Semiconductor device and manufacturing method thereof

• US 10,332,996 B2
• Filed: 12/03/2015
• Issued: 06/25/2019
• Est. Priority Date: 12/04/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Sakata, Junichiro, Ohara, Hiroki
• Primary Examiner(s): Zhu, Sheng-Bai
• Application Number:
  US14/958,066
• Publication Number:
  US 20160093734A1
• Time in Patent Office: 1,300 Days
• Field of Search: 257368, 257 72, 257 13, 257 57, 257 59, 438156, 438522
• CPC Class Codes: H01L 21/28176 with a treatment, e.g. annealing, after the formation of the definitive gate conductor
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 29/4966 the conductor material next to the insulator being a composite material, e.g. organic material, TiN, MoSi2 H01L29/4908, H01L29/4983 take precedence
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/7831 with multiple gate structure FinFETs or MuGFETs H01L29/7855, thin film transistors H01L29/78645
• CPC Class Codes: H01L 29/78642 Vertical transistors
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A semiconductor device for high power application in which a novel semiconductor material having high mass productivity is provided. An oxide semiconductor film is formed, and then, first heat treatment is performed on the exposed oxide semiconductor film in order to reduce impurities such as moisture or hydrogen in the oxide semiconductor film. Next, in order to further reduce impurities such as moisture or hydrogen in the oxide semiconductor film, oxygen is added to the oxide semiconductor film by an ion implantation method, an ion doping method, or the like, and after that, second heat treatment is performed on the exposed oxide semiconductor film.

Claims

1. A semiconductor device comprising:

a first gate electrode over a substrate;

a first insulating layer over the first gate electrode;

an oxide semiconductor layer over the first insulating layer;

a source electrode and a drain electrode electrically connected to the oxide semiconductor layer;

a second gate electrode over the source electrode and the drain electrode; and

a second insulating layer over the second gate electrode, wherein an end portion of the second gate electrode and one of the source electrode and the drain electrode overlap each other, wherein the second gate electrode contains at least one of indium oxide, tin oxide, zinc oxide, an alloy of indium oxide and tin oxide, and an alloy of indium oxide and zinc oxide, and wherein the second gate electrode is in an electrically floating state, wherein the second gate electrode covers an entire top surface of the oxide semiconductor layer.

2. The semiconductor device according to claim 1, wherein the semiconductor device is incorporated in one selected from the group consisting of an e-book reader, a display device, a portable game machine, a mobile phone, and a portable information terminal.

3. The semiconductor device according to claim 1, wherein the second gate electrode has a thickness of 10 nm to 400 nm.

4. A semiconductor device comprising:

a first gate electrode over a substrate;

a first insulating layer over the first gate electrode;

an oxide semiconductor layer over the first insulating layer;

a source electrode and a drain electrode electrically connected to the oxide semiconductor layer;

a second gate electrode over the source electrode and the drain electrode; and

a second insulating layer over the second gate electrode, wherein an end portion of the second gate electrode and one of the source electrode and the drain electrode overlap each other, wherein the second gate electrode contains at least one of indium oxide, tin oxide, zinc oxide, an alloy of indium oxide and tin oxide, and an alloy of indium oxide and zinc oxide, and wherein the second gate electrode is electrically insulated to be in an electrically floating state, wherein the second gate electrode covers an entire top surface of the oxide semiconductor layer.

5. The semiconductor device according to claim 4, wherein the semiconductor device is incorporated in one selected from the group consisting of an e-book reader, a display device, a portable game machine, a mobile phone, and a portable information terminal.

6. The semiconductor device according to claim 4, wherein the second gate electrode has a thickness of 10 nm to 400 nm.