Having Structure Increasing Breakdown Voltage (e.g., Guard Ring, Field Plate, Etc.) Patents (Class 438/140)
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Patent number: 6787400Abstract: An electrostatic discharge protection device is formed in a substrate and contains a drain area of a first dopant concentration abutting an extended drain area having a dopant concentration lower than the first dopant concentration. Similarly, a highly doped source area abuts a lower doped source extension area. The source and drain are laterally bounded by oxide regions and covered by an insulation layer. The areas of lower doping prevent charge crowding during an electrostatic discharge event by resistively forcing current though the nearly planer bottom surface of the drain, rather than the curved drain extension. In addition, a highly doped buried layer can abut an area of a graded doping level. By adjusting the doping levels of the graded areas and the buried layers, the substrate breakdown voltage is pre-selected.Type: GrantFiled: January 16, 2003Date of Patent: September 7, 2004Assignee: Micron Technology, Inc.Inventors: Stephen R. Porter, Manny K. Ma, Stephen Casper, Kevin Duesman
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Patent number: 6773968Abstract: Area efficient static memory cells and arrays containing p-n-p-n or n-p-n-p transistors which can be latched-up in a bistable on state. Each transistor memory cell includes a gate which is pulse biased during the write operation to latch-up the cell. Also provided are linked memory cells in which the transistors share common regions.Type: GrantFiled: July 3, 2000Date of Patent: August 10, 2004Assignee: Micron Technology, Inc.Inventors: Leonard Forbes, Wendell P. Noble, Jr.
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Publication number: 20040097019Abstract: A semiconductor component includes a substrate (110) having a surface, a channel region (120, 220) located in the substrate, a non-electrically conductive region (130) substantially located below a substantially planar plane defined by the surface of the substrate, a drift region (140, 240) located in the substrate and between the channel region and the non-electrically conductive region, and an electrically floating region (150, 350, 450, 550) located in the substrate and contiguous with the non-electrically conductive region.Type: ApplicationFiled: July 7, 2003Publication date: May 20, 2004Inventors: Edouard D. de Fresart, Patrice Parris, Richard Joseph De Souza
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Publication number: 20040087065Abstract: A power semiconductor device has an active region that includes a drift region. At least a portion of the drift region is provided in a membrane which has opposed top and bottom surfaces. In one embodiment, the top surface of the membrane has electrical terminals connected directly or indirectly thereto to allow a voltage to be applied laterally across the drift region. In another embodiment, at least one electrical terminal is connected directly or indirectly to the top surface and at least one electrical terminal is connected directly or indirectly to the bottom surface to allow a voltage to be applied vertically across the drift region. In each of these embodiments, the bottom surface of the membrane does not have a semiconductor substrate positioned adjacent thereto.Type: ApplicationFiled: October 29, 2003Publication date: May 6, 2004Applicant: CAMBRIDGE SEMICONDUCTOR LIMITEDInventors: Florin Udrea, Gehan A.J. Amaratunga
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Patent number: 6709900Abstract: A power integrated circuit architecture (10) having a high side transistor (100) interposed between a control circuit (152) and a low side transistor (100) to reduce the effects of the low side transistor on the operation of the control circuit. The low side transistor has a heavily p-doped region (56) designed to reduce minority carrier lifetime and improve minority carrier collection to reduce the minority carriers from disturbing the control circuit. The low side transistor has a guardring (16) tied to an analog ground, whereby the control circuit is tied to a digital ground, such that the collection of the minority carriers into the analog ground does not disturb the operation of the control circuit. The low side transistor is comprised of multiple transistor arrays (90) partitioned by at least one deep n-type region (16), which deep n-type region forms a guardring about the respective transistor array.Type: GrantFiled: June 11, 2002Date of Patent: March 23, 2004Assignee: Texas Instruments IncorporatedInventors: Taylor R. Efland, David A. Grant, Ramanathan Ramani, Dale Skelton, David D. Briggs, Chin-Yu Tsai
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Patent number: 6706567Abstract: A high voltage device prevents or minimizes the lowering of a maximum operating voltage range. Bulk resistances of the drift regions are reduced by forming trenches within the drift regions and filling the trenches with conductive polysilicon layers. The polysilicon layers reduce the bulk resistances and prevents or minimizes the operation of parasitic bipolar junction transistors typically formed when the high voltage device is manufactured.Type: GrantFiled: May 24, 2001Date of Patent: March 16, 2004Assignee: Hynix Semiconductor, Inc.Inventor: Lee-Yeun Hwang
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Publication number: 20040031987Abstract: A method for fabricating a transistor configuration including at least one trench transistor cell has a gate electrode and a field electrode disposed in a trench below the gate electrode. The trenches are formed in a semiconductor substrate. A drift zone, a channel zone, and a source zone are in each case provided in the semiconductor substrate. According to the invention, the source zone and/or the channel zone are formed at the earliest after the introduction of the trenches into the semiconductor substrate by implantation and diffusion.Type: ApplicationFiled: March 19, 2003Publication date: February 19, 2004Inventors: Ralf Henninger, Franz Hirler, Joachim Krumrey, Walter Rieger, Martin Polzl, Heimo Hofer
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Patent number: 6673657Abstract: A kill index classification method for prioritizing relational aspects of topological defect intersections, particularly in association with an intermediate analytical testing stage of a multi-stage semiconductor fabrication process. The method relates to an analysis of the geometrical relationship between non-predetermined portion(s), generally referred to as defects, and the surrounding predetermined topology of a conductive semiconductor pattern, to determine the effect of defects on the functionality and reliability of a wafer, and particularly an examined die thereon. Further, in accordance with this geometrical information, a preferred classification of the effects of defects into a numerical value, the “kill index”, is achieved. Preferably, this kill index is strongly linked, correlated and related to the damage caused by the defect to the functionality and/or reliability of the underlying integrated circuit.Type: GrantFiled: July 11, 2002Date of Patent: January 6, 2004Assignee: Applied Materials, Inc.Inventors: Ayelet Pnueli, Ariel Ben-Porath
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Publication number: 20030228721Abstract: A power integrated circuit architecture (10) having a high side transistor (100) interposed between a control circuit (152) and a low side transistor (100) to reduce the effects of the low side transistor on the operation of the control circuit. The low side transistor has a heavily p-doped region (56) designed to reduce minority carrier lifetime and improve minority carrier collection to reduce the minority carriers from disturbing the control circuit. The low side transistor has a guardring (16) tied to an analog ground, whereby the control circuit is tied to a digital ground, such that the collection of the minority carriers into the analog ground does not disturb the operation of the control circuit. The low side transistor is comprised of multiple transistor arrays (90) partitioned by at least one deep n-type region (16), which deep n-type region forms a guardring about the respective transistor array.Type: ApplicationFiled: June 11, 2002Publication date: December 11, 2003Inventors: Taylor R. Efland, David A. Grant, Ramanathan Ramani, Dale Skelton, David D. Briggs, Chin-Yu Tsai
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Patent number: 6660570Abstract: A high voltage semiconductor device including a semiconductor substrate on which a semi-insulating polycrystalline silicon layer is formed to alleviate electric field concentration in a field region, is disclosed. A thermal oxide layer is formed on the semi-insulating polycrystalline silicon layer to serve as a protective layer. The thermal oxide layer forms a good interface with the semi-insulating polycrystalline silicon layer compared to a wet etched oxide layer or a chemical vapor deposition (CVD) oxide layer, thereby decreasing the amount of leakage current. In addition, compared to a dual semi-insulating polycrystalline silicon layer, the thermal oxide layer exhibits a high surface protection effect and a high resistance against dielectric breakdown. It also allows a great reduction in fabrication time.Type: GrantFiled: May 8, 2002Date of Patent: December 9, 2003Assignee: Fairchild Korea Semiconductor, Ltd.Inventors: Jin-kyeong Kim, Jong-min Kim, Kyung-wook Kim, Tae-hoon Kim, Cheol Choi, Chang-wook Kim
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Publication number: 20030157753Abstract: A method for manufacturing a gate pad protection structure applied in a power semiconductor device is provided. The method includes steps of (a) forming a gate oxide layer on a substrate, (b) forming a polysilicon layer on the gate oxide layer, (c) forming a polysilicon window and a polysilicon window array on the polysilicon layer, and (d) performing an ion implantation via the polysilicon window and the polysilicon window array.Type: ApplicationFiled: December 30, 2002Publication date: August 21, 2003Inventors: Jun Zeng, Ming-Jiang Zhou, Tzong-Shiann Wu
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Publication number: 20030148559Abstract: A semiconductor device includes an improved drain drift layer structure of alternating conductivity types, that is easy to manufacture, and that facilitates realizing a high current capacity and a high breakdown voltage and to provide a method of manufacturing the semiconductor device. The vertical MOSFET according to the invention includes an alternating-conductivity-type drain drift layer on an n+-type drain layer as a substrate. The alternating-conductivity-type drain drift layer is formed of n-type drift current path regions and p-type partition regions alternately arranged laterally with each other. The n-type drift current path regions and p-type partition regions extend in perpendicular to n+-type drain layer. Each p-type partition region is formed by vertically connecting p-type buried diffusion unit regions Up. The n-type drift current path regions are residual regions, left after connecting p-type buried diffusion unit regions Up, with the conductivity type thereof unchanged.Type: ApplicationFiled: February 28, 2003Publication date: August 7, 2003Applicant: Fuji Electric, Co., Ltd.Inventors: Yasuhiko Onishi, Tatsuhiko Fujihira, Susumu Iwamoto, Takahiro Sato
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Patent number: 6586283Abstract: An apparatus and a method for protecting charge storage elements from photo-induced currents in silicon integrated circuits are provided. In order to protect against photo-induced currents that are generated outside the storage node circuits themselves, an n-well guard ring is placed as closely as possible to the transistors and other elements in the storage node circuits. As a result there is a minimum of exposed silicon area in which light can produce current in areas next to the storage node circuits, and the n-well guard ring captures photo-induced currents that are generated outside the storage node circuits. In order to protect against the photo-induced currents that are generated inside the storage node circuits, an aluminum interconnect layer is placed on top of the storage node circuit, separated by an insulating layer of silicon dioxide. This creates a shield against the light and protects the storage node circuit by reflecting light away.Type: GrantFiled: March 30, 2000Date of Patent: July 1, 2003Assignee: Agilent Technologies, Inc.Inventors: John J. Corcoran, Travis N. Blalock, Paul J. Vande Voorde, Thomas A. Knotts, Neela B. Gaddis
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Publication number: 20030116777Abstract: A cascaded diode acting as all ESD protection device with reduced substrate leakage current is disclosed. The cascaded diode is composed of a chain of coupled similar elemental diodes, each composed of an n-well in a p-substrate, the n-well having p regions and n regions, and a deep n-well disposed under and connected to the n-well. The first elemental diode has its p region electrically connected to a pin or pad that is the higher potential end of a portion of an integrated circuit to be protected, its n region electrically connected to the p region of an intermediate elemental diode. The p region of an intermediate diode is connected electrically to the n region of the preceding elemental diode and the n region of an intermediate elemental diode is connected electrically to the p region of the following elemental diode.Type: ApplicationFiled: February 3, 2003Publication date: June 26, 2003Applicant: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANYInventor: Ta-Lee Yu
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Patent number: 6576934Abstract: An embedded SCR in conjunction with a Gated-NMOS is created for protecting a chip input or output pad from ESD, by inserting a p+ diffusion and the n-well in the drain side and a part of the drain to forms a low-trigger, high efficiency SCR. The device layout is such that the drain connection is tightly tied together at the p+ diffusion and the n+ drain making that connection very short and, thereby, preventing latch-up. The parasitic SCR is contained entirely within the n+ diffusion (the source of the grounded gate NMOS transistor) at either side of the structure and, therefore, called an embedded SCR. For a 12 volt I/O device each of two n+ drains is placed in its own n-type doped drain (ndd) area straddling halfway the n-well. The structure is repeated as required and a p+ diffusion is implanted at both perimeters and connected to the nearest n+ source and a reference voltage.Type: GrantFiled: October 22, 2002Date of Patent: June 10, 2003Assignee: Taiwan Semiconductor Manufacturing CompanyInventors: Tao Cheng, Jian-Hsing Lee
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Patent number: 6576960Abstract: An electrostatic discharge protection device is formed in a substrate and contains a drain area of a first dopant concentration abutting an extended drain area having a dopant concentration lower than the first dopant concentration. Similarly, a highly doped source area abuts a lower doped source extension area. The source and drain are laterally bounded by oxide regions and covered by an insulation layer. The areas of lower doping prevent charge crowding during an electrostatic discharge event by resistively forcing current though the nearly planer bottom surface of the drain, rather than the curved drain extension. In addition, a highly doped buried layer can abut an area of a graded doping level. By adjusting the doping levels of the graded areas and the buried layers, the substrate breakdown voltage is pre-selected.Type: GrantFiled: March 11, 2002Date of Patent: June 10, 2003Assignee: Micron Technology, Inc.Inventors: Stephen R. Porter, Manny K. Ma, Stephen Casper, Kevin Duesman
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Patent number: 6566223Abstract: A high voltage integrated switching device includes at least one high voltage switching circuit, preferably employing DMOS technology and characterized by a breakdown voltage of at least 100 volts, on a dielectrically isolated, bonded and vertically trenched silicon substrate. Multiple high-voltage switching circuits may be located in close proximity on a single substrate without circuit breakdown or shorting during circuit operation. The circuit may further include one or more low- and/or intermediate-voltage circuits employing, for example, CMOS and bipolar technologies on the same silicon substrate and located in close proximity without voltage breakdown during circuit operation.Type: GrantFiled: August 15, 2000Date of Patent: May 20, 2003Assignee: C. P. Clare CorporationInventors: Nestore A. Polce, Scotten W. Jones, Mark F. Heisig
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Patent number: 6534347Abstract: A silicon semiconductor die comprises a heavily doped silicon substrate and an upper layer comprising doped silicon of a first conduction type disposed on the substrate. The upper layer comprises a well region of a second, opposite conduction type adjacent an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon. Both the well region and adjacent edge termination zone are disposed at an upper surface of the upper layer, and an oxide layer overlies the upper layer and the edge termination zone. A process for forming a silicon die having improved edge termination. The process comprises forming an upper layer comprising doped silicon of a first conduction type on a heavily doped silicon substrate, and forming an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon at an upper surface of the upper layer.Type: GrantFiled: February 23, 2001Date of Patent: March 18, 2003Assignee: Intersil CorporationInventors: Jun Zeng, Gary Mark Dolry, Praveen MurAleedharan
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Patent number: 6515302Abstract: An insulated gate field effect transistor is disclosed. The transistor includes a semi-insulating silicon carbide substrate, an epitaxial layer of silicon carbide layer adjacent the semi-insulating substrate for providing a drift region having a first conductivity type, and source and drain regions in the epitaxial layer having the same conductivity type as the drift region. A channel region is in the epitaxial layer, has portions between the source and the drain regions, and has the opposite conductivity type from the source and drain regions. The transistor includes contacts to the epitaxial layer for the source, drain and channel regions, an insulating layer over the channel region of the epitaxial layer, and a gate contact adjacent the insulating layer and the channel region.Type: GrantFiled: April 12, 2000Date of Patent: February 4, 2003Assignee: Purdue Research FoundationInventors: James Albert Cooper, Jr., Michael R. Melloch, Jayarama Shenoy, Jan Spitz
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Patent number: 6509617Abstract: A semiconductor device according to the present invention includes a first guard ring having conductivity of one of N and P types and a second guard ring formed adjacent to the first guard ring and having conductivity of the other type. The first guard ring is formed by a plurality of land shaped well regions each correspondingly to one cell or a plurality of I/O cells and at least one of the well regions is connected to a first power source line and ay least one of the remaining well regions is connected to a second power source line.Type: GrantFiled: August 21, 2001Date of Patent: January 21, 2003Assignee: Rohm Co., Ltd.Inventor: Noriaki Hiraga
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Publication number: 20030001216Abstract: A semiconductor component includes a substrate (110) having a surface, a channel region (120, 220) located in the substrate, a non-electrically conductive region (130) substantially located below a substantially planar plane defined by the surface of the substrate, a drift region (140, 240) located in the substrate and between the channel region and the non-electrically conductive region, and an electrically floating region (150, 350, 450, 550) located in the substrate and contiguous with the non-electrically conductive region.Type: ApplicationFiled: June 27, 2001Publication date: January 2, 2003Applicant: Motorola, Inc.Inventors: Edouard D. de Fresart, Patrice Parris, Richard Joseph De Souza
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Publication number: 20020155644Abstract: A plasma process reactor is disclosed that allows for greater control in varying the functional temperature range for enhancing semiconductor processing and reactor cleaning. The temperature is controlled by splitting the process gas flow from a single gas manifold that injects the process gas behind the gas distribution plate into two streams where the first stream goes behind the gas distribution plate and the second stream is injected directly into the chamber. By decreasing the fraction of flow that is injected behind the gas distribution plate, the temperature of the gas distribution plate can be increased. The increasing of the temperature of the gas distribution plate results in higher O2 plasma removal rates of deposited material from the gas distribution plate. Additionally, the higher plasma temperature aids other processes that only operate at elevated temperatures not possible in a fixed temperature reactor.Type: ApplicationFiled: April 22, 2002Publication date: October 24, 2002Inventors: Kevin G. Donohoe, Guy T. Blalock
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Patent number: 6468837Abstract: A semiconductor device (10) comprises a reduced surface field (RESURF) implant (14). A field oxide layer (20), having a length, is formed over the RESURF implant (14). A field plate (12) extends from a near-side of the field oxide layer (20) and over at least one-half of the length of the field oxide layer (20).Type: GrantFiled: August 1, 2000Date of Patent: October 22, 2002Assignee: Texas Instruments IncorporatedInventors: Sameer P. Pendharkar, Taylor R. Efland
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Publication number: 20020149067Abstract: The present invention relates to an NMOS transistor structure which comprises a p-well region in a semiconductor substrate, an n-type source region in the p-well region, and an n-type drain region in the p-well region. The source and drain regions are laterally spaced apart from one another and define a p-type channel region therebetween in the p-well region. The NMOS transistor further comprises a gate having a gate electrode and a gate oxide overlying the channel region of the p-well region. A PDUF region underlies the p-well region and exhibits a resistivity which is less than the p-well region, wherein the PDUF region lowers a resistance associated with the p-well region at high drain voltages. The lowered resistance decreases a gain associated with a parasitic bipolar transistor and increases an injection induced breakdown voltage characteristic of the NMOS transistor structure.Type: ApplicationFiled: April 12, 2001Publication date: October 17, 2002Inventors: Jozef C. Mitros, James R. Todd, Xiaoju Wu
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Patent number: 6465283Abstract: A structure and fabrication method using latch-up implantation to improve latch-up immunity in CMOS circuit. The impedance of parasitic SCR conducting path is raised by performing an ion-implantation process on a cathode and an anode of a parasitic SCR which may induce latch-up phenomenon. Thus, the parasitic SCR is thus not easily to be conducted with a higher resistance to noise. Therefore, the latch-up immunity can be improved. In addition, the ion implantation process can be performed to achieve the objective of preventing latch-up effect without consuming more area for layout, thus greatly enhances the flexibility in circuit design.Type: GrantFiled: September 5, 2000Date of Patent: October 15, 2002Assignee: Industrial Technology Research InstituteInventors: Chyh-Yih Chang, Ming-Dou Ker, Hsin-Chin Jiang, Jeng-Jie Peng
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Publication number: 20020142522Abstract: A kill index classification method for prioritizing relational aspects of topological defect intersections, particularly in association with an intermediate analytical testing stage of a multi-stage semiconductor fabrication process. The method relates to an analysis of the geometrical relationship between non-predetermined portion(s), generally referred to as defects, and the surrounding predetermined topology of a conductive semiconductor pattern, to determine the effect of defects on the functionality and reliability of a wafer, and particularly an examined die thereon. Further, in accordance with this geometrical information, a preferred classification of the effects of defects into a numerical value, the “kill index”, is achieved. Preferably, this kill index is strongly linked, correlated and related to the damage caused by the defect to the functionality and/or reliability of the underlying integrated circuit.Type: ApplicationFiled: March 30, 2001Publication date: October 3, 2002Inventors: Ayelet Pnueli, Ariel Ben-Porath
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Publication number: 20020137264Abstract: Disclosed is a method for fabricating thin wafer insulated gate bipolar transistors (IGBTs), in which a portion on the back side of the device region is removed to form a hollow region with a depth that results in a device region thickness equivalent to the thickness of a thin wafer while the rest of the wafer remains its standard thickness. In other words, the method according to the present invention is suitable for the currently used wafer transfer stations under thin wafer conditions. The non-punch-through type insulated gate bipolar transistor (NPT-IGBT) fabricated with this method gets rid of an epi-layer and the “lifetime killer” process. The punch-through type insulated gate bipolar transistor (PT-IGBT) fabricated with this method has higher switching efficiency due to reduced injection efficiency of the p+-type minority carriers.Type: ApplicationFiled: March 23, 2001Publication date: September 26, 2002Inventors: Ming-Jer Kao, Chien-Chung Hung, Jeng-Hua Wei, Jih-Shin Ho
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Patent number: 6444510Abstract: An ESD device and method using parasitic bipolar transistors that are silicided. The first embodiment is a parasitic Bipolar Junction Transistor comprised of n+/n−/p−/n−/n+ regions. The emitter is formed of the second N+ region and the second N− well. The parasitic base is formed by the p− substrate or well. The collector is formed of the first well and the first n+ region. The benefit of the first embodiment is the trigger voltage is lower because the junction between the n− well (emitter) and P− substrate (base) and the junction between P− substrate (base) and the n− well have lower cross over concentrations. The second embodiment is similar to the first embodiment with the addition of the first gate. The first gate is preferably connected to the first n+ region and the Vpad. The third embodiment contains the same elements as the second embodiment with the addition of a third n+ region.Type: GrantFiled: December 3, 2001Date of Patent: September 3, 2002Assignee: Nano Silicon Pte. Ltd.Inventors: David Hu, Jun Cai
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Publication number: 20020109184Abstract: An improved n-channel integrated lateral DMOS (10) in which a buried body region (30), beneath and self-aligned to the source (18) and normal body diffusions, provides a low impedance path for holes emitted at the drain region (16). This greatly reduces secondary electron generation, and accordingly reduces the gain of the parasitic PNP bipolar device. The reduced regeneration in turn raises the critical field value, and hence the safe operating area.Type: ApplicationFiled: December 31, 2001Publication date: August 15, 2002Applicant: Texas instruments IncorporatedInventors: Philip L. Hower, Taylor R. Efland
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Publication number: 20020093065Abstract: A semiconductor device has a gate electrode formed extending on a first and second gate insulation films formed on P type semiconductor substrate, an N+ type source region adjacent to one end of the gate electrode, an N−type drain region facing said source region through a channel region, having high impurity concentration peak at a position of the predetermined depth at least in said substrate under said first gate insulation film, and formed so that high impurity concentration becomes low at a region near surface of the substrate, an N− type drain region formed so as to range to the N− type drain region, an N+ type drain region separated from the other end of said gate electrode and included in said N− type drain region, and an N type layer formed so as to span from one end portion of said first gate insulation film to said N+ type drain region.Type: ApplicationFiled: April 10, 2001Publication date: July 18, 2002Inventors: Shuichi Kikuchi, Eiji Nishibe, Takuya Suzuki
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Publication number: 20020048856Abstract: A method for testing a semiconductor memory device according to one embodiment comprises the steps of: checking data in all addresses of the semiconductor memory device for correctness in-units of m×n bits: ending if it is determined that data in all the semiconductor memory device; if there is a defective address, comparing each m-bit data constituting the (m×n)-bit data corresponding to the defective address with its expected value; and if the comparison result indicates that the m-bit data is erroneous, determining whether the defective semiconductor memory device can be repaired. Due to this step, man hours required for testing a semiconductor memory device having a wide data bus of an (m×n)-bit width can be considerably reduced.Type: ApplicationFiled: January 18, 2001Publication date: April 25, 2002Inventors: Atsuo Mangyo, Manabu Miura, Makoto Hatakenaka
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Publication number: 20020048857Abstract: A product pattern and a test pattern for managing a focus offset value are patterned onto a product wafer by means of exposure, and is patterned onto the product wafer by means of exposure The exposed product wafer is developed. A measurement section measures the dimension of the test pattern patterned on the product wafer. On the basis of the thus-measured dimension of the test pattern, the focus offset value set in a system for manufacturing a semiconductor device is computed by a computation section. The focus offset value set in a projection optical system of the system for manufacturing a semiconductor device is adjusted by means of an adjustment section so as to become identical with the computed focus offset value.Type: ApplicationFiled: February 2, 2001Publication date: April 25, 2002Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Takayuki Saito, Tadashi Miyagi, Takuya Matsushita
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Publication number: 20020045295Abstract: A semiconductor device according to the present invention includes a first guard ring having conductivity of one of N and P types and a second guard ring formed adjacent to the first guard ring and having conductivity of the other type. The first guard ring is formed by a plurality of land shaped well regions each correspondingly to one cell or a plurality of I/O cells and at least one of the well regions is connected to a first power source line and ay least one of the remaining well regions is connected to a second power source line.Type: ApplicationFiled: August 21, 2001Publication date: April 18, 2002Inventor: Noriaki Hiraga
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Patent number: 6362026Abstract: A silicon semiconductor die comprises a heavily doped silicon substrate and an upper layer comprising doped silicon of a first conduction type disposed on the substrate. The upper layer comprises a well region of a second, opposite conduction type adjacent an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon. Both the well region and adjacent edge termination zone are disposed at an upper surface of the upper layer, and an oxide layer overlies the upper layer and the edge termination zone. A process for forming a silicon die having improved edge termination. The process comprises forming an upper layer comprising doped silicon of a first conduction type on a heavily doped silicon substrate, and forming an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon at an upper surface of the upper layer.Type: GrantFiled: March 23, 2001Date of Patent: March 26, 2002Assignee: Intersil Americas Inc.Inventors: Jun Zeng, Gary Mark Dolry, Praveen MurAleedharan
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Patent number: 6355508Abstract: An electrostatic discharge protection device is formed in a substrate and contains a drain area of a first dopant concentration abutting an extended drain area having a dopant concentration lower than the first dopant concentration. Similarly, a highly doped source area abuts a lower doped source extension area. The source and drain are laterally bounded by oxide regions and covered by an insulation layer. The areas of lower doping prevent charge crowding during an electrostatic discharge event by resistively forcing current though the nearly planer bottom surface of the drain, rather than the curved drain extension. In addition, a highly doped buried layer can abut an area of a graded doping level. By adjusting the doping levels of the graded areas and the buried layers, the substrate breakdown voltage is pre-selected.Type: GrantFiled: April 12, 1999Date of Patent: March 12, 2002Assignee: Micron Technology, Inc.Inventors: Stephen R. Porter, Manny K. Ma, Stephen Casper, Kevin Duesman
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Publication number: 20010034085Abstract: A shallow impurity diffusion layer adjacent to a gate electrode is formed by forming a side-wall insulating film of the gate electrode twice, and a MOS transistor of the salicide type having improved short-channel effect is embodied. An impurity diffusion layer portion not adjacent to a gate electrode of a source/drain region is formed first by self-alignment with a first side-wall insulating film. After an impurity diffusion layer adjacent to the gate electrode is formed by self-alignment with the gate electrode, a second side-wall insulating film is formed. Silicide films are formed on the gate electrode and source/drain region by self-alignment with the second side-wall insulating film.Type: ApplicationFiled: March 30, 2001Publication date: October 25, 2001Applicant: Kabushiki Kaisha ToshibaInventors: Takeo Nakayama, Akira Hokazono
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Patent number: 6306690Abstract: The invention comprises an integrated circuit including integral high and low-voltage peripheral transistors and a method for making the integrated circuit. In one aspect of the invention, a method of integrating high and low voltage transistors into a floating gate memory array comprises the steps of forming a tunnel oxide layer outwardly from a semiconductor substrate, forming a floating gate layer disposed outwardly from the tunnel oxide layer and forming an insulator layer disposed outwardly from the floating gate layer to create a first intermediate structure. The method further includes the steps of masking a first region and a second region of the first intermediate structure leaving a third region unmasked, removing at least a portion of the insulator layer, the floating gate layer and the tunnel oxide layer from the third region and forming a first dielectric layer disposed outwardly from the substrate in a region approximately coextensive with the third region.Type: GrantFiled: September 2, 1999Date of Patent: October 23, 2001Assignee: Texas Instruments IncorporatedInventors: Cetin Kaya, Stanton P. Ashburn
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Patent number: 6300171Abstract: 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: GrantFiled: December 7, 1999Date of Patent: October 9, 2001Assignee: STMicroelectronics S.r.l.Inventor: Ferruccio Frisina
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Publication number: 20010015467Abstract: The present invention discloses a method for fabricating a transistor for a semiconductor device. The transistor requires and controls a high voltage, when using an anti-fuse circuit capable of carrying out a repair operation after packaging, thereby improving the operation property and yield of the device.Type: ApplicationFiled: January 2, 2001Publication date: August 23, 2001Inventors: Tae Hyoung Huh, Joong Shik Shin
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Publication number: 20010010385Abstract: Inner trenches (11) of a trenched Schottky rectifier (1a; 1b; 1c; 1d) bound a plurality of rectifier areas (43a) where the Schottky electrode (3) forms a Schottky barrier 43 with a drift region (4). A perimeter trench (18) extends around the outer perimeter of the plurality of rectifier areas (43a). These trenches (11, 18) accommodate respective inner field-electrodes (31) and a perimeter field-electrode (38) that are connected to the Schottky electrode (3). The inner field-electrodes (11) are capacitively coupled to the drift region (4) via dielectric material (21) that lines the inner trenches (11). The perimeter field-electrode (38) is capacitively coupled across dielectric material (28) on the inside wall (18a) of the perimeter trench 18, without acting on any outside wall (18b). Furthermore, the inner and perimeter trenches (11, 18) are closely spaced and the intermediate areas (4a, 4b) of the drift region (4) are lowly doped.Type: ApplicationFiled: February 1, 2001Publication date: August 2, 2001Applicant: U.S. Philips CorporationInventors: Erwin A. Hijzen, Raymond J.E. Hueting
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Patent number: 6204097Abstract: A semiconductor device (10) having a termination structure (25) and a reduced on-resistance. The termination structure (25) is fabricated using the same processing steps that were used for manufacturing an active device region (21). The termination structure (25) and the active device region (21) are formed by etching trenches (22, 23) into a drift layer (14). The trenches (22, 23) are filled with a doped polysilicon trench fill material (24), which is subsequently planarized. The semiconductor device (10) is formed in the trenches (22) filled with the polysilicon trench fill material (24) that are in the active region. The trenches (23) filled with the polysilicon trench fill material (24) in a termination region serve as termination structures.Type: GrantFiled: March 1, 1999Date of Patent: March 20, 2001Assignee: Semiconductor Components Industries, LLCInventors: Zheng Shen, Francine Y. Robb, Stephen P. Robb
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Patent number: 6190948Abstract: Power semiconductor devices having overlapping floating field plates include a primary field plate and a plurality of floating field plates which are formed on an electrically insulating region and capacitively coupled together in series between an active region of a power semiconductor device and a floating field ring. Preferably, the capacitive coupling is achieved by overlapping at least portions of the floating field plates. According to one embodiment, a power semiconductor device comprises a semiconductor substrate having a first region of first conductivity type therein extending to a face thereof and a second region of second conductivity type in the first region of first conductivity type and forming a P-N junction therewith.Type: GrantFiled: December 12, 1997Date of Patent: February 20, 2001Assignee: Fairchild Korea Semiconductor Ltd.Inventor: Kyung-Wook Seok
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Patent number: 6150200Abstract: A semiconductor device (10) is formed in a semiconductor substrate (11) and an epitaxial layer (14). The semiconductor device includes a p-type body region (16), a source region (17), a channel region (19), and a drain region (34) formed in the epitaxial layer (14). A doped region (13) is formed in the semiconductor substrate (11) to reduce the drift resistance of the semiconductor device (10). The drain region (34) is formed from a plurality of doped regions (30-33) that can be formed with high energy implants.Type: GrantFiled: April 3, 1998Date of Patent: November 21, 2000Assignee: Motorola, Inc.Inventor: Steven L. Merchant
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Patent number: 6146926Abstract: A lateral gate, vertical drift region transistor including a drain positioned on one surface of a substrate and a doped structure having a buried region therein positioned on the other surface of the substrate. The buried region defining a drift region in the doped structure extending vertically from the substrate and further defining a doped region in communication with the drift region and adjacent the surface of the doped structure. A source positioned on the doped structure in communication with the doped region and an implant region positioned in the doped region adjacent the surface and in communication with the source and buried region. An insulating layer positioned on the doped structure with a metal gate positioned on the insulating layer so as to define an inversion region in the implant region extending laterally adjacent the control terminal and communicating with the drift region and the source.Type: GrantFiled: August 19, 1998Date of Patent: November 14, 2000Assignee: Motorola, Inc.Inventors: Mohit Bhatnagar, Charles E. Weitzel
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Patent number: 6114193Abstract: A method for preventing the snap down effect in a power rectifier with higher breakdown voltage comprises the step of forming an isolation layer between the semiconductor substrate and the epitaxy layer. The isolation layer can prevent the dislocation occurred upon the semiconductor substrate from influencing the p-n junction atop. Therefore, the power rectifier manufactured by the method of the present invention can work under a higher breakdown voltage exceeding 450 V with reduced cost.Type: GrantFiled: May 5, 1998Date of Patent: September 5, 2000Assignee: Vishay Lite-On Power Semicon Corp.Inventors: Yen Hui Chang, Kuo Wei Chiang
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Patent number: 5998245Abstract: The ESD circuit of the present invention comprises a protection device, and output circuitry. The ESD circuitry illustratively comprises an NMOS and PMOS transistor and two protective diodes. However, in place of the NMOS and PMOS transistors, any two-terminal protection device may be used. The protection device of the present invention comprises the diodes of the ESD circuitry. These diodes are formed within the seal-ring structure of an IC. The seal-ring structure is formed using the following steps. First, a field oxide is grown. N.sup.+ and P.sup.+ impurities are diffused into the substrate. An insulating layer is then grown over the oxide, P.sup.+, and N.sup.+ regions. The insulating layer is etched back, uncovering the substrate, P.sup.+ region, and a portion of the N.sup.+ region. Similarly, a thick aluminum layer is deposited and etched back to form a first connection layer. Subsequently, an insulating layer is formed over the first insulating layer.Type: GrantFiled: March 18, 1998Date of Patent: December 7, 1999Assignee: Winbond Electronics CorporationInventor: Ta-Lee Yu
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Patent number: 5981349Abstract: The breakdown voltage of a semiconductor device, such as a transistor fabricated in a device region in and abutting the surface of a semiconductor body with a field oxide surrounding the device region, is improved by etching the field oxide abutting the device region to reduce the thickness thereof to about 0.6-1.4 .mu.m and then forming a field plate in the recessed field oxide which is capacitively coupled to the underlying semiconductor body. The field plate can be floating, connected to a voltage potential, or connected to the semiconductor device.Type: GrantFiled: September 29, 1997Date of Patent: November 9, 1999Assignee: Spectrian, Inc.Inventor: Francois Hebert
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Patent number: 5970321Abstract: A semiconductor package having positioned therein a protection layer which protects the integrated circuit chip from electrostatic discharge (ESD) damage. The protection layer is made of a material that has at steady state a high electrical resistance, but when a high ESD potential is applied to it, it becomes highly conductive. A preferred material is SurgX.TM., which is a polymer. The layer is positioned to shunt the potential away from the chip, and can be positioned operatively between a signal lead and a power plane or between different signal leads. That is, the protection layer can be sandwiched between the lead and the conductive member, or the lead can be within the layer. Another preferred construction incorporates the protection material in a tape construction as a thin layer sandwiched between and bonded to a layer of leads and a ground plane.Type: GrantFiled: September 25, 1997Date of Patent: October 19, 1999Assignee: LSI Logic CorporationInventor: James W. Hively
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Patent number: 5962878Abstract: In a bidirectional surge protection device formed on a semiconductor substrate, buried layers, which have the same conduction type as and are higher in impurity concentration than the semiconductor substrate, are formed on the entire surfaces of the device regions provided on both surfaces of the semiconductor substrate or formed under emitter-push restraining layers alone, wherein injection of minority carriers from a surface opposite to the surface on which the device operates is restrained to lower a holding current. As a result, the bidirectional surge protection device easily becomes OFF once it becomes ON.Type: GrantFiled: September 16, 1998Date of Patent: October 5, 1999Assignee: Citizen Watch Co., Ltd.Inventor: Toru Takizawa
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Patent number: 5830783Abstract: A monolithic semiconductor device having an edge structure that facilitates integrating high power devices an logic devices on the same substrate. The semiconductor device includes on a substrate of a first type of doping, a control region of a second type of doping, which is provided with an edge region, and a power region of a second type of doping. In the edge region, at least one channel is provided which is adapted to divide the edge region into regions that are electrically isolated from each other, the region at the channel being covered with a field plate. A method for producing such an edge structure in combination with the production execution of the monolithic device is also disclosed herein.Type: GrantFiled: December 3, 1996Date of Patent: November 3, 1998Assignee: Consorzio per la Ricerca sulla Microeletrronica nel MezzogiornoInventors: Natale Aiello, Atanasio LaBarbera, Salvatore Leonardi