Semiconductor Energy Laboratory Co., Ltd.

Sachiaki Teduka

Shunpei Yamazaki

Yasuhiro Jinbo

Koji Dairiki

Satoshi Toriumi

Hideaki Kuwabara

Makoto Furuno

Makoto Foruno

After a gate insulating film is formed over a gate electrode, in order to improve the quality of a microcrystalline semiconductor film which is formed in an early stage of deposition, a film near an interface with the gate insulating film is formed under a first deposition condition in which a deposition rate is low but the quality of a film to be formed is high, and then, a film is further deposited under a second deposition condition in which a deposition rate is high. Then, a buffer layer is formed to be in contact with the microcrystalline semiconductor film. Further, plasma treatment with a rare gas such as argon or hydrogen plasma treatment is performed before formation of the film under the first deposition condition for removing adsorbed water on a substrate.

Method for manufacturing semiconductor device

An object is to provide a manufacturing method of a microcrystalline semiconductor film with favorable quality over a large-area substrate. After forming a gate insulating film over a gate electrode, in order to improve quality of a microcrystalline semiconductor film formed in an initial stage, glow discharge plasma is generated by supplying high-frequency powers with different frequencies, and a lower part of the film near an interface with the gate insulating film is formed under a first film formation condition, which is low in film formation rate but results in a good quality film. Thereafter, an upper part of the film is deposited under a second film formation condition with higher film formation rate, and further, a buffer layer is stacked on the microcrystalline semiconductor film.

Manufacturing method of semiconductor device

In a case of forming a bottom-gate thin film transistor, a step of forming a microcrystalline semiconductor film over a gate insulating film by a plasma CVD method, and a step of forming an amorphous semiconductor film over the microcrystalline semiconductor film are performed. In the step of forming the microcrystalline semiconductor film, the pressure in the reaction chamber is set at or below 10Pa once, the substrate temperature is set in the range of 120&#xb0; C. to 220&#xb0; C., plasma is generated by introducing hydrogen and a silicon gas, hydrogen plasma is made to act on a reaction product formed on a surface of the gate insulating film to perform removal while performing film formation. Moreover, the plasma is generated by applying a first high-frequency electric power of an HF band a second high-frequency electric power of a VHF band superimposed on each other.

Method of manufacturing display device

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Atsugi, Japan

Sachiaki Teduka