Method for manufacturing semiconductor device

• US 10,186,619 B2
• Filed: 09/15/2016
• Issued: 01/22/2019
• Est. Priority Date: 11/20/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Hosoba, Miyuki, Sakata, Junichiro, Ohara, Hiroki, Yamazaki, Shunpei
• Primary Examiner(s): Campbell, Shaun M
• Application Number:
  US15/265,936
• Publication Number:
  US 20170005204A1
• Time in Patent Office: 859 Days
• Field of Search: None
• CPC Class Codes: G02F 1/133302 Rigid substrates, e.g. inorganic substrates
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133531 characterised by the arrangement of polariser or analyser axes
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: H01L 21/02107 Forming insulating materials on a substrate
• 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 21/02672 using crystallisation enhancing elements
• 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 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 21/67115 mainly by radiation
• CPC Class Codes: H01L 27/1225 : with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/127 : with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• 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 29/7869 : 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: H10K 59/1213 : the pixel elements being TFTs

Abstract

An object is to provide a semiconductor device having stable electric characteristics in which an oxide semiconductor is used. An oxide semiconductor layer is subjected to heat treatment for dehydration or dehydrogenation treatment in a nitrogen gas or an inert gas atmosphere such as a rare gas (e.g., argon or helium) or under reduced pressure and to a cooling step for treatment for supplying oxygen in an atmosphere of oxygen, an atmosphere of oxygen and nitrogen, or the air (having a dew point of preferably lower than or equal to −40° C., still preferably lower than or equal to −50° C.) atmosphere. The oxide semiconductor layer is thus highly purified, whereby an i-type oxide semiconductor layer is formed. A semiconductor device including a thin film transistor having the oxide semiconductor layer is manufactured.

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 over the substrate and the gate electrode;

forming an oxide semiconductor layer over the gate insulating film by sputtering;

performing a first heat treatment on the oxide semiconductor layer to reduce a hydrogen concentration of the oxide semiconductor layer;

supplying oxygen into the oxide semiconductor layer during cooling after performing the first heat treatment and before forming a source electrode and a drain electrode over the oxide semiconductor layer;

forming an insulating film over the oxide semiconductor layer, the source electrode, and the drain electrode; and

performing a second heat treatment after forming the insulating film.

2. The method of claim 1, wherein the first heat treatment is performed at a first temperature of greater than 300°

C.

3. The method of claim 1, wherein the supplying oxygen is performed at a second temperature of greater than 350°

C.

4. The method of claim 1, wherein the oxide semiconductor layer is formed during removal of moisture from a deposition chamber.

5. The method of claim 4, wherein moisture is removed by a vacuum pump.

6. The method of claim 1, wherein the first heat treatment is performed in a first treatment chamber and the supplying oxygen is performed in a second treatment chamber.

7. The method of claim 1, further comprising:

performing a plasma treatment after forming the source electrode and the drain electrode.

8. The method of claim 1, wherein a proportion of an oxygen flow rate is 100% in the step of forming the oxide semiconductor layer.

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

forming a gate electrode over a substrate;

forming a gate insulating film over the substrate and the gate electrode;

forming an oxide semiconductor layer over the gate insulating film by sputtering;

performing a first heat treatment on the oxide semiconductor layer to reduce a hydrogen concentration of the oxide semiconductor layer;

supplying oxygen into the oxide semiconductor layer by performing a cooling treatment after performing the first heat treatment;

forming a source electrode and a drain electrode over the oxide semiconductor layer;

forming an insulating film over the oxide semiconductor laver, the source electrode, and the drain electrode; and

performing a second heat treatment after forming the insulating film.

10. The method of claim 9, wherein the first heat treatment is performed at a first temperature of greater than 300°

C.

11. The method of claim 9, wherein the cooling treatment is performed in an atmosphere of oxygen.

12. The method of claim 9, wherein the cooling treatment is performed in an atmosphere of oxygen and nitrogen.

13. The method of claim 9, wherein the cooling treatment is performed in an atmosphere of air with dew point of lower than or equal to −

40°

C.

14. The method of claim 9, wherein the oxide semiconductor layer is formed during removal of moisture from a deposition chamber.

15. The method of claim 14, wherein moisture is removed by a vacuum pump.

16. The method of claim 9, wherein the first heat treatment is performed in a first treatment chamber and the supplying oxygen is performed in a second treatment chamber.

17. The method of claim 9, further comprising:

performing a plasma treatment after forming the source electrode and the drain electrode.

18. The method of claim 9, wherein a proportion of an oxygen flow rate is 100% in the step of forming the oxide semiconductor layer.