Manufacturing method of semiconductor device

• US 8,945,982 B2
• Filed: 04/21/2011
• Issued: 02/03/2015
• Est. Priority Date: 04/23/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Garber, Charles
• Assistant Examiner(s): Stevenson, Andre C
• Application Number:
  US13/091,190
• Publication Number:
  US 20110263091A1
• Time in Patent Office: 1,384 Days
• Field of Search: None
• US Class Current: 438/104
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• 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 29/401 Multistep manufacturing processes
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 29/42356 Disposition, e.g. buried gate electrode H01L29/42324 and H01L29/4234 take precedence
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• 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

Disclosed is a semiconductor device using an oxide semiconductor, with stable electric characteristics and high reliability. In a process for manufacturing a bottom-gate transistor including an oxide semiconductor film, dehydration or dehydrogenation is performed by heat treatment and oxygen doping treatment is performed. The transistor including a gate insulating film subjected to the oxygen doping treatment and the oxide semiconductor film subjected to the dehydration or dehydrogenation by the heat treatment is a transistor having high reliability in which the amount of change in threshold voltage of the transistor by the bias-temperature stress (BT) test can be reduced.

Claims

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

forming a gate electrode layer;

forming a gate insulating film over the gate electrode layer, wherein the gate insulating film contains an oxygen atom at a ratio greater than a stoichiometric proportion and less than four times as high as the stoichiometric proportion;

performing a first heat treatment on the gate insulating film so as to remove water or hydroxide from the gate insulating film;

forming an oxide semiconductor film over the gate insulating film so as to overlap with the gate electrode layer;

performing a second heat treatment on the oxide semiconductor film so as to remove water or hydroxide from the oxide semiconductor film;

forming a source electrode layer and a drain electrode layer which are electrically connected to the oxide semiconductor film; and

forming an insulating film over the oxide semiconductor film, the source electrode layer, and the drain electrode layer so as to be in contact with the oxide semiconductor film, wherein the insulating film contains an oxygen atom at a ratio greater than a stoichiometric proportion and less than four times as high as the stoichiometric proportion.

2. The method for manufacturing a semiconductor device, according to claim 1, wherein the gate insulating film is formed by a plasma CVD method or a sputtering method.

3. The method for manufacturing a semiconductor device, according to claim 1, wherein at least one of the gate insulating film and the insulating film is an insulating film containing a component element of the oxide semiconductor film.

4. The method for manufacturing a semiconductor device, according to claim 1,

wherein at least one of the gate insulating film and the insulating film is a stack of a first insulating film containing a component element of the oxide semiconductor film and a second insulating film containing an element which is different from the component element of the first insulating film, and

wherein the first insulating film is in contact with the oxide semiconductor film.

5. The method for manufacturing a semiconductor device, according to claim 1, wherein at least one of the gate insulating film and the insulating film is an insulating film containing gallium oxide.

6. The method for manufacturing a semiconductor device, according to claim 1,

wherein at least one of the gate insulating film and the insulating film is a stack of a first insulating film containing gallium oxide and a second insulating film containing a material other than gallium oxide, and

wherein the first insulating film is in contact with the oxide semiconductor film.

7. The method for manufacturing a semiconductor device, according to claim 1, wherein a second insulating film containing nitrogen is formed to cover the insulating film.

8. The method for manufacturing a semiconductor device, according to claim 1, wherein an oxygen doping treatment is performed on the gate insulating film.

17. The method for manufacturing a semiconductor device, according to claim 1, wherein the step of performing the second heat treatment on the oxide semiconductor film is performed in an inert gas.

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

forming a gate electrode layer;

forming a gate insulating film over the gate electrode layer, wherein the gate insulating film contains an oxygen atom at a ratio greater than a stoichiometric proportion and less than four times as high as the stoichiometric proportion;

performing a first heat treatment on the gate insulating film so as to remove water or hydroxide from the gate insulating film;

forming an oxide semiconductor film over the gate insulating film so as to overlap with the gate electrode layer;

performing a second heat treatment on the oxide semiconductor film so as to remove water or hydroxide from the oxide semiconductor film;

forming a source electrode layer and a drain electrode layer which are electrically connected to the oxide semiconductor film;

forming an insulating film over the oxide semiconductor film, the source electrode layer, and the drain electrode layer so as to be in contact with the oxide semiconductor film, wherein the insulating film contains an oxygen atom at a ratio greater than a stoichiometric proportion and less than four times as high as the stoichiometric proportion; and

performing a third heat treatment on the insulating film so as to supply an oxygen to the oxide semiconductor film from the insulating film.

10. The method for manufacturing a semiconductor device, according to claim 9, wherein the gate insulating film is formed by a plasma CVD method or a sputtering method.

11. The method for manufacturing a semiconductor device, according to claim 9, wherein at least one of the gate insulating film and the insulating film is an insulating film containing a component element of the oxide semiconductor film.

12. The method for manufacturing a semiconductor device, according to claim 9,

wherein at least one of the gate insulating film and the insulating film is a stack of a first insulating film containing a component element of the oxide semiconductor film and a second insulating film containing an element which is different from the component element of the first insulating film, and

wherein the first insulating film is in contact with the oxide semiconductor film.

13. The method for manufacturing a semiconductor device, according to claim 9, wherein at least one of the gate insulating film and the insulating film is an insulating film containing gallium oxide.

14. The method for manufacturing a semiconductor device, according to claim 9,

wherein at least one of the gate insulating film and the insulating film is a stack of a first insulating film containing gallium oxide and a second insulating film containing a material other than gallium oxide,

wherein the first insulating film is in contact with the oxide semiconductor film.

15. The method for manufacturing a semiconductor device, according to claim 9, wherein a second insulating film containing nitrogen is formed to cover the insulating film.

16. The method for manufacturing a semiconductor device, according to claim 9, wherein an oxygen doping treatment is performed on the gate insulating film.

18. The method for manufacturing a semiconductor device, according to claim 9, wherein the step of performing the second heat treatment on the oxide semiconductor film is performed in an inert gas.