Including Multiple Implantation Steps Patents (Class 438/519)
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Patent number: 6387766Abstract: In an integrated circuit with low threshold voltage differences of the transistors and a manufacturing process for such an integrated circuit, MOS transistors of different lengths but having threshold voltages that are substantially the same are made by avoiding dopant peaks at the channel edges by an angled nitrogen implantation, so that implantation paths at those edges are occupied by nitrogen atoms.Type: GrantFiled: October 29, 1999Date of Patent: May 14, 2002Assignee: Infineon Technologies AGInventor: Dirk Schumann
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Patent number: 6383850Abstract: In a region on the left hand of FIG. 1 with respect to the gate electrode (107), a first source region (103a), a body-potential drawing region (105) and a second source region (103b) are formed in this order along the vertical direction of this figure. The first and second source regions (103a, 103b) are of n+ type, and the body-potential drawing region (105) is of p+ type. In a thin-film transistor (100), the body-potential drawing region (105) can draw and fix a body potential.Type: GrantFiled: January 4, 2001Date of Patent: May 7, 2002Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Yuuichi Hirano
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Patent number: 6358802Abstract: There is disclosed a semiconductor device which includes a semiconductor substrate having an element region and source and drain regions, a gate dielectric film containing nitrogen formed in the element region of said semiconductor substrate, a gate electrode formed on the gate dielectric film, a first dielectric film formed adjacent to the gate electrode so as to define a side wall therefor, a second dielectric film formed so as to cover the gate electrode and the first dielectric film, the second dielectric film being doped with nitrogen, and a third dielectric film formed so as to cover the second dielectric film, the third dielectric film being formed of silicon nitride. A method for manufacturing such a semiconductor device is also described.Type: GrantFiled: April 23, 1999Date of Patent: March 19, 2002Assignee: NEC CorporationInventor: Noriaki Oda
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Patent number: 6352900Abstract: A method for controlled oxide growth on transistor gates. A first film (40) is formed on a semiconductor substrate (10). The film is implanted with a first species and patterned to form a transistor gate (45) . The transistor gate (45) and the semiconductor substrate (10) is implanted with a second species and the transistor gate (45) oxidized to produce an oxide film (80) on the side surface of the transistor gate (45).Type: GrantFiled: July 18, 2000Date of Patent: March 5, 2002Assignee: Texas Instruments IncorporatedInventors: Manoj Mehrotra, Jerry Che-Jen Hu, Amitava Chatterjee, Mark S. Rodder
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Publication number: 20020011630Abstract: Provided is a semiconductor device having a semiconductor resistance element, which is capable of suppressing a variation in characteristics of the semiconductor resistance element due to an acceptor concentration difficult to be controlled, thereby stably improving the yield of a semiconductor integrated circuit using the semiconductor device. The device includes an n-type semiconductor resistance region formed in the surface of a compound semiconductor substrate, and a p-type buried region formed between the n-type semiconductor resistance region and a substrate region 21S of the compound semiconductor substrate. An acceptor of the p-type buried region is set to be higher than an acceptor concentration in the substrate region and lower than a doner concentration in the n-type semiconductor resistance region, whereby the effect of the acceptor concentration in the substrate on the semiconductor resistance region can be avoided.Type: ApplicationFiled: May 21, 2001Publication date: January 31, 2002Inventor: Tsutomu Imoto
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Patent number: 6339015Abstract: A non-volatile random access memory (NVRAM) cell and methods of forming thereof are disclosed. The NVRAM cell includes a substrate having source and drain regions. A spike having a sharp tip extends in the source region. Instead of a single spike, two adjacent spikes are included in the source. Alternatively, in addition to the single spike in the source, two adjacent spikes are included in the drain. The two adjacent spikes have one tip pointing toward the floating gate and two tips pointing away from the floating gate. The spikes provide high electric field to facilitate charge movement between the floating gate and the source region. A tunnel oxide layer separates the floating gate from the substrate. A gate oxide and a control gate are also formed over the floating gate. The single spike is formed by preferentially etching the substrate along a selected crystal plane through an opening formed in a mask that covers the substrate.Type: GrantFiled: May 18, 2000Date of Patent: January 15, 2002Assignee: International Business Machines CorporationInventors: John A. Bracchitta, James S. Nakos
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Patent number: 6333244Abstract: A method of fabricating an integrated circuit with ultra-shallow source/drain junctions utilizes a dual amorphization technique. The technique creates a shallow amorphous region and a deep amorphous region. The shallow amorphous region is between 10-15 nm below the top surface of the substrate, and the deep amorphous region is between 150-200 nm below the top surface of the substrate. The process can be utilized for P-channel or N-channel metal oxide semiconductor field effect transistors (MOSFETs). In the case of a P-channel MOSFET, a nitrogen barrier is formed in the P-channel gate prior to p+ doping. Annealing the gate conductor is done in a step separate from the source/drain region annealing step.Type: GrantFiled: January 26, 2000Date of Patent: December 25, 2001Assignee: Advanced Micro Devices, Inc.Inventor: Bin Yu
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Publication number: 20010053589Abstract: Method of manufacturing an edge structure for a high voltage semiconductor device, including a first step of forming a first semiconductor layer of a first conductivity type, a second step of forming a first mask over the top surface of the first semiconductor layer, a third step of removing portions of the first mask in order to form at least one opening in it, a fourth step of introducing dopant of a second conductivity type in the first semiconductor layer through the at least one opening, a fifth step of completely removing the first mask and of forming a second semiconductor layer of the first conductivity type over the first semiconductor layer, a sixth step of diffusing the dopant implanted in the first semiconductor layer in order to form a doped region of the second conductivity type in the first and second semiconductor layers.Type: ApplicationFiled: August 8, 2001Publication date: December 20, 2001Inventor: Ferruccio Frisina
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Publication number: 20010037939Abstract: A sample table for holding a silicon substrate into which an impurity is introduced is provided in the lower portion of a vacuum chamber. A high frequency power source is connected to the sample table through a coupling capacitor. The high frequency power source has a self-bias of 500 V, for example. Gas introducing means for introducing a sputtering gas such as an argon gas is provided on the bottom of the vacuum chamber. A solid target which contains an impurity which should be introduced, for example, boron is provided in the upper portion of the vacuum chamber.Type: ApplicationFiled: August 7, 1996Publication date: November 8, 2001Applicant: Hiroaki NakaokaInventors: HIROAKI NAKAOKA, BUNJI MIZUNO, MICHIHIKO TAKASE, ICHIROU NAKAYAMA
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Patent number: 6303475Abstract: Silicon carbide power devices are fabricated by masking the surface of a silicon carbide substrate to define an opening at the substrate, implanting p-type dopants into the silicon carbide substrate through the opening at implant energy and dosage that form a deep p-type implant, and implanting n-type dopants into the silicon carbide substrate through the opening at implant energy and dosage that form a shallow n-type implant relative to the deep p-type implant. The deep p-type implant and the shallow n-type implant are annealed at less than 1650° C., but preferably more than about 1500°. The annealing preferably takes place for between about five minutes and about thirty minutes. Ramp-up time from room temperature to the anneal temperature is also controlled to be less than about one hundred minutes but more than about thirty minutes. Ramp-down time after annealing is also controlled by decreasing the temperature from the annealing temperature to below about 1500° C.Type: GrantFiled: November 30, 1999Date of Patent: October 16, 2001Assignee: Cree, Inc.Inventors: Alexander Suvorov, John W. Palmour, Ranbir Singh
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Patent number: 6291323Abstract: The present invention relates to the formation of trench isolation structures that isolate active areas and a preferred doping in the fabrication of a CMOS device with a minimized number of masks. Ions of a P-type dopant are implanted into a semiconductor substrate having therein a P-well and an N-well. Each of the N-well and P-well has therein a trench. The ions of the P-type dopant are implanted beneath each of the trenches in the P-well and the N-well to create a first P-type dopant concentration profile in the semiconductor substrate, wherein the P-well and the N-well are substantially unimplanted by the ions of the P-type dopant in active areas adjacent to the respective trenches therein. A second implanting ions of a P-type dopant is made into the semiconductor substrate. The second implanting is beneath each of the trenches in the P-well and the N-well to form a second P-type dopant concentration profile.Type: GrantFiled: August 9, 1999Date of Patent: September 18, 2001Assignee: Micron Technology, Inc.Inventor: Fernando Gonzalez
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Patent number: 6274466Abstract: A method for fabricating a semiconductor device to increase the effective concentration of a doped region. A first dopant is implanted into a substrate. A second dopant is implanted into the substrate. The first dopant has a lower diffusion coefficient, a higher energy gap, and a higher atomic mass than those of the second dopant.Type: GrantFiled: June 9, 1999Date of Patent: August 14, 2001Assignee: United Microelectronics Corp.Inventors: Chung-Po Hsu, Ming-Chi Lin
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Patent number: 6271105Abstract: A method is provided for forming a multiple well of a semiconductor device is provided. By this method, a pocket well region of a first conductivity type is formed over a predetermined first region of a semiconductor substrate of a first conductivity type, using a first photolithography process. A first deep well region of a second conductivity type is then formed under the pocket well region in a self-aligned manner. A peripheral well region of the first conductivity type is selectively formed in a predetermined second region of the semiconductor substrate apart from the pocket well region, using a second photolithography process.Type: GrantFiled: May 21, 1999Date of Patent: August 7, 2001Assignee: Samsung Electronics Co., Ltd.Inventors: Joon-mo Kwon, Sung-young Lee
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Publication number: 20010004546Abstract: A heat conductive mold is provided in which boron nitride powder has a magnetic field which is oriented in a fixed direction within a polymer. The polymer is preferably at least one selected from silicon rubber, epoxy, Polyimide and polyurethane. The content of the boron nitride powder is from twenty-two 400 weight parts to 100 weight parts ofpolymer. A method is also provided in which a heat conductive mold of excellent heat conductivity is provided. The method includes impressing a magnetic field to the polymer composition containing boron nitride powder. The magnetic field impressed on the boron nitride powder, in the composition is impressed to have a fixed direction. The field is set after the direction is established. As an alternative, the method may include pressing the magnetic field to the polymer composition including the boron nitride powder and also a solvent.Type: ApplicationFiled: December 8, 2000Publication date: June 21, 2001Inventors: Masayuki Tobita, Shinya Tateda, Tsunehisa Kimura, Masahumi Yamato
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Publication number: 20010001694Abstract: In one aspect, the invention includes a method of maintaining dimensions of an opening in a semiconductive material stencil mask comprising providing two different dopants within a periphery of the opening, the dopants each being provided to a concentration of at least about 1017 atoms/cm3.Type: ApplicationFiled: December 12, 2000Publication date: May 24, 2001Inventor: J. Brett Rolfson
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Patent number: 6200884Abstract: A method for making a ULSI MOSFET chip includes masking areas such as transistor gates with photoresist mask regions. Prior to ion implantation, the top shoulders of the mask regions are etched away, to round off the shoulders. This promotes subsequent efficient quasi-vertical ion implantation, commonly referred to as “high aspect ratio implantation” in the semiconductor industry.Type: GrantFiled: July 31, 1999Date of Patent: March 13, 2001Assignee: Advanced Micro Devices, Inc.Inventors: Chih-Yuh Yang, Mark S. Chang
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Patent number: 6111277Abstract: A semiconductor device such as a light emitting semiconductor device comprising a mask layer having opening areas and a selective growing layer comprising a semiconductor grown selectively by way of the mask layer, with each of the mask layer and the selective growing layer being disposed by two or more layers alternately. The semiconductor device is manufactured by a step of laminating on a substrate a mask layer having opening areas and a selective growing layer comprising a semiconductor grown selectively way of a mask layer, each by two or more layers alternately and a subsequent step of laminating semiconductor layers thereon. Threading dislocations in the underlying layer are interrupted by the first mask layer and the second mask layer and do not propagate to the semiconductor layer. The density of the threading dislocations is lowered over the entire surface and the layer thickness can be reduced.Type: GrantFiled: October 21, 1998Date of Patent: August 29, 2000Assignee: Sony CorporationInventor: Masao Ikeda
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Patent number: 6107142Abstract: Silicon carbide power devices are fabricated by implanting p-type dopants into a silicon carbide substrate through an opening in a mask, to form a deep p-type implant. N-type dopants are implanted into the silicon carbide substrates through the same opening in the mask, to form a shallow n-type implant relative to the p-type implant. Annealing is then performed at temperature and time that is sufficient to laterally diffuse the deep p-type implant to the surface of the silicon carbide substrate surrounding the shallow n-type implant, without vertically diffusing the p-type implant to the surface of the silicon carbide substrate through the shallow n-type implant. Accordingly, self-aligned shallow and deep implants may be performed by ion implantation, and a well-controlled channel may be formed by the annealing that promotes significant diffusion of the p-type dopant having high diffusivity, while the n-type dopant having low diffusivity remains relatively fixed.Type: GrantFiled: June 8, 1998Date of Patent: August 22, 2000Assignee: Cree Research, Inc.Inventors: Alexander Suvorov, John W. Palmour, Ranbir Singh
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Patent number: 6100147Abstract: A process for manufacturing a high performance transistor with self-aligned dopant profile. The process involves forming a source/drain mask pattern on a substrate. With a first implant material, unmasked portions of the substrate are doped to form source/drain regions of the substrate. The source-drain mask is removed and an oxidation layer is grown, where portions of the oxidation layer formed from doped regions of the substrate have heights that are greater than heights of portions of the oxidation layer formed from un-doped regions of the substrate, thereby forming a gate mask. The doped portions of the substrate are self-aligned with gate regions of the substrate. The gate regions are doped, and gate electrodes are formed. The gate mask is removed to expose source/drain regions of the substrate for further fabrication.Type: GrantFiled: April 16, 1998Date of Patent: August 8, 2000Assignee: Advanced Micro Devices, Inc.Inventors: Mark I. Gardner, Mark C. Gilmer
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Patent number: 6100169Abstract: Silicon carbide power devices are fabricated by masking the surface of a silicon carbide substrate to define an opening at the substrate, implanting p-type dopants into the silicon carbide substrate through the opening at implant energy and dosage that form a deep p-type implant, and implanting n-type dopants into the silicon carbide substrate through the opening at implant energy and dosage that form a shallow n-type implant relative to the deep p-type implant. The deep p-type implant and the shallow n-type implant are annealed at less than 1650.degree. C., but preferably more than about 1500.degree.. The annealing preferably takes place for between about five minutes and about thirty minutes. Ramp-up time from room temperature to the anneal temperature is also controlled to be less than about one hundred minutes but more than about thirty minutes. Ramp-down time after annealing is also controlled by decreasing the temperature from the annealing temperature to below about 1500.degree. C.Type: GrantFiled: June 8, 1998Date of Patent: August 8, 2000Assignee: Cree, Inc.Inventors: Alexander Suvorov, John W. Palmour, Ranbir Singh
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Patent number: 6083814Abstract: A method for producing a pn-junction for a semiconductor device of SiC intended to have at least one lateral zone of junction termination with a lower doping concentration of a first conductivity type than a main zone for smearing out the electrical field at said junction comprising at least the step of applying a first layer of SiC over the entire surface and on top of a second layer of SiC. A mask is applied on the first layer over a portion thereof where said main zone and an ohmic contact are to be formed. It is after that etched through the first layer to the second layer while leaving a main zone of said first layer and a contact layer thereof under said mask.Type: GrantFiled: September 3, 1998Date of Patent: July 4, 2000Assignee: ABB Research Ltd.Inventor: Per-.ANG.ke Nilsson
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Patent number: 6046096Abstract: A method of fabricating a compound semiconductor layer structure including a layer containing nitrogen is provided. In a method of fabricating a device including a compound semiconductor layer structure, a portion of crystal of compound semiconductor, which is to be at least a portion of a function layer of the device, is irradiated with material including at least nitrogen, and element of V group of the irradiated portion is substituted by the nitrogen. In a fabrication method, a thickness of the N-substituted layer does not exceed its critical layer thickness. In a fabrication method, a depth of the N-substituted portion is controlled by using material for oppressing the substitution by nitrogen.Type: GrantFiled: September 29, 1997Date of Patent: April 4, 2000Assignee: Canon Kabushiki KaishaInventor: Toshihiko Ouchi
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Patent number: 6043143Abstract: A method of improving contact resistance in a multi-layer heterostructure comprising the steps of providing a substrate, growing a crystalline material on the substrate, and doping close to an interface of the substrate and the crystalline material with n-silicon to provide continuity at the interface.Type: GrantFiled: May 4, 1998Date of Patent: March 28, 2000Assignee: Motorola, Inc.Inventor: Kumar Shiralagi
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Patent number: 5976923Abstract: 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: GrantFiled: December 8, 1998Date of Patent: November 2, 1999Assignee: United Microelectronics Corp.Inventor: Ming-Tsung Tung
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Patent number: 5956593Abstract: An improved semiconductor device including an MOS capacitance is provided, having enhanced MOS capacitance accuracy. A well of a first conductivity type is formed at the main surface of a semiconductor substrate. The above-described well is removed immediately under a capacitance dope layer.Type: GrantFiled: May 27, 1998Date of Patent: September 21, 1999Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masaki Kijima, Akinobu Manabe
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Patent number: 5885857Abstract: A resin molded semiconductor device having wiring layers and interlayer insulating layers inclusive of an SOG film, capable of suppressing generation of cracks in an SOG film to be caused by thermal stress. In the outer peripheral area of a semiconductor chip, via holes are formed in an interlayer insulating layer inclusive of an SOG film to substantially reduce residual SOG film. As an underlying layer of the interlayer insulating layer inclusive of the SOG film, dummy wiring patterns are formed to thin the SOG film on the dummy wiring patterns. Dummy wiring patterns may also be formed by using a higher level wiring layer, burying the via holes and contacting the lower level dummy wiring patterns.Type: GrantFiled: January 15, 1998Date of Patent: March 23, 1999Assignee: Yamaha CorporationInventors: Takahisa Yamaha, Yushi Inoue, Masaru Naito
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Patent number: 5885874Abstract: A method of making enhancement-mode and depletion-mode IGFETs is disclosed.Type: GrantFiled: April 21, 1997Date of Patent: March 23, 1999Assignee: Advanced Micro Devices, Inc.Inventor: Mark I. Gardner
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Patent number: 5856231Abstract: A process for producing high-resistance SiC from low-resistance SiC starting material. The flat (shallow) donor levels of a prevailing nitrogen impurity are overcompensated by admixture of a trivalent doping element with the concentration of the doping element in the SiC being such that it changes the conductivity type from a n-conductivity to a p-conductivity. In addition, a transition element is added having donor levels approximately in the middle of the SiC energy gap, so that the excess acceptor levels are in turn compensated and a high specific resistance is achieved.Type: GrantFiled: April 12, 1996Date of Patent: January 5, 1999Assignee: Daimler-Benz AktiengesellschaftInventors: Ekkehard Niemann, Juergen Schneider, Harald Mueller, Karin Maier, deceased, Hildegard Inge Maier, heiress, Elke Maier, heiress
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Patent number: 5837572Abstract: An integrated circuit is provided having both NMOS transistors and PMOS transistors. The NMOS transistor junction regions are preferably formed before the PMOS transistor junction regions with pre-defined anneal temperatures applied after select implant steps. Both the NMOS and PMOS transistor junction are graded such that the drain areas include a relatively large LDD implant area and the source junctions do not. Whatever LDD area pre-existing in the source implanted with a higher concentration source/drain or MDD implant. The ensuing integrated circuit is therefore a CMOS circuit having asymmetrical transistor junctions and carefully controlled implant and anneal sequences. The asymmetrical junctions are retained, or at least optimized, by controlling the anneal temperatures such that diffusivity distances of n-type implants are relatively similar to p-type implants. Diffusivity is controlled by regulating the post-implant anneal temperatures of p-type implants lesser than previous n-type implants.Type: GrantFiled: January 10, 1997Date of Patent: November 17, 1998Assignee: Advanced Micro Devices, Inc.Inventors: Mark I. Gardner, Fred N. Hause, H. Jim Fulford, Jr.