The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 26, 1999
Filed:
Jan. 16, 1998
John R Cutter, Macclesfield, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
In a MOSFET or other high voltage device, an annular channel stopper (4) extends around the outer periphery (14) of a body portion (11) with which a device region (15) forms a p-n junction (5) operable under high reverse bias in at least one mode of operation of the device. A field plate structure (34, 34a, 34b, 34c) on an insulating layer (24) over the body portion (11) extends towards the outer periphery (14) to spread a depletion layer from the reverse-biased p-n junction (5) towards the outer periphery (14). The channel stopper (4) comprises concentrically doped stopper regions (41 to 44) with different doping concentrations and/or region widths and/or spacings, giving to the body portion (11) a non-uniform doping profile the doping of which, under the field plate structure (34, 34a, 34b, 34c), increases with distance (D) towards the outer periphery (14) to slow progressively the spread of the depletion layer under the field plate structure (34, 34a, 34b, 34c). This field plate structure (34, 34a, 34b, 34c) connected to the device region (15) and/or to a field region (35) can extend laterally over the whole of the body portion (11) between the device region (15) and a doped channel stopper region (41) in the vicinity of the outer periphery (14), and without the complication of any field plate connected to the channel stopper (4).