# US 12,113,124 B2 · Semiconductor device and method for manufacturing the same

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- Number: US 12,113,124 B2
- Document ID: US12113124B2
- Status: Granted
- Kind: B2
- Application number: 17/863,437
- Filed: 2022-07-13
- Published: 2022-11-03
- Granted: 2024-10-08
- Earliest claimed: 2009-09-24
- Assignees: Semiconductor Energy Laboratory Co., Ltd.
- Applicants: Semiconductor Energy Laboratory Co., Ltd.
- Inventors: Shunpei Yamazaki; Takahiro Tsuji; Kunihiko Suzuki
- Web page: https://patentgrep.com/patent/US12113124B2

## CPC

- H10D 99/00: Subject matter not provided for in other groups of this subclass
- H10D 30/031: {of thin-film transistors [TFT]}
- H10D 30/6704: {having supplementary regions or layers in the thin films or in the insulated bulk substrates for controlling properties of the device}
- H10D 30/6755: {Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate}
- H10D 62/40: Crystalline structures
- H10D 86/423: {comprising semiconductor materials not belonging to the Group IV, e.g. InGaZnO}
- H10D 86/60: wherein the TFTs are in active matrices
- H10P 14/3426: {Oxides}
- H10P 14/3434: {being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424)}
- H10P 14/3456: {Polycrystalline}
- H10P 14/3802: {Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth}
- H10P 74/207: {Electrical properties, e.g. testing or measuring of resistance, deep levels or capacitance-voltage characteristics}
- H10D 30/0312: {characterised by the gate electrodes}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

An object is to provide a high reliability thin film transistor using an oxide semiconductor layer which has stable electric characteristics. In the thin film transistor in which an oxide semiconductor layer is used, the amount of change in threshold voltage of the thin film transistor before and after a BT test is made to be 2 V or less, preferably 1.5 V or less, more preferably 1 V or less, whereby the semiconductor device which has high reliability and stable electric characteristics can be manufactured. In particular, in a display device which is one embodiment of the semiconductor device, a malfunction such as display unevenness due to change in threshold voltage can be reduced.

## Claims

### Claim 1

A semiconductor device comprising:
a pixel over a substrate; and
a driver circuit over the substrate, the driver circuit electrically connected to the pixel through a scan line,
wherein the pixel comprises a first transistor and a light-emitting element electrically connected to the first transistor,
wherein the driver circuit comprises a second transistor,
wherein each of the first transistor and the second transistor comprises:
a source electrode and a drain electrode over the substrate;
an oxide semiconductor layer over the source electrode and the drain electrode;
a first gate electrode overlapping the oxide semiconductor layer; and
a gate insulating layer between the oxide semiconductor layer and the first gate electrode,
wherein the first transistor has a single-gate structure,
wherein the second transistor further comprises a second gate electrode overlapping the oxide semiconductor layer of the second transistor,
wherein the oxide semiconductor layer of the second transistor is positioned between the first gate electrode of the second transistor and the second gate electrode of the second transistor, and
wherein the first gate electrode of the second transistor and the second gate electrode of the second transistor are at the same potential.

### Claim 2 (depends on 1)

The semiconductor device according to claim 1, wherein the oxide semiconductor layer comprises indium, gallium, and zinc.

### Claim 3

A semiconductor device comprising:
a pixel over a substrate; and
a driver circuit over the substrate, the driver circuit electrically connected to the pixel through a scan line,
wherein the pixel comprises a first transistor and a light-emitting element electrically connected to the first transistor,
wherein the driver circuit comprises a second transistor,
wherein each of the first transistor and the second transistor comprises:
a source electrode and a drain electrode over the substrate;
an oxide semiconductor layer over the source electrode and the drain electrode;
a first gate electrode overlapping the oxide semiconductor layer; and
a gate insulating layer between the oxide semiconductor layer and the first gate electrode,
wherein the first transistor has a single-gate structure,
wherein the second transistor further comprises a second gate electrode overlapping the oxide semiconductor layer of the second transistor,
wherein the oxide semiconductor layer of the second transistor is positioned between the first gate electrode of the second transistor and the second gate electrode of the second transistor,
wherein the first gate electrode of the second transistor and the second gate electrode of the second transistor are at the same potential, and
wherein the first gate electrode comprises a first titanium layer, an aluminum layer over the first titanium layer, and a second titanium layer over the aluminum layer.

### Claim 4 (depends on 3)

The semiconductor device according to claim 3, wherein the oxide semiconductor layer comprises indium, gallium, and zinc.