Patents by Inventor Adam Zhong
Adam Zhong 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: 9343463Abstract: The structure and method of formation of an integrated CMOS level and active device level that can be a memory device level. The integration includes the formation of a “super-flat” interface between the two levels formed by the patterning of a full complement of active and dummy interconnecting vias using two separate patterning and etch processes. The active vias connect memory devices in the upper device level to connecting pads in the lower CMOS level. The dummy vias may extend up to an etch stop layer formed over the CMOS layer or may be stopped at an intermediate etch stop layer formed within the device level. The dummy vias thereby contact memory devices but do not connect them to active elements in the CMOS level.Type: GrantFiled: September 29, 2009Date of Patent: May 17, 2016Assignee: Headway Technologies, Inc.Inventors: Tom Zhong, Adam Zhong, Wai-Ming J. Kan, Chyu-Jiuh Torng
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Patent number: 8324698Abstract: A STT-MRAM integration scheme is disclosed wherein the connection between a MTJ and CMOS metal is simplified by forming an intermediate via contact (VAC) on a CMOS landing pad, a metal (VAM) pad that contacts and covers the VAC, and a MTJ on the VAM. A dual damascene process is performed to connect BIT line metal to CMOS landing pads through VAC/VAM/MTJ stacks in a device region, and to connect BIT line connection pads to CMOS connection pads through BIT connection vias outside the device region. The VAM pad is a single layer or composite made of Ta, TaN, or other conductors which serves as a diffusion barrier, has a highly smooth surface for MTJ formation, and provides excellent selectivity with refill dielectric materials during a chemical mechanical polish process. Each VAC is from 500 to 3000 Angstroms thick to minimize additional circuit resistance and minimize etch burden.Type: GrantFiled: January 4, 2011Date of Patent: December 4, 2012Assignee: MagIC Technologies, Inc.Inventors: Tom Zhong, Chyu-Jiuh Torng, Rongfu Xiao, Adam Zhong, Wai-Ming Johnson Kan, Daniel Liu
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Patent number: 8183061Abstract: A STT-MRAM integration scheme is disclosed wherein the connection between a MTJ and CMOS metal is simplified by forming an intermediate via contact (VAC) on a CMOS landing pad, a metal (VAM) pad that contacts and covers the VAC, and a MTJ on the VAM. A dual damascene process is performed to connect BIT line metal to CMOS landing pads through VAC/VAM/MTJ stacks in a device region, and to connect BIT line connection pads to CMOS connection pads through BIT connection vias outside the device region. The VAM pad is a single layer or composite made of Ta, TaN, or other conductors which serves as a diffusion barrier, has a highly smooth surface for MTJ formation, and provides excellent selectivity with refill dielectric materials during a chemical mechanical polish process. Each VAC is from 500 to 3000 Angstroms thick to minimize additional circuit resistance and minimize etch burden.Type: GrantFiled: February 7, 2011Date of Patent: May 22, 2012Assignee: MagIC Technologies, Inc.Inventors: Tom Zhong, Chyu-Jiuh Torng, Rongfu Xiao, Adam Zhong, Wai-Ming Johnson Kan, Daniel Liu
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Patent number: 8133745Abstract: A method for forming a MTJ in a STT-MRAM is disclosed in which the easy-axis CD is determined independently of the hard-axis CD. One approach involves two photolithography steps and two etch steps to form a post in a hard mask which is transferred through a MTJ stack of layers by a third etch process. Optionally, the third etch may stop on the tunnel barrier or in the free layer. A second embodiment involves forming a first parallel line pattern on a hard mask layer and transferring the line pattern through the MTJ stack with a first etch step. A planar insulation layer is formed adjacent to the sidewalls in the line pattern and then a second parallel line pattern is formed which is transferred by a second etch through the MTJ stack to form a post pattern. Etch end point may be controlled independently for hard-axis and easy-axis dimensions.Type: GrantFiled: October 17, 2007Date of Patent: March 13, 2012Assignee: MagIC Technologies, Inc.Inventors: Tom Zhong, Rongfu Xiao, Chyu-Jiuh Torng, Adam Zhong
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Patent number: 8105948Abstract: A process is described for making contact to the buried capping layers of GMR and MTJ devices without the need to form and fill via holes. CMP is applied to the structure in three steps: (1) conventional CMP (2) a Highly Selective Slurry (HSS) is substituted for the conventional slurry to just expose the capping layer, and (3) the HSS is diluted and used to clean the surface as well as to cause a slight protrusion of the capping layers above the surrounding dielectric surface, making it easier the contact them without damaging the devices below.Type: GrantFiled: February 14, 2008Date of Patent: January 31, 2012Assignee: MagIC Technologies, Inc.Inventors: Adam Zhong, Wai-Ming Kan, Tom Zhong, Chyu-Jiuh Torng
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Publication number: 20110129946Abstract: A STT-MRAM integration scheme is disclosed wherein the connection between a MTJ and CMOS metal is simplified by forming an intermediate via contact (VAC) on a CMOS landing pad, a metal (VAM) pad that contacts and covers the VAC, and a MTJ on the VAM. A dual damascene process is performed to connect BIT line metal to CMOS landing pads through VAC/VAM/MTJ stacks in a device region, and to connect BIT line connection pads to CMOS connection pads through BIT connection vias outside the device region. The VAM pad is a single layer or composite made of Ta, TaN, or other conductors which serves as a diffusion barrier, has a highly smooth surface for MTJ formation, and provides excellent selectivity with refill dielectric materials during a chemical mechanical polish process. Each VAC is from 500 to 3000 Angstroms thick to minimize additional circuit resistance and minimize etch burden.Type: ApplicationFiled: February 7, 2011Publication date: June 2, 2011Inventors: Tom Zhong, Chyu-Jiuh Torng, Rongfu Xiao, Adam Zhong, Wai-Ming Johnson Kan, Daniel Liu
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Publication number: 20110101478Abstract: A STT-MRAM integration scheme is disclosed wherein the connection between a MTJ and CMOS metal is simplified by forming an intermediate via contact (VAC) on a CMOS landing pad, a metal (VAM) pad that contacts and covers the VAC, and a MTJ on the VAM. A dual damascene process is performed to connect BIT line metal to CMOS landing pads through VAC/VAM/MTJ stacks in a device region, and to connect BIT line connection pads to CMOS connection pads through BIT connection vias outside the device region. The VAM pad is a single layer or composite made of Ta, TaN, or other conductors which serves as a diffusion barrier, has a highly smooth surface for MTJ formation, and provides excellent selectivity with refill dielectric materials during a chemical mechanical polish process. Each VAC is from 500 to 3000 Angstroms thick to minimize additional circuit resistance and minimize etch burden.Type: ApplicationFiled: January 4, 2011Publication date: May 5, 2011Inventors: Tom Zhong, Chyu-Jiuh Torng, Rongfu Xiao, Adam Zhong, Wai-Ming Johnson Kan, Daniel Liu
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Patent number: 7919407Abstract: Described herein are novel, cost effective and scalable methods for integrating a CMOS level with a memory cell level to form a field induced MRAM device. The memory portion of the device includes N parallel word lines, which may be clad, overlaid by M parallel bit lines orthogonal to the word lines and individual patterned memory cells formed on previously patterned electrodes at the N×M intersections of the two sets of lines. The memory portion is integrated with a CMOS level and the connection between levels is facilitated by the formation of interconnecting vias between the N×M electrodes and corresponding pads in the CMOS level and by word line connection pads in the memory device level and corresponding metal pads in the CMOS level.Type: GrantFiled: November 17, 2009Date of Patent: April 5, 2011Assignee: MagIC Technologies, Inc.Inventors: Tom Zhong, Wai-Ming Johnson Kan, Daniel Liu, Adam Zhong, Chyu-Jiuh Torng
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Publication number: 20110073917Abstract: The structure and method of formation of an integrated CMOS level and active device level that can be a memory device level. The integration includes the formation of a “super-flat” interface between the two levels formed by the patterning of a full complement of active and dummy interconnecting vias using two separate patterning and etch processes. The active vias connect memory devices in the upper device level to connecting pads in the lower CMOS level. The dummy vias may extend up to an etch stop layer formed over the CMOS layer or may be stopped at an intermediate etch stop layer formed within the device level. The dummy vias thereby contact memory devices but do not connect them to active elements in the CMOS level.Type: ApplicationFiled: September 29, 2009Publication date: March 31, 2011Inventors: Tom Zhong, Adam Zhong, Wai-Ming J. Kan, Chyu-Jiuh Torng
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Patent number: 7884433Abstract: A STT-MRAM integration scheme is disclosed wherein the connection between a MTJ and CMOS metal is simplified by forming an intermediate via contact (VAC) on a CMOS landing pad, a metal (VAM) pad that contacts and covers the VAC, and a MTJ on the VAM. A dual damascene process is performed to connect BIT line metal to CMOS landing pads through VAC/VAM/MTJ stacks in a device region, and to connect BIT line connection pads to CMOS connection pads through BIT connection vias outside the device region. The VAM pad is a single layer or composite made of Ta, TaN, or other conductors which serves as a diffusion barrier, has a highly smooth surface for MTJ formation, and provides excellent selectivity with refill dielectric materials during a chemical mechanical polish process. Each VAC is from 500 to 3000 Angstroms thick to minimize additional circuit resistance and minimize etch burden.Type: GrantFiled: October 31, 2008Date of Patent: February 8, 2011Assignee: MagIC Technologies, Inc.Inventors: Tom Zhong, Chyu-Jiuh Torng, Rongfu Xiao, Adam Zhong, Wai-Ming Johnson Kan, Daniel Liu
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Publication number: 20100109106Abstract: A STT-MRAM integration scheme is disclosed wherein the connection between a MTJ and CMOS metal is simplified by forming an intermediate via contact (VAC) on a CMOS landing pad, a metal (VAM) pad that contacts and covers the VAC, and a MTJ on the VAM. A dual damascene process is performed to connect BIT line metal to CMOS landing pads through VAC/VAM/MTJ stacks in a device region, and to connect BIT line connection pads to CMOS connection pads through BIT connection vias outside the device region. The VAM pad is a single layer or composite made of Ta, TaN, or other conductors which serves as a diffusion barrier, has a highly smooth surface for MTJ formation, and provides excellent selectivity with refill dielectric materials during a chemical mechanical polish process. Each VAC is from 500 to 3000 Angstroms thick to minimize additional circuit resistance and minimize etch burden.Type: ApplicationFiled: October 31, 2008Publication date: May 6, 2010Inventors: Tom Zhong, Chyu-Jiuh Torng, Rongfu Xiao, Adam Zhong, Wai-Ming Johnson Kan, Daniel Liu
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Publication number: 20090209102Abstract: A process is described for making contact to the buried capping layers of GMR and MTJ devices without the need to form and fill via holes. CMP is applied to the structure in three steps: (1) conventional CMP (2) a Highly Selective Slurry (HSS) is substituted for the conventional slurry to just expose the capping layer, and (3) the HSS is diluted and used to clean the surface as well as to cause a slight protrusion of the capping layers above the surrounding dielectric surface, making it easier the contact them without damaging the devices below.Type: ApplicationFiled: February 14, 2008Publication date: August 20, 2009Inventors: Adam Zhong, Wai-Ming Kan, Tom Zhong, Chyu-Jiuh Torng
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Publication number: 20090104718Abstract: A method for forming a MTJ in a STT-MRAM is disclosed in which the easy-axis CD is determined independently of the hard-axis CD. One approach involves two photolithography steps and two etch steps to form a post in a hard mask which is transferred through a MTJ stack of layers by a third etch process. Optionally, the third etch may stop on the tunnel barrier or in the free layer. A second embodiment involves forming a first parallel line pattern on a hard mask layer and transferring the line pattern through the MTJ stack with a first etch step. A planar insulation layer is formed adjacent to the sidewalls in the line pattern and then a second parallel line pattern is formed which is transferred by a second etch through the MTJ stack to form a post pattern. Etch end point may be controlled independently for hard-axis and easy-axis dimensions.Type: ApplicationFiled: October 17, 2007Publication date: April 23, 2009Inventors: Tom Zhong, Rongfu Xiao, Chyu-Jiuh Torng, Adam Zhong
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Publication number: 20090078927Abstract: A composite hard mask is disclosed that enables sub-100 nm sized MTJ cells to be formed for advanced devices such as spin torque MRAMs. The hard mask has a lower non-magnetic metallic layer such as Ru to magnetically isolate an overlying middle metallic spacer such as MnPt from an underlying free layer. The middle metallic spacer provides a height margin during subsequent processing to avoid shorting between a bit line and the MTJ cell in the final device. An upper conductive layer may be made of Ta and is thin enough to allow a MTJ pattern in a thin overlying photoresist layer to be transferred through the Ta during a fluorocarbon etch without consuming all of the photoresist. The MTJ pattern is transferred through the remaining hard mask layers and underlying MTJ stack of layers with a second etch step using a C, H, and O etch gas composition.Type: ApplicationFiled: September 20, 2007Publication date: March 26, 2009Inventors: Rongfu Xiao, Chyu-Jiuh Torng, Tom Zhong, Witold Kula, Adam Zhong
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Patent number: 7508700Abstract: An MTJ pattern layout for a memory device is disclosed that includes two CMP assist features outside active MTJ device blocks. A first plurality of dummy MTJ devices is located in two dummy bands formed around an active MTJ device block. The inner dummy band is separated from the outer dummy band by the MTJ ILD layer and has a MTJ device density essentially the same as the MTJ device block. The outer dummy band has a MTJ device density at least 10% greater than the inner dummy band. The inner dummy band serves to minimize CMP edge effect in the MTJ device block while the outer dummy band improves planarization. A second plurality of dummy MTJ devices is employed in contact pads outside the outer dummy band and is formed between a WL ILD layer and a BIT ILD layer thereby minimizing delamination of the MTJ ILD layer.Type: GrantFiled: March 15, 2007Date of Patent: March 24, 2009Assignee: Magic Technologies, Inc.Inventors: Tom Zhong, Terry Kin Ting Ko, Chyu-Jiuh Torng, Wai-Ming Kan, Adam Zhong
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Publication number: 20080225576Abstract: An MTJ pattern layout for a memory device is disclosed that includes two CMP assist features outside active MTJ device blocks. A first plurality of dummy MTJ devices is located in two dummy bands formed around an active MTJ device block. The inner dummy band is separated from the outer dummy band by the MTJ ILD layer and has a MTJ device density essentially the same as the MTJ device block. The outer dummy band has a MTJ device density at least 10% greater than the inner dummy band. The inner dummy band serves to minimize CMP edge effect in the MTJ device block while the outer dummy band improves planarization. A second plurality of dummy MTJ devices is employed in contact pads outside the outer dummy band and is formed between a WL ILD layer and a BIT ILD layer thereby minimizing delamination of the MTJ ILD layer.Type: ApplicationFiled: March 15, 2007Publication date: September 18, 2008Inventors: Tom Zhong, Terry Kin Ting Ko, Chyu-Jiuh Torng, Wai-Ming Kan, Adam Zhong
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Patent number: 6706282Abstract: Dosage forms and methods for the controlled release of antidepressives, such as exemplified by phenoxyethyl substituted-1,2,4-triazolones, as a suspension or a slurry over a prolonged period of time are described.Type: GrantFiled: November 1, 1999Date of Patent: March 16, 2004Inventors: Evangeline Cruz, Noymi Yam, Adam Zhong, Atul Devdatt Ayer, Padmanabh Bhatt
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Publication number: 20010031279Abstract: Dosage forms and methods for the controlled release of antidepressives, such as exemplified by phenoxyethyl substituted-1,2,4-triazolones, over a prolonged period of time are described.Type: ApplicationFiled: May 25, 2001Publication date: October 18, 2001Inventors: Evangeline Cruz, Noymi Yam, Adam Zhong, Atul Devdatt Ayer, Padmanabh Bhatt