Patents by Inventor Klaus Schuegraf
Klaus Schuegraf has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8154904Abstract: A storage system and method for operating the storage system that uses reversible resistance-switching elements is described. Techniques are disclosed herein for varying programming conditions to account for different resistances that memory cells have. These techniques can program memory cells in fewer attempts, which can save time and/or power. Techniques are disclosed herein for achieving a high programming bandwidth while reducing the worst case current and/or power consumption. In one embodiment, a page mapping scheme is provided that programs multiple memory cells in parallel in a way that reduces the worst case current and/or power consumption.Type: GrantFiled: June 19, 2009Date of Patent: April 10, 2012Assignee: SanDisk 3D LLCInventors: Deepak C. Sekar, Klaus Schuegraf, Roy Scheuerlein
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Patent number: 7876620Abstract: Read disturb is reduced in non-volatile storage. In one aspect, when a read command is received from a host for reading a selected word line, a word line which is not selected for reading is randomly chosen and its storage elements are sensed to determine optimized read compare levels for reading the selected word line. Or, a refresh operation may be indicated for the entire block based on an error correction metric obtained in reading the storage elements of the chosen word line. This is useful especially when the selected word line is repeatedly selected for reading, exposing the other word lines to additional read disturb. In another aspect, when multiple data states are stored, one read compare level is obtained from sensing, e.g., from a threshold voltage distribution, and other read compare levels are derived from a formula.Type: GrantFiled: July 8, 2010Date of Patent: January 25, 2011Assignee: Sandisk CorporationInventors: Nima Mokhlesi, Klaus Schuegraf
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Publication number: 20100321977Abstract: A storage system and method for operating the storage system that uses reversible resistance-switching elements is described. Techniques are disclosed herein for varying programming conditions to account for different resistances that memory cells have. These techniques can program memory cells in fewer attempts, which can save time and/or power. Techniques are disclosed herein for achieving a high programming bandwidth while reducing the worst case current and/or power consumption. In one embodiment, a page mapping scheme is provided that programs multiple memory cells in parallel in a way that reduces the worst case current and/or power consumption.Type: ApplicationFiled: June 19, 2009Publication date: December 23, 2010Inventors: Deepak C. Sekar, Klaus Schuegraf, Roy Scheuerlein
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Publication number: 20100270608Abstract: Semiconductor devices are provided with encapsulating films for protection of sidewall features during fabrication processes, such as etching to form isolation regions. In a non-volatile flash memory, for example, a trench isolation process is divided into segments to incorporate an encapsulating film along the sidewalls of charge storage material. A pattern is formed over the layer stack followed by etching the charge storage material to form strips elongated in the column direction across the substrate, with a layer of tunnel dielectric material therebetween. Before etching the substrate, an encapsulating film is formed along the sidewalls of the strips of charge storage material. The encapsulating film can protect the sidewalls of the charge storage material during subsequent cleaning, oxidation and etch processes. In another example, the encapsulating film is simultaneously formed while etching to form strips of charge storage material and the isolation trenches.Type: ApplicationFiled: April 20, 2010Publication date: October 28, 2010Inventors: Tuan Pham, Sanghyun Lee, Masato Horiike, Klaus Schuegraf, Masaaki Higashitani, Keiichi Isono
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Publication number: 20100271874Abstract: Read disturb is reduced in non-volatile storage. In one aspect, when a read command is received from a host for reading a selected word line, a word line which is not selected for reading is randomly chosen and its storage elements are sensed to determine optimized read compare levels for reading the selected word line. Or, a refresh operation may be indicated for the entire block based on an error correction metric obtained in reading the storage elements of the chosen word line. This is useful especially when the selected word line is repeatedly selected for reading, exposing the other word lines to additional read disturb. In another aspect, when multiple data states are stored, one read compare level is obtained from sensing, e.g., from a threshold voltage distribution, and other read compare levels are derived from a formula.Type: ApplicationFiled: July 8, 2010Publication date: October 28, 2010Inventors: Nima Mokhlesi, Klaus Schuegraf
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Patent number: 7808831Abstract: Read disturb is reduced in non-volatile storage. In one aspect, when a read command is received from a host for reading a selected word line, a word line which is not selected for reading is randomly chosen and its storage elements are sensed to determine optimized read compare levels for reading the selected word line. Or, a refresh operation may be indicated for the entire block based on an error correction metric obtained in reading the storage elements of the chosen word line. This is useful especially when the selected word line is repeatedly selected for reading, exposing the other word lines to additional read disturb. In another aspect, when multiple data states are stored, one read compare level is obtained from sensing, e.g., from a threshold voltage distribution, and other read compare levels are derived from a formula.Type: GrantFiled: June 30, 2008Date of Patent: October 5, 2010Assignee: Sandisk CorporationInventors: Nima Mokhlesi, Klaus Schuegraf
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Publication number: 20100117069Abstract: Optimized electrodes for ReRAM memory cells and methods for forming the same are discloses. One aspect comprises forming a first electrode, forming a state change element in contact with the first electrode, treating the state change element, and forming a second electrode. Treating the state change element increases the barrier height at the interface between the second electrode and the state change element. Another aspect comprises forming a first electrode in a manner to deliberately establish a certain degree of amorphization in the first electrode, forming a state change element in contact with the first electrode. The degree of amorphization of the first electrode is either at least as great as the degree of amorphization of the state change element or no more than 5 percent less than the degree of amorphization of the state change element.Type: ApplicationFiled: February 3, 2009Publication date: May 13, 2010Inventors: Depak C. Sekar, April Schricker, Xiying Chen, Klaus Schuegraf, Raghuveer S. Makala
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Publication number: 20090323412Abstract: Read disturb is reduced in non-volatile storage. In one aspect, when a read command is received from a host for reading a selected word line, a word line which is not selected for reading is randomly chosen and its storage elements are sensed to determine optimized read compare levels for reading the selected word line. Or, a refresh operation may be indicated for the entire block based on an error correction metric obtained in reading the storage elements of the chosen word line. This is useful especially when the selected word line is repeatedly selected for reading, exposing the other word lines to additional read disturb. In another aspect, when multiple data states are stored, one read compare level is obtained from sensing, e.g., from a threshold voltage distribution, and other read compare levels are derived from a formula.Type: ApplicationFiled: June 30, 2008Publication date: December 31, 2009Inventors: Nima Mokhlesi, Klaus Schuegraf
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Publication number: 20060231902Abstract: Isolation structures having trenches formed on both sides of a LOCOS structure are disclosed. A semiconductor structure pad oxide layer is enlarged by local oxidation of silicon to form a field oxide. An etchback causes the thinnest portions of the field oxide to recede, such that a portion of the semiconductor substrate is exposed. An etch, through the exposed portion of the semiconductor substrate, forms a microtrench between the field oxide and the nitride layer with a lateral dimension that is less than that currently achievable by conventional photolithography. In another embodiment, formation of the microtrench is carried out as set forth above, but the nitride layer is immediately removed following trench formation. Alternatively, the pad oxide layer is stripped and a new oxide layer is regrown that substantially covers all exposed surfaces of active areas of the semiconductor substrate.Type: ApplicationFiled: June 14, 2006Publication date: October 19, 2006Inventors: Fernando Gonzalez, Mike Violette, Nanseng Jeng, Aftab Ahmad, Klaus Schuegraf
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Publication number: 20060216902Abstract: Thin film metal-insulator-metal capacitors having enhanced surface area are formed by a substituting metal for silicon in a preformed electrode geometry. The resulting metal structures are advantageous for high-density DRAM applications since they have good conductivity, enhanced surface area and are compatible with capacitor dielectric materials having high dielectric constant.Type: ApplicationFiled: May 12, 2006Publication date: September 28, 2006Inventor: Klaus Schuegraf
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Publication number: 20050087833Abstract: A shallow trench isolation is disclosed wherein the trench depth is reduced beyond that achieved in prior art processes. The reduced trench depth helps to eliminate the formation of voids during the trench refill process and provides for greater planarity in the final isolation structure. Effective device isolation is achieved with a reduced trench depth by utilizing refilling dielectric materials having low dielectric constant.Type: ApplicationFiled: December 13, 2004Publication date: April 28, 2005Inventors: Klaus Schuegraf, Aftab Ahmad
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Publication number: 20050012158Abstract: A semiconductor structure pad oxide layer is enlarged by local oxidation of silicon to form a field oxide. An etchback causes the thinnest portions of the field oxide to recede such that a portion of the semiconductor substrate is exposed. An etch through the exposed portion of the semiconductor substrate forms a microtrench between the field oxide and the nitride layer with a lateral dimension that is less than that currently achievable by conventional photolithography. The microtrench is then filled by oxide or nitride growth or by deposition of a dielectric material. In another embodiment, formation of the microtrench is carried out as set forth above, but the nitride layer is removed immediately following trench formation. Alternatively, the pad oxide layer is stripped and a new oxide layer is regrown that substantially covers all exposed surfaces of active areas of the semiconductor substrate.Type: ApplicationFiled: July 27, 2004Publication date: January 20, 2005Inventors: Fernando Gonzalez, Mike Violette, Nanseng Jeng, Aftab Ahmad, Klaus Schuegraf
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Publication number: 20050009364Abstract: The invention provides semiconductor processing methods of depositing SiO2 on a substrate. In a preferred aspect, the invention provides methods of reducing the formation of undesired reaction intermediates in a chemical vapor deposition (CVD) decomposition reaction. In one implementation, the method is performed by feeding at least one of H2O and H2O2 into a reactor with an organic silicon precursor. For example, in one exemplary implementation, such components are, in gaseous form, fed separately into the reactor. In another exemplary implementation, such components are combined in liquid form prior to introduction into the reactor, and thereafter rendered into a gaseous form for provision into the reactor. The invention can be practiced with or in both hot wall and cold wall CVD systems.Type: ApplicationFiled: August 9, 2004Publication date: January 13, 2005Inventor: Klaus Schuegraf
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Patent number: 6809395Abstract: A semiconductor structure pad oxide layer is enlarged by local oxidation of silicon to form a field oxide. An etchback causes the thinnest portions of the field oxide to recede such that a portion of the semiconductor substrate is exposed. An etch through the exposed portion of the semiconductor substrate forms a microtrench between the field oxide and the nitride layer with a lateral dimension that is less than that currently achievable by conventional photolithography. The microtrench is then filled by oxide or nitride growth or by deposition of a dielectric material. In another embodiment, formation of the microtrench is carried out as set forth above, but the nitride layer is removed immediately following trench formation. Alternatively, the pad oxide layer is stripped and a new oxide layer is regrown that substantially covers all exposed surfaces of active areas of the semiconductor substrate.Type: GrantFiled: August 6, 1999Date of Patent: October 26, 2004Assignee: Micron Technology, Inc.Inventors: Fernando Gonzales, Mike Violette, Nanseng Jeng, Aftab Ahmad, Klaus Schuegraf
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Patent number: 6597057Abstract: A structure includes an etch stop layer and a cap layer. The etch stop layer is situated over a first oxide isolation region and a second oxide isolation region in a wafer. A window is situated in the cap layer and the etch stop layer. The window exposes a surface of the wafer situated between the first oxide isolation region and the second oxide isolation region. The surface is cleaned for epitaxially growing a semiconductor. The etch stop layer can comprise, for example, silicon. The cap layer can comprise, for example, silicon nitride, amorphous silicon or polycrystalline silicon. According to one embodiment, the structure can further comprise an epitaxially grown silicon-germanium structure on the surface. According to one embodiment, the surface includes a single crystal silicon collector and a base grown on the single crystal silicon collector, where the base is an epitaxially grown silicon-germanium structure.Type: GrantFiled: July 10, 2002Date of Patent: July 22, 2003Assignee: Newport Fab, LLCInventors: Klaus Schuegraf, David L. Chapek
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Publication number: 20020182882Abstract: According to a disclosed embodiment, the surface of a semiconductor wafer is covered by an etch stop layer. For example, the etch stop layer can be composed of silicon dioxide. A cap layer is then fabricated over the etch stop layer. For example, the cap layer can be a polycrystalline silicon layer fabricated over the etch stop layer. The cap layer is then selectively etched down to the etch stop layer creating an opening in the cap layer according to a pattern. The pattern can be formed, for example, by covering the cap layer with photoresist and selective etching. Selective etching can be accomplished by using a dry etch process which etches the cap layer without substantially etching the etch stop layer. The etch stop layer is then removed using, for example, a hydrogen-fluoride cleaning process. A semiconductor crystal is then grown by epitaxial deposition in the opening. For example, the semiconductor crystal can be silicon-germanium. Moreover, a single crystal semiconductor structure of high quality, i.Type: ApplicationFiled: July 10, 2002Publication date: December 5, 2002Applicant: Conexant Systems, Inc.Inventors: Klaus Schuegraf, David L. Chapek
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Patent number: 6459562Abstract: An improved thin-film capacitor and methods for forming the same on a surface of a substrate are disclosed. The capacitor includes a bottom conducting plate formed by depositing conductive material within a trench of an insulating layer and planarizing the conducting and insulating layers. A dielectric film is then deposited on the substrate surface, such that at least a portion of the dielectric material remains over the bottom conducting plate. The dielectric film is formed by depositing a first layer of dielectric and then immersing the top of the first layer of dielectric in gaseous plasmas in a single or a series of steps to change the composition of the first layer of deposited dielectric stack. The additional steps of immersion in a plasma is used to improve the desired performance of the dielectric for capacitor applications such as improved reliability, reduced leakage currents and for tuning voltage coefficients of the capacitor.Type: GrantFiled: May 22, 2001Date of Patent: October 1, 2002Assignee: Conexant Systems, Inc.Inventors: Arjun KarRoy, Klaus Schuegraf
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Patent number: 6444591Abstract: According to a disclosed embodiment, the surface of a semiconductor wafer is covered by an etch stop layer. For example, the etch stop layer can be composed of silicon dioxide. A cap layer is then fabricated over the etch stop layer. For example, the cap layer can be a polycrystalline silicon layer fabricated over the etch stop layer. The cap layer is then selectively etched down to the etch stop layer creating an opening in the cap layer according to a pattern. The pattern can be formed, for example, by covering the cap layer with photoresist and selective etching. Selective etching can be accomplished by using a dry etch process which etches the cap layer without substantially etching the etch stop layer. The etch stop layer is then removed using, for example, a hydrogen-fluoride cleaning process. A semiconductor crystal is then grown by epitaxial deposition in the opening. For example, the semiconductor crystal can be silicon-germanium. Moreover, a single crystal semiconductor structure of high quality, i.Type: GrantFiled: September 30, 2000Date of Patent: September 3, 2002Assignee: Newport Fab, LLCInventors: Klaus Schuegraf, David L. Chapek
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Publication number: 20020041942Abstract: A method of making a gas-impermeable, chemically inert container wall structure comprising the steps of providing a base layer of an organic polymeric material; conducting a pair of reactive gases to the surface of the base layer preferably by pulsed gas injection; heating the gases preferably by microwave energy pulses sufficiently to create a plasma which causes chemical reaction of the gases to form an inorganic vapor compound which becomes deposited on the surface, and continuing the conducting and heating until the compound vapor deposit on the surface forms a gas-impermeable, chemically inert barrier layer of the desired thickness on the surface. Various wall structures and apparatus for making them are also disclosed.Type: ApplicationFiled: September 13, 2001Publication date: April 11, 2002Inventors: Manfred R. Kuehnle, Arno Hagenlocher, Klaus Schuegraf, Hermann Statz
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Patent number: 6090685Abstract: A semiconductor structure pad oxide layer is enlarged by local oxidation of silicon to form a field oxide. An etchback causes the thinnest portions of the field oxide to recede such that a portion of the semiconductor substrate is exposed. An etch through the exposed portion of the semiconductor substrate forms a microtrench between the field oxide and the nitride layer with a lateral dimension that is less than that currently achievable by conventional photolithography. The microtrench is then filled by oxide or nitride growth or by deposition of a dielectric material. In another embodiment, formation of the microtrench is carried out as set forth above, but the nitride layer is removed immediately following trench formation. Alternatively, the pad oxide layer is stripped and a new oxide layer is regrown that substantially covers all exposed surfaces of active areas of the semiconductor substrate.Type: GrantFiled: August 22, 1997Date of Patent: July 18, 2000Assignee: Micron Technology Inc.Inventors: Fernando Gonzales, Mike Violette, Nanseng Jeng, Aftab Ahmad, Klaus Schuegraf