: A method forms, in a CMOS semiconductor substrate, P- and N-wells having independently optimized field regions and active regions. In one embodiment, P- and N-wells are formed by (i) creating in successive steps the field regions of the P- and N-wells; (ii) creating an oxide layer over the field regions, (iii) creating in successive steps the active regions. The method achieves the P- and N-wells without increasing the number of photoresist masking steps. In addition, optical alignment targets (OATs) are optionally formed simultaneously with these P- and N-wells without increasing the total number of process steps.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: July 20, 1999
    Assignee: Integrated Device Technology, Inc.
    Inventors: Jeong Y. Choi, Chuen-Der Lien
  • Patent number: 5909616
    Abstract: A method of forming a field effect transistor includes, a) providing a gate over a semiconductor substrate, the gate having a thickness; b) providing an insulating dielectric layer over the gate, the insulating dielectric layer being provided to a thickness which is greater than the gate thickness to provide an outer dielectric layer surface which is above the gate; c) patterning and etching the insulating dielectric layer to provide openings therethrough to the substrate to define and expose active area adjacent the gate for formation of one of PMOS type or NMOS type diffusion regions; d) providing a layer of conductive material over the insulating dielectric layer and within the openings; e) providing the one of PMOS or NMOS type diffusion regions within the substrate relative to the first openings; and f) etching back the conductive layer to define electrically conductive projections which are isolated from one another within the openings.
    Type: Grant
    Filed: December 2, 1997
    Date of Patent: June 1, 1999
    Assignee: Micron Technology, Inc.
    Inventor: Charles H. Dennison
  • Patent number: 5904520
    Abstract: A gate oxide and a first conducting layer are formed on a substrate, and then the first conducting layer is patterned and a gate in a NMOS region is formed. A LDD, a sidewall spacer, and a drain/source in the NMOS region are then formed in series. A layer of hard mask is formed. The layer of hard mask and the first conducting layer are patterned and a gate in a PMOS region is formed. A LDD, a sidewall spacer, and a drain/source in the NMOS region are then formed in series.
    Type: Grant
    Filed: January 5, 1998
    Date of Patent: May 18, 1999
    Assignee: Utek Semiconductor Corp.
    Inventors: Shiou-Han Liaw, Feng-Ling Hsiao
  • Patent number: 5897348
    Abstract: A method to fabricate simultaneously a CMOS transistor and an ESD protective transistor in a silicon substrate is disclosed. The NMOS transistor and PMOS transistor in the portion of the CMOS transistor have both anti-punchthrough and salicide structures and individually with n-LDD and p-LDD structure, respectively. The structure of ESD protective devices is fabricated with self-aligned silicide but without LDD, thus the degradation of ESD protection can be solved. The problems of accumulative aberration in scaled devices can also be alleviated through using blanket ion implantation technology and salicide process to reduce the mask count as shown in the invention.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: April 27, 1999
    Assignee: Texas Instruments - Acer Incorporated
    Inventor: Shye-Lin Wu
  • Patent number: 5895238
    Abstract: A method for manufacturing a semiconductor device having impurity doped regions serving as source and drain and a semiconductor device obtained by the application of the same method are disclosed. In the method, a semiconductor substrate having a gate oxide is prepared, and a gate electrode is formed on the gate oxide. A first dielectric film is formed on the semiconductor substrate impurity ions of a first conductive type into the semiconductor substrate while permitting the gate electrode and the first dielectric film formed on the side walls of the gate electrode to serve as self-aligning masks. Then, a second dielectric film to be deposited on the first dielectric film, and an anisotropic etching is effected on at least on the second dielectric film to form on the side walls of the gate electrode spacers having a prescribed profile.
    Type: Grant
    Filed: December 9, 1997
    Date of Patent: April 20, 1999
    Assignee: NEC Corporation
    Inventor: Hitoshi Mitani
  • Patent number: 5885887
    Abstract: A method of making an IGFET with a selectively doped multilevel polysilicon gate that includes upper and lower polysilicon gate levels is disclosed.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: March 23, 1999
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Frederick N. Hause, Robert Dawson, H. Jim Fulford Jr., Mark I. Gardner, Mark W. Michael, Bradley T. Moore, Derick J. Wristers
  • Patent number: 5882964
    Abstract: In order to produce an integrated CMOS circuit, a dielectric layer and a silicon layer are applied to a substrate. During the formation of insulation structurers which insulate neighboring active regions in the substrate, the silicon layer is structured in such a way that it has separate sub-regions which are subsequently doped differently. By full-surface deposition of an electrically conductive layer and common structuring of the electrically conductive layer and the structured silicon layer differently doped gate electrodes and a metallization plane, by which the gate electrodes are electrically connected, are formed. Division of the silicon layer before doping prevents lateral dopant diffusion.
    Type: Grant
    Filed: September 24, 1996
    Date of Patent: March 16, 1999
    Assignee: Siemens Aktiengesellschaft
    Inventor: Udo Schwalke
  • Patent number: 5877050
    Abstract: A method of making N-channel and P-channel IGFETs is disclosed. The method includes, in sequence, the steps of partially doping a first source and a first drain in a first active region of a semiconductor substrate, applying a first tube anneal while a second active region of the semiconductor substrate is devoid of source/drain doping, partially doping a second source and a second drain in the second active region, applying a second tube anneal, fully doping the first source and the first drain, applying a first rapid thermal anneal, fully doping the second source and the second drain, and applying a second rapid thermal anneal. Advantageously, the first and second tube anneals provide control over the channel junction locations, and the first and second rapid thermal anneals provide rapid drive-in for subsequent source/drain doping spaced from the channel junctions.
    Type: Grant
    Filed: September 3, 1996
    Date of Patent: March 2, 1999
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Mark I. Gardner, Derick J. Wristers, H. Jim Fulford, Jr.
  • Patent number: 5861329
    Abstract: A method of fabricating a metal-oxide semiconductor (MOS) transistor is provided. This method is devised particularly to reduce the level of degradation to the MOS transistor caused by hot carriers. In the fabrication process, a plasma treatment is applied to the wafer to as to cause the forming of a thin layer of silicon nitride on the wafer which covers the gate and the lightly-doped diffusion (LDD) regions on the source/drain regions of the MOS transistor. This thin layer of silicon nitride acts as a barrier which prevents hot carriers from crossing the gate dielectric layer, such that the degradation of the MOS transistor due to hot carriers crossing the gate dielectric layer can be greatly minimized.
    Type: Grant
    Filed: December 12, 1996
    Date of Patent: January 19, 1999
    Assignee: United Microelectrics Corp.
    Inventors: Wen-Kuan Yeh, Coming Chen, Meng-Jin Tsai, Jih-Wen Chou
  • Patent number: 5861330
    Abstract: The preferred embodiment of the present invention overcomes the limitations of the prior art and provides a device and method to increase the latch-up immunity of CMOS devices by forming implants at the well edges. The preferred method uses hybrid resist to form these implants at the edges of the N-wells and/or P-wells. The implants reduce the lifetime of minority carriers in the parasitic transistor, and hence reduce the gain of the parasitic transistor. This reduces the propensity of the CMOS device to latch-up. The preferred embodiment method allows these implants to be formed without requiring additional masking steps over prior art methods. Furthermore, the preferred method for forming the implants results in implants that are self aligned to the edges of the wells.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: January 19, 1999
    Assignee: International Business Machines Corporation
    Inventors: Faye D. Baker, Jeffrey S. Brown, Robert J. Gauthier, Jr., Steven J. Holmes, Robert K. Leidy, Edward J. Nowak, Steven H. Voldman
  • Patent number: 5858827
    Abstract: A method of manufacturing MOS semiconductor device, is disclosed, in which considerations are given to the influence of threshold value on ion implantation, and the dose of impurity to be ion implanted for forming high impurity concentration regions as source and drain regions is set to a value, at which the threshold value is substantially constant with impurity dose changes (the impurity dose being set to 10.sup.15 per cm.sup.2 or below for n-type impurity region). Thus, it is made possible to adequately set and control the threshold value, thus solving particularly the problem of reverse short channel effect and permitting formation of MOS parts with different threshold values.
    Type: Grant
    Filed: May 27, 1997
    Date of Patent: January 12, 1999
    Assignee: Sony Corporation
    Inventor: Keiichi Ono
  • Patent number: 5858847
    Abstract: The present invention provides a method of manufacturing a lightly doped drain (LDD) structure using a polymer layer to define the LDD. The polymer layer is formed in an etch step which defines the gate electrode. The method begins by forming spaced field oxide regions 12 in a substrate 10. Next, a gate oxide layer 14, and a material layer 18 and a hard mask layer 22 are sequentially formed over the active area and the field oxide regions 12. A photo resist block 24 is formed over the hard mask layer 22 over the active area. The hard mask layer 22 is etched using the photo resist block 24 as a mask forming a hard mask block 22. The etch simultaneously forms a polymer layer 26 over the a top and sidewalls of the photo resist block 24 and over the sidewalls of the hard mask block. Impurities ions are implanted into the substrate in the active area using the polymer layer 26 as a mask forming highly doped drain regions 30 in the substrate 10. Next, the photo resist block 24 and the polymer layer 26 are removed.
    Type: Grant
    Filed: March 28, 1997
    Date of Patent: January 12, 1999
    Assignee: Chartered Semiconductor Manufacturing, Ltd.
    Inventors: Mei Sheng Zhou, Yelehanka Ramachandramurthy Pradeep, Dajiang Xu
  • Patent number: 5851865
    Abstract: A gate oxide layer and a polysilicon layer are formed in sequence over the major surface of a semiconductor substrate. A photoresist layer is formed on the polysilicon layer and an opening is formed in the photoresist layer. Using the photoresist layer as a mask, boron is ion implanted through the polysilicon layer and the gate oxide layer into the semiconductor substrate. Phosphorus is next ion implanted into the polysilicon layer by using the photoresist layer as a mask. Different ion species are ion implanted into the semiconductor substrate and the polysilicon layer, respectively, by using the same photoresist layer, thus decreasing the number of photoetching steps in manufacture of semiconductor devices.
    Type: Grant
    Filed: September 4, 1996
    Date of Patent: December 22, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hidetoshi Koike
  • Patent number: 5849615
    Abstract: In one aspect of the invention, a semiconductor processing method includes: a) providing a semiconductor substrate; b) defining a first conductivity type region and a second conductivity type region of the semiconductor substrate; c) providing a first transistor gate over the first type region which defines a first source area and a first drain area operatively adjacent thereto; d) providing a second transistor gate over the second type region which defines a second source area and a second drain area operatively adjacent thereto; and e) blanket implanting a conductivity enhancing dopant of the second conductivity type through the first source and drain areas of the first conductivity region and the second source and drain areas of the second conductivity region to provide second conductivity type regular LDD implant regions within the substrate operatively adjacent the first transistor gate and to provide second conductivity type halo implant regions within the substrate operatively adjacent the second trans
    Type: Grant
    Filed: February 22, 1996
    Date of Patent: December 15, 1998
    Assignee: Micron Technology, Inc.
    Inventors: Aftab Ahmad, Kirk Prall
  • Patent number: 5846857
    Abstract: N- and P-channel transistor characteristics are independently optimized for CMOS semiconductor devices with design features of 0.25 microns and under. Removable second sidewall spacers are formed on the N-channel transistor gate electrode having first sidewall spacers thereon. Ion implantation is conducted to form N-type moderately/heavily doped implants followed by activation annealing. The second sidewall spacer is then removed from the P-channel transistor leaving first sidewall spacers thereon serving as an ion implantation mask for the P-type lightly doped implants. Subsequently, third sidewall spacers are formed on the P-channel gate electrode having first sidewall spacers thereon followed by ion implantation to form the P-type moderately or heavily doped implants, with subsequent activation annealing. Embodiments enable complete independent control of the channel lengths of the N- and P-channel transistors by varying the width of the first, second and third sidewall spacers.
    Type: Grant
    Filed: September 5, 1997
    Date of Patent: December 8, 1998
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Dong-Hyuk Ju
  • Patent number: 5834352
    Abstract: Methods of forming integrated circuits containing high and low voltage insulated-gate field effect transistors (IGFET) include the steps of forming first and second insulating layers having unequal thicknesses at first and second locations on a face of a semiconductor substrate, respectively, and then forming first and second gate electrodes on the first and second insulating layers, respectively. Formation of the source and drain regions of a high voltage IGFET is then initiated by implanting first dopants of first conductivity type through the first insulating layer and into the first location, using the first gate electrode as an implant mask. Formation of the source and drain regions (e.g., LDD) of the low voltage IGFET is then initiated by implanting second dopants of first conductivity type into the first and second insulating layers.
    Type: Grant
    Filed: August 28, 1996
    Date of Patent: November 10, 1998
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jeong-hyuk Choi
  • Patent number: 5834347
    Abstract: A P-type impurity is doped by oblique ion implantation into N-type impurity diffusion layers formed respectively on both sides of a gate electrode of a Pch MOS transistor, thereby canceling the impurity of at least a portion of an N-type region overlapped by the gate electrode, to thereby suppress a rise in the threshold voltage of the P-channel type MIS transistor due to the N-type impurity diffusion layer and suppress fluctuations in the amount of current that can be made to flow and the current-driving capacity.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: November 10, 1998
    Assignee: Nippondenso Co., Ltd.
    Inventors: Shigemitsu Fukatsu, Ryoichi Kubokoya, Kenji Shiratori, Nobuyuki Ooya
  • Patent number: 5830789
    Abstract: A substrate has defined therein one or more active regions. A layer of polysilicon is deposited and patterned to form gates for various CMOS devices. A masking layer is then deposited and selectively etched to leave exposed portions of the substrate. Dopants of a first conductivity type are implanted into the exposed portions of the substrate to form one or more well regions of the first conductivity type. Using this masking layer and the polysilicon gates left exposed thereby as a mask, dopants of a second conductivity type are then implanted into the substrate to form source and drain regions of the second conductivity type in the well regions of the first conductivity type. The masking layer is then removed. In this manner, source and drain regions may be formed using the same masking layer used to define the well within which the source and drain regions lie, thereby reducing both time and expense in the fabrication of CMOS devices.
    Type: Grant
    Filed: November 19, 1996
    Date of Patent: November 3, 1998
    Assignee: Integrated Device Technology, Inc.
    Inventors: Chuen-Der Lien, Jeong Yeol Choi
  • Patent number: 5827763
    Abstract: A method of forming a multiple transistor channel doping in a semiconductor substrate utilizes a unique photoresist sequence. A pattern of a first resist in first and second locations on first and second different areas of the semiconductor substrate is formed, respectively. A pattern of a second resist is then formed on the second area, wherein the second resist covers the first resist pattern in the second location. The first resist is selected for being immune from the second resist. Ions are then implanted in the first area to form a first conductivity type well having a first multiple transistor channel doping profile. The second resist pattern is then removed and a pattern of a third resist is formed on the first area, wherein the third resist covers the first resist pattern in the first location. In addition, the first resist is selected for being immune from the third resist.
    Type: Grant
    Filed: January 30, 1997
    Date of Patent: October 27, 1998
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Mark I. Gardner, Fred Hause
  • Patent number: 5814541
    Abstract: A method of manufacturing semiconductor devices yielding devices having impurity regions that are more shallow and exhibit less lateral diffusion than devices manufactured in accordance with prior art techniques. First, arsenic is introduced into a substrate. After the introduction of arsenic, phosphorus is introduced to the same portion of the substrate. The introductions of arsenic and phosphorus may be accomplished using diffusion or ion implantation techniques.
    Type: Grant
    Filed: April 18, 1995
    Date of Patent: September 29, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hideki Shibata
  • Patent number: 5780330
    Abstract: First and second conductivity type regions are produced in a polysilicon layer using only a single masking step. In one embodiment, the polysilicon layer is doped to a first conductivity type. A first oxide layer is then formed and patterned over the polysilicon layer to cover a first region and expose a second region of the polysilicon layer. The exposed second region of the polysilicon layer is then counter-doped, with the first oxide layer acting as a mask to prevent counter-doping of the underlying first region of the polysilicon layer. In accordance with the present invention, n-channel devices with n-type or p-type polysilicon gates and p-channel devices with p-type or n-type polysilicon gates can be formed without having to add a single process step. Thus, n-channel and p-channel devices with two different threshold voltages can be realized without adding a single process step.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: July 14, 1998
    Assignee: Integrated Device Technology, Inc.
    Inventor: Jeong Yeol Choi
  • Patent number: 5759883
    Abstract: In a method of manufacturing a semiconductor integrated circuit device composed of a bipolar transistor and metal-oxide-semiconductor (MOS) transistors, first and second gate electrode structures are formed to have polysilicon layers having no impurity implanted and to be provided on a gate oxide film. First impurity ions are implanted in self-alignment with said first gate electrode structure to form an N-channel MOS transistor. Second impurity ions are implanted in self-alignment with said second gate electrode structure to form a P-channel MOS transistor after a bipolar transistor is formed.
    Type: Grant
    Filed: November 20, 1996
    Date of Patent: June 2, 1998
    Assignee: NEC Corporation
    Inventor: Yasushi Kinoshita
  • Patent number: 5736440
    Abstract: A semiconductor processing method of forming complementary NMOS and PMOS field effect transistors on a substrate comprises the following steps: (a) providing a first conductivity type region and a second conductivity type region of the semiconductor substrate, one of the first and second type regions being an n-type region and the other being a p-type region; (b) providing a first transistor gate over the first conductivity type region, the first transistor gate defining the gate of a second conductivity type field effect transistor; (c) providing a second transistor gate over the second conductivity type region, the second transistor gate defining the gate of a first conductivity type field effect transistor; (d) providing an implant masking layer over the first conductivity type region; and (e) ion implanting a second conductivity type dopant into the first conductivity type region through the implant masking layer to define graded junction regions for the second conductivity type field effect transistor an
    Type: Grant
    Filed: November 27, 1995
    Date of Patent: April 7, 1998
    Assignee: Micron Technology, Inc.
    Inventor: Monte Manning