Patents Assigned to MEMC Electronics Materials, Inc.
-
Patent number: 8529860Abstract: Methods for producing silicon tetrafluoride by acid digestion of fluoride salts of alkali metal or alkaline earth metal and aluminum, optionally, in the presence of a source of silicon; methods for producing silane that include acid digestion of by-products of silane production to produce silicon tetrafluoride.Type: GrantFiled: December 15, 2010Date of Patent: September 10, 2013Assignee: MEMC Electronics Materials, Inc.Inventors: Satish Bhusarapu, Puneet Gupta
-
Patent number: 7878883Abstract: A system and method for slicing an ingot into wafers using the wire saw process. A slurry collection system collects and supplies slurry to a slurry handling system for controlling temperatures and/or flow rates of the slurry thereby providing slurry output at a controlled temperature and/or a controlled flow rate to slicing system for cutting the ingot, which may be preheated.Type: GrantFiled: January 10, 2007Date of Patent: February 1, 2011Assignee: MEMC Electronics Materials, Inc.Inventors: Puneet Gupta, Milind S. Kulkarni, Carlo Zavattari, Roland R. Vandamme
-
Patent number: 7618879Abstract: This invention is directed to a process for heat-treating a single crystal silicon segment to influence the profile of minority carrier recombination centers in the segment. The segment is subjected to a heat-treatment to form crystal lattice vacancies, the vacancies being formed in the bulk of the silicon. The segment is then cooled at a rate which allows some, but not all, of the crystal lattice vacancies to diffuse to the front surface to produce a segment having the desired vacancy concentration profile. Platinum atoms are then in-diffused into the silicon matrix such that the resulting platinum concentration profile is substantially related to the concentration profile of the crystal lattice vacancies.Type: GrantFiled: June 14, 2007Date of Patent: November 17, 2009Assignee: MEMC Electronics Materials, Inc.Inventor: Robert J. Falster
-
Patent number: 7217320Abstract: The present invention relates to a process for preparing a single crystal silicon ingot, as well as to the ingot or wafer resulting therefrom. The process comprises controlling (i) a growth velocity, v, (ii) an average axial temperature gradient, G0, and (iii) a cooling rate of the crystal from solidification to about 750° C., in order to cause the formation of a segment having a first axially symmetric region extending radially inward from the lateral surface of the ingot wherein silicon self-interstitials are the predominant intrinsic point defect, and a second axially symmetric region extending radially inward from the first and toward the central axis of the ingot.Type: GrantFiled: December 7, 2004Date of Patent: May 15, 2007Assignee: MEMC Electronics Materials, Inc.Inventors: Chang Bum Kim, Steven L. Kimbel, Jeffrey L. Libbert, Mohsen Banan
-
Patent number: 7008874Abstract: The present invention is directed to a process for reclaiming for reuse a single crystal silicon wafer removed from an aborted semiconductor device fabrication process. The process includes (a) subjecting the wafer to an oxide growth step to form an oxide layer having a thickness greater than 2 nanometers, (b) thinning the wafer by removing material from substantially the entire front surface to provide a thinned wafer having a thinned precipitate free zone, and (c) polishing the front surface of the thinned wafer to a specular finish.Type: GrantFiled: December 13, 2001Date of Patent: March 7, 2006Assignee: MEMC Electronics Materials, Inc.Inventor: Robert J. Falster
-
Patent number: 6942733Abstract: A fluid sealing system is provided for use in a crystal puller for growing a monocrystalline ingot. The crystal puller has a housing, a fluid flow path contained in the housing, and a fluid passage through a wall of the housing for passage of fluid. The fluid sealing system includes a fluid connector head adapted for connection to the fluid passage and to the fluid flow path to establish fluid communication between the fluid flow path and the outside of the housing. The head has a port adapted for fluid communication with the fluid passage through the wall of the housing. First and second seals around the port are adapted for sealing engagement with the head. A space is defined generally between the first and second seals, and a leak detector is arranged to monitor the space for detecting fluid leakage past at least one of the seals.Type: GrantFiled: June 19, 2003Date of Patent: September 13, 2005Assignee: MEMC Electronics Materials, Inc.Inventors: Carl F. Cherko, Robert D. Cook
-
Patent number: 6686260Abstract: A process for heat-treating a single crystal silicon wafer to dissolve agglomerated vacancy defects and to influence the precipitation behavior of oxygen in the wafer in a subsequent thermal processing step. The process includes subjecting the wafer to a heat treatment to dissolve agglomerated vacancy defects, rapid thermally annealing the heat-treated wafer to cause the formation of crystal lattice vacancies throughout the wafer and controlling the cooling rate of the annealed wafer to allow some, but not all, of the crystal lattice vacancies to diffuse to the front surface to produce a wafer having a nonuniform vacancy concentration with the concentration of vacancies in the bulk of the wafer being greater than the concentration in the surface layer.Type: GrantFiled: February 4, 2002Date of Patent: February 3, 2004Assignee: MEMC Electronics Materials, Inc.Inventors: Robert J. Falster, Martin Jeffrey Binns, Harold W. Korb
-
Patent number: 6227944Abstract: A method for processing a semiconductor wafer sliced from a single-crystal ingot comprises subjecting the front and back surfaces of the wafer to a lapping operation to reduce the thickness of the wafer and to remove damage caused during slicing of the wafer. The wafer is then subjected to an etching operation to further reduce the thickness of the wafer and to further remove damage remaining after the lapping operation. The wafer is subsequently subjected to a double-side polishing operation to uniformly remove damage from the front and back surfaces caused by the lapping and etching operations, thereby improving the flatness of the wafer and leaving polished front and back surfaces. Finally, the back surface of the wafer is subjected to a back surface damaging operation in which damage is induced in the back surface of the wafer while the front surface is substantially protected against being damaged or roughened.Type: GrantFiled: March 25, 1999Date of Patent: May 8, 2001Assignee: MEMC Electronics Materials, Inc.Inventors: Yun-Biao Xin, Ichiro Yoshimura, Henry F. Erk, Ralph V. Vogelgesang, Stephen Wayne Hensiek
-
Patent number: 6112738Abstract: Methods of slicing ingots of semiconductor material into wafers using a wire saw. The wire saw includes a wire that is movable in a forward direction and a reverse direction for slicing the ingots. The methods include defining an identification region of each wafer to be sliced from the ingots and aligning an alignment feature of the ingots in approximately the same position relative to the wire saw for each of the ingots. The identification region of the wafer is adapted for marking with an identification mark after slicing. The methods also include slicing the ingot into wafers with the wire saw. The slicing step includes moving the wire in the forward and reverse directions during slicing except when slicing in the identification region of each wafer and moving the wire only in the forward direction when slicing in the identification region of each wafer. In slicing the ingot into wafers, thickness variations relative to the size of the identification mark are reduced in the identification region.Type: GrantFiled: April 2, 1999Date of Patent: September 5, 2000Assignee: MEMC Electronics Materials, Inc.Inventors: Dale A. Witte, Tracy Ragan
-
Patent number: 6089285Abstract: A method of supplying source material in a crystal puller used to grow single crystal semiconductor material. Generally, the method includes receiving a bulk container of the source material at a facility having the crystal puller and configuring the bulk container for gravity feed of the source material from the container. The bulk container is transported to the crystal puller and a predetermined quantity of source material is dispensed directly from the bulk container into the crystal puller. Apparatus and a system for use in supplying source material are also disclosed.Type: GrantFiled: April 29, 1998Date of Patent: July 18, 2000Assignee: MEMC Electronics Materials, Inc.Inventors: Mark DeStefano, James Dean Eoff, Sr., Thomas H. Schulte, John M. Anderson, Eng Chin Yau, Donald R. Ruggeri, David W. Baldwin, Charles Lawrence Badino
-
Patent number: 5964953Abstract: The present invention is directed to a process for removing aluminum contamination from the surface of an etched semiconductor wafer. The process is carried out by first lapping a semiconductor wafer in a lapping slurry containing aluminum, etching the wafer, and finally immersing the wafer in an aqueous bath, the bath comprising an alkaline component and a surfactant.Type: GrantFiled: May 26, 1998Date of Patent: October 12, 1999Assignee: MEMC Electronics Materials, Inc.Inventor: Gianpaolo Mettifogo
-
Patent number: 5746834Abstract: A reactor for depositing a material on a semiconductor wafer by a chemical vapor deposition process using a reactant gas. The reactor includes a shell defining a reaction chamber sized to receive at least one semiconductor wafer. The shell has a jet port cavity opening into the reaction chamber and extending away from the reaction chamber. The reactor also includes a reactant gas delivery system for delivering the reactant gas to the reaction chamber. The reactant gas delivery system includes a nozzle positioned within the jet port cavity for directing the reactant gas into the reaction chamber, a reactant gas source, and a reactant gas line extending between the reactant gas source and the nozzle. The reactor also includes a purge gas delivery system for delivering a purge gas to the reaction chamber.Type: GrantFiled: January 4, 1996Date of Patent: May 5, 1998Assignee: MEMC Electronics Materials, Inc.Inventor: Thomas Martin Hanley