Patents by Inventor Omkaram Nalamasu
Omkaram Nalamasu 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: 6680150Abstract: Sidelobe formation in photolithographic patterns is suppressed by non-rectangular, non-circular contact openings formed in attenuated phase shift photomasks. The contact openings may be diamond-shaped, star-shaped, cross-shaped, or various other shapes which include multiple vertices. The contact opening shapes may include only straight line segments or they may include rounded segments. The contact openings may be arranged in various relative configurations such as in arrays in which the contact openings are sized and spaced by sub-wavelength dimensions. A method for forming contact openings on a photosensitive film uses the attenuated phase shift photomask to form a contact pattern free of pattern defects. A computer readable medium includes instructions for causing a photomask manufacturing tool to generate the attenuated phase-shift photomask.Type: GrantFiled: May 25, 2001Date of Patent: January 20, 2004Assignee: Agere Systems Inc.Inventors: James W. Blatchford, Jr., Omkaram Nalamasu, Stanley Pau
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Publication number: 20030227688Abstract: A micro-lens array and a method for making are described. The micro-lens array includes a base element and a plurality of lenses formed of an epoxy and including nanoparticles. The micro-lens array is formed from a master micro-lens array, which is placed within a replica micro-lens making assembly. The master micro-lens array is coated with an anti-stiction material prior to having an elastomeric material positioned over it and cured. Removal of the elastomeric material provides a plurality of cavities, which are filled with an epoxy including nanoparticles. Curing of the epoxy finishes the fabrication of the micro-lens array. The lenses of the micro-lens array are formed from a colloidal suspension of nanoparticles and resin.Type: ApplicationFiled: May 30, 2002Publication date: December 11, 2003Inventors: Francis M. Houlihan, Madanagopal V. Kunnavakkam, James A. Liddle, Omkaram Nalamasu
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Patent number: 6537867Abstract: A digit signal processor capable of operating at 100 MHZ with a 1.0 volt power supply. The digital signal processor is fabricated by application of strong phase-shift lithography to obtain a 0.12 &mgr;m gate dimension. A dual-mask process is utilized to improve resolution thereby producing high speed, low-voltage processors. A n+/p+ dual-Poly:Si module, and dopant penetration suppression techniques may be utilized.Type: GrantFiled: August 2, 2000Date of Patent: March 25, 2003Assignee: Agere Systems Inc.Inventors: Ronald L. Freyman, Isik C. Kizilyalli, Ross A. Kohler, Omkaram Nalamasu, Mark R. Pinto, Joseph R. Radosevich, Robert M. Vella, George P. Watson
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Publication number: 20020187434Abstract: A lithographic process is disclosed. In the process, devices are fabricated by a sequence of steps in which materials are deposited on a substrate and patterned. These patterned layers are used to form devices, such as semiconductor devices, optical devices and the like over the substrate. The desired pattern is formed by introducing an image of a first pattern in a layer of energy sensitive material. The image is then developed to form a pattern with features having a first size. Subsequently, the pattern is exposed to an isotropic liquid etchant to reduce the size of the features to a second, smaller size. The pattern having the features of the second, smaller size is then transferred into the underlying substrate or a layer of material formed over the substrate.Type: ApplicationFiled: August 7, 2001Publication date: December 12, 2002Inventors: James W. Blatchford, John Frackoviak, Roscoe T. Luce, Omkaram Nalamasu, Allen G. Timko
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Publication number: 20020177078Abstract: Sidelobe formation in photolithographic patterns is suppressed by nonrectangular, non-circular contact openings formed in attenuated phase shift photomasks. The contact openings may be diamond-shaped, star-shaped, cross-shaped, or various other shapes which include multiple vertices. The contact opening shapes may include only straight line segments or they may include rounded segments. The contact openings may be arranged in various relative configurations such as in arrays in which the contact openings are sized and spaced by sub-wavelength dimensions. A method for forming contact openings on a photosensitive film uses the attenuated phase shift photomask to form a contact pattern free of pattern defects. A computer readable medium includes instructions for causing a photomask manufacturing tool to generate the attenuated phase-shift photomask.Type: ApplicationFiled: May 25, 2001Publication date: November 28, 2002Inventors: James W. Blatchford, Omkaram Nalamasu, Stanley Pau
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Patent number: 6392787Abstract: An improved lithographic process for fabricating articles comprising photonic band gap materials with micron-scale periodicities is provided, the process readily capable of being performed by current lithographic processes and equipment. The process involves providing a three-dimensional structure made up of a plurality of stacked layers, where each layer contains a substantially planar lattice of shapes of a first material, typically silicon, with interstices between the shapes. Each shape contacts at least one shape of an adjacent layer, the interstices throughout the plurality of layers are interconnected, and the interstices comprise a second material, e.g., silicon dioxide. Typically, the second material is etched from the interconnected interstices to provide a structure of the first material and air, this structure designed to provide a particular photonic band gap.Type: GrantFiled: September 1, 2000Date of Patent: May 21, 2002Assignee: Agere Systems Guardian Corp.Inventors: Raymond A. Cirelli, Omkaram Nalamasu, Sanjay Patel, Stanley Pau, George P Watson, Christopher Alan White, Robert Waverly Zehner
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Patent number: 6296984Abstract: A process for device fabrication and resist materials that are used in the process are disclosed. The resist material contains acid labile groups either pendant to the polymer or to a dissolution inhibitor that is combined with the polymer. The acid labile groups significantly decrease the solubility of the polymer in a solution of aqueous base. The resist material also contains a photoacid generator and a radical scavenger. The radical scavenger reduces the amount of aromatic compounds outgassed from the resist during the lithographic process. A film of the resist material is formed on a substrate and exposed to delineating radiation. The radiation induces a chemical change in the resist material rendering the exposed resist material substantially more soluble in aqueous base solution than the unexposed portion of the resist material. The image introduced into the resist material is developed using conventional techniques, and the resulting pattern is then transferred into the underlying substrate.Type: GrantFiled: March 12, 1999Date of Patent: October 2, 2001Assignees: Agere Systems Guardian Corp., Arch Specialty Chemicals, Inc.Inventors: Allen H. Gabor, Francis Michael Houlihan, Omkaram Nalamasu
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Patent number: 6251546Abstract: An improved attenuated phase-shifting mask (APSM) for use with an imaging tool for forming a patterned feature on a photoresist layer of a semiconductor wafer. The APSM has a transmissive region for substantially transmitting light therethrough to form a projected image substantially shaped as the patterned feature on the photoresist layer. The APSM also has an attenuating and phase-shifting region, contiguous with the transmissive region, for absorbing a portion of the light incident thereon and for shifting the phase of the incident light by a predetermined number of degrees relative to that of the light transmitted through the transmissive region so as to destructively interfere with the light transmitted through the transmissive region and to project a background image.Type: GrantFiled: September 16, 1999Date of Patent: June 26, 2001Assignee: Agere Systems Guardian Corp.Inventors: Raymond Andrew Cirelli, Omkaram Nalamasu, Stanley Pau, George Patrick Watson
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Patent number: 6218057Abstract: A lithographic process for making an article such as a semiconductor device or a lithographic mask is disclosed. In the process, articles are fabricated by a sequence of steps in which materials are deposited on a substrate and patterned. These patterned layers are used to form devices on the semiconductor substrate. The desired pattern is formed by introducing an image of a first pattern in a layer of energy sensitive material. The image is then developed to form a first pattern. A layer of energy sensitive material is then formed over the first pattern. An image of a second pattern is then formed in the layer of energy sensitive material formed over the first pattern. The second pattern is then developed. The desired pattern is then developed from the first pattern and the second pattern.Type: GrantFiled: April 16, 1999Date of Patent: April 17, 2001Assignee: Lucent Technologies Inc.Inventors: Raymond Andrew Cirelli, Omkaram Nalamasu, Stanley Pau, George Patrick Watson
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Patent number: 6159665Abstract: Photoacid generators advantageous for use in applications such as photoacid generators used in chemically amplified resists are disclosed. These compounds are based on an ortho nitro benzyl configuration employing an .alpha. substituent having high bulk, steric characteristics, and electron withdrawing ability. The enhanced efficacy is particularly found in compounds both having a suitable .alpha. substituent and a second ortho substituent with large electron withdrawing and steric effects.Type: GrantFiled: June 17, 1993Date of Patent: December 12, 2000Assignee: Lucent Technologies Inc.Inventors: Evelyn Chin, Francis Michael Houlihan, Omkaram Nalamasu
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Patent number: 5998099Abstract: A process for device fabrication and resist materials that are used in the process are disclosed. The resist material contains a substituted amine-containing component and a polymer. The substituted-amine containing component is either a photoacid generator, or an amine additive to the resist material that also contains a photoacid generator. The resist material contains acid labile groups either pendant to the polymer or to a dissolution inhibitor that is combined with the polymer. The acid labile groups significantly decrease the solubility of the polymer in a solution of aqueous base. A film of the resist material is formed on a substrate and exposed to delineating radiation. The radiation induces a chemical change in the resist material rendering the exposed resist material substantially more soluble in aqueous base solution than the unexposed portion of the resist material.Type: GrantFiled: May 22, 1998Date of Patent: December 7, 1999Assignee: Lucent Technologies Inc.Inventors: Francis Michael Houlihan, Omkaram Nalamasu, Thomas Ingolf Wallow
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Patent number: 5958654Abstract: A process for device fabrication is disclosed. In the process, an energy sensitive material is formed on a substrate. The energy sensitive resist material contains a polymer or a polymer blend in combination with an energy-sensitive material such as a photoacid generator. At least three substituents are distributed on the polymer blend. The first of these substituents is a hydroxyl (OH) group. The second of these substituents is an acid-sensitive or acid labile group which is cleaved in the presence of acid and replaced by an OH group. The third of these substituents forms hydrogen bonds with the first group. The ratio of the number of OH substituents relative to the number of substituents that hydrogen bond to the OH substituents (mole percent) is about 40:1 to at least about 1:1. The relative amounts of the first and third substituents is selected to provide a resist material with a glass transition temperature of at least about 60.degree..Type: GrantFiled: August 25, 1997Date of Patent: September 28, 1999Assignee: Lucent Technologies Inc.Inventors: Mary Ellen Galvin-Donoghue, Francis Michael Houlihan, Janet Mihoko Kometani, Omkaram Nalamasu, Thomas Xavier Neenan
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Patent number: 5879857Abstract: A process for device fabrication and resist materials that are used in the process are disclosed. The resist material contains a polymer in combination with a dissolution inhibitor and a photoacid generator (PAG). The dissolution inhibitor is the condensation reaction product of a saturated polycyclic hydrocarbon compound with at least one hydroxy (OH) substituent and a difunctional saturated linear, branched, or cyclic hydrocarbon compound wherein the functional groups are either carboxylic acid or carboxylic acid chloride groups. The condensation product has at least two polycylic moieties. The polymer optionally has acid labile groups pendant thereto which significantly decrease the solubility of the polymer in a solution of aqueous base. A film of the resist material is formed on a substrate and exposed to delineating radiation.Type: GrantFiled: March 7, 1997Date of Patent: March 9, 1999Assignee: Lucent Technologies Inc.Inventors: Edwin Arthur Chandross, Francis Michael Houlihan, Omkaram Nalamasu, Elsa Reichmanis, Thomas Ingolf Wallow
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Patent number: 5843624Abstract: The present invention is directed to a process for device fabrication and resist materials that are used in the process. The resist material contains a polymer that is the polymerization product of a monomer that contains alicyclic moieties and at least one other monomer. The polymer is formed by free radical polymerization, and the resulting polymer either has alicyclic moieties incorporated into the polymer backbone or pendant to the polymer backbone via saturated hydrocarbon linkages. Other monomers are selected for polymerization with the alicyclic moiety-containing monomer on the basis of the ability of the monomer to copolymerize by free radical polymerization.Type: GrantFiled: February 21, 1997Date of Patent: December 1, 1998Assignee: Lucent Technologies Inc.Inventors: Francis Michael Houlihan, Omkaram Nalamasu, Elsa Reichmanis, Thomas Ingolf Wallow
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Patent number: 5830619Abstract: Photoacid generators advantageous for use in applications such as photoacid generators used in chemically amplified resists are disclosed. These compounds are based on an ortho nitro benzyl configuration employing an .alpha. substituent having high bulk, steric characteristics, and electron withdrawing ability. The enhanced efficacy is particularly found in compounds both having a suitable .alpha. substituent and a second ortho substituent with large electron withdrawing and steric effects.Type: GrantFiled: January 7, 1997Date of Patent: November 3, 1998Assignee: Lucent Technologies Inc.Inventors: Evelyn Chin, Francis Michael Houlihan, Omkaram Nalamasu
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Patent number: 5750312Abstract: It has been found that surface reactions with basic materials such as amines found in the processing environment during lithographic processing contribute to a loss of linewidth control for resists such as chemically amplified resists. This loss in linewidth results from the reaction of the acid generated by exposing radiation with, for example, the amine resulting in a lack of chemical reaction where such reaction is desired. The problem is solved in one embodiment by employing an acid containing barrier layer on the resist.Type: GrantFiled: May 2, 1994Date of Patent: May 12, 1998Assignee: Lucent Technologies Inc.Inventors: Edwin Arthur Chandross, Omkaram Nalamasu, Elsa Reichmanis, Gary Newton Taylor, Larry Flack Thompson
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Patent number: 5741629Abstract: Polymers suitable for chemically amplified resists based on styrene chemistry are advantageously formed with a meta substituent on the phenyl ring of the styrene moiety. Additionally, polymers for such applications including, but not limited to, meta substituted polymers are advantageously formed by reacting a first monomer having a first protective group with a second monomer having a second protective group. After polymerization, the second protective group is removed without substantially affecting the first protective group. For example, if the first protective group is an alkoxy carbonyl group, and the second protective group is a silyl ether group, treatment with a lower alcohol with trace amounts of acid transforms the silyl group into an OH-moiety without affecting the alkoxy carbonyl group.Type: GrantFiled: October 15, 1996Date of Patent: April 21, 1998Assignee: Lucent Technologies Inc.Inventors: Edwin Arthur Chandross, Janet Mihoko Kometani, Omkaram Nalamasu, Elsa Reichmanis, Kathryn Elizabeth Uhrich