Patents by Inventor Jeong Y. Choi
Jeong Y. Choi 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: 8587046Abstract: An embedded memory system includes an array of random access memory (RAM) cells, on the same substrate as an array of logic transistors. Each RAM cell includes an access transistor and a capacitor structure. The capacitor structure is fabricated by forming a metal-insulator-metal capacitor in a dielectric layer. The embedded RAM system includes fewer metal layers in the memory region than in the logic region.Type: GrantFiled: July 26, 2011Date of Patent: November 19, 2013Assignee: MoSys, Inc.Inventor: Jeong Y Choi
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Patent number: 8460995Abstract: An embedded memory system includes an array of random access memory (RAM) cells, on the same substrate as an array of logic transistors. Each RAM cell includes an access transistor and a capacitor structure. The capacitor structure is fabricated by forming a metal-insulator-metal capacitor in a dielectric layer. The embedded RAM system includes fewer metal layers in the memory region than in the logic region.Type: GrantFiled: July 30, 2010Date of Patent: June 11, 2013Assignee: MoSys, Inc.Inventor: Jeong Y. Choi
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Patent number: 8361863Abstract: A method of forming an embedded DRAM cell having multiple-thickness gate dielectrics. An oxidation-enhancing dopant is selectively implanted into a well region in an area that is exposed by a first mask. A thermal oxidation step simultaneously produces the field dielectric for two distinct devices each having a different oxide thickness. The method is applicable to quad-density DRAM cells using fewer oxidation steps. The method is also applicable to planar DRAM cells, and does not require increasing the number of masks during the fabrication of planar DRAM cells.Type: GrantFiled: November 13, 2008Date of Patent: January 29, 2013Assignee: MoSys, Inc.Inventor: Jeong Y. Choi
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Patent number: 8238169Abstract: A method and apparatus for selectively restoring data in a non-volatile memory array based on failure type. Weakened data and erroneous data are identified by performing two readings of a specific memory section. Alternatively, an error correction code is used after a first reading of data to identify erroneous data. The manner in which data is restored will depend on whether the data changed because of an erase failure or a program failure. If only a program failure occurred then the data will be reprogrammed without an intervening erase step. If the data experienced an erase failure, then the data will be erased prior to being programmed with correct data.Type: GrantFiled: February 15, 2011Date of Patent: August 7, 2012Assignee: MoSys, Inc.Inventors: Jeong Y. Choi, Stephen Fung
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Publication number: 20120056257Abstract: A method and system in which an embedded memory is fabricated in accordance with a conventional logic process includes one or more non-volatile memory cells, each having an access transistor and a capacitor, which share a common floating gate electrode. The coupling capacitor is provided with a dielectric layer having a thickness greater than the dielectric layer of the access transistor. Regions under the capacitor are implanted with a high dose implant to form an electrically shorted doped area in the channel region of the capacitor. The high dose implant improves the coupling ratio of the capacitor and enhances the uniformity of the capacitor's oxide layer.Type: ApplicationFiled: September 2, 2010Publication date: March 8, 2012Applicant: MoSys, Inc.Inventor: Jeong Y. Choi
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Publication number: 20120025285Abstract: An embedded memory system includes an array of random access memory (RAM) cells, on the same substrate as an array of logic transistors. Each RAM cell includes an access transistor and a capacitor structure. The capacitor structure is fabricated by forming a metal-insulator-metal capacitor in a dielectric layer.Type: ApplicationFiled: July 26, 2011Publication date: February 2, 2012Applicant: MOSYS, INC.Inventor: Jeong Y. Choi
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Publication number: 20120025347Abstract: An embedded memory system includes an array of dynamic random access memory (DRAM) cells, on the same substrate as an array of logic transistors. Each DRAM cell includes an access transistor and a capacitor structure. The capacitor structure is fabricated by forming a metal-insulator-metal capacitor in a dielectric layer.Type: ApplicationFiled: July 30, 2010Publication date: February 2, 2012Applicant: MoSys, Inc.Inventor: Jeong Y. Choi
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Publication number: 20110216596Abstract: A non-volatile memory cell having enhanced protection against mobile ions. The electric field within the memory cell is controlled in a manner that minimizes migration of mobile ions toward the floating gate. Each conductive layer in the memory cell is biased to reduce the flow of mobile ions toward the floating gate. The memory cell is preferably manufactured using a conventional logic process.Type: ApplicationFiled: March 4, 2010Publication date: September 8, 2011Applicant: Mosys, Inc.Inventor: Jeong Y. Choi
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Publication number: 20110141812Abstract: A method and apparatus for selectively restoring data in a non-volatile memory array based on failure type. Weakened data and erroneous data are identified by performing two readings of a specific memory section. Alternatively, an error correction code is used after a first reading of data to identify erroneous data. The manner in which data is restored will depend on whether the data changed because of an erase failure or a program failure. If only a program failure occurred then the data will be reprogrammed without an intervening erase step. If the data experienced an erase failure, then the data will be erased prior to being programmed with correct data.Type: ApplicationFiled: February 15, 2011Publication date: June 16, 2011Applicant: MoSys, Inc.Inventors: Jeong Y. Choi, Stephen Fung
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Patent number: 7929359Abstract: An embedded memory system that includes DRAM cells and logic transistors. The capacitor of the embedded memory responds to a positive bias voltage of ½ Vdd. The wordline driver of a p-channel access transistor applying the positive power supply voltage when the p-channel access FET is not being accessed and a voltage lower than the threshold voltage of the p-channel access FET is being accessed. For DRAM cells containing an n-channel access FET, the wordline driver applies either a negative voltage or the ground voltage to the n-channel access FET when the DRAM cell is not being accessed. A second voltage composed of Vdd and a boosted voltage is applied to the n-channel FET when the DRAM cell is being accessed.Type: GrantFiled: November 13, 2008Date of Patent: April 19, 2011Assignee: MoSys, Inc.Inventors: Jae Hong Jeong, Jeong Y. Choi
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Patent number: 7894270Abstract: A method and apparatus for selectively restoring data in a non-volatile memory array based on failure type. Weakened data and erroneous data are identified by performing two readings of a specific memory section. Alternatively, an error correction code is used after a first reading of data to identify erroneous data. The manner in which data is restored will depend on whether the data changed because of an erase failure or a program failure. If only a program failure occurred then the data will be reprogrammed without an intervening erase step. If the data experienced an erase failure, then the data will be erased prior to being programmed with correct data.Type: GrantFiled: February 11, 2009Date of Patent: February 22, 2011Assignee: MoSys, Inc.Inventors: Jeong Y. Choi, Stephen Fung
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Patent number: 7835890Abstract: The present invention is directed to a number of improvements in methods for reliability simulations in aged circuits whose operation has been degraded through hot-carrier or other effects. A plurality of different circuit stress times can be simulated within a single run. Different aging criteria may be used for different circuit blocks, circuit block types, devices, device models and device types. The user may specify the degradation of selected circuit blocks, circuit block types, devices, device models and device types independently of the simulation. Device degradation can be characterized in tables. Continuous degradation levels can be quantized. Techniques are also described for representing the aged device in the netlist as the fresh device augmented with a plurality of independent current sources connected between its terminals to mimic the effects of aging in the device. The use of device model cards with age parameters is also described.Type: GrantFiled: October 4, 2007Date of Patent: November 16, 2010Assignee: Cadence Design Systems, Inc.Inventors: Lifeng Wu, Zhihong Liu, Alvin I. Chen, Jeong Y. Choi, Bruce W. McGaughy
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Publication number: 20100202203Abstract: A method and apparatus for selectively restoring data in a non-volatile memory array based on failure type. Weakened data and erroneous data are identified by performing two readings of a specific memory section. Alternatively, an error correction code is used after a first reading of data to identify erroneous data. The manner in which data is restored will depend on whether the data changed because of an erase failure or a program failure. If only a program failure occurred then the data will be reprogrammed without an intervening erase step. If the data experienced an erase failure, then the data will be erased prior to being programmed with correct data.Type: ApplicationFiled: February 11, 2009Publication date: August 12, 2010Applicant: Mosys, Inc.Inventors: Jeong Y. Choi, Stephen Fung
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Publication number: 20100140680Abstract: A process flow for creating a non-volatile memory cell, the process flow including the steps of forming a doped well in a semiconducting portion of a substrate, forming a gate dielectric layer on top of the substrate, depositing a first polysilicon layer on top of the gate dielectric layer, patterning and etching the first polysilicon layer, selectively oxidizing the first polysilicon layer, implanting lightly-doped source/drain regions into the well, forming sidewall spacers adjacent the first polysilicon layer, implanting source/drain regions into the well, thereby forming a channel area, depositing a dielectric layer on top of the first polysilicon layer, depositing a second polysilicon layer on top of the dielectric layer, forming a masking layer on the second polysilicon layer, and etching both the second polysilicon layer and the dielectric layer using the masking layer.Type: ApplicationFiled: December 9, 2008Publication date: June 10, 2010Applicant: MoSys, Inc.Inventors: Jeong Y. Choi, Kameswara K. Rao
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Publication number: 20100118596Abstract: An embedded memory system that includes DRAM cells and logic transistors. The capacitor of the embedded memory responds to a positive bias voltage of ½ Vdd. The wordline driver of a p-channel access transistor applying the positive power supply voltage when the p-channel access FET is not being accessed and a voltage lower than the threshold voltage of the p-channel access FET is being accessed. For DRAM cells containing an n-channel access FET, the wordline driver applies either a negative voltage or the ground voltage to the n-channel access FET when the DRAM cell is not being accessed. A second voltage composed of Vdd and a boosted voltage is applied to the n-channel FET when the DRAM cell is being accessed.Type: ApplicationFiled: November 13, 2008Publication date: May 13, 2010Applicant: Mosys, IncInventors: Jae Hong Jeong, Jeong Y. Choi
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Publication number: 20100120213Abstract: A method of forming an embedded DRAM cell having multiple-thickness gate dielectrics. An oxidation-enhancing dopant is selectively implanted into a well region in an area that is exposed by a first mask. A thermal oxidation step simultaneously produces the field dielectric for two distinct devices each having a different oxide thickness. The method is applicable to quad-density DRAM cells using fewer oxidation steps. The method is also applicable to planar DRAM cells, and does not require increasing the number of masks during the fabrication of planar DRAM cells.Type: ApplicationFiled: November 13, 2008Publication date: May 13, 2010Applicant: Mosys, Inc.Inventor: Jeong Y. Choi
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Publication number: 20090299716Abstract: The present invention is directed to a number of improvements in methods for hot-carrier device degradation modeling and extraction. Several improvements are presented for the improvement of building device degradation models, including allowing the user to select a device parameter used to build the device degradation model independent of the device parameter selected. The user can also select the functional relation between stress time and degradation level. To further improve accuracy, multiple acceleration parameters can be used to account for different regions of the degradation process. Analytical functions may be used to represent aged device model parameters, either directly or by fitting measured device parameters versus device age values, allowing devices with different age values to share the same device model. The concept of binning is extended to include device degradation. In addition to a binning based on device width and length, age is added.Type: ApplicationFiled: June 17, 2009Publication date: December 3, 2009Inventors: Zhihong Liu, Lifeng Wu, Jeong Y. Choi, Ping Chen, Alvin I. Chen, Gang Zhang
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Patent number: 7567891Abstract: The present invention is directed to a number of improvements in methods for hot-carrier device degradation modeling and extraction. Several improvements are presented for the improvement of building device degradation models, including allowing the user to select a device parameter used to build the device degradation model independent of the device parameter selected. The user can also select the functional relation between stress time and degradation level. To further improve accuracy, multiple acceleration parameters can be used to account for different regions of the degradation process. Analytical functions may be used to represent aged device model parameters, either directly or by fitting measured device parameters versus device age values, allowing devices with different age values to share the same device model. The concept of binning is extended to include device degradation. In addition to a binning based on device width and length, age is added.Type: GrantFiled: September 27, 2001Date of Patent: July 28, 2009Assignee: Cadence Design Systems, Inc.Inventors: Zhihong Liu, Lifeng Wu, Jeong Y. Choi, Ping Chen, Alvin I. Chen, Gang Zhang
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Patent number: 7292968Abstract: The present invention is directed to a number of improvements in methods for reliability simulations in aged circuits whose operation has been degraded through hot-carrier or other effects. A plurality of different circuit stress times can be simulated within a single run. Different aging criteria may be used for different circuit blocks, circuit block types, devices, device models and device types. The user may specify the degradation of selected circuit blocks, circuit block types, devices, device models and device types independently of the simulation. Device degradation can be characterized in tables. Continuous degradation levels can be quantized. Techniques are also described for representing the aged device in the netlist as the fresh device augmented with a plurality of independent current sources connected between its terminals to mimic the effects of aging in the device. The use of device model cards with age parameters is also described.Type: GrantFiled: April 11, 2001Date of Patent: November 6, 2007Assignee: Cadence Design Systems, Inc.Inventors: Lifeng Wu, Zhihong Liu, Alvin I. Chen, Jeong Y. Choi, Bruce W. McGaughy
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Patent number: 7219045Abstract: The present invention is directed to methods for reliability simulations in aged circuits whose operation has been degraded through hot-carrier or other effects by allowing design rules on degradation to be included in the netlist. Once the hot-carrier circuit simulation is launched, the rules are checked and the reliability design rule violations are reported. The process can be performed on either the layout or schematic window. The design rule criteria can be any device parameter and can be expressed in absolute or relative terms. The criteria can be based on device type, model card name, instance geometry, or temperature. Additionally, values can be set prior to beginning the simulation.Type: GrantFiled: September 27, 2001Date of Patent: May 15, 2007Assignee: Cadence Design Systems, Inc.Inventors: Lifeng Wu, Jeong Y. Choi, Alvin I. Chen, Jingkun Fang