Patents by Inventor Tao-Cheng Lu

Tao-Cheng Lu 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).

  • Patent number: 7106563
    Abstract: An I/O pad ESD protection circuit is composed of a SCR circuit, a first diode, a second diode, and an anti-latch-up circuit. The SCR circuit has a first connection terminal and a second connection terminal, respectively coupled to the I/O pad and the ground voltage, so as to discharge the electrostatic charges. The anti-latch-up circuit has two terminals, which are respectively coupled to the voltage source and the ground voltage, and another connection terminal, used to send an anti-latch-up signal to the SCR for changing the activating rate. The latch-up phenomenon is avoided.
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: September 12, 2006
    Assignee: MAXRONIX International Co., Ltd.
    Inventors: Chun Hsiang Lai, Meng Huang Liu, Tao Cheng Lu
  • Publication number: 20060189081
    Abstract: A lateral double diffused metal oxide semiconductor (LDMOS) device, and method of fabricating such a device, are provided. The method comprises the steps of: (a) providing a substrate of a first conductivity type; (b) forming within the substrate a well region of a second conductivity type, the well region having a super steep retrograde (SSR) well profile in which a doping concentration changes with depth so as to provide a lighter doping concentration in a surface region of the well region than in a region below the surface region of the well region; (c) forming a gate layer which partly overlies the well region and is insulated from the well region; and (d) forming one of a source region and a drain region in the well region. The presence of the SSR well region provides a lighter surface doping to enable a higher breakdown voltage to be obtained within the LDMOS device, and heavier sub-surface doping to decrease the on-resistance.
    Type: Application
    Filed: February 23, 2005
    Publication date: August 24, 2006
    Applicant: Macronix International Co., Ltd
    Inventors: Chia-Lun Hsu, Mu-Yi Liu, Tao-Cheng Lu, Ichen Yang, Kuan-Po Chen
  • Patent number: 7057938
    Abstract: One embodiment of the present invention provides a system having a nonvolatile memory comprising a p type semiconductor substrate, an oxide layer over the p type semiconductor substrate, a nitride layer over the oxide layer, an additional oxide layer over the nitride layer, a gate over the additional oxide layer, two N+ junctions in the p type semiconductor layer, a source and drain respectively formed in the two N+ junctions, a first bit and a second bit in the nonvolatile memory, and accordingly at least two states of operation (i.e., erase and program) therefor. That is, one bit in the nonvolatile memory can either be in an erase state or program state. For erasing a bit, electrons are injected at the gate of the nonvolatile memory. For programming a bit, electric holes are injected or electrons are reduced for that bit.
    Type: Grant
    Filed: January 14, 2004
    Date of Patent: June 6, 2006
    Assignee: Macronix International Co., Ltd.
    Inventors: Chih Chieh Yeh, Hung Yueh Chen, Yi Ying Liao, Wen Jer Tsai, Tao Cheng Lu
  • Patent number: 7035147
    Abstract: The invention provides a nonvolatile memory and corresponding method having an optimal memory erase function and, more particularly, a method for erasing a nonvolatile memory comprising a source, a gate, a drain, a channel and a trapping layer. The method according to a preferred embodiment of the invention generally comprises the steps of applying a non-zero gate voltage to the gate, applying a non-zero source voltage to the source, applying a non-zero drain voltage to the drain in each erase shot wherein the drain voltage is generally higher in magnitude than the source voltage, generating hot holes in the nonvolatile memory, injecting the generated hot holes in the trapping layer near drain junction, and accordingly erasing the nonvolatile memory.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: April 25, 2006
    Assignee: Macronix International Co., Ltd.
    Inventors: Chih Chieh Yeh, Wen Jer Tsai, Tao Cheng Lu
  • Patent number: 7031196
    Abstract: A method of programming the memory cell comprises setting the memory cell to an initial state of a first gate threshold voltage, performing a processing sequence including: applying a voltage bias between the gate and the first junction region to cause electric hole to migrate towards and be retained in the trapping layer, and evaluating a read current generated in response to the voltage bias to determine whether a second gate threshold voltage is reached, wherein the second gate threshold voltage is lower than the first gate threshold voltage. The processing sequence is repeated a number of times by varying one or more time the voltage bias between the gate and the first junction region until the second gate threshold voltage is reached and the memory cell is in a program state.
    Type: Grant
    Filed: January 14, 2004
    Date of Patent: April 18, 2006
    Assignee: Macronix International Co., Ltd.
    Inventors: Chih-Chieh Yeh, Wen-Jer Tsai, Tao-Cheng Lu
  • Patent number: 7012305
    Abstract: An electro-static discharge (ESD) protection circuit for a dual polarity I/O pad is provided. The protection circuit includes a substrate of first type; a deep well region of second type disposed in the first type substrate; a well region of first type disposed in the second type deep well region; a first transistor disposed over the well region of first type, wherein the first transistor has a first source, a first gate and a first drain; a second transistor disposed over the substrate of first type, wherein the second transistor has a second source, a second gate and a second drain, and the second source is connected with the first drain, and both of them are disposed in a portion of the well region of first type, the deep well region of second type and the substrate of first type; a first doped region is disposed in the first type well region and laterally adjacent to the first source; a second doped region is disposed in the substrate of first type and laterally adjacent to the second drain.
    Type: Grant
    Filed: February 12, 2004
    Date of Patent: March 14, 2006
    Assignee: MACRONIX International Co., Ltd.
    Inventors: Shin Su, Chun-Hsiang Lai, Chia-Ling Lu, Yen-Hung Yeh, Tao-Cheng Lu
  • Publication number: 20060044718
    Abstract: A device for connection between supply buses in mixed power integrated circuits includes a diode in series with a transistor with an active p-ring in a semiconductor substrate. The active p-ring surrounds the source and drain of the transistor with a conductive region having the same conductivity type as the semiconductor substrate. A control circuit coupled to the p-ring applies a bias voltage in response to an ESD event affecting the first and second conductors. The bias voltage tends to inject carriers into the semiconductor substrate which enables discharge of the short voltage pulse via a parasitic SCR in the substrate from the anode of the diode to the source of the transistor.
    Type: Application
    Filed: September 2, 2004
    Publication date: March 2, 2006
    Applicant: MACRONIX INTERNATIONAL CO., LTD.
    Inventors: Shin Su, Chun-Hsiang Lai, Cha-Ling Lu, Yen-Hung Yeh, Tao-Cheng Lu
  • Patent number: 7002849
    Abstract: A method for programming and erasing a non-volatile memory with a nitride tunneling layer is described. The non-volatile memory is programmed by applying a first voltage to the gate and grounding the substrate to turn on a channel between the source and the drain, and applying a second voltage to the drain and grounding the source to induce a current in the channel and thereby to generate hot electrons therein. The hot electrons are injected into a charge-trapping layer of the non-volatile and trapped therein through the nitride tunneling layer. The non-volatile memory is erased by applying a first positive bias to the drain, applying a second positive bias to the gate, and grounding the source and the substrate to generate hot electron holes in the channel region. The hot electron holes are injected into the charge-trapping layer through the nitride tunneling layer.
    Type: Grant
    Filed: November 5, 2004
    Date of Patent: February 21, 2006
    Assignee: MACRONIX International Co., Ltd.
    Inventors: Tso-Hung Fan, Yen-Hung Yeh, Kwang-Yang Chan, Mu-Yi Liu, Tao-Cheng Lu
  • Publication number: 20060033149
    Abstract: An EEPROM cell includes first and second assist gates on opposite sides of a charge retaining insulating layer. Current in the EEPROM memory cell flows between inversion layers, which are created in response to a bias applied to the assist gates. The insulating layer can include silicon nitride, which is provided between layers of silicon dioxide above the channel region, such that these layers can constitute a dielectric stack, which can be fabricated to occupy a relatively small area.
    Type: Application
    Filed: August 2, 2005
    Publication date: February 16, 2006
    Inventors: Mu-Yi Liu, Tao-Cheng Lu
  • Patent number: 6996011
    Abstract: A NAND-type erasable programmable read only memory (EEPROM) device formed of a number of substantially identical EEPROM cells with each EEPROM cell being capable of storing two bits of information. A simple method for operating the memory comprises erasing, programming, and reading the device.
    Type: Grant
    Filed: May 26, 2004
    Date of Patent: February 7, 2006
    Assignee: Macronix International Co., Ltd.
    Inventors: Chih Chieh Yeh, Wen Jer Tsai, Tao Cheng Lu
  • Publication number: 20060017102
    Abstract: An LDMOS device and method of fabrication are provided. The LDMOS device has a substrate with a source region and a drain region formed in the substrate. An insulating layer is provided on a portion of the substrate between the source and the drain region, such that a planar interface is provided between the insulating layer and a surface of the substrate. An insulating member is then formed on a portion of the insulating layer, and a gate layer is formed over part of the insulating member and the insulating layer. By employing such a structure, it has been found that a flat current path exists which enables the on-resistance to be decreased whilst maintaining a high breakdown voltage.
    Type: Application
    Filed: April 7, 2005
    Publication date: January 26, 2006
    Applicant: Macronix International Co., Ltd.
    Inventors: Mu-Yi Liu, Chia-Lun Hsu, Ichen Yang, Kuan-Po Chen, Tao-Cheng Lu
  • Publication number: 20050270844
    Abstract: A programming method of the multi-level flash memory comprises shooting a programming voltage that is increasing upwards stepwise each time into the gate of the multi-level flash memory, and following, shooting a program verify voltage that is decreasing downwards to program a multi-level in the multi-level flash memory and shooting an additional programming voltage into the multi-level flash memory after the last program verify voltage is shot. An erasing method of the multi-level flash memory comprises shooting an erasing voltage that is decreasing downwards stepwise each time into a gate of the multi-level flash memory, and following, shooting a erase verify voltage that is increasing upwards to erase a multi-level in the multi-level flash memory and shooting an additional voltage into the multi-level flash memory after the last erase verify voltage is shot.
    Type: Application
    Filed: August 4, 2005
    Publication date: December 8, 2005
    Inventors: Tso-Hung Fan, Chih-Chieh Yeh, Tao-Cheng Lu
  • Publication number: 20050269641
    Abstract: An electrostatic discharge (ESD) protection circuit coupled to an input pad comprises a diode formed in a substrate and coupled to the input pad; a P deep well formed in the substrate; an N well formed in the P deep well; a first P+ doped region in the N well; and an NMOS transistor formed on the substrate, comprising a gate, a source and a drain, wherein the drain is formed in the N well and coupled to a Vcc, and the source is formed in the P deep well; and a second P+ doped region formed in the P deep well. The ESD protection circuit uses a smaller area than the conventional ESD protection circuit.
    Type: Application
    Filed: November 12, 2004
    Publication date: December 8, 2005
    Inventors: Chun-Hsiang Lai, Shin Su, Chia-Ling Lu, Yen-Hung Yeh, Tao-Cheng Lu
  • Patent number: 6965504
    Abstract: An ESD protection apparatus for a high-voltage input pad comprises a modulator connected between the input pad and a snapback device with first and second guard rings surrounding the modulator, third guard ring surrounding the snapback device, and first and second guard ring control circuits to control the guard rings such that the protection apparatus has higher triggering and holding voltages under normal operation and lower triggering and holding voltages under ESD event.
    Type: Grant
    Filed: November 26, 2002
    Date of Patent: November 15, 2005
    Assignee: Macronix International Co., Ltd.
    Inventors: Meng-Huang Liu, Chun-Hsiang Lai, Shin Su, Tao-Cheng Lu
  • Publication number: 20050237813
    Abstract: A process and a memory architecture for operating a charge trapping memory cell is provided. The method for operating the memory cell includes establishing a high threshold state in the memory cell by injecting negative charge into the charge trapping structure to set a high state threshold. The method includes using a self-converging biasing procedure to establish a low threshold state for the memory cell by reducing the negative charge in the charge trapping structure to set the threshold voltage for the cell to a low threshold state. The negative charge is reduced in the memory cell by applying a bias procedure including at least one bias pulse. The bias pulse balances charge flow into and out of the charge trapping layer to achieve self-convergence on a desired threshold level. Thereby, an over-erase condition is avoided.
    Type: Application
    Filed: June 24, 2004
    Publication date: October 27, 2005
    Inventors: Nian-Kai Zous, Wen-Jer Tsai, Hung-Yueh Chen, Tao-Cheng Lu
  • Patent number: 6958934
    Abstract: A programming method of the multi-level flash memory comprises shooting a programming voltage that is increasing upwards stepwise each time into the gate of the multi-level flash memory, and following, shooting a program verify voltage that is decreasing downwards to program a multi-level in the multi-level flash memory and shooting an additional programming voltage into the multi-level flash memory after the last program verify voltage is shot. An erasing method of the multi-level flash memory comprises shooting an erasing voltage that is decreasing downwards stepwise each time into a gate of the multi-level flash memory, and following, shooting a erase verify voltage that is increasing upwards to erase a multi-level in the multi-level flash memory and shooting an additional voltage into the multi-level flash memory after the last erase verify voltage is shot.
    Type: Grant
    Filed: November 15, 2002
    Date of Patent: October 25, 2005
    Assignee: Macronix International Co., Ltd.
    Inventors: Tso-Hung Fan, Chih-Chieh Yeh, Tao-Cheng Lu
  • Patent number: 6947267
    Abstract: The present invention relates an electrostatic discharge (ESD) protection device that is applied to a mixed voltage circuit assembly. The device comprises a RC controlled circuit subassembly and a field transistor, which the RC controlled circuit is coupled with the mixed voltage circuit assembly to substantially control the ESD protection device to be ON or OFF. The field transistor is coupled between a first power supply and a second power supply of said mixed voltage circuit assembly, which is off on the condition of a normal operating condition and is conducting as an ESD event occurred.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: September 20, 2005
    Assignee: Macronix International Co., Ltd.
    Inventors: Meng-Huang Liu, Chun-Hsiang Lai, Shin Su, Tao-Cheng Lu
  • Patent number: 6933540
    Abstract: An ESD protection apparatus for dual-polarity input pad comprises a triple-well formed with a first, second and third regions to form an SCR structure. A first and second ground connection regions of opposite conductivity types are formed on the first region, a first and second input connection regions of opposite conductivity types are formed in the third region, and a bridge region is formed across the second region and extends to the first and third regions. Under normal operation, the first, second, and third regions form two back-to-back diodes. Under positive polarity ESD event, breakdown is occurred between the bridge and first regions to thereby trigger an SCR circuit for positive polarity ESD protection. Under negative polarity ESD event, breakdown is occurred between the bridge and third regions to thereby trigger an SCR circuit for negative polarity ESD protection.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: August 23, 2005
    Assignee: Macronix International Co., Ltd.
    Inventors: Meng-Huang Liu, Chun-Hsiang Lai, Shin Su, Tao-Cheng Lu
  • Patent number: 6919604
    Abstract: The present invention provides a PMSCR (bridging modified lateral modified silicon controlled rectifier having first conductivity type) with a guard ring controlled circuit. The present invention utilizes controlled circuit such as switch to control functionally of guard ring of PMSCR. In normal operation, the switch is of low impedance such that the guard ring is short to anode and collects electrons to enhance the power-zapping immunity. Furthermore, during the ESD (electrostatic discharge) event, the switch is of high impedance such that the guard ring is non-functional. Thus, the PMSCR with guard ring control circuit can enhance both the ESD performance and the power-zapping immunity in the application of the HV (high voltage) pad.
    Type: Grant
    Filed: October 31, 2003
    Date of Patent: July 19, 2005
    Assignee: Macronix International Co., Ltd.
    Inventors: Chen-Shang Lai, Meng-Huang Liu, Shin Su, Tao-Cheng Lu
  • Patent number: 6919607
    Abstract: A structure of a 2-bit mask ROM device and a fabrication method thereof are provided. The memory structure includes a substrate, a gate structure, a 2-bit coding implantation region, a spacer, a buried drain region, an isolation structure and a word line. The gate structure is disposed on the substrate, while the coding implantation region is located in the substrate under the side of the gate structure. Further, at least one spacer is arranged beside the side of the gate structure and a buried drain region is disposed in the substrate beside the side of the spacer. Moreover, the buried drain region and the coding implantation region further comprise a buffer region in between. Additionally, an insulation structure is arranged on the substrate that is above the buried drain region, while the word lien is disposed on the gate structure.
    Type: Grant
    Filed: May 8, 2002
    Date of Patent: July 19, 2005
    Assignee: MACRONIX International Co., Ltd.
    Inventors: Mu-Yi Liu, Kwang-Yang Chan, Yen-Hung Yeh, Tso-Hung Fan, Tao-Cheng Lu