Patent ID: 6285041
Filing Date: 2001-09-04
Classification: H01L

Abstract:
A thin-film transistor comprising:a substrate;a layered structure formed on said substrate;said layered structure including a semiconductor film having a first subfilm located on one side of said semiconductor film and a second subfilm located on the other side thereof;said first subfilm forming an electrically conductive channel of said transistor;said second subfilm having a high-resistance part with a high electric resistance, a source contact region connected to one end of said high-resistance part, and a drain contact region connected to the other end of said high-resistance part;said high-resistance part being located in a back channel section of said electrically conductive channel and containing an n-type impurity and a p-type impurity;a gate insulating film formed to be contacted and overlapped with the first subfilm of said semiconductor film;a gate electrode formed to be overlapped with said gate insulating film;a source electrode formed to be contacted with and electrically connected to said source contact region of said second subfilm of said semiconductor film and electrically isolated from said high-resistance part; anda drain electrode formed to be contacted with and electrically connected to said drain contact region of said second subfilm of said semiconductor film and electrically isolated from said high-resistance part;wherein said high-resistance part located in said back channel section serves to suppress a leakage current flowing between said source electrode and said drain electrode;wherein said semiconductor film is made of an undoped semiconductor material;and wherein said semiconductor film has a pair of n-type regions contacted with said source and drain electrodes, respectively,and wherein said high-resistance part of said back channel section is located on a same side of said semiconductor film as that of said pair of n-type regions;said layered structure further comprising an additional film containing a p-type impurity contacted with said back channel section of said semiconductor film.