Patents by Inventor Shengan Xiao

Shengan Xiao 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).

  • Publication number: 20110306189
    Abstract: A method of etching and tilling deep trenches is disclosed, which includes: forming an ONO(oxide-nitride-oxide) sandwich layer on a semiconductor substrate; forming deep trenches by using top oxide of the sandwich layer as a stop layer; removing the top oxide and middle SiN of the sandwich layer; tilling the deep trenches with epitaxial film or polysilicon film; polishing the wafer to get a planarized surface by stopping at the surface of the bottom oxide layer; removing the bottom oxide layer.
    Type: Application
    Filed: June 8, 2011
    Publication date: December 15, 2011
    Inventors: Xiaohua Cheng, Shengan Xiao
  • Publication number: 20110287613
    Abstract: A manufacturing method of superjunction structure is disclosed. After the growth of an epitaxial layer on a substrate, deep trenches are etched in the epitaxial layer. A mixture of silicon source gas, hydrogen gas, halide gas and doping gas is used for trench tilling by means of epitaxial growth. The epitaxial growth rate on trench sidewalls near the bottom of the trench is set to be higher than that near the top of the trench by adjusting the flow rates of the silicon source gas and the halide gas and other parameters. By changing the flow rate of the doping gas at different stages of the epitaxial filling process, the trenches can be filled with epitaxial layers of different doping concentrations, with higher doping concentration near the bottom and lower doping concentration near the top.
    Type: Application
    Filed: May 12, 2011
    Publication date: November 24, 2011
    Inventors: Jiquan Liu, Shengan Xiao
  • Publication number: 20110241110
    Abstract: A terminal structure for superjunction device is disclosed. The terminal structure comprises from inside out at least one P type implantation ring and several P type trench rings formed in an N type epitaxial layer to form alternating P type and N type regions. A channel cut-off ring is formed at the border of the device. The P type implantation ring is formed adjacent to the active area of the device and covers at least one trench ring. A terminal dielectric layer is formed to cover the P type implantation ring and the trench rings. A plurality of field plates are formed above the terminal dielectric layer. Methods of manufacturing terminal structure are also disclosed.
    Type: Application
    Filed: March 30, 2011
    Publication date: October 6, 2011
    Inventors: Shengan Xiao, Fei Wang, Yanping Liu
  • Publication number: 20110241156
    Abstract: Methods for manufacturing a semiconductor device with alternating P type and N type semiconductor conductive regions are disclosed. One method includes forming a trench in an N type epitaxial layer; forming carbon-contained silicon layer on sidewalls of the trench; and filling the trench with P type semiconductor layer. In another method, the carbon-contained silicon layer is replaced by a carbon film formed by diffusion process. The carbon-contained silicon layer or the carbon film can effectively inhibit the diffusion of P type impurities into the N type semiconductor layers. Further, a semiconductor device having carbon-contained layer or carbon film formed between P type and N type conductive layers is also disclosed.
    Type: Application
    Filed: April 5, 2011
    Publication date: October 6, 2011
    Inventor: Shengan Xiao
  • Publication number: 20110006304
    Abstract: The invention is related to a semiconductor device with alternately arranged P-type and N-type thin semiconductor layers and method for manufacturing the same. For P-type device, the method includes trench formation, thermal oxide formation on trench sidewalls, N-type silicon formation in trenches, N-type impurity diffusion through thermal oxide into P-type epitaxial layer, oxidation of N-type silicon in trenches and oxide removal. In the semiconductor device, N-type thin semiconductor layers are formed by N-type impurity diffusion through oxide to P-type epitaxial layers, and trenches are filled with oxide. With this method, relatively low concentration impurity in high voltage device can be realized by current mass production process, and the device development cost and manufacturing cost are decreased.
    Type: Application
    Filed: July 8, 2010
    Publication date: January 13, 2011
    Applicant: SHANGHAI HUA HONG NEC ELECTRONICS COMPANY, LIMITED
    Inventors: Shengan Xiao, Feng Han