Thin-film transistor

Abstract

Abstract PURPOSE:To suppress an abnormal increase in a drain current at a negative gate voltage and to suppress a leak current in an OFF state by a method wherein a source electrode and a drain electrode are provided on a semiconductor film I via a semiconductor film II which is of a prescribed conductivity type and whose impurity concentration is higher than that of the semiconductor film I. CONSTITUTION:A gate electrode 1 and a patterning gate insulating film 2 are deposited; after that, i-layer a-Si 3 (2000Angstrom ) and n-type a-Si 4 (400Angstrom ) are deposited and are patterned to be islandlike; after that, n-type a-Si 5 is deposited; then, a metal to be used as a source electrode and a drain electrode is deposited. Here, a two-layer structure by a metal coming into contact with an n-type semiconductor and by a metal 7 to be used as a wiring part is formed. Then, a pattern for the source electrode and the drain electrode is formed; the metal part is etched. The n-type a-Si is etched by making use of the metal as a mask; a structure whose i-layer side has been covered with the n-type semiconductor film is completed. An increase in a drain current at a negative gate voltage as a target can be suppressed; an ideal OFF characteristic is obtained.

Inventors

• 👤 Masahiko Akiyama
• 👤 政彦 秋山

Bibliographic Details