Method of manufacturing semiconductor device

• US 10,615,052 B2
• Filed: 05/29/2018
• Issued: 04/07/2020
• Est. Priority Date: 03/11/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Sato, Yuhei, Sato, Keiji, Maruyama, Tetsunori, Koezuka, Junichi
• Primary Examiner(s): Wilczewski, Mary A
• Application Number:
  US15/991,080
• Publication Number:
  US 20180277392A1
• Time in Patent Office: 679 Days
• CPC Class Codes: H01L 21/02175 characterised by the metal H01L21/02197 takes precedence
• CPC Class Codes: H01L 21/02252 formation by plasma treatment, e.g. plasma oxidation of the substrate after treatment of an insulating film by plasma H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02636 Selective deposition, e.g. simultaneous growth of mono- and non-monocrystalline semiconductor materials
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• 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 21/383 using diffusion into or out of a solid from or into a gaseous phase
• CPC Class Codes: H01L 21/40 Alloying of impurity materials, e.g. doping materials, electrode materials, with a semiconductor body
• 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 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/66742 Thin film unipolar transistors
• 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

Abstract

In a manufacturing process of a transistor including an oxide semiconductor film, oxygen doping treatment is performed on the oxide semiconductor film, and then heat treatment is performed on the oxide semiconductor film and an aluminum oxide film provided over the oxide semiconductor film. Consequently, an oxide semiconductor film which includes a region containing more oxygen than a stoichiometric composition is formed. The transistor formed using the oxide semiconductor film can have high reliability because the amount of change in the threshold voltage of the transistor by a bias-temperature stress test (BT test) is reduced.

Claims

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

forming a first insulating film;

forming an oxide semiconductor film over the first insulating film;

performing a first heat treatment on the oxide semiconductor film;

forming a second insulating film comprising aluminum oxide by sputtering over the oxide semiconductor film after performing the first heat treatment;

adding oxygen into the oxide semiconductor film by an oxygen doping treatment after forming the second insulating film; and

performing a second heat treatment on the oxide semiconductor film and the second insulating film after adding oxygen,

wherein the step of adding oxygen into the oxide semiconductor film comprises a step of forming a region in the oxide semiconductor film where amount of oxygen exceeds that in a stoichiometric composition.

2. The method according to claim 1, further comprising the step of forming an oxide insulating film over the oxide semiconductor film and before forming the second insulating film.

3. The method according to claim 1, wherein the step of adding oxygen into the oxide semiconductor film comprises a step of forming an interfacial region in the first insulating film between the oxide semiconductor film and the first insulating film where amount of oxygen exceeds that in a stoichiometric composition.

4. The method according to claim 1, wherein the step of adding oxygen into the oxide semiconductor film comprises a step of forming an interfacial region in the second insulating film between the oxide semiconductor film and the second insulating film where amount of oxygen exceeds that in a stoichiometric composition.

5. The method according to claim 1, wherein oxygen concentration in the oxide semiconductor film after the step of adding oxygen into the oxide semiconductor film is higher or equal to 10¹⁸ cm⁻

3 and lower or equal to 3×

10²¹ cm<sup>−

3</sup>.

6. The method according to claim 1, wherein the first heat treatment is performed in a first atmosphere comprising an inert gas and then performed in a second atmosphere comprising oxygen.

7. The method according to claim 1, wherein the second heat treatment is performed in a third atmosphere comprising at least one of nitrogen, oxygen, and a rare gas, and

wherein impurity concentration in the third atmosphere is lower than or equal to 1 ppm.

8. The method according to claim 1, comprising the step of:

forming a gate electrode, wherein the first insulating film is formed over the gate electrode.

9. The method according to claim 1, comprising the steps of:

forming a gate electrode over the second insulating film; and

forming a third insulating film over the gate electrode.

10. The method according to claim 1, wherein the first insulating film and the oxide semiconductor film are successively formed without exposure to air.

11. The method according to claim 1, wherein the first heat treatment is performed at a temperature higher than or equal to 250°

C. and lower than or equal to 700°

C.

12. The method according to claim 1, wherein the second heat treatment is performed at a temperature higher than or equal to 350°

C. and lower than or equal to 650°

C.

13. The method according to claim 1, wherein the oxide semiconductor film comprises a crystalline region.

14. The method according to claim 1, wherein the oxide semiconductor film has an island shape.

15. The method according to claim 1, wherein the oxide semiconductor film comprises indium, gallium, and zinc.

16. The method according to claim 1, comprising the step of forming a source electrode and a drain electrode over the oxide semiconductor film after performing the first heat treatment, wherein the second insulating film is formed over the source electrode and the drain electrode.

17. The method according to claim 1, wherein the second heat treatment includes a step of increasing crystallinity of the oxide semiconductor film.

18. The method according to claim 1, wherein the oxygen doping treatment is oxygen ion implantation treatment.