Patents by Inventor Chao-I Wu

Chao-I Wu 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: 7085168
    Abstract: A method for programming one or more memory cells is disclosed. The one or more memory cells need to be two sides operated. After verifying both sides of each memory cell to identify the sides of the memory cells to be programmed, a programming voltage pulse is given to the first sides of the memory cells identified to be programmed. Another verification process is performed for both sides of each memory cell to identify the sides of the memory cells to be programmed. Next, a programming voltage pulse is given to the second sides of the memory cells identified to be programmed. The verifying both sides, programming the first sides, verifying both sides, and programming the second sides will continue until the both sides of each memory cell are programmed to a target programming voltage. The target programming voltage might have multiple voltage levels.
    Type: Grant
    Filed: December 30, 2004
    Date of Patent: August 1, 2006
    Assignee: Macronix International Co., Ltd.
    Inventors: Ming-Hsiu Lee, Chao-I Wu, Tzu-Hsuan Hsu
  • Publication number: 20060145307
    Abstract: A semiconductor device having high-aspect-ratio PN-junctions is provided. The semiconductor device includes a conducting layer. The semiconductor device further includes a plurality of first doped regions formed over the conducting layer. The sidewalls of the doped regions are doped to form PN-junctions. The semiconductor device also includes a plurality of second doped regions over the first doped regions.
    Type: Application
    Filed: December 30, 2004
    Publication date: July 6, 2006
    Inventors: Chao-I Wu, Ming Lee
  • Publication number: 20060146615
    Abstract: A memory cell with a charge-trapping structure stores multiple bits. A biasing arrangement is applied to one part of the charge-trapping structure of the memory cell to store a high threshold state, and a biasing arrangement is applied to another part of the charge-trapping structure tending to raise its threshold voltage without exceeding a maximum threshold voltage of the low threshold state, reducing the read disturb effect between different parts of the memory cell. In another charge-trapping memory cell, when a biasing arrangement is applied to the memory cell to store a higher threshold state, the biasing arrangement tends to cause different parts of the charge-trapping structure of the memory cell to store a higher threshold state, and when a biasing arrangement is applied to the memory cell to store a lower threshold state, the biasing arrangement tends to cause different parts of the charge-trapping structure of the memory cell to store a lower threshold state.
    Type: Application
    Filed: December 30, 2004
    Publication date: July 6, 2006
    Applicant: MACRONIX INTERNATIONAL CO., LTD.
    Inventor: Chao-I Wu
  • Publication number: 20060146603
    Abstract: A method is provided of forming an assisted charge memory (AC-memory) cell. The method uses a two-sided charge trap memory cell that includes a two-sided charge trapping layer. A charge is formed in at least a portion of the two-sided charge trapping layer. One side (AC-side) of the two-sided charge trapping layer always has a fixed high threshold voltage (Vt) level which is the assisted charge for the AC-memory cell. The other side (data-side) is used for memory operations.
    Type: Application
    Filed: December 1, 2005
    Publication date: July 6, 2006
    Inventors: Ming-Chang Kuo, Chao-I Wu, Ming-Hsin Lee, Tzu-Hsuan Hsu
  • Publication number: 20060146613
    Abstract: A method for programming one or more memory cells is disclosed. The one or more memory cells need to be two sides operated. After verifying both sides of each memory cell to identify the sides of the memory cells to be programmed, a programming voltage pulse is given to the first sides of the memory cells identified to be programmed. Another verification process is performed for both sides of each memory cell to identify the sides of the memory cells to be programmed. Next, a programming voltage pulse is given to the second sides of the memory cells identified to be programmed. The verifying both sides, programming the first sides, verifying both sides, and programming the second sides will continue until the both sides of each memory cell are programmed to a target programming voltage. The target programming voltage might have multiple voltage levels.
    Type: Application
    Filed: December 30, 2004
    Publication date: July 6, 2006
    Inventors: Ming-Hsiu Lee, Chao-I Wu, Tzu-Hsuan Hsu
  • Publication number: 20060141709
    Abstract: A method of programming data regions in a nitride read-only memory cell is described. In an erased state, the nitride read-only memory cell exhibits a low Vt value. A data region that is to be programmed to a highest Vt value is programmed first. Remaining data regions in the nitride read-only memory cell are programmed in a time order according to their descending Vt values. For a nitride read-only memory cell that, in an erased state, exhibits a high Vt value, a data region that is to be programmed to a lowest Vt value is programmed first with remaining data regions programmed in a time order according to their ascending Vt values.
    Type: Application
    Filed: December 29, 2004
    Publication date: June 29, 2006
    Inventors: Hsiang-Lan Lung, Chao-I Wu
  • Patent number: 7054192
    Abstract: A method of two-sided asymmetric programming with a one-sided read for a Nitride Read Only Memory (NROM) cell with different quantity of stored charges uses the different interaction of the two bits to control the operation window of the threshold voltage. Due to the increase of the threshold voltage operation window of a NROM cell, four, eight, and sixteen memory states of a NROM cell can be achieved through the combination of the left bit, the right bit, the quantity of charge, and the charge position of its two bits.
    Type: Grant
    Filed: February 26, 2004
    Date of Patent: May 30, 2006
    Assignee: Macronix International Co., Ltd.
    Inventor: Chao I. Wu
  • Publication number: 20060104105
    Abstract: A method of determining an optimal reading voltage for reading a two-side non-volatile memory programmed with a threshold voltage Vt is described. A first side of a memory cell is programmed to Vt, and then an I1-Vg curve of the first side and an I2-Vg curve of the second side are measured, wherein Vg is the gate voltage. A Gm1-Vg curve and a Gm2-Vg curve are plotted, wherein Gm1=dI1/dVg and Gm2=dI2/dVg. The optimal reading voltage VgO is determined as the gate voltage at the intersection of Gm1 and Gm2, corresponding to a maximal total current window Wm(=I2(VgO)?I1(VgO)).
    Type: Application
    Filed: November 17, 2004
    Publication date: May 18, 2006
    Inventors: Tzu-Hsuan Hsu, Ming-Hsiu Lee, Chao-I Wu, Hsiang-Lan Lung
  • Patent number: 7038928
    Abstract: A method of determining an optimal reading voltage for reading a two-side non-volatile memory programmed with a threshold voltage Vt is described. A first side of a memory cell is programmed to Vt, and then an I1-Vg curve of the first side and an I2-Vg curve of the second side are measured, wherein Vg is the gate voltage. A Gm1-Vg curve and a Gm2-Vg curve are plotted, wherein Gm1=dI1/dVg and Gm2=dI2/dVg. The optimal reading voltage VgO is determined as the gate voltage at the intersection of Gm1 and Gm2, corresponding to a maximal total current window Wm (=I2(VgO)?I1(VgO)).
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: May 2, 2006
    Assignee: Macronix International Co., Ltd.
    Inventors: Tzu-Hsuan Hsu, Ming-Hsiu Lee, Chao-I Wu, Hsiang-Lan Lung
  • Publication number: 20050286312
    Abstract: A method of identifying logical information in a cell, particularly in a programming by hot hole injection nitride electron storage (PHINES) cell by one-side reading scheme is disclosed. The method comprise steps of: erasing the first region and the second region of PHINES cell by increasing a local threshold voltage (Vt) to a certain value; programming at least one of the first region and the second region of the PHINES cell by hot hole injection; and reading a logical state of the PHINES cell by measuring an output current of one of the first region and the second region; wherein different quantity of the output current is caused by interaction between different quantity of the hot hole stored in the first region and the second region, so as to determine the logical state of the PHINES cell by one-side reading scheme.
    Type: Application
    Filed: June 23, 2004
    Publication date: December 29, 2005
    Inventors: Chao-I Wu, Ming-Hsiu Lee, Tzu-Hsuan Hsu
  • Publication number: 20050281085
    Abstract: A circuit and method for self-converging programming of a charge storage memory cell, such as NROM or floating gate flash. The method includes determining a data value from one of more than two data values to be stored in the memory cell, and applying a gate voltage to the control gate at one of a predetermined set of gate voltage levels selected in response to the determined data value. Programming parameters are controlled to establish a self-converging threshold state that is determined by the selected gate voltage. In this manner, the threshold voltage converges on a target threshold corresponding with the determined data value for the memory cell. Program verify operations are reduced or eliminated in various embodiments, reducing the overall time required for the program operation, and improving device performance. A second portion of the program operation can include verify operations to improve threshold margins across the array.
    Type: Application
    Filed: May 20, 2005
    Publication date: December 22, 2005
    Applicant: Macronix International Co., Ltd.
    Inventor: Chao-I Wu
  • Publication number: 20050237816
    Abstract: A memory cell with a charge trapping structure is programmed using refill cycles that include a program pulse followed by a charge balancing pulse that causes ejection of electrons from the charge trapping structure. The refill cycle causes a blue spectrum shift in the charge trap distribution in the charge trapping structure. The algorithm includes program verify operations after the program pulse, and completes when a successful program verify operation occurs after a number of refill cycles.
    Type: Application
    Filed: June 24, 2004
    Publication date: October 27, 2005
    Inventors: Hang-Ting Lue, Yen-Hao Shih, Kuang Yeu Hsieh, Ming-Hsiu Lee, Chao-I Wu, Tzu-Hsuan Hsu
  • Publication number: 20050219906
    Abstract: A circuit and method for self-converging programming of a charge storage memory cell, such as NROM or floating gate flash. The method includes determining a data value from one of more than two data values to be stored in the memory cell, and applying a gate voltage to the control gate at one of a predetermined set of gate voltage levels selected in response to the determined data value. Programming parameters are controlled to establish a self-converging threshold state that is determined by the selected gate voltage. In this manner, the threshold voltage converges on a target threshold corresponding with the determined data value for the memory cell. Program verify operations are reduced or eliminated in various embodiments, reducing the overall time required for the program operation, and improving device performance. A second portion of the program operation can include verify operations to improve threshold margins across the array.
    Type: Application
    Filed: May 20, 2005
    Publication date: October 6, 2005
    Applicant: Macronix International Co., Ltd.
    Inventor: Chao-I Wu
  • Patent number: 6952038
    Abstract: A 3D polysilicon ROM including an isolated SiO2 layer on a silicon substrate, and an N+ polysilicon layer on the isolated SiO2 layer. The N+ polysilicon layer is further defined by a plurality of parallel, separate word lines. A first oxide layer fills the space between the word lines. A dielectric layer is deposited on the word lines and the first oxide layer. A P? polysilicon layer is deposited on the dielectric layer and further defines a plurality of parallel, separate bit lines. The bit lines overlap the word lines, from a top view, to form an approximately cross shape. The neck structure may be individually formed between the P? and N+ polysilicon layers by wet etching the dielectric layer with dilute hydrofluoric acid. A second oxide layer fills the space between the bit lines and is on the word lines and the first oxide layer.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: October 4, 2005
    Assignee: Macronix International Co., Ltd.
    Inventors: Tzu-Hsuan Hsu, Ming-Hsiu Lee, Hsiang-Lan Lung, Chao-I Wu
  • Patent number: 6937511
    Abstract: A circuit and method for self-converging programming of a charge storage memory cell, such as NROM or floating gate flash, having a source and a drain in a substrate, a charge storage element and a control gate. The method includes applying source voltage, inducing a body effect that increases the effective threshold, and increasing the source voltage along with the drain voltage to moderate hot electron injection efficiency during the program operation, at least during a portion of the program operation in which convergence on a target threshold occurs. A selected gate voltage is applied during the operation to establish the target threshold voltage. In multiple bit cells, the gate voltage is set according to the data values to be stored, enabling self-convergence at more than one target threshold.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: August 30, 2005
    Assignee: Macronix International Co., Ltd.
    Inventors: Tzu-Hsuan Hsu, Chao-I Wu
  • Publication number: 20050162922
    Abstract: A circuit and method for self-converging programming of a charge storage memory cell, such as NROM or floating gate flash, having a source and a drain in a substrate, a charge storage element and a control gate. The method includes applying source voltage, inducing a body effect that increases the effective threshold, and increasing the source voltage along with the drain voltage to moderate hot electron injection efficiency during the program operation, at least during a portion of the program operation in which convergence on a target threshold occurs. A selected gate voltage is applied during the operation to establish the target threshold voltage. In multiple bit cells, the gate voltage is set according to the data values to be stored, enabling self-convergence at more than one target threshold.
    Type: Application
    Filed: January 27, 2004
    Publication date: July 28, 2005
    Applicant: Macronix International Co., Ltd.
    Inventors: Tzu-Hsuan Hsu, Chao-I Wu
  • Publication number: 20050124116
    Abstract: A 3D polysilicon read only memory at least including: a silicon substrate, an isolated silicon dioxide (SiO2) layer, a N-Type heavily doped (N+) polysilicon layer, a first oxide layer, a dielectric layer, a P-Type lightly doped (P?) polysilicon layer, at least a neck structure, and a second oxide layer. The isolated SiO2 layer is deposited on the silicon substrate, and the N+ polysilicon layer is deposited on the isolated SiO2 layer. The N+ polysilicon layer is further defined a plurality of parallel, separate word lines (WL), and the first oxide layer is filled in the space between the word lines. The dielectric layer is deposited on the word lines and the first oxide layer. The P-Type lightly doped (P?) polysilicon layer is deposited on the dielectric layer and is further defined a plurality of parallel, separate bit lines (BL). The bit lines overlap the word lines, from a top view, to form a shape approximately as a cross.
    Type: Application
    Filed: December 8, 2003
    Publication date: June 9, 2005
    Inventors: Tzu-Hsuan Hsu, Ming-Hsiu Lee, Hsiang-Lan Lung, Chao-I Wu
  • Patent number: 6903410
    Abstract: An electrically erasable programmable read only memory cell has a stacking layer, a gate conductive layer, a first source/drain region, a second source/drain region, a first pocket implant doping region, and a second pocket implant doping region. The stacking layer is disposed over a substrate. The gate conductive layer is located on the stacking layer. The first source/drain region and the second source/drain region are respectively disposed over the substrate on two sides of the gate conductive layer. The first pocket implant doping region is disposed over the substrate under the stacking layer, and adjacent to the first source/drain region. The second pocket implant doping region is disposed over the substrate under the stacking layer, and adjacent to the second source/drain region, wherein the doping concentration of the first pocket implant region is different from that of the second pocket implant region.
    Type: Grant
    Filed: August 2, 2004
    Date of Patent: June 7, 2005
    Assignee: Macronix International Co., Ltd
    Inventors: Chao-I Wu, Ming-Hsiu Lee
  • Patent number: 6890819
    Abstract: A method for forming a PN junction is described. A stacked structure consisting of an N-doped (or P-doped) layer, a dielectric layer and a nucleation layer is formed, and then an insulating layer is formed having an opening therein. A P-doped (or N-doped) polysilicon or amorphous silicon layer is filled into the opening, and then annealed to convert into a single-crystal silicon layer. Then, the dielectric layer is broken down to form a PN junction.
    Type: Grant
    Filed: September 18, 2003
    Date of Patent: May 10, 2005
    Assignee: MACRONIX International Co., Ltd.
    Inventors: Chao-I Wu, Ming-Hsiu Lee
  • Publication number: 20050062079
    Abstract: A method for forming a PN junction is described. A stacked structure consisting of an N-doped (or P-doped) layer, a dielectric layer and a nucleation layer is formed, and then an insulating layer is formed having an opening therein. A P-doped (or N-doped) polysilicon or amorphous silicon layer is filled into the opening, and then annealed to convert into a single-crystal silicon layer. Then, the dielectric layer is broken down to form a PN junction.
    Type: Application
    Filed: September 18, 2003
    Publication date: March 24, 2005
    Inventors: Chao-I Wu, Ming-Hsiu Lee