Method for manufacturing semiconductor device

• US 8,871,565 B2
• Filed: 08/31/2011
• Issued: 10/28/2014
• Est. Priority Date: 09/13/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Nonaka, Yusuke, Inoue, Takayuki, Tsubuku, Masashi, Akimoto, Kengo, Miyanaga, Akiharu
• Primary Examiner(s): Garber, Charles
• Assistant Examiner(s): ISAAC, STANETTA D
• Application Number:
  US13/222,513
• Publication Number:
  US 20120064664A1
• Time in Patent Office: 1,154 Days
• Field of Search: 438/104
• US Class Current: 438/104
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 23/564 Details not otherwise provided for, e.g. protection against moisture getters H01L23/26
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• 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
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

An object is to manufacture a semiconductor device including an oxide semiconductor film, which has stable electric characteristics and high reliability. A crystalline oxide semiconductor film is formed, without performing a plurality of steps, as follows: by utilizing a difference in atomic weight of plural kinds of atoms included in an oxide semiconductor target, zinc with low atomic weight is preferentially deposited on an oxide insulating film to form a seed crystal including zinc; and tin, indium, or the like with high atomic weight is deposited on the seed crystal while causing crystal growth. Further, a crystalline oxide semiconductor film is formed by causing crystal growth using a seed crystal with a hexagonal crystal structure including zinc as a nucleus, whereby a single crystal oxide semiconductor film or a substantially single crystal oxide semiconductor film is formed.

Claims

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

forming a gate electrode over a substrate;

forming a gate insulating film comprising an oxide insulating film over the gate electrode;

forming a seed crystal with a hexagonal crystal structure including zinc by a sputtering method over the gate insulating film;

causing a crystal growth using the seed crystal as a nucleus while depositing indium over the seed crystal to form a crystalline oxide semiconductor film having a hexagonal crystal structure;

performing a heat treatment on the crystalline oxide semiconductor film;

etching the crystalline oxide semiconductor film after the heat treatment; and

forming a pair of electrodes over the crystalline oxide semiconductor film after the etching step.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the seed crystal with a hexagonal structure including zinc is zinc oxide.

3. The method for manufacturing a semiconductor device according to claim 1, wherein the crystalline oxide semiconductor is formed while the substrate is heated at a temperature higher than or equal to 200°

C. and lower than or equal to 400°

C.

4. The method for manufacturing a semiconductor device according to claim 1, wherein the crystal included in the seed crystal or the crystal included in the crystalline oxide semiconductor film has a c-axis which is substantially perpendicular to a plan surface of the substrate.

5. The method for manufacturing a semiconductor device according to claim 1, wherein a temperature of the heat treatment is a temperature at which hydrogen included in the crystalline oxide semiconductor film is released.

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

forming a gate electrode over a substrate;

forming a gate insulating film comprising an oxide insulating film over the gate electrode;

forming a seed crystal with a hexagonal crystal structure including zinc by a sputtering method over the gate insulating film;

causing a crystal growth using the seed crystal as a nucleus while depositing indium over the seed crystal to form a crystalline oxide semiconductor film having a hexagonal crystal structure;

performing a heat treatment on the crystalline oxide semiconductor film;

etching the crystalline oxide semiconductor film after the heat treatment;

forming a pair of electrodes over the crystalline oxide semiconductor film after the etching step; and

forming an insulating film over the pair of electrodes.

7. The method for manufacturing a semiconductor device according to claim 6, wherein the seed crystal with a hexagonal structure including zinc is zinc oxide.

8. The method for manufacturing a semiconductor device according to claim 6, wherein the crystalline oxide semiconductor is formed while the substrate is heated at a temperature higher than or equal to 200°

C. and lower than or equal to 400°

C.

9. The method for manufacturing a semiconductor device according to claim 6, wherein the crystal included in the seed crystal or the crystal included in the crystalline oxide semiconductor film has a c-axis which is substantially perpendicular to a plan surface of the substrate.

10. The method for manufacturing a semiconductor device according to claim 6, wherein a temperature of the heat treatment is a temperature at which hydrogen included in the crystalline oxide semiconductor film is released.