Patents by Inventor Deepak Ramappa
Deepak Ramappa 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: 20160326636Abstract: Methods of affecting a material's properties through the implantation of ions, such as by using a plasma processing apparatus with a plasma sheath modifier. In this way, properties such as resistance to chemicals, adhesiveness, hydrophobicity, and hydrophilicity, may be affected. These methods can be applied to a variety of technologies. In some cases, ion implantation is used in the manufacture of printer heads to reduce clogging by increasing the materials hydrophobicity. In other embodiments, MEMS and NEMS devices are produced using ion implantation to change the properties of fluid channels and other structures. In addition, ion implantation can be used to affect a material's resistance to chemicals, such as acids.Type: ApplicationFiled: July 20, 2016Publication date: November 10, 2016Inventors: Ludovic Godet, Christopher Hatem, Deepak Ramappa, Xianfeng Lu, Anthony Renau, Patrick Martin
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Patent number: 9425027Abstract: Methods of affecting a material's properties through the implantation of ions, such as by using a plasma processing apparatus with a plasma sheath modifier. In this way, properties such as resistance to chemicals, adhesiveness, hydrophobicity, and hydrophilicity, may be affected. These methods can be applied to a variety of technologies. In some cases, ion implantation is used in the manufacture of printer heads to reduce clogging by increasing the materials hydrophobicity. In other embodiments, MEMS and NEMS devices are produced using ion implantation to change the properties of fluid channels and other structures. In addition, ion implantation can be used to affect a material's resistance to chemicals, such as acids.Type: GrantFiled: May 14, 2012Date of Patent: August 23, 2016Assignee: Varian Semiconductor Equipment Associates, Inc.Inventors: Ludovic Godet, Christopher Hatem, Deepak Ramappa, Xianfeng Lu, Anthony Renau, Patrick Martin
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Patent number: 9330917Abstract: Methods of forming a passivation layer on a workpiece are disclosed. These methods utilize a SiC forming polymer to form the passivation layer. In addition, while the polymer is being heated to form SiC, a second result, such as annealing of the underlying workpiece, or firing of the metal contacts is achieved. For example, the workpiece may be implanted prior to coating it with the polymer. When the workpiece is heated, SiC is formed and the workpiece is annealed. In another embodiment, a workpiece is coating with the SiC forming polymer and metal pattern is applied to the polymer. The firing of workpiece causes the metal contacts to form and also forms SiC on the workpiece.Type: GrantFiled: February 20, 2013Date of Patent: May 3, 2016Assignee: Varian Semiconductor Equipment Associates, Inc.Inventors: Nicholas Bateman, Deepak Ramappa
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Patent number: 8815634Abstract: Dark currents within a photosensitive device are reduced through improved implantation of a species during its fabrication. Dark currents can be caused by defects in the photo-diode device, caused during the annealing, implanting or other processing steps used during fabrication. By amorphizing the workpiece in the photo-diode region, the number of defects can be reduced thereby reducing this cause of dark current. Dark current is also caused by stress induced by an adjacent STI, where the stress caused by the liner and fill material exacerbate defects in the workpiece. By amorphizing the sidewalls and bottom surface of the trench, defects created during the etching process can be reduced. This reduction in defects also decreases dark current in the photosensitive device.Type: GrantFiled: October 28, 2009Date of Patent: August 26, 2014Assignee: Varian Semiconductor Equipment Associates, Inc.Inventors: Deepak Ramappa, Dennis Rodier
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Patent number: 8778465Abstract: Methods of creating porous materials, such as silicon, are described. In some embodiments, plasma sheath modification is used to create ion beams of various incidence angles. These ion beams may, in some cases, form a focused ion beam. The wide range of incidence angles allows the material to be deposited amorphously. The porosity and pore size can be varied by changing various process parameters. In other embodiments, porous oxides can be created by adding oxygen to previously created layers of porous material.Type: GrantFiled: May 11, 2012Date of Patent: July 15, 2014Assignee: Varian Semiconductor Equipment Associates, Inc.Inventors: Ludovic Godet, Xiangfeng Lu, Deepak Ramappa
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Publication number: 20140154834Abstract: A method of tailoring the dopant profile of a substrate by utilizing two different dopants, each having a different diffusivity is disclosed. The substrate may be, for example, a solar cell. By introducing two different dopants, such as by ion implantation, furnace diffusion, or paste, it is possible to create the desired dopant profile. In addition, the dopants may be introduced simultaneously, partially simultaneously, or sequentially. Dopant pairs preferably consist of one lighter species and one heavier species, where the lighter species has a greater diffusivity. For example, dopant pairs such as boron and gallium, boron and indium, phosphorus and arsenic, and phosphorus and antimony, can be utilized.Type: ApplicationFiled: May 9, 2013Publication date: June 5, 2014Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.Inventors: Nicholas P.T. Bateman, Atul Gupta, Christopher Hatem, Deepak Ramappa
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Patent number: 8658513Abstract: An improved method of creating LED arrays is disclosed. A p-type layer, multi-quantum well and n-type layer are disposed on a substrate. The device is then etched to expose portions of the n-type layer. To create the necessary electrical isolation between adjacent LEDs, an ion implantation is performed to create a non-conductive implanted region. In some embodiments, an implanted region extends through the p-type layer, MQW and n-type layer. In another embodiment, a first implanted region is created in the n-type layer. In addition, a second implanted region is created in the p-type layer and multi-quantum well immediately adjacent to etched n-type layer. In some embodiments, the ion implantation is done perpendicular to the substrate. In other embodiments, the implant is performed at an angle.Type: GrantFiled: May 2, 2011Date of Patent: February 25, 2014Assignee: Varian Semiconductor Equipment Associates, Inc.Inventors: Fareen Adeni Khaja, Deepak Ramappa, San Yu, Chi-Chun Chen
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Patent number: 8603900Abstract: Methods of improving the anti-reflection properties of one or more dielectric layers and reducing surface recombination of generated carriers of a solar cell are disclosed. In some embodiments, dopants are introduced into the dielectric layers to improve their anti-reflection properties. In other embodiments, species are introduced into the dielectric layers to create electrical fields which repel the minority carriers away from the surface and toward the contacts. In another embodiment, mobiles species are introduced to the anti-reflective coating, which cause carrier to be repelled from the surface of the solar cell. By creating a barrier at the surface of the solar cell, undesired recombination at the surface may be reduced.Type: GrantFiled: October 25, 2010Date of Patent: December 10, 2013Assignee: Varian Semiconductor Equipment Associates, Inc.Inventor: Deepak Ramappa
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Patent number: 8586460Abstract: Methods of enabling the use of high wavelength lasers to create shallow melt junctions are disclosed. In some embodiments, the substrate may be preamorphized to change its absorption characteristics prior to the implantation of a dopant. In other embodiments, a single implant may serve to amorphize the substrate and provide dopant. Once the substrate is sufficiently amorphized, a laser melt anneal may be performed. Due to the changes in the absorption characteristics of the substrate, longer wavelength lasers may be used for the anneal, thereby reducing cost.Type: GrantFiled: September 21, 2011Date of Patent: November 19, 2013Assignee: Varian Semiconductor Equipment Associates, Inc.Inventor: Deepak Ramappa
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Patent number: 8465909Abstract: Various methods of utilizing the physical and chemical property differences between amorphized and crystalline silicon are used to create masks that can be used for subsequent implants. In some embodiments, the difference in film growth between amorphous and crystalline silicon is used to create the mask. In other embodiments, the difference in reflectivity or light absorption between amorphous and crystalline silicon is used to create the mask. In other embodiments, differences in the characteristics of doped and undoped silicon is used to create masks.Type: GrantFiled: November 1, 2010Date of Patent: June 18, 2013Assignee: Varian Semiconductor Equipment Associates, Inc.Inventors: Nicholas P. T. Bateman, Helen L. Maynard, Benjamin B. Riordon, Christopher R. Hatem, Deepak Ramappa
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Patent number: 8461032Abstract: A method of tailoring the dopant profile of a substrate by utilizing two different dopants, each having a different diffusivity is disclosed. The substrate may be, for example, a solar cell. By introducing two different dopants, such as by ion implantation, furnace diffusion, or paste, it is possible to create the desired dopant profile. In addition, the dopants may be introduced simultaneously, partially simultaneously, or sequentially. Dopant pairs preferably consist of one lighter species and one heavier species, where the lighter species has a greater diffusivity. For example, dopant pairs such as boron and gallium, boron and indium, phosphorus and arsenic, and phosphorus and antimony, can be utilized.Type: GrantFiled: March 4, 2009Date of Patent: June 11, 2013Assignee: Varian Semiconductor Equipment Associates, Inc.Inventors: Nicholas Bateman, Atul Gupta, Christopher Hatem, Deepak Ramappa
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Publication number: 20130143353Abstract: At least part of a dielectric layer is implanted to form implanted regions. The implanted regions affect the etch rate of the dielectric layer during the formation of the openings through the dielectric layer. Metal contacts may be formed within these openings. The dielectric layer, which may be SiO2 or other materials, may be part of a solar cell or other device.Type: ApplicationFiled: December 2, 2011Publication date: June 6, 2013Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.Inventor: Deepak Ramappa
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Publication number: 20130005155Abstract: Methods of improving charge trapping are disclosed. One such method includes forming an oxide-nitride-oxide tunnel stack and a silicon nitride layer on the oxide-nitride-oxide tunnel stack. This silicon nitride layer is implanted with ions. These ions may function as electron traps or as fields. The silicon nitride layer may be part of a flash memory device.Type: ApplicationFiled: September 11, 2012Publication date: January 3, 2013Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATE, INC.Inventors: Deepak RAMAPPA, Kyu-Ha SHIM
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Publication number: 20120288637Abstract: Methods of affecting a material's properties through the implantation of ions, such as by using a plasma processing apparatus with a plasma sheath modifier. In this way, properties such as resistance to chemicals, adhesiveness, hydrophobicity, and hydrophilicity, may be affected. These methods can be applied to a variety of technologies. In some cases, ion implantation is used in the manufacture of printer heads to reduce clogging by increasing the materials hydrophobicity. In other embodiments, MEMS and NEMS devices are produced using ion implantation to change the properties of fluid channels and other structures. In addition, ion implantation can be used to affect a material's resistance to chemicals, such as acids.Type: ApplicationFiled: May 14, 2012Publication date: November 15, 2012Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.Inventors: Ludovic Godet, Christopher Hatem, Deepak Ramappa, Xianfeng Lu, Anthony Renau, Patrick Martin
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Publication number: 20120289030Abstract: Methods of creating porous materials, such as silicon, are described. In some embodiments, plasma sheath modification is used to create ion beams of various incidence angles. These ion beams may, in some cases, form a focused ion beam. The wide range of incidence angles allows the material to be deposited amorphously. The porosity and pore size can be varied by changing various process parameters. In other embodiments, porous oxides can be created by adding oxygen to previously created layers of porous material.Type: ApplicationFiled: May 11, 2012Publication date: November 15, 2012Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.Inventors: Ludovic Godet, Xianfeng Lu, Deepak Ramappa
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Patent number: 8283265Abstract: Methods of improving charge trapping are disclosed. One such method includes forming an oxide-nitride-oxide tunnel stack and a silicon nitride layer on the oxide-nitride-oxide tunnel stack. This silicon nitride layer is implanted with ions. These ions may function as electron traps or as fields. The silicon nitride layer may be part of a flash memory device.Type: GrantFiled: December 17, 2009Date of Patent: October 9, 2012Assignee: Varian Semiconductor Equipment Associates, Inc.Inventors: Deepak Ramappa, Kyu-Ha Shim
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Publication number: 20120156860Abstract: A method of cleaving a substrate is disclosed. A species, such as hydrogen or helium, is implanted into a substrate to form a layer of microbubbles. The substrate is then annealed a pressure greater than atmosphere. This annealing may be performed in the presence of the species that was implanted. This diffuses the species into the substrate. The substrate is then cleaved along the layer of microbubbles. Other steps to form an oxide layer or to bond to a handle also may be included.Type: ApplicationFiled: February 17, 2012Publication date: June 21, 2012Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.Inventors: Deepak RAMAPPA, Julian G. BLAKE
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Patent number: 8153496Abstract: An improved method of doping a substrate is disclosed. The method is particularly beneficial to the creation of interdigitated back contact (IBC) solar cells. A patterned implant is performed to introduce a first dopant to a portion of the solar cell. After this implant is done, an oxidation layer is grown on the surface. The oxide layer grows more quickly over the implanted region than over the non-implanted region. An etching process is then performed to remove a thickness of oxide, which is equal to the thickness over the non-implanted regions. A second blanket implant is then performed. Due to the presence of oxide on portions of the solar cell, this blanket implant only implants ions in those regions which were not implanted previously.Type: GrantFiled: March 7, 2011Date of Patent: April 10, 2012Assignee: Varian Semiconductor Equipment Associates, Inc.Inventor: Deepak Ramappa
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Patent number: 8148237Abstract: A method of cleaving a substrate is disclosed. A species, such as hydrogen or helium, is implanted into a substrate to form a layer of microbubbles. The substrate is then annealed a pressure greater than atmosphere. This annealing may be performed in the presence of the species that was implanted. This diffuses the species into the substrate. The substrate is then cleaved along the layer of microbubbles. Other steps to form an oxide layer or to bond to a handle also may be included.Type: GrantFiled: August 5, 2010Date of Patent: April 3, 2012Assignee: Varian Semiconductor Equipment Associates, Inc.Inventors: Deepak Ramappa, Julian G. Blake
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Publication number: 20120077305Abstract: Methods of enabling the use of high wavelength lasers to create shallow melt junctions are disclosed. In some embodiments, the substrate may be preamorphized to change its absorption characteristics prior to the implantation of a dopant. In other embodiments, a single implant may serve to amorphize the substrate and provide dopant. Once the substrate is sufficiently amorphized, a laser melt anneal may be performed. Due to the changes in the absorption characteristics of the substrate, longer wavelength lasers may be used for the anneal, thereby reducing cost.Type: ApplicationFiled: September 21, 2011Publication date: March 29, 2012Applicant: VARIAN SEMICONDUCTOR EQUIPMENT ASSOCIATES, INC.Inventor: Deepak Ramappa