Semiconductor Energy Laboratory Co., Ltd.

Yuki Imoto

Tetsunori Maruyama

Shunpei Yamazaki

Junichiro Sakata

Junichi Koezuka

Yuji Asano

Kenichi Okazaki

Yuta Endo

Takashi Shimazu

Motoki Nakashima

Mitsuo Mashiyama

Masahiro Watanabe

Hitomi Sato

Akiharu Miyanaga

Masayuki Sakakura

Jun Koyama

Yuhei Sato

Takashi Hamada

Satoshi Toriumi

Ryunosuke Honda

Toru Takayama

Tetsuhiro Tanaka

Tatsuya Honda

Yusuke Nonaka

Takuya Hirohashi

Yasumasa Yamane

Takatsugu Omata

Erika Takahashi

Takayuki Saito

Noriaki Uto

Yuko Takabayashi

Hitomi Shionoya

There have been cases where transistors formed using oxide semiconductors are inferior in reliability to transistors formed using amorphous silicon. Thus, in the present invention, a semiconductor device including a highly reliable transistor formed using an oxide semiconductor is manufactured. An oxide semiconductor film is deposited by a sputtering method, using a sputtering target including an oxide semiconductor having crystallinity, and in which the direction of the c-axis of a crystal is parallel to a normal vector of the top surface of the oxide semiconductor. The target is formed by mixing raw materials so that its composition ratio can obtain a crystal structure.

Sputtering target, method for manufacturing sputtering target, and method for forming thin film

Semiconductor device comprising oxide semiconductor film

Many of the physical properties of a silicon semiconductor have already been understood, whereas many of the physical properties of an oxide semiconductor have been still unclear. In particular, an adverse effect of an impurity on an oxide semiconductor has been still unclear. In view of the above, a structure is disclosed in which an impurity that influences electrical characteristics of a semiconductor device including an oxide semiconductor layer is prevented or is eliminated. A semiconductor device which includes a gate electrode, an oxide semiconductor layer, and a gate insulating layer provided between the gate electrode and the oxide semiconductor layer and in which the nitrogen concentration in the oxide semiconductor layer is 1&#xd7;10atoms/cmor less is provided.

Semiconductor device and method for manufacturing the same

A minute transistor is provided that includes a first insulator, a second insulator, a first, conductor, a second conductor, and third conductor, in which an angle is formed between a side surface of the first insulator and a top surface of the first conductor, and a length between the first conductor and a surface of the second conductor closest to the first conductor is at least greater than a length between the first conductor and the third conductor.

Semiconductor device and manufacturing method of the same

A minute transistor with low parasitic capacitance, high frequency characteristics, favorable electrical characteristics, stable electrical characteristics, and low off-state current is provided. A semiconductor device includes a semiconductor over a substrate, a source and a drain over the semiconductor, a first insulator over the source and the drain, a second insulator over the semiconductor, a third insulator in contact with a side surface of the first insulator and over the second insulator, and a gate over the third insulator. The semiconductor includes a first region overlapping with the source, a second region overlapping with the drain, and a third region overlapping with the gate. The length between a top surface of the third region of the semiconductor and a bottom surface of the gate is longer than the length between the first region and the third region.

The amount of water and hydrogen contained in an oxide semiconductor film is reduced, and oxygen is supplied sufficiently from a base film to the oxide semiconductor film in order to reduce oxygen deficiencies. A stacked base film is formed, a first heat treatment is performed, an oxide semiconductor film is formed over and in contact with the stacked base film, and a second heat treatment is performed. In the stacked base film, a first base film and a second base film are stacked in this order. The first base film is an insulating oxide film from which oxygen is released by heating. The second base film is an insulating metal oxide film. An oxygen diffusion coefficient of the second base film is smaller than that of the first base film.

Method for manufacturing oxide semiconductor device

The silicon nitride layerformed by plasma CVD using a gas containing a hydrogen compound such as silane (SiH) and ammonia (NH) is provided on and in direct contact with the oxide semiconductor layerused for the resistor, and the silicon nitride layeris provided over the oxide semiconductor layerused for the thin film transistorwith the silicon oxide layerserving as a barrier layer interposed therebetween. Therefore, a higher concentration of hydrogen is introduced into the oxide semiconductor layerthan into the oxide semiconductor layer. As a result, the resistance of the oxide semiconductor layerused for the resistoris made lower than that of the oxide semiconductor layerused for the thin film transistor

Driver circuit with oxide semiconductor layers having varying hydrogen concentrations

An object is to provide a thin film transistor and a method for manufacturing the thin film transistor including an oxide semiconductor with a controlled threshold voltage, high operation speed, a relatively easy manufacturing process, and sufficient reliability. An impurity having influence on carrier concentration in the oxide semiconductor layer, such as a hydrogen atom or a compound containing a hydrogen atom such as HO, may be eliminated. An oxide insulating layer containing a large number of defects such as dangling bonds may be formed in contact with the oxide semiconductor layer, such that the impurity diffuses into the oxide insulating layer and the impurity concentration in the oxide semiconductor layer is reduced. The oxide semiconductor layer or the oxide insulating layer in contact with the oxide semiconductor layer may be formed in a deposition chamber which is evacuated with use of a cryopump whereby the impurity concentration is reduced.

Semiconductor element and method for manufacturing the same

A semiconductor device having excellent electric characteristics and a method for manufacturing the semiconductor device are provided. A method for manufacturing a semiconductor device includes the steps of: forming a gate electrode; forming a gate insulating film to cover the gate electrode; forming an oxide semiconductor film over the gate insulating film; forming a hydrogen permeable film over the oxide semiconductor film; forming a hydrogen capture film over the hydrogen permeable film; performing heat treatment to release hydrogen from the oxide semiconductor film; forming a source electrode and a drain electrode to be in contact with a part of the oxide semiconductor film; and removing an exposed portion of the hydrogen capture film to form a channel protective film formed of the hydrogen permeable film. A semiconductor device manufactured by the above method is also provided.

Semiconductor device and manufacturing method thereof

Method of manufacturing semiconductor device including transistor and resistor incorporating hydrogen in oxide semiconductor

In the transistor including an oxide semiconductor film, which includes a film for capturing hydrogen from the oxide semiconductor film (a hydrogen capture film) and a film for diffusing hydrogen (a hydrogen permeable film), hydrogen is transferred from the oxide semiconductor film to the hydrogen capture film through the hydrogen permeable film by heat treatment. Specifically, a base film or a protective film of the transistor including an oxide semiconductor film has a stacked-layer structure of the hydrogen capture film and the hydrogen permeable film. At this time, the hydrogen permeable film is formed on a side which is in contact with the oxide semiconductor film. After that, hydrogen released from the oxide semiconductor film is transferred to the hydrogen capture film through the hydrogen permeable film by the heat treatment.

Growing community of inventors

Atsugi, Japan

Yuki Imoto