Semiconductor Energy Laboratory Co., Ltd.

Tanaka Kikinzoku Kogyo K.k.

Tokushima University

Kojiro Shiraishi

Shunpei Yamazaki

Kengo Akimoto

Hidekazu Miyairi

Akiharu Miyanaga

Takafumi Mizoguchi

Masashi Tsubuku

Konami Izumi

Mayumi Yamaguchi

Kunihiro Shima

Yuya Kato

Kunihiro Tanaka

Kenji Goto

Michimasa Okubo

Kenichi Hamada

Eiichi Honda

Emi Takegawa

It is an object to provide a semiconductor device including a thin film transistor with favorable electric properties and high reliability, and a method for manufacturing the semiconductor device with high productivity. In an inverted staggered (bottom gate) thin film transistor, an oxide semiconductor film containing In, Ga, and Zn is used as a semiconductor layer, and a buffer layer formed using a metal oxide layer is provided between the semiconductor layer and a source and drain electrode layers. The metal oxide layer is intentionally provided as the buffer layer between the semiconductor layer and the source and drain electrode layers, whereby ohmic contact is obtained.

Semiconductor device and method for manufacturing the same

An embodiment is to include an inverted staggered (bottom gate structure) thin film transistor in which an oxide semiconductor film containing In, Ga, and Zn is used as a semiconductor layer and a buffer layer is provided between the semiconductor layer and a source and drain electrode layers. The buffer layer having higher carrier concentration than the semiconductor layer is provided intentionally between the source and drain electrode layers and the semiconductor layer, whereby an ohmic contact is formed.

The present invention relates to a medical Au&#x2014;Pt&#x2014;Pd alloy including Au, Pt, Pd, and inevitable impurities. The alloy has an alloy composition inside a polygon (A1-A2-A3-A4-A5-A6) surrounded by straight lines connected at point A1 (Au: 37.9 atom %, Pt: 0.1 atom %, and Pd: 62 atom %), point A2 (Au: 79.9 atom %, Pt: 0.1 atom %, and Pd: 20 atom %), point A3 (Au: 79.9 atom %, Pt: 20 atom %, and Pd: 0.1 atom %), point A4 (Au: 69.9 atom %, Pt: 30 atom %, and Pd: 0.1 atom %), point A5 (Au: 49 atom %, Pt: 30 atom %, and Pd: 21 atom %), and point A6 (Au: 39 atom %, Pt: 40 atom %, and Pd: 21 atom %) in a Au&#x2014;Pt&#x2014;Pd ternary state diagram. The metal structure of the alloy is optimized, and the metal structure is close to a single-phase structure, and has little precipitation of a Au-rich phase and a Pt-rich phase different in composition from a mother phase.

Medical Au-Pt-Pd alloy

To offer a semiconductor device including a thin film transistor having excellent characteristics and high reliability and a method for manufacturing the semiconductor device without variation. The summary is to include an inverted-staggered (bottom-gate structure) thin film transistor in which an oxide semiconductor film containing In, Ga, and Zn is used for a semiconductor layer and a buffer layer is provided between the semiconductor layer and source and drain electrode layers. An ohmic contact is formed by intentionally providing a buffer layer containing In, Ga, and Zn and having a higher carrier concentration than the semiconductor layer between the semiconductor layer and the source and drain electrode layers.

Semiconductor device and manufacturing method thereof

To provide a semiconductor device including a thin film transistor having excellent electric characteristics and high reliability and a manufacturing method of the semiconductor device with high mass productivity. The summary is that an inverted-staggered (bottom-gate) thin film transistor is included in which an oxide semiconductor film containing In, Ga, and Zn is used as a semiconductor layer, a channel protective layer is provided in a region that overlaps a channel formation region of the semiconductor layer, and a buffer layer is provided between the semiconductor layer and source and drain electrodes. An ohmic contact is formed by intentionally providing the buffer layer having a higher carrier concentration than the semiconductor layer between the semiconductor layer and the source and drain electrodes.

An object is to provide a method for manufacturing a semiconductor device without exposing a specific layer to moisture or the like at all. A thin film element is manufactured in such a manner that a first film, a second film, and a third film are stacked in this order; a resist mask is formed over the third film; a mask layer is formed by etching the third film with the use of the resist mask; the resist mask is removed; a second layer and a first layer are formed by performing dry etching on the second film and the first film with the use of the mask layer; a fourth film is formed to cover at least the second layer and the first layer; and sidewall layers are formed to cover at least the entire side surfaces of the first layer by performing etch back on the fourth film.

Thin film element, semiconductor device, and method for manufacturing the same

In an active matrix display device, electric characteristics of thin film transistors included in a circuit are important, and performance of the display device depends on the electric characteristics. Thus, by using an oxide semiconductor film including In, Ga, and Zn for an inverted staggered thin film transistor, variation in electric characteristics of the thin film transistor can be reduced. Three layers of a gate insulating film, an oxide semiconductor layer and a channel protective layer are successively formed by a sputtering method without being exposed to air. Further, in the oxide semiconductor layer, the thickness of a region overlapping with the channel protective film is larger than that of a region in contact with a conductive film.

Provided is a method for manufacturing a semiconductor device so as not expose a semiconductor layer to moisture and the number of masks is reduced. For example, a first conductive film, a first insulating film, a semiconductor film, a second conductive film, and a mask film are formed. The first mask film is processed to form a first mask layer. Dry etching is performed on the first insulating film, the semiconductor film, and the second conductive film with the use of the first mask layer to form a thin film stack body, so that a surface of the first conductive film is at least exposed. Sidewall insulating layers covering side surfaces of the thin film stack body are formed. The first conductive film is side-etched to form a first electrode. A second electrode layer is formed with the second mask layer.

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Isehara, Japan

Kojiro Shiraishi