Patents by Inventor Iftikhar Ahmad
Iftikhar Ahmad 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).
-
Publication number: 20180130638Abstract: A microwave processing system includes: a broadband variable frequency microwave (VFM) source; a plurality of waveguide applicators, each of which includes a waveguide transition and is capable of supporting a selected subset of frequencies within the bandwidth of the broadband VFM source; a microwave switching means allowing the microwave source to be connected to any one of the waveguide transitions so that microwave power is delivered to the corresponding waveguide applicator; and wherein each of the waveguide applicators includes at least one channel through which a microwave transparent tube may be run so that process fluid flowing through the tube may be exposed to microwave power in the applicator. A related method is also disclosed.Type: ApplicationFiled: October 26, 2017Publication date: May 10, 2018Inventors: Iftikhar Ahmad, Clayton R. DeCamillis, Richard C. Hazelhurst, Michael L. Hampton
-
Patent number: 9859457Abstract: A template for a semiconductor device is made by providing an AGN substrate, growing a first layer of Group III nitrides on the substrate, depositing a thin metal layer on the first layer, annealing the metal such as gold so that it agglomerates to form a pattern of islands on the first layer; transferring the pattern into the first layer by etching then removing excess metal; and then depositing a second Group III nitride layer on the first layer. The second layer, through lateral overgrowth, coalesces over the gaps in the island pattern leaving a smooth surface with low defect density. A Group III semiconductor device may then be grown on the template, which may then be removed. Chlorine gas may be used for etching the pattern in the first layer and the remaining gold removed with aqua regia.Type: GrantFiled: May 18, 2015Date of Patent: January 2, 2018Assignee: Nitek, Inc.Inventors: Vinod Adivarahan, Asif Khan, Iftikhar Ahmad, Bin Zhang, Alexander Lunev
-
Patent number: 9750091Abstract: An apparatus for thermal treatment of coatings on substrates includes a microwave applicator cavity; a microwave power supply to deliver power to the cavity; a thermally insulated microwave-transparent compartment within the cavity, large enough to contain the coated substrate while occupying no more than 50% of the total volume of the cavity; a means of supporting the coated substrate within the compartment; an adjustable IR heating source in the compartment and facing the substrate so that a selected amount of IR heating may be applied to the substrate; and, a non-contacting temperature measurement device to measure the temperature of the coating. Related methods for using the apparatus to process different kinds of films are also disclosed.Type: GrantFiled: October 15, 2012Date of Patent: August 29, 2017Assignees: APPLIED MATERIALS, INC., HELLER INDUSTRIES, INC.Inventors: Iftikhar Ahmad, Clayton R. DeCamillis, Robert J Schauer, James E. Neville
-
Publication number: 20170090284Abstract: A method for curing photosensitive polyimide (PSPI) films includes the steps of: depositing a PSPI film on a selected substrate, and curing the film by microwave heating at a selected temperature from about 200 to 340° C. in a selected atmosphere containing an oxygen concentration from about 20 to 200,000 ppm. The process atmosphere may be static or flowing. The addition of oxygen improves the removal of acrylate residue and improves the Tg of the cured film, while the low processing temperature characteristic of the microwave process prevents the oxygen from damaging the polyimide backbone. The method may further include the steps of photopatterning and developing the PSPI film prior to curing. The process is particularly suitable for dielectric films on silicon for electronic applications.Type: ApplicationFiled: December 12, 2016Publication date: March 30, 2017Inventors: ROBERT L. HUBBARD, IFTIKHAR AHMAD
-
Publication number: 20170077491Abstract: An apparatus for processing battery electrodes includes: a microwave applicator cavity with slots on opposite ends to allow a continuous sheet to move through the cavity in a first direction; a processing chamber constructed of microwave-transparent material, disposed within the applicator cavity and surrounding the continuous sheet, the processing chamber having slots to allow the continuous sheet to pass through it; a microwave power supply to deliver power to the applicator cavity; a source of heated gas providing a controlled gas flow through the processing chamber in a direction opposite the first direction; and, at least one non-contacting temperature measuring device positioned to measure a surface temperature at a selected location on the continuous sheet as it passes through the processing chamber. The apparatus is particularly suited for removing polar solvents from porous electrode coatings. A related method is also disclosed.Type: ApplicationFiled: September 1, 2016Publication date: March 16, 2017Inventors: Iftikhar Ahmad, Andrew Cardin, Clayton DeCamillis, Michael Hampton, James E. Webb, JR., Pu Zhang, William Hicks, Peter H. Aurora
-
Patent number: 9538586Abstract: An apparatus for thermal treatment of dielectric films on substrates comprises: a microwave applicator cavity and microwave power source; a workpiece to be heated in the cavity, comprising a porous coating on a selected substrate; and, a means of introducing a controlled amount of a polar solvent into said porous coating immediately before heating by said microwave power. The interaction of the polar solvent with the microwaves enhances the efficiency of the process, to shorten process time and reduce thermal budget. A related method comprises the steps of: depositing a porous film on a substrate; soft baking the film to a selected state of dryness; introducing a controlled amount of a polar solvent into the soft baked film; and, applying microwave energy to heat the film via interaction with the polar solvent.Type: GrantFiled: April 15, 2014Date of Patent: January 3, 2017Assignee: APPLIED MATERIALS, INC.Inventor: Iftikhar Ahmad
-
Patent number: 9519221Abstract: A method for curing photosensitive polyimide (PSPI) films includes the steps of: depositing a PSPI film on a selected substrate, and curing the film by microwave heating at a selected temperature from about 200 to 340° C. in a selected atmosphere containing an oxygen concentration from about 20 to 200,000 ppm. The process atmosphere may be static or flowing. The addition of oxygen improves the removal of acrylate residue and improves the Tg of the cured film, while the low processing temperature characteristic of the microwave process prevents the oxygen from damaging the polyimide backbone. The method may further include the steps of photopatterning and developing the PSPI film prior to curing. The process is particularly suitable for dielectric films on silicon for electronic applications.Type: GrantFiled: January 12, 2015Date of Patent: December 13, 2016Assignee: APPLIED MATERIALS, INC.Inventors: Robert L. Hubbard, Iftikhar Ahmad
-
Patent number: 9508616Abstract: A method for forming a multilayer structure comprises the steps of: depositing a first polymerizable layer on a substrate; applying microwave energy to the polymerizable layer while monitoring at least one property of the layer; and, ending the application of microwave energy when the monitored property indicates that the polymerizable layer has reached a desired degree of cure. The property monitored may be optical, e.g., Raman spectrum, or electrical, e.g., dielectric loss. This process control strategy lowers the overall thermal budget, and is especially suitable for curing polymer films on silicon. The method may be used repetitively to cure multiple layers of polymeric material when a thicker film is needed.Type: GrantFiled: May 11, 2012Date of Patent: November 29, 2016Assignee: APPLIED MATERIALS, INC.Inventors: Iftikhar Ahmad, Robert L. Hubbard
-
Patent number: 9414445Abstract: A method for processing a dielectric film on a substrate comprises: depositing a porous dielectric film on a substrate; removing the porogen; stuffing the film with a protective polymeric material; performing at least one intermediate processing step on the stuffed dielectric film; placing the film in a microwave applicator cavity and heating to a first temperature to partially burn out the polymeric material; introducing a controlled amount of a polar solvent into the porosity created by the partial burn out; applying microwave energy to heat the film to a second selected temperature below the boiling point of the solvent to clean away remaining polymeric material; and applying microwave energy to heat the film to a third temperature above the boiling point of the solvent to completely burnout the residues of polymeric material. The interaction of the polar solvent with the microwaves enhances the efficiency of the cleaning process.Type: GrantFiled: April 15, 2014Date of Patent: August 9, 2016Assignee: APPLIED MATERIALS, INC.Inventors: Iftikhar Ahmad, Mikhail Baklanov, Liping Zhang
-
Publication number: 20150341991Abstract: An apparatus for heating a semiconductor wafer includes: a microwave source; an applicator cavity; and, a fixture for supporting a wafer in the cavity. The fixture comprises a dielectric mechanical support for the wafer and a grounded metallic ring movably positioned parallel to and concentric with the wafer at some distance from the wafer, to adjust the microwave power distribution to compensate for edge effects. A closed-loop feedback system adjusts the distance based on wafer edge and center temperatures. A method for heating a semiconductor wafer comprises: a. placing the wafer in a microwave cavity; b. supporting the wafer on a fixture comprising a dielectric wafer support and a grounded metallic ring movably positioned at some distance from the wafer; c. introducing microwave power into the cavity to heat the wafer; and d. adjusting the distance between wafer and ring to modify the power distribution near the wafer edge.Type: ApplicationFiled: June 1, 2015Publication date: November 26, 2015Inventors: Joseph M. Wander, Zakaryae Fathi, Keith R. Hicks, Clayton R. DeCamillis, Iftikhar Ahmad
-
Publication number: 20150263221Abstract: A template for a semiconductor device is made by providing an AGN substrate, growing a first layer of Group III nitrides on the substrate, depositing a thin metal layer on the first layer, annealing the metal such as gold so that it agglomerates to form a pattern of islands on the first layer; transferring the pattern into the first layer by etching then removing excess metal; and then depositing a second Group III nitride layer on the first layer. The second layer, through lateral overgrowth, coalesces over the gaps in the island pattern leaving a smooth surface with low defect density. A Group III semiconductor device may then be grown on the template, which may then be removed. Chlorine gas may be used for etching the pattern in the first layer and the remaining gold removed with aqua regia.Type: ApplicationFiled: May 18, 2015Publication date: September 17, 2015Inventors: Vinod Adivarahan, Asif KHAN, Iftikhar Ahmad, Bin Zhang, Alexander Lunev
-
Publication number: 20150198890Abstract: A method for curing photosensitive polyimide (PSPI) films includes the steps of: depositing a PSPI film on a selected substrate, and curing the film by microwave heating at a selected temperature from about 200 to 340° C. in a selected atmosphere containing an oxygen concentration from about 20 to 200,000 ppm. The process atmosphere may be static or flowing. The addition of oxygen improves the removal of acrylate residue and improves the Tg of the cured film, while the low processing temperature characteristic of the microwave process prevents the oxygen from damaging the polyimide backbone. The method may further include the steps of photopatterning and developing the PSPI film prior to curing. The process is particularly suitable for dielectric films on silicon for electronic applications.Type: ApplicationFiled: January 12, 2015Publication date: July 16, 2015Applicant: Applied Materials, Inc.Inventors: Robert L. Hubbard, Iftikhar Ahmad
-
Patent number: 9048270Abstract: An apparatus for heating a semiconductor wafer includes: a microwave source; an applicator cavity; and, a fixture for supporting a wafer in the cavity. The fixture contains a dielectric mechanical support for the wafer and a grounded metallic ring movably positioned parallel to and concentric with the wafer at some distance from the wafer, to adjust the microwave power distribution to compensate for edge effects. A closed-loop feedback system adjusts the distance based on wafer edge and center temperatures. A method for heating a semiconductor wafer includes: a. placing the wafer in a microwave cavity; b. supporting the wafer on a fixture having a dielectric wafer support and a grounded metallic ring movably positioned at some distance from the wafer; c. introducing microwave power into the cavity to heat the wafer; and d. adjusting the distance between wafer and ring to modify the power distribution near the wafer edge.Type: GrantFiled: March 25, 2011Date of Patent: June 2, 2015Inventors: Joseph M. Wander, Zakaryae Fathi, Keith R. Hicks, Clayton R. DeCamillis, Iftikhar Ahmad
-
Publication number: 20150074988Abstract: A method for making a lithium-ion cell includes depositing an electrode material as a coating on a substrate of the lithium-ion cell, irradiating the deposited electrode material with microwave radiation of varying frequency, wetting the irradiated electrode material with a non-aqueous electrolyte solution, and sealing the wetted electrode material in an air-tight enclosure.Type: ApplicationFiled: March 14, 2013Publication date: March 19, 2015Inventors: Chad Allison, Iftikhar Ahmad
-
Publication number: 20140322922Abstract: An apparatus for thermal treatment of dielectric films on substrates comprises: a microwave applicator cavity and microwave power source; a workpiece to be heated in the cavity, comprising a porous coating on a selected substrate; and, a means of introducing a controlled amount of a polar solvent into said porous coating immediately before heating by said microwave power. The interaction of the polar solvent with the microwaves enhances the efficiency of the process, to shorten process time and reduce thermal budget. A related method comprises the steps of: depositing a porous film on a substrate; soft baking the film to a selected state of dryness; introducing a controlled amount of a polar solvent into the soft baked film; and, applying microwave energy to heat the film via interaction with the polar solvent.Type: ApplicationFiled: April 15, 2014Publication date: October 30, 2014Inventor: Iftikhar Ahmad
-
Publication number: 20140319129Abstract: An apparatus for thermal treatment of dielectric films on substrates comprises: a microwave applicator cavity and microwave power source; a workpiece to be heated in the cavity, comprising a porous coating on a selected substrate; and, a means of introducing a controlled amount of a polar species into the porous coating immediately before heating by the microwave power. The interaction of the polar species with the microwaves enhances the efficiency of the process, to shorten process time and reduce thermal budget. A related method comprises the steps of: depositing a porous film on a substrate; soft baking the film to a selected state of dryness; introducing a controlled amount of a polar species into the soft baked film; and, applying microwave energy to heat the film via interaction with the polar species.Type: ApplicationFiled: April 15, 2014Publication date: October 30, 2014Inventor: Iftikhar Ahmad
-
Publication number: 20140322921Abstract: A method for processing a dielectric film on a substrate comprises: depositing a porous dielectric film on a substrate; removing the porogen; stuffing the film with a protective polymeric material; performing at least one intermediate processing step on the stuffed dielectric film; placing the film in a microwave applicator cavity and heating to a first temperature to partially burn out the polymeric material; introducing a controlled amount of a polar solvent into the porosity created by the partial burn out; applying microwave energy to heat the film to a second selected temperature below the boiling point of the solvent to clean away remaining polymeric material; and applying microwave energy to heat the film to a third temperature above the boiling point of the solvent to completely burnout the residues of polymeric material. The interaction of the polar solvent with the microwaves enhances the efficiency of the cleaning process.Type: ApplicationFiled: April 15, 2014Publication date: October 30, 2014Inventors: Iftikhar Ahmad, Mikhail Baklanov, Liping Zhang
-
Publication number: 20140103030Abstract: An apparatus for thermal treatment of coatings on substrates includes a microwave applicator cavity; a microwave power supply to deliver power to the cavity; a thermally insulated microwave-transparent compartment within the cavity, large enough to contain the coated substrate while occupying no more than 50% of the total volume of the cavity; a means of supporting the coated substrate within the compartment; an adjustable IR heating source in the compartment and facing the substrate so that a selected amount of IR heating may be applied to the substrate; and, a non-contacting temperature measurement device to measure the temperature of the coating. Related methods for using the apparatus to process different kinds of films are also disclosed.Type: ApplicationFiled: October 15, 2012Publication date: April 17, 2014Inventors: Iftikhar Ahmad, Clayton R. DeCamillis, Robert J. Schauer, James E. Neville
-
Publication number: 20130299953Abstract: A multilayer structure comprises: a substrate; and, a plurality of polymerizable layers successively deposited on the substrate, with each successive layer having a greater dielectric polarizability than the preceding layer(s), so that each successive layer will absorb microwave energy preferentially to the preceding layer(s). In this way, successive layers can be cured without over-curing the preceding layers. The individual layers are preferably materials from a single chemical family (e.g., epoxies, polyimides, PBO, etc.) and have similar properties after curing. The dielectric polarizabilities may be adjusted by modifying such factors as chain endcap dipole strength, cross-linker dipole strength, promoter, solvent, and backbone type. The invention is particularly suitable for producing various polymer layers on silicon for electronic applications. An associated method is also disclosed.Type: ApplicationFiled: May 11, 2012Publication date: November 14, 2013Inventors: Robert L. Hubbard, Iftikhar Ahmad
-
Publication number: 20130302917Abstract: A method for forming a multilayer structure comprises the steps of: depositing a first polymerizable layer on a substrate; applying microwave energy to the polymerizable layer while monitoring at least one property of the layer; and, ending the application of microwave energy when the monitored property indicates that the polymerizable layer has reached a desired degree of cure. The property monitored may be optical, e.g., Raman spectrum, or electrical, e.g., dielectric loss. This process control strategy lowers the overall thermal budget, and is especially suitable for curing polymer films on silicon. The method may be used repetitively to cure multiple layers of polymeric material when a thicker film is needed.Type: ApplicationFiled: May 11, 2012Publication date: November 14, 2013Inventors: Iftikhar Ahmad, Hubbard Robert