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:
Sep. 10, 1991
Filed:
Aug. 08, 1989
Keith H Nicholas, Reigate, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
A TFT is fabricated by providing on a substrate (10), and over a gate (12), a sequentially formed multi-layer structure consisting of a gate insulator layer (14), an intrinsic semiconductor, e.g. a-Si or polysilicon, layer (16) for the channel, a doped semiconductor, e.g. n type a-Si or polysilicon, layer (18) for source and drain contact regions and a passivating layer (20). The layer (18) extends completely over and covers the channel region of the layer (16). Thereafter, the portion (30) of layer (18) overlying the channel region is converted by a compensating doping implant to a highly resistive form separating the source and drain contact regions, and windows (22, 24) are defined in the passivating layer (20) into which source and drain contacts (26, 28) are deposited. In this way critical interfaces are protected from contamination. The TFT is suitable for use as a switching element in active matrix display devices, e.g. LC-TVs.