Patents Assigned to Hong Kong Applied Science and Technology Research Insstitute Company, Limited
  • Patent number: 10665584
    Abstract: A well-less Transient Voltage Suppressor (TVS) Silicon-Controlled Rectifier (SCR) has a P+ anode region that is not in an N-well. The P+ anode region 20 is surrounded by N+ isolation regions near the surface, and a deep N+ region underneath that is formed in a p-substrate. A N+ cathode region is formed in the p-substrate. The deep N+ region has a doping of 5×1018 to 5×1019/cm3, compared to a doping of 1×1016/cm3 for a typical N-well, or a doping of 1×1013 to 1×1015/cm3 for the p-substrate. The high doping in the deep N+ region causes a recombination current that can shunt half of the anode current. Since the deep N+ region is much shallower than an N-well, the sidewall capacitance is greatly reduced, allowing for higher speed applications.
    Type: Grant
    Filed: March 7, 2019
    Date of Patent: May 26, 2020
    Assignee: Hong Kong Applied Science and Technology Research Insstitute Company, Limited
    Inventors: Chenyue Ma, Chun-Kit Yam, Xiao Huo