Shallow Diffusion Patents (Class 148/DIG144)
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Patent number: 5925574Abstract: A method of producing a bipolar transistor composed of collector, base and emitter regions disposed sequentially on a semiconductor substrate. According to the method, a semiconductor layer is deposited on the collector region, the semiconductor layer is cleaned to expose an active surface, an impurity source gas is applied to the exposed active surface while heating the substrate to form an impurity adsorption layer, the impurity is diffused into the semiconductor layer to form the base region, another semiconductor layer is deposited on the base region, this semiconductor layer is cleaned to expose an active surface, another impurity source gas is applied to the exposed active surface while heating the substrate to form another impurity adsorption layer, and impurity is diffused into the semiconductor layer to from the impurity adsorption layer to form the emitter region.Type: GrantFiled: April 10, 1992Date of Patent: July 20, 1999Assignee: Seiko Instruments Inc.Inventors: Kenji Aoki, Tadao Akamine, Yoshikazu Kojima
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Patent number: 5834368Abstract: A method for manufacturing an integrated circuit, wherein, before providing an IC composite by forming a metal film on an IC assembly which includes a semiconductor substrate and a silicon part formed along the substrate and consisting essentially of silicon, an amorphous region is formed into the silicon part. The IC composite is subjected to first primary and secondary heat treatments in a nitrogen atmosphere and then to a second heat treatment at 600.degree.-700.degree. C., 700.degree.-900.degree. C., and 700.degree.-900.degree. C. to turn the metal film on the silicon part into a metal silicide film of excellent uniformity. The assembly has a silicon dioxide portion, on which the metal film is turned during the first primary and secondary heat treatments into a metal nitride film. The second heat treatment is carried out after the removal of the metal nitride film.Type: GrantFiled: March 10, 1997Date of Patent: November 10, 1998Assignee: NEC CorporationInventors: Hiroshi Kawaguchi, Isami Sakai
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Patent number: 5747378Abstract: A method of damage-free doping for forming a dynamic random access memory cell is disclosed herein. A phosphoric silicate glass is deposited as a diffusion source. The phosphorous ions of phosphoric silicate glass can be diffused into a substrate to form the source/drain regions by a high temperature during a thermal annealing process. Next, a thermal oxide layer is formed on the gate electrode and the surface of the substrate by the thermal oxidation process. The thermal oxide layer can prevent ions from diffusing into the substrate during the subsequent thermal treatment process. Therefore, the present invention can reduce the damage of a dynamic random access memory.Type: GrantFiled: May 27, 1997Date of Patent: May 5, 1998Assignee: Mosel Vitelic Inc.Inventors: Der-Tsyr Fan, Chon-Shin Jou, Ting-S. Wang
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Patent number: 5674777Abstract: The present invention is related to a method for fabricating a silicon electronic device having a boron diffusion source layer, includes steps of: a) providing a silicon substrate; b) depositing a silicon layer on said silicon substrate; and c) growing a silicon-boron binary compound layer on said silicon layer as said boron diffusion source. When the Si-B layer is formed by a UHV/CVD process according to the present invention, the boron concentration in the Si-B binary compound layer will be extraordinary high (up to 1.times.10.sup.21 to 5.times.10.sup.22 atoms/cm.sup.3).Type: GrantFiled: December 14, 1995Date of Patent: October 7, 1997Assignee: National Science CouncilInventors: Tung-Po Chen, Tan-Fu Lei, Chun-Yen Chang
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Patent number: 5670391Abstract: Transient enhanced diffusion (TED) of dopants is reduced by bring the surface closer to the implant damage prior to the annealing process.Type: GrantFiled: August 7, 1995Date of Patent: September 23, 1997Assignee: Lucent Technologies Inc.Inventors: Desmond R. Lim, Conor Stefan Rafferty
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Patent number: 5599734Abstract: A method for fabricating an MOS transistor includes the steps of forming a gate insulating layer on a substrate of a first conductivity-type, forming a gate on the gate insulating layer, forming a disposable layer over an entire surface of the substrate and the gate, the disposable layer having a first conductivity-type impurity and a second conductivity-type impurity of a higher concentration than that of the first conductivity-type impurity, and forming a source and drain area of the second conductivity-type impurity on the substrate by diffusing the second conductivity-type impurity of the disposable layer into the substrate by means of an annealing process, wherein the disposable layer includes a BPSG layer, wherein the BPSG layer is a B+PSG layer which is doped with a higher dopant concentration of boron than that of phosphorus to make a p-type MOS transistor.Type: GrantFiled: June 6, 1995Date of Patent: February 4, 1997Assignee: LG Semicon Co., Ltd.Inventors: Jeong S. Byun, Sang J. Choi
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Patent number: 5518945Abstract: A method of fabricating a lightly doped drain MOSFET device with a built in etch stop is disclosed. After forming a gate electrode on a substrate through conventional methods, a conformal doped layer is deposited on the gate electrode. A conformal layer of nitride is then deposited on the conformal doped layer. The nitride layer is etched, with the etch stopping on the conformal doped layer, thereby forming nitride spacers. Deep source and drain regions are formed by either ion implantation or diffusion. The device is then heat treated so that light diffusion occurs under the nitride spacers and heavy diffusion occurs outside the spacer region. The method is applicable to N-substrate (P-channel), P-substrate (N-channel), and complementary metal oxide semiconductor (CMOS) devices.Type: GrantFiled: May 5, 1995Date of Patent: May 21, 1996Assignee: International Business Machines CorporationInventors: John A. Bracchitta, Gabriel Hartstein, Stephen A. Mongeon, Anthony C. Speranza
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Patent number: 5453389Abstract: A method for manufacturing bipolar semiconductor devices wherein damage to the active regions of the devices due to the direct implantation of impurities is suppressed. A material is selectively deposited on a semiconductor substrate, the material having a characteristic such that formation of the material occurs on some substances such as silicon and polysilicon, and formation of the material is suppressed on other substances such as silicon dioxide and silicon nitride. Impurities are introduced into the material rather than into the substrate. The impurities are then diffused into the active regions by standard processes such as rapid thermal anneal (RTA) or furnace anneal. The material generally contains germanium, and usually is a polycrystalline silicon-germanium alloy. The diffusion depth of the impurities may be controlled with great precision by manipulating several parameters.Type: GrantFiled: August 27, 1993Date of Patent: September 26, 1995Assignee: National Semiconductor, Inc.Inventors: Robert J. Strain, Sheldon Aronowitz
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Patent number: 5444024Abstract: A method is provided for controlling growth of silicide to a defined thickness based upon the relative position of peak concentration density depth within a layer of titanium. The titanium layer is deposited over silicon and namely over the silicon junction regions. Thereafter the titanium is implanted with argon ions. The argon ions are implanted at a peak concentration density level corresponding to a depth relative to the upper surface of the titanium. The peak concentration density depth can vary depending upon the dosage and implant energies of the ion implanter. Preferably, the peak concentration density depth is at a midpoint between the upper and lower surfaces of the titanium or at an elevational level beneath the midpoint and above the lower surface of the titanium. Subsequent anneal of the argon-implanted titanium causes the argon atoms to occupy a diffusion area normally taken by silicon consumed and growing within overlying titanium.Type: GrantFiled: June 10, 1994Date of Patent: August 22, 1995Assignee: Advanced Micro Devices, Inc.Inventors: Mohammed Anjum, Ibrahim K. Burki, Craig W. Christian
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Patent number: 5310711Abstract: Very shallow electrical junctions may be formed in an oxide free surface of a semiconductor by introducing an inert or reducing gas into a vacuum processing chamber, heating the semiconductor to between 750.degree. C. and 1100.degree. C., introducing a dilute solution of a dopant gas into the chamber, and exposing the semiconductor to the gases for about 0.5 to about 100 minutes, preferably between 10 and 30 minutes. A relatively wide range of surface dopant concentrations may be achieved thereby with dopant concentration controlled independent of junction depth. Non-oxide free semiconductor surfaces may be made oxide free by first heating the semiconductor surface in the presence of the reducing gas. This technique provides uniform surface dopant concentrations and is suitable for the formation of junctions in deep trenches and other features having high aspect ratios.Type: GrantFiled: August 2, 1993Date of Patent: May 10, 1994Assignee: Hewlett-Packard CompanyInventors: Clifford I. Drowley, John E. Turner
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Patent number: 5227329Abstract: A boron doped amorphous silicon film is formed by CVD under the conditions of a pressure lower than 1 atm and a temperature higher than 200.degree. C. and lower than 400.degree. C. by using at least one of disilane and trisilane, and diborane as source gases. Since the resultant amorphous silicon film can diffuse impurities at a lower temperature than in the case of the polycrystalline silicon film formed by the conventional method, a pn junction much shallower than in the prior art can be formed.Type: GrantFiled: August 30, 1991Date of Patent: July 13, 1993Assignee: Hitachi, Ltd.Inventors: Takashi Kobayashi, Shimpei Iijima, Atsushi Hiraiwa, Nobuyoshi Kobayashi, Takashi Hashimoto, Mitsuo Nanba
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Patent number: 5183777Abstract: A method of forming a shallow junction comprises the step of: forming a film including a hydrogen compound with one element selected from the group of boron, phosphorus arsenic to a thickness of several atom layers to 1000 .ANG. on a silicon substrate and annealing the film, whereby an impurity region having a depth of 1000 .ANG. or less and an impurity concentration of 10.sup.18 to 10.sup.21 cm.sup.-3 is formed in the surface layer of the silicon layer.Type: GrantFiled: September 13, 1991Date of Patent: February 2, 1993Assignee: Fujitsu LimitedInventors: Masahiko Doki, Michiko Takei
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Patent number: 5118633Abstract: Sources and drains of MOS transistors are formed after the formation of an emitter of a bipolar transistor, whereby the sources and drains are made smaller in thickness than the emitter. Since the sources and drains are not subjected to a high-temperature heat treatment conducted in the formation of the emitter, there is no fear of increase in thickness of the sources and drains caused by the diffusion of impurities. There can be formed a BiCMOS having a high integration density and superior characteristics.Type: GrantFiled: July 25, 1990Date of Patent: June 2, 1992Assignee: Hitachi, Ltd.Inventors: Kazuhiko Sagara, Kiyoo Itoh, Goro Kitsukawa, Yoshifumi Kawamoto, Yoshiki Kawajiri