Semiconductor device and method for manufacturing the same
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorShunpei Yamazaki
Life of this patent
Estimating the term…
Abstract
To give stable electrical characteristics to and improve reliability of a semiconductor device including a transistor in which an oxide semiconductor film is used for a channel formation region. As a base film, an insulating film or an oxide semiconductor film is used. A single-layer metal film is formed over the base film. After that, a resist mask is formed, and etching is performed plural times. Accordingly, electrodes each including projecting portions when seen in cross-section are formed. Even when a gate insulating film over the source electrode layer and the drain electrode layer or an oxide semiconductor film has a small thickness, disconnection of the gate insulating film is unlikely to occur.
Claims13
A semiconductor device comprising:
- a first conductive layer;
- a first insulating film over the first conductive layer;
- an oxide semiconductor film which is over the first insulating film and comprises a channel formation region;
- a source electrode layer and a drain electrode layer which are over the oxide semiconductor film and are electrically connected to the oxide semiconductor film;
- a second insulating film over the oxide semiconductor film, the source electrode layer, and the drain electrode layer;
- and
- a second conductive layer which is over the second insulating film and overlaps with the channel formation region,
- wherein the source electrode layer and the drain electrode layer are single-layer metal films and each include projecting portions extending in the channel length direction, and
- wherein some of the projecting portions which overlap with the oxide semiconductor film overlap with the first conductive layer.
A semiconductor device comprises:
- a first conductive layer;
- a first insulating film over the first conductive layer;
- a second insulating film containing gallium oxide over the first insulating film;
- an oxide semiconductor film which is over and in contact with the second insulating film and comprises a channel formation region;
- a source electrode layer and a drain electrode layer which are over the oxide semiconductor film and are electrically connected to the oxide semiconductor film;
- a third insulating film containing gallium oxide over the oxide semiconductor film, the source electrode layer, and the drain electrode layer;
- a second conductive layer which is over the third insulating film and overlaps with the channel formation region,
- wherein the source electrode layer and the drain electrode layer are single-layer metal films and each include projecting portions extending in the channel length direction, and
- wherein some of the projecting portions which overlap with the oxide semiconductor film overlap with the first conductive layer.
Dependencies are inferred from the claim text.