Autodoping Patents (Class 148/DIG7)
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Patent number: 5525529Abstract: A process is disclosed for inhibiting undesired diffusion of implanted dopants during and after dopant activation, as can occur during source/drain anneal. Undesired dopant diffusion is minimized by a dopant blocking layer, which is applied to the semiconductor body prior to dopant activation, and preferably prior to dopant implantation. The composition of the blocking layer is selected in accordance with the diffusion mechanism of the dopant to be implanted so that the concentration of lattice vacancies or interstitials (depending upon the dopant diffusion mechanism) is reduced, thereby inhibiting undesired migration of the implanted species.Type: GrantFiled: November 16, 1994Date of Patent: June 11, 1996Assignee: Texas Instruments IncorporatedInventor: Richard L. Guldi
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Patent number: 5461002Abstract: Doped areas on semiconductor components are made by applying to a portion of the surface of a semiconductor substrate an oxide forming mask layer which contains dopant, said semiconductor substrate with the mask layer being heated to a temperature sufficient for diffusion of part of the dopant from the mask layer to the semiconductor substrate, where also undesirable auto-doping of the unprotected surfaces of the semiconductor substrate takes place during the doping process, for which reason the auto-doped areas of the semiconductor substrate are etched away by alkaline etching or plasma etching, said mask layer constituting a protective barrier for the doped areas below the mask layer. In the production of a solar cell with two doped areas of the P and N conductor types, respectively, the distance between the two doped areas may be used for adjusting the gradient of the dark current with a diode biased in the blocking direction.Type: GrantFiled: January 14, 1993Date of Patent: October 24, 1995Inventor: Yakov Safir
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Patent number: 5236544Abstract: A process of growing a monocrystal on an insulating film provided on a metal electrode, which comprises: providing a semiconductor film on a substrate having a metal electrode and an insulating film; causing the semiconductor film and the insulating film to undergo the solid phase reaction at the interface therebetween; forming a monocrystalline cohering body of the semiconductor film at the opening of the insulating film by applying annealing for cohesion of the semiconductor film on the metal electrode; and allowing a monocrystal to grow with the monocrystalline cohering body as a seed.Type: GrantFiled: June 26, 1990Date of Patent: August 17, 1993Assignee: Canon Kabushiki KaishaInventor: Kenji Yamagata
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Patent number: 5104828Abstract: An improved method for planarizing the surface of an dielectric deposited over a semiconductor substrate. The substrate is pressed face down against a table which has been coated with an abrasive material. In this way, the upper surface of the interlayer dielectric contacts the abrasive. Rotational movement of the wafer relative to the table facilitates removal of the protruding portions of the interlayer dielectric by the abrasive. Post-planarization step height variation is minimized by simultaneously cooling the table and the abrasive material during the abrasive or polishing process. By maintaining the table and the abrasive at about 10 degrees Celsius the step height variation is reduced by a factor of 2 over that normally realized in the prior art.Type: GrantFiled: March 1, 1990Date of Patent: April 14, 1992Assignee: Intel CorporationInventors: Seiichi Morimoto, Robert J. Patterson
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Patent number: 5047365Abstract: A heterostructure bipolar transistor is formed by a process of steps of holding an N-type gallium arsenide body using as an emitter region in a high vacuum of 10.sup.-9 torr to 10.sup.-13 torr at a first temperature of 400.degree. C. to 1,000.degree. C. where arsenic on a surface of the gallium arsenide body drifts away, lowering the first temperature to a second temperature of 300.degree. C. to 400.degree. C. to start a molecular beam epitaxial growth of a germanium, and forming an N-type germanium layer using as a collector region.Type: GrantFiled: March 27, 1989Date of Patent: September 10, 1991Assignee: NEC CorporationInventors: Masafumi Kawanaka, Jun'ichi Sone, Tooru Kimura
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Patent number: 4894349Abstract: A process for forming a vapor-phase epitaxial growth layer on a silicon wafer having a buried layer of a high As or B concentration. This vapor-phase epitaxial growth process is performed in two steps of (i) performing a vapor-phase epitaxial growth at a relatively low temperature by using a reaction gas containing at least one kind selected from a group consisting of SiH.sub.x F.sub.4-x (x=0 to 3) and Si.sub.2 H.sub.x F.sub.6-x (x=0-5) and at least one kind selected from a group consisting of SiH.sub.4 and Si.sub.2 H.sub.6, and (ii) performing a vapor-phase epitaxial growth under a condition which allows a higher growth rate that in the step (i) by using a reaction gas containing SiH.sub.4 or Si.sub.2 H.sub.6 which may or may not be accompanied with silane fluoride.Type: GrantFiled: December 15, 1988Date of Patent: January 16, 1990Assignee: Kabushiki Kaisha ToshibaInventors: Yoshihiko Saito, Yoshiaki Matsushita
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Patent number: 4859626Abstract: A method of forming thin epitaxial layers by subjecting a substrate to a high temperature prebake followed by a medium temperature capping seal and a low temperature deposition is disclosed. In a preferred embodiment the epitaxial layer is formed by low pressure chemical vapor deposition of dichlorosilane. The method has been demonstrated to alleviate the increase in autodoping and epitaxial defects normally associated with lowering the deposition temperature.Type: GrantFiled: June 3, 1988Date of Patent: August 22, 1989Assignee: Texas Instruments IncorporatedInventor: Rick L. Wise
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Patent number: 4855250Abstract: A method of manufacturing a semiconductor light emitting device by forming a compound semiconductor structure with homo- or heterojunction therein having a first p-type compound semiconductor crystal layer at the top of the structure, growing a second p-type compound semiconductor crystal layer on the structure in a reactor, wherein, before the beginning of the crystal growth step, a p-type dopant is caused to flow into the reactor in which the structure is placed. In some embodiments, the flow of the p-type dopant continues after the completion of the crystal growth.Type: GrantFiled: December 28, 1987Date of Patent: August 8, 1989Assignee: Kabushiki Kaisha ToshibaInventors: Motoyuki Yamamoto, Yasuhiko Tsuburai
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Patent number: 4687682Abstract: Sealing the backside of a semiconductor wafer prevents evaporation of the dopant (typically boron) when an epitaxial layer is grown on the front (active) side, thereby preventing autodoping of the epitaxial layer with excess dopant. The present technique deposits an oxide layer during the ramp-up of the furnace that also deposits the nitride cap, thereby avoiding an extra process step. It also avoids the higher temperatures required for the prior-art technique of growing the oxide layer, resulting in lower oxygen precipitation due to the capping process and a greater yield of usable wafers.Type: GrantFiled: May 2, 1986Date of Patent: August 18, 1987Assignee: American Telephone and Telegraph Company, AT&T Technologies, Inc.Inventor: Jeffrey T. Koze
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Patent number: 4668330Abstract: The invention described herein describes certain test wafers to be used in diagnosing heavy metal contamination in furnaces used in the manufacture of electronic devices and the method of referencing such wafers to a common wafer source for establishing an accurate baseline for a furnace to determine if it is functioning adequately or if an impurity or contaminant problem exists.Type: GrantFiled: December 5, 1985Date of Patent: May 26, 1987Assignee: Monsanto CompanyInventor: Paul F. Golden
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Patent number: 4662956Abstract: A method for the prevention of dopant diffusion from the back side of a doped semiconductor substrate during epitaxial layer growth. The entire surface of the substrate is first covered with a cleanly etchable material. Around the entire first layer is formed a second dopant diffusion barrier layer. The front sides of the layers are then selectively etched away to expose the front side of the substrate upon which the epitaxial layer will be grown without contamination of dopant diffusion from the sealed back side of the substrate.Type: GrantFiled: April 1, 1985Date of Patent: May 5, 1987Assignee: Motorola, Inc.Inventors: Scott S. Roth, Joe Steinberg, H. Scott Morgan
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Method for minimizing autodoping during epitaxial deposition utilizing a graded pattern subcollector
Patent number: 4571275Abstract: The method suggests the replacement of all or part of the solid or blanket buried region, typically a subcollector region of a bipolar transistor, by a mesh or stripe shaped subcollector. During subsequent thermal processing involving growth of the epitaxial layer, the stripes will at least partially merge, resulting in a solid subcollector. The method of minimizing autodoping implies only a special design of the subcollector mask. Therefore, there is no longer any need for technological changes either in the process or in the equipment. The method also applies to other buried layers, such as, subemitters, resistors, bottom isolation regions, etc.Type: GrantFiled: December 19, 1983Date of Patent: February 18, 1986Assignee: International Business Machines CorporationInventor: Tor W. Moksvold -
Patent number: 4554030Abstract: A monocrystalline layer of one semiconductor material is grown onto a surface of a monocrystalline semiconductor body by means of molecular beam epitaxy. During such growth, the semiconductor body is kept at such a low temperature that a non-monocrystalline layer is obtained. The non-monocrystalline layer is then converted by a heat treatment into a monocrystalline form. Accordingly, an abrupt junction between the two semiconductor materials is obtained.Type: GrantFiled: March 2, 1984Date of Patent: November 19, 1985Inventors: Jan Haisma, Poul K. Larsen, Tim De Jong, Johannes F. Van der Veen, Willem A. S. Douma, Frans W. Saris