Fujitsu Corporation

Masahiro Okabe

Ken-ichi Oki

Tamotsu Wada

Tsutomu Tanaka

Ken-ichi Yanai

Yutaka Takizawa

Koji Ohgata

Mari Hodate

Junichi Watanabe

Michiko Takei

Yasuyoshi Mishima

Kenichi Oki

Yoshio Nagahiro

Teruhiko Ichimura

Jun Inoue

Tomotaka Matsumoto

Tatsuya Kakehi

Kohji Ohgata

Norihisa Matsumoto

Ken-iti Yanai

Yuji Murata

A thin film transistor matrix device comprises an insulating substrate, a plurality of picture element electrodes arranged in a matrix on the insulating substrate, source electrodes connected to the respective picture element electrodes, drain electrodes opposed to the respective source electrodes, operational semiconductor layers sandwiched by the source electrodes and the drain electrodes, and gate electrodes formed on the operational semiconductor layers through gate insulating films, each gate electrode being narrowed with respect to the associated gate insulating film so that side walls of the gate electrode forms a step with respect to side walls of the associated gate insulating film which is a substrate of the gate electrode. The gate electrode is made narrower with respect to the gate insulating film to form a step between the side walls of the gate electrode with respect to those of the gate insulating film, whereby leak currents from the source electrode or the drain electrode to the gate electrode along the mesa side surfaces of the TFT can be simply suppressed. Accordingly a TFT matrix device having little wasteful current consumption can be realized.

Thin film transistor matrix device

Thin film transistor matrix device and method for fabricating the same

A thin film transistor matrix device is fabricated by forming a transparent conductor film and a metal film on an insulating substrate in this order. The metal film and the transparent conductor film are together patterned to form picture element electrodes, and drain bus lines or gate bus lines. Source electrodes and drain electrodes may also be formed from the transparent conductor film and metal film. A semiconductor layer, an insulating film and a conductor film may be formed on the entire surface in this order. In this case, the conductor film, the insulator film and the semiconductor layer are patterned to form an active layer from the semiconductor layer, gate insulating films from the insulating film, and gate electrodes and gate bus lines from the conductor film. By patterning the conductor film, the insulating film and the semiconductor layer, the metal film of the picture element electrodes and drain bus lines is exposed. Alternatively, the metal film may be patterned with the semiconductor layer, insulating film and conductor film to expose the transparent conductor film. A current is applied to the drain bus lines or gate bus lines in an electrolyte solution to selectively form a film on the drain bus lines or gate bus lines. The film may be a protecting film serving as a mask to allow the metal film on the picture element electrodes to be etched.

Method for fabricating a thin film transistor matrix device

A method of manufacturing a semiconductor device according to the present invention includes a process of introducing impurities into a semiconductor layer with a gate electrode and a resist film as a mask after a resist film is formed on the top and the side of the gate electrode by soaking the gate electrode on a semiconductor layer in an electrolyte containing resist and applying voltage to the gate electrode.

Method of manufacturing thin film transistors in a liquid crystal display

A crystal silicon film deposited on an insulating film made of a binary system material or a binary system semiconductor film formed by an atomic layer deposition method has a grain as large as approximately 200 nm. Thus, the mobility of carriers is increased. The crystal silicon thereof is grown within a temperature range of 250.degree. C. to 400.degree. C. Accordingly, when a planar type thin film transistor, an inverted stagger type thin film transistor or a stagger type thin film transistor is formed using crystal silicon formed on these films made of a binary system material, transistor characteristics thereof are improved. Further, when an impurity containing silicon film is formed by a chemical vapor deposition method between a source electrode and a drain electrode of a thin film transistor and a silicon film connected to these electrodes, and a flow rate of impurity containing gas is regulated so that impurity density becomes larger as approaching to the source electrode and the drain electrode, a leakage current in an OFF-state of the transistor is reduced. Since the impurity containing silicon film is grown by a chemical vapor deposition method in this case, the impurity density thereof can be controlled easily and the control accuracy is also improved.

Method for forming a film and method for manufacturing a thin film

Growing community of inventors

Kawasaki, Japan

Masahiro Okabe