Method for manufacturing semiconductor device

• US 9,449,852 B2
• Filed: 06/26/2014
• Issued: 09/20/2016
• Est. Priority Date: 04/28/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): MULPURI, SAVITRI
• Application Number:
  US14/316,065
• Publication Number:
  US 20140308777A1
• Time in Patent Office: 817 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• CPC Class Codes: H01L 21/465 Chemical or electrical treatment, e.g. electrolytic etching to form insulating layers H01L21/469
• CPC Class Codes: H01L 21/477 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/38 - H01L21/449 and H01L21/461 - H01L21/475 take precedence
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• 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 29/78606 with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 take precedence
• 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 including an oxide semiconductor with stable electric characteristics and high reliability is provided. An island-shaped oxide semiconductor layer is formed by using a resist mask, the resist mask is removed, oxygen is introduced (added) to the oxide semiconductor layer, and heat treatment is performed. The removal of the resist mask, introduction of the oxygen, and heat treatment are performed successively without exposure to the air. Through the oxygen introduction and heat treatment, impurities such as hydrogen, moisture, a hydroxyl group, or hydride are intentionally removed from the oxide semiconductor layer, whereby the oxide semiconductor layer is highly purified. Chlorine may be introduced to an insulating layer over which the oxide semiconductor layer is formed before formation of the oxide semiconductor layer. By introducing chlorine, hydrogen in the insulating layer can be fixed, thereby preventing diffusion of hydrogen from the insulating layer into the oxide semiconductor layer.

Claims

1. A method of manufacturing a semiconductor device, comprising the steps of:

forming a first insulating layer;

performing a plasma treatment using a chlorine gas to concurrently introduce chlorine and oxygen to the first insulating layer;

forming an oxide semiconductor layer over the first insulating layer;

forming a second insulating layer over the oxide semiconductor layer;

introducing oxygen to the oxide semiconductor layer through the second insulating layer;

performing a heat treatment on the oxide semiconductor layer;

etching a part of the second insulating layer after performing the heat treatment; and

forming a source electrode and a drain electrode electrically connected to the oxide semiconductor layer after introducing the oxygen to the oxide semiconductor layer.

2. The method of manufacturing a semiconductor device according to claim 1, wherein the oxide semiconductor layer and the second insulating layer are etched at a same step.

3. The method of manufacturing a semiconductor device according to claim 1, wherein the second insulating layer is an island-shape.

4. The method of manufacturing a semiconductor device according to claim 1, wherein the second insulating layer is formed only over a channel formation region of the oxide semiconductor layer.

5. The method of manufacturing a semiconductor device according to claim 1, wherein the second insulating layer comprises gallium oxide.

6. The method of manufacturing a semiconductor device according to claim 1, wherein the oxide semiconductor layer comprises In and Ga.

7. The method of manufacturing a semiconductor device according to claim 1, wherein the oxygen introduced to the oxide semiconductor layer comprises an oxygen radical or an oxygen ion.

8. A method of manufacturing a semiconductor device, comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating layer over the gate electrode;

performing a plasma treatment using a chlorine gas to concurrently introduce chlorine and oxygen to the gate insulating layer;

forming an oxide semiconductor layer over the gate insulating layer;

forming an insulating layer over the oxide semiconductor layer;

introducing oxygen to the oxide semiconductor layer through the insulating layer;

performing a heat treatment on the oxide semiconductor layer;

etching a part of the insulating layer after performing the heat treatment; and

forming a source electrode and a drain electrode electrically connected to the oxide semiconductor layer after introducing the oxygen to the oxide semiconductor layer.

9. The method of manufacturing a semiconductor device according to claim 8, wherein the oxide semiconductor layer and the insulating layer are etched at a same step.

10. The method of manufacturing a semiconductor device according to claim 8, wherein the insulating layer is an island-shape.

11. The method of manufacturing a semiconductor device according to claim 8, wherein the insulating layer is formed only over a channel formation region of the oxide semiconductor layer.

12. The method of manufacturing a semiconductor device according to claim 8, wherein the insulating layer comprises gallium oxide.

13. The method of manufacturing a semiconductor device according to claim 8, wherein the oxide semiconductor layer comprises In and Ga.

14. The method of manufacturing a semiconductor device according to claim 8, wherein the oxygen introduced to the oxide semiconductor layer comprises an oxygen radical or an oxygen ion.