Patents by Inventor Wen Jer Tsai

Wen Jer Tsai 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: 6444523
    Abstract: A fabrication method for a memory device with a floating gate is provided. A substrate is provided. A channel doping step is performed on the substrate, wherein the actual threshold voltage of the subsequently formed memory device becomes greater than the preset threshold voltage. A stack gate and source/drain regions are then sequentially formed on the substrate to complete the formation of the memory device. The drain-turn-on leakage is prevented by an increase of the actual threshold voltage.
    Type: Grant
    Filed: May 18, 2001
    Date of Patent: September 3, 2002
    Assignee: Macronix International Co., Ltd.
    Inventors: Tso-Hung Fan, Tao-Cheng Lu, Wen-Jer Tsai, Samuel Pan
  • Publication number: 20020100011
    Abstract: A macro model of a programmable NROM for simulating the characters of the NROM under programming operation. Charges are stored in a portion of the nitride material layer to for a charge trapped region when the NROM is programmed. A normal MOS symbol element and a short channel MOS symbol element are respectively represent a MOS without having the charge trapped region and a MOS with a charge trapped region. Moreover, the normal MOS symbol element is series with the short channel MOS symbol element, wherein a source of the short channel MOS symbol element is coupled with a drain of the normal MOS symbol element.
    Type: Application
    Filed: March 22, 2001
    Publication date: July 25, 2002
    Inventors: Yao Wen Chang, Tao Cheng Lu, Wen Jer Tsai
  • Publication number: 20020086473
    Abstract: A process for fabricating CMOS transistor of IC devices that is free from short-changed effects is disclosed. The process of fabrication first forms a gate structure that has a gate polysilicon on top of a gate oxide layer on the surface of the IC substrate. A first spacer is then formed on the sidewall of the gate structure. Lightly-doped source/drain regions are then formed for the transistor by implanting impurities into the source/drain regions of the transistor. A second sidewall spacer then covers the first sidewall spacer. Heavily-doped source/drain regions underneath the lightly-doped source/drain regions are then formed by performing a source/drain implantation procedure. Finally, impurities in the lightly- and heavily-doped source/drain regions are then driven-in into the channel region of the transistor in a rapid thermal annealing procedure.
    Type: Application
    Filed: March 6, 2001
    Publication date: July 4, 2002
    Inventors: Wen-Jer Tsai, Tao-Cheng Lu, Hung-Sui Lin, Han-Chao Lai
  • Publication number: 20020036939
    Abstract: A qualification test method for a non-volatile memory includes determining a relation curve between the programming voltage and the lifetime of the memory cell. A programming voltage with respect to the memory array within the expected lifetime is estimated. According to the relation curve, the accelerating test voltage and the test time period corresponding to the programming voltage operated in the expected lifetime are computed out. The test is performed for the test time period under the accelerating test voltage. All the memory cells at the programmed state are tested to see if the original programmed state still remains. If the programmed state remains, the memory array is judged to have the life period. If the programmed state does not remain, the memory array is judged to have no the life period.
    Type: Application
    Filed: August 30, 2001
    Publication date: March 28, 2002
    Inventors: Wen-Jer Tsai, Nian-Kai Zous, Ta-Hui Wang
  • Patent number: 6320786
    Abstract: A method of controlling the multi-state NROM. A program is executed to inject electric charges that are trapped inside a nitride layer of the NROM. The amount of electric charges trapped inside the nitride layer is controlled so that the memory cell can have different threshold voltages. To read from the memory cell, a first variable voltage is applied to the gate electrode. According to the range of a second variable voltage applied to the drain terminal, three different potential levels, from the smallest to the largest, including a first potential level, a second potential level and a third potential level are set. The second input voltage is adjusted to the first potential level. When a high current is sensed, a first storage state is assumed. If little current is detected, the second input voltage is adjusted to the second potential level. When a high current is sensed, a second storage state is assumed.
    Type: Grant
    Filed: February 5, 2001
    Date of Patent: November 20, 2001
    Assignee: Macronix International Co., Ltd.
    Inventors: Yao Wen Chang, Wen Jer Tsai, Tao Cheng Lu
  • Patent number: 6215697
    Abstract: A multi-level memory cell device and method for self-converged programming which includes a memory cell switchably coupled to a non-programmable reference cell (or dummy cell), the cells arranged in respective arrays. A current source voltage between the source node and ground of the cells is relational to the threshold voltage, so as the threshold voltage is increased, the current source voltage decreases. The threshold voltage of the dummy cell is set by a stable voltage source. The memory cell is programmed and the current source voltage of the memory cell is compared to the current source voltage of the reference cell and therefore the difference in the voltages can be used to sense convergence of the programmed cell with a target threshold level set on the reference cell. A controller is also included between the reference cell and memory cell for adjusting the threshold voltage of the dummy cell according to the gate coupling ratio of the floating gate memory cell.
    Type: Grant
    Filed: January 14, 1999
    Date of Patent: April 10, 2001
    Assignee: Macronix International Co., Ltd.
    Inventors: Tao Cheng Lu, Der Shin Shyu, Shi Xian Chen, Wen Jer Tsai, Mam Tsung Wang
  • Patent number: 6181604
    Abstract: A method for programming a semiconductor memory device, such as an EPROM or a Flash EPROM, which combines the advantages of ramping down a source voltage with the advantages associated with increasing a gate voltage. A programming period is divided into a program disturbance inhibited period and a program period. The programming period is further divided into sub-program periods, with each sub-program period having a program disturbance and a program period. A wordline WL voltage may increase with each sub-program period to improve the programming speed. Also, the program disturbance period may only be performed for the first sub-program period. Each sub-program period may also include a verify period, in order to implement a program and verify technique suitable for programming multi-level Flash EPROMS.
    Type: Grant
    Filed: July 22, 1999
    Date of Patent: January 30, 2001
    Assignee: Macronix International Co., Ltd.
    Inventors: Tao Cheng Lu, Wen Jer Tsai, Mam Tsung Wang, Chin Hsi Lin, Ful Long Ni
  • Patent number: D440969
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: April 24, 2001
    Assignee: Shin Jiuh Corp.
    Inventor: Wen-Jer Tsai