Patents by Inventor Rajiv M. Ranade
Rajiv M. Ranade 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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Publication number: 20130143397Abstract: An organic planarizing layer (OPL) is formed atop a semiconductor substrate which includes a plurality of gate lines thereon. Each gate line includes at least a high k gate dielectric and a metal gate. A patterned photoresist having at least one pattern formed therein is then positioned atop the OPL. The at least one pattern in the photoresist is perpendicular to each of the gate lines. The pattern is then transferred by etching into the OPL and portions of each of the underlying gate lines to provide a plurality of gate stacks each including at least a high k gate dielectric portion and a metal gate portion. The patterned photoresist and the remaining OPL layer are then removed utilizing a sequence of steps including first contacting with a first acid, second contacting with an aqueous cerium-containing solution, and third contacting with a second acid.Type: ApplicationFiled: September 13, 2012Publication date: June 6, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nicholas C.M. Fuller, Pratik P. Joshi, Mahmoud Khojasteh, Rajiv M. Ranade, George G. Totir
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Patent number: 8455366Abstract: An organic planarizing layer (OPL) is formed atop a semiconductor substrate which includes a plurality of gate lines thereon. Each gate line includes at least a high k gate dielectric and a metal gate. A patterned photoresist having at least one pattern formed therein is then positioned atop the OPL. The at least one pattern in the photoresist is perpendicular to each of the gate lines. The pattern is then transferred by etching into the OPL and portions of each of the underlying gate lines to provide a plurality of gate stacks each including at least a high k gate dielectric portion and a metal gate portion. The patterned photoresist and the remaining OPL layer are then removed utilizing a sequence of steps including first contacting with a first acid, second contacting with an aqueous cerium-containing solution, and third contacting with a second acid.Type: GrantFiled: September 13, 2012Date of Patent: June 4, 2013Assignee: International Business Machines CorporationInventors: Nicholas C. M. Fuller, Pratik P. Joshi, Mahmoud Khojasteh, Rajiv M. Ranade, George G. Totir
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Patent number: 8367556Abstract: An organic planarizing layer (OPL) is formed atop a semiconductor substrate which includes a plurality of gate lines thereon. Each gate line includes at least a high k gate dielectric and a metal gate. A patterned photoresist having at least one pattern formed therein is then positioned atop the OPL. The at least one pattern in the photoresist is perpendicular to each of the gate lines. The pattern is then transferred by etching into the OPL and portions of each of the underlying gate lines to provide a plurality of gate stacks each including at least a high k gate dielectric portion and a metal gate portion. The patterned photoresist and the remaining OPL layer are then removed utilizing a sequence of steps including first contacting with a first acid, second contacting with an aqueous cerium-containing solution, and third contacting with a second acid.Type: GrantFiled: December 1, 2011Date of Patent: February 5, 2013Assignee: International Business Machines CorporationInventors: Nicholas C. M. Fuller, Pratik P. Joshi, Mahmoud Khojasteh, Rajiv M. Ranade, George G. Totir
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Patent number: 7700378Abstract: A method and system for controlling a dimension of an etched feature. The method includes: measuring a mask feature formed on a top surface of a layer on a substrate to obtain a mask feature dimension value; and calculating a mask trim plasma etch time based on the mask feature dimension value, a mask feature dimension target value, a total of selected radio frequency power-on times of a plasma etch tool since an event occurring to a chamber or chambers of a plasma etch tool for plasma etching the layer, and an etch bias target for a layer feature to be formed from the layer where the layer is not protected by the mask feature during a plasma etch of the layer.Type: GrantFiled: October 15, 2007Date of Patent: April 20, 2010Assignee: International Business Machines CorporationInventors: Gary Walter Behm, Teresita Quitua Magtoto, Rajiv M. Ranade
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Publication number: 20080190446Abstract: A “wafer-less” etch chamber cleaning method varies the capacitance applied to radio frequency components of the chuck that is within the etch chamber (varies impedance of the chuck) so as to cause electric field lines within the etch chamber to terminate (bend) away from the chuck. Then the etch chamber can be cleaned using a very aggressive etch chemistry (e.g., NF3) that would otherwise damage the chuck; however, the electric field lines protect the chuck from the etch chemistry. The capacitance is varied according to a pre-established model. Further, the process evaluates the effectiveness of the pre-established model to produce feedback and constantly adjusts the pre-established model to increase the effectiveness of the cleaning process (according to the feedback).Type: ApplicationFiled: February 13, 2007Publication date: August 14, 2008Inventors: Rajiv M. Ranade, Subhash B. Kulkarni, Ole Krogh, Sukesh Patel
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Patent number: 7291285Abstract: A method and system for controlling a dimension of an etched feature. The method includes: measuring a mask feature formed on a top surface of a layer on a substrate to obtain a mask feature dimension value; and calculating a mask trim plasma etch time based on the mask feature dimension value, a mask feature dimension target value, a total of selected radio frequency power-on times of a plasma etch tool since an event occurring to a chamber or chambers of a plasma etch tool for plasma etching the layer, and an etch bias target for a layer feature to be formed from the layer where the layer is not protected by the mask feature during a plasma etch of the layer.Type: GrantFiled: May 10, 2005Date of Patent: November 6, 2007Assignee: International Business Machines CorporationInventors: Gary Walter Behm, Teresita Quitua Magtoto, Rajiv M. Ranade
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Patent number: 7144769Abstract: A method of forming at least one deep trench structure having an increased trench depth is provided. The method includes providing at least one deep trench having sidewalls that extend to a common bottom wall in a surface of a substrate. Each deep trench has initial dimensions that are wider than targeted dimensions for the deep trenches. To reduce the initial dimensions to that of the targeted dimensions, an epitaxial silicon film is formed selectively or non-selectively on at least some portions of the sidewalls using a low-temperature ultra-high vacuum epitaxial silicon growth tehnique.Type: GrantFiled: July 27, 2004Date of Patent: December 5, 2006Assignee: International Business Machines CorporationInventors: Kevin K. Chan, Subhash B. Kulkarni, Gangadhara S. Mathad, Rajiv M. Ranade
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Patent number: 7091081Abstract: A method is provided for patterning a semiconductor region, which can be heavily doped. A patterned mask is provided above the semiconductor region. A portion of the semiconductor region exposed by the patterned mask is etched in an environment including a polymerizing fluorocarbon, e.g., a chlorine-free fluorocarbon having a high ratio of carbon to fluorine atoms, and at least one non-polymerizing substance selected from the group consisting of non-polymerizing fluorocarbons, e.g. those having a low ratio of carbon to fluorine atoms, and hydrogenated fluorocarbons. The method preferably passivates the sidewalls of the patterned semiconductor region, such that a lower region of semiconductor material below the patterned region can be directionally etched without eroding the thus passivated patterned region.Type: GrantFiled: May 21, 2004Date of Patent: August 15, 2006Assignee: International Business Machines CorporationInventors: Sadanand V. Deshpande, Rajiv M. Ranade, George K. Worth
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Patent number: 6984529Abstract: A method of fabricating a magnetic tunnel junction (MTJ) device is provided. A patterned hard mask is oxidized to form a surface oxide thereon. An MTJ stack is etched in alignment with the patterned hard mask after the oxidizing of the patterned hard mask. Preferably, the MTJ stack etch recipe includes chlorine and oxygen. Etch selectivity between the hard mask and the MTJ stack is improved.Type: GrantFiled: September 10, 2003Date of Patent: January 10, 2006Assignees: Infineon Technologies AG, International Business Machines CorporationInventors: George Stojakovic, Rajiv M. Ranade, Ihar Kasko, Joachim Neutzel, Keith R. Milkove, Russell D. Allen, Kim Poong Mee Lee, legal representative, Young Hoon Lee, deceased
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Patent number: 6858441Abstract: A method of manufacturing a resistive semiconductor memory device (100), comprising depositing an insulating layer (132) over a workpiece (30), and defining a pattern for a plurality of alignment marks (128) and a plurality of conductive lines (112) within the insulating layer (132). A conductive material is deposited over the wafer to fill the alignment mark (128) and conductive line (112) patterns. The insulating layer (132) top surface is chemically-mechanically polished to remove excess conductive material from the insulating layer (132) and form conductive lines (112), while leaving conductive material remaining within the alignment marks (128). A masking layer (140) is formed over the conductive lines (112), and at least a portion of the conductive material is removed from within the alignment marks (128). The alignment marks (128) are used for alignment of subsequently deposited layers of the resistive memory device (100).Type: GrantFiled: September 4, 2002Date of Patent: February 22, 2005Assignee: Infineon Technologies AGInventors: Joachim Nuetzel, Xian J. Ning, Kia-Seng Low, Gill Yong Lee, Rajiv M. Ranade, Ravikumar Ramachandran
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Patent number: 6821864Abstract: A method of forming at least one deep trench structure having an increased trench depth is provided. The method includes providing at least one deep trench having sidewalls that extend to a common bottom wall in a surface of a substrate. Each deep trench has initial dimensions that are wider than targeted dimensions for the deep trenches. To reduce the initial dimensions to that of the targeted dimensions, an epitaxial silicon film is formed selectively or non-selectively on at least some portions of the sidewalls using a low-temperature ultra-high vacuum epitaxial silicon growth tehnique.Type: GrantFiled: March 7, 2002Date of Patent: November 23, 2004Assignee: International Business Machines CorporationInventors: Kevin K. Chan, Subhash B. Kulkarni, Gangadhara S. Mathad, Rajiv M. Ranade
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Patent number: 6743727Abstract: A method of etching a deep, high aspect ratio opening in a silicon substrate includes etching the substrate with a first plasma formed using a first gaseous mixture including a bromine containing gas, an oxygen containing gas and a first fluorine containing gas. The etching process with the first gaseous mixture produces a sidewall passivating deposit, which builds up near the opening entrance. To reduce this buildup, and to increase the average etching rate, the sidewall passivating deposit is periodically thinned by forming a second plasma using a mixture containing silane and a second fluorine containing gas. The substrate remains in the same plasma reactor chamber during the entire process and the plasma is continuously maintained during the thinning step. Holes of a depth greater than 40 times the width may be produced using repeated cycles of etching and thinning.Type: GrantFiled: June 5, 2001Date of Patent: June 1, 2004Assignee: International Business Machines CorporationInventors: Gangadhara S. Mathad, Siddhartha Panda, Rajiv M. Ranade
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Patent number: 6709917Abstract: A method of fabricating a high aspect ratio deep trench in a semiconductor substrate comprising reducing the formation of a passivation film during the etching of the trench by including a first step of contacting the substrate in which the deep trench is to be formed with a fluorine poor or low concentration of a fluorine gas in the plasma of etchant gases for etching the high aspect ratio deep trench, followed by a second step of increasing the concentration of the fluorine containing gas to create a fluorine-rich plasma while lowering the chamber pressure of the reactor and RF power. Preferably, the second step is introduced periodically during the etching of a deep trench in an alternating manner.Type: GrantFiled: May 13, 2002Date of Patent: March 23, 2004Assignee: International Business Machines CorporationInventors: Siddhartha Panda, Rajiv M. Ranade, Gangadhara S. Mathad
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Publication number: 20040043579Abstract: A method of manufacturing a resistive semiconductor memory device (100), comprising depositing an insulating layer (132) over a workpiece (30), and defining a pattern for a plurality of alignment marks (128) and a plurality of conductive lines (112) within the insulating layer (132). A conductive material is deposited over the wafer to fill the alignment mark (128) and conductive line (112) patterns. The insulating layer (132) top surface is chemically-mechanically polished to remove excess conductive material from the insulating layer (132) and form conductive lines (112), while leaving conductive material remaining within the alignment marks (128). A masking layer (140) is formed over the conductive lines (112), and at least a portion of the conductive material is removed from within the alignment marks (128). The alignment marks (128) are used for alignment of subsequently deposited layers of the resistive memory device (100).Type: ApplicationFiled: September 4, 2002Publication date: March 4, 2004Inventors: Joachim Nuetzel, Xian J. Ning, Kia-Seng Low, Gill Yong Lee, Rajiv M. Ranade, Ravikumar Ramachandran
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Publication number: 20030211686Abstract: A method of fabricating a high aspect ratio deep trench in a semiconductor substrate comprising reducing the formation of a passivation film during the etching of the trench by including a first step of contacting the substrate in which the deep trench is to be formed with a fluorine poor or low concentration of a fluorine gas in the plasma of etchant gases for etching the high aspect ratio deep trench, followed by a second step of increasing the concentration of the fluorine containing gas to create a fluorine-rich plasma while lowering the chamber pressure of the reactor and RF power. Preferably, the second step is introduced periodically during the etching of a deep trench in an alternating manner.Type: ApplicationFiled: May 13, 2002Publication date: November 13, 2003Applicants: International Business Machines Corporation, Infineon Technologies North America Corp.Inventors: Siddhartha Panda, Rajiv M. Ranade, G. S. Mathad
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Publication number: 20030170951Abstract: A method of forming at least one deep trench structure having an increased trench depth is provided. The method includes providing at least one deep trench having sidewalls that extend to a common bottom wall in a surface of a substrate. Each deep trench has initial dimensions that are wider than targeted dimensions for the deep trenches. To reduce the initial dimensions to that of the targeted dimensions, an epitaxial silicon film is formed selectively or non-selectively on at least some portions of the sidewalls using a low-temperature ultra-high vacuum epitaxial silicon growth tehnique.Type: ApplicationFiled: March 7, 2002Publication date: September 11, 2003Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Kevin K. Chan, Subhash B. Kulkarni, Gangadhara S. Mathad, Rajiv M. Ranade
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Publication number: 20020179570Abstract: A method of etching a deep, high aspect ratio opening in a silicon substrate includes etching the substrate with a first plasma formed using a first gaseous mixture including a bromine containing gas, an oxygen containing gas and a first fluorine containing gas. The etching process with the first gaseous mixture produces a sidewall passivating deposit, which builds up near the opening entrance. To reduce this buildup, and to increase the average etching rate, the sidewall passivating deposit is periodically thinned by forming a second plasma using a mixture containing silane and a second fluorine containing gas. The substrate remains in the same plasma reactor chamber during the entire process and the plasma is continuously maintained during the thinning step. Holes of a depth greater than 40 times the width may be produced using repeated cycles of etching and thinning.Type: ApplicationFiled: June 5, 2001Publication date: December 5, 2002Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Gangadhara S. Mathad, Siddhartha Panda, Rajiv M. Ranade
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Patent number: 6284666Abstract: A method of minimizing RIE lag (i.e., the neutral and ion fluxes at the bottom of a deep trench (DT) created during the construction of the trench opening using a side wall film deposition)) in DRAMs having a large aspect ratio (i.e., <30:1) is described. The method forms a passivation film to the extent necessary for preventing isotropic etching of the substrate, hence maintaining the required profile and the shape of the DT within the substrate. The RIE process described provides a partial DT etched into a substrate to achieve the predetermined depth. The passivation film is allowed to grow to a certain thickness still below the extent that it would close the opening of the deep trench. Alternatively, the passivation film is removed by a non-RIE etching process. The non-RIE process that removes the film can be wet etched with chemicals, such as hydrofluoric acid (buffered or non buffered) or, alternatively, using vapor phase and/or non-ionized chemicals, such as anhydrous hydrofluoric acid.Type: GrantFiled: May 31, 2000Date of Patent: September 4, 2001Assignee: International Business Machines CorporationInventors: Munir D. Naeem, Gangadhara S. Mathad, Byeong Yeol Kim, Stephan P. Kudelka, Brian S. Lee, Heon Lee, Elizabeth Morales, Young-Jin Park, Rajiv M. Ranade
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Patent number: 5891807Abstract: A method for forming a bottle shaped trench 20 in a semiconductor substrate 10 includes reactive ion etching a trench having a tapered top portion 25 in the semiconductor device and continuing to reactive ion etch while increasing the temperature of the semiconductor device to impart a reentrant profile 22 to the trench.Type: GrantFiled: September 25, 1997Date of Patent: April 6, 1999Assignees: Siemens Aktiengesellschaft, International Business Machines CorporationInventors: K. Paul Muller, Rajiv M. Ranade, Stefan Schmitz