US 2016/0240683 A1Published application

Semiconductor device and display device including the semiconductor device

AssigneeSemiconductor Energy Laboratory Co., Ltd.

InventorsHiroyuki MIYAKE, Junichi KOEZUKA, Kenichi OKAZAKI, Daisuke KUROSAKI, Yukinori SHIMA, Satoru SAITO

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Abstract

To reduce parasitic capacitance in a semiconductor device having a transistor including an oxide semiconductor. The transistor includes a first gate electrode, a first gate insulating film over the first gate electrode, an oxide semiconductor film over the first gate insulating film, and source and drain electrodes electrically connected to the oxide semiconductor film. The oxide semiconductor film includes a first oxide semiconductor film on the first gate electrode side and a second oxide semiconductor film over the first oxide semiconductor film. The atomic proportion of In is larger than the atomic proportion of M (M is Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf) in the first oxide semiconductor film, and the atomic proportion of In in the second oxide semiconductor film is smaller than that in the first oxide semiconductor film.

Claims25

Dependent claims

A semiconductor device comprising:

a transistor comprising:
an oxide semiconductor film;
a first gate electrode, the oxide semiconductor film overlapping with the first gate electrode;
a first gate insulating film between the oxide semiconductor film and the first gate electrode;
a source electrode electrically connected to the oxide semiconductor film;
and
a drain electrode electrically connected to the oxide semiconductor film,
wherein the oxide semiconductor film comprises:
a first oxide semiconductor film in contact with the first gate insulating film;
and
a second oxide semiconductor film in contact with the first oxide semiconductor film,
wherein an atomic proportion of In is larger than an atomic proportion of M in the first oxide semiconductor film,
wherein M is Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf,
wherein an atomic proportion of In in the second oxide semiconductor film is smaller than the atomic proportion of In in the first oxide semiconductor film,
wherein the oxide semiconductor film comprises a first region overlapping with the first gate electrode, a second region overlapping with the source electrode, and a third region overlapping with the drain electrode, and
wherein the first region does not comprise the second region and the third region.

13 more elements

A semiconductor device comprising:

a transistor comprising:
a first gate electrode;
a first gate insulating film over the first gate electrode;
an oxide semiconductor film over the first gate insulating film;
a source electrode electrically connected to the oxide semiconductor film;
a drain electrode electrically connected to the oxide semiconductor film;
a second gate insulating film over the oxide semiconductor film;
and
a second gate electrode over the second gate insulating film,
wherein the oxide semiconductor film comprises:
a first oxide semiconductor film;
and
a second oxide semiconductor film over the first oxide semiconductor film,
wherein an atomic proportion of In is larger than an atomic proportion of M in the first oxide semiconductor film,
wherein M is Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf,
wherein an atomic proportion of In in the second oxide semiconductor film is smaller than the atomic proportion of In in the first oxide semiconductor film,
wherein the oxide semiconductor film comprises a first region overlapping with the first gate electrode, a second region overlapping with the source electrode, a third region overlapping with the drain electrode, and a fourth region overlapping with the second gate electrode, and
wherein the first region or the fourth region does not comprise the second region and the third region.

15 more elements

A semiconductor device comprising:

a transistor comprising:
a first gate electrode;
a first gate insulating film over the first gate electrode;
an oxide semiconductor film over the first gate insulating film;
a source electrode electrically connected to the oxide semiconductor film;
a drain electrode electrically connected to the oxide semiconductor film;
a second gate insulating film over the oxide semiconductor film;
and
a second gate electrode over the second gate insulating film,
wherein the oxide semiconductor film comprises:
a first oxide semiconductor film;
and
a second oxide semiconductor film over the first oxide semiconductor film,
wherein an atomic proportion of In is larger than an atomic proportion of M in the first oxide semiconductor film,
wherein M is Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf,
wherein an atomic proportion of In in the second oxide semiconductor film is smaller than the atomic proportion of In in the first oxide semiconductor film,
wherein the oxide semiconductor film comprises a first region overlapping with the first gate electrode, a second region overlapping with the source electrode, a third region overlapping with the drain electrode, and a fourth region overlapping with the second gate electrode, and
wherein the first region or the fourth region does not comprise the second region or the third region.

15 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/012,403Filed 1 Feb 2016
Priority: JP 2015-02502112 Feb 2015
Published: 18 Aug 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H10D 30/6755
Characterised by the active materials: oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate
H10D 30/6757
Thin-film transistors [TFT]: characterised by the structure of the channel, e.g. transverse or longitudinal shape or doping profile
H10D 86/423
Having a particular composition, shape or crystalline structure of the active layer: comprising semiconductor materials not belonging to the Group…
H10D 86/441
Characterised by multiple TFTs: interconnections, e.g. scanning lines