INSULATING FILM, FORMATION METHOD THEREOF, SEMICONDUCTOR DEVICE, AND MANUFACTURING METHOD THEREOF

• US 20130126861A1
• Filed: 11/13/2012
• Published: 05/23/2013
• Est. Priority Date: 11/18/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: TANAKA, Tetsuhiro, TAKAHASHI, Erika, IMOTO, Yuki, SATO, Yuhei
• Granted Patent: US 8,969,130 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02189 the material containing zirconium, e.g. ZrO2
• CPC Class Codes: H01L 21/02194 the material containing more than one metal element
• CPC Class Codes: H01L 21/02266 deposition by physical ablation of a target, e.g. sputtering, reactive sputtering, physical vapour deposition or pulsed laser deposition
• 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 29/78603 characterised by the insulating substrate or support H01L29/78657 takes 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: Y10T 428/24628 Nonplanar uniform thickness material

Abstract

An amorphous region with low density is formed in an oxide insulating film containing zirconium. The amount of oxygen released from such an oxide insulating film containing zirconium by heating is large and a temperature at which oxygen is released is higher in the oxide insulating film than in a conventional oxide film (e.g., a silicon oxide film). When the insulating film is formed using a sputtering target containing zirconium in an oxygen atmosphere, the temperature of a surface on which the insulating film is formed may be controlled to be lower than a temperature at which a film to be formed starts to crystallize.

Claims

1. A method for forming an insulating film, the method comprising the step of:

forming the insulating film in an atmosphere comprising oxygen by a sputtering method,

wherein a target used in the sputtering method comprises zirconium,

wherein a first temperature of a surface on which the insulating film is formed is controlled to be lower than a second temperature at which the insulating film is completely crystallized, and

wherein the insulating film is formed so that an amorphous region comprising oxygen in excess of a stoichiometric composition in a crystalline state is formed in a part of the insulating film.

2. The method for forming an insulating film, according to claim 1, wherein the target further comprises yttrium.

3. The method for forming an insulating film, according to claim 1, wherein the first temperature is higher than or equal to 20°

C. and lower than or equal to 100°

C.

4. The method for forming an insulating film, according to claim 1, wherein a partial pressure of oxygen in the atmosphere comprising oxygen is greater than or equal to 25% and less than or equal to 100%.

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

forming a first insulating film by the method for forming an insulating film, according to claim 1;

forming an oxide semiconductor layer;

forming a gate insulating layer;

forming a gate electrode;

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

performing a heat treatment on the first insulating film and the oxide semiconductor layer at temperatures at which oxygen in the first insulating film is eliminated from the first insulating film after the steps of forming the first insulating film and forming the oxide semiconductor layer,

wherein the first insulating film and the oxide semiconductor layer are formed in contact with each other.

6. The method for manufacturing a semiconductor device, according to claim 5, wherein the heat treatment is performed at a temperature higher than or equal to 350°

C.

7. The method for manufacturing a semiconductor device, according to claim 5, wherein the oxide semiconductor layer is formed over the gate electrode with the gate insulating layer interposed therebetween.

8. The method for manufacturing a semiconductor device, according to claim 5, wherein the gate electrode is formed over the oxide semiconductor layer with the gate insulating layer interposed therebetween.

9. An insulating film comprising zirconium oxide, wherein the insulating film comprises an amorphous region and a cavity.

10. The insulating film according to claim 9, wherein a detection intensity of mass number 32 with respect to a temperature obtained by thermal desorption spectroscopy has at least one peak.

11. The insulating film according to claim 10, wherein the detection intensity has a peak at a temperature higher than or equal to 350°

C.

12. The insulating film according to claim 9, further comprising yttrium, wherein a film density of the insulating film is higher than or equal to 5.40 g/cm³ and lower than or equal to 5.95 g/cm³.

13. A semiconductor device comprising:

the insulating film according to claim 9;

an oxide semiconductor layer;

a gate insulating layer;

a gate electrode;

a source electrode; and

a drain electrode,

wherein the insulating film is provided in contact with the oxide semiconductor layer.

14. The semiconductor device according to claim 13, wherein the oxide semiconductor layer is provided over the gate electrode with the gate insulating layer interposed therebetween.

15. The semiconductor device according to claim 13, wherein the gate electrode is provided over the oxide semiconductor layer with the gate insulating layer interposed therebetween.

16. The semiconductor device according to claim 13,

wherein the gate insulating layer comprises zirconium, and

wherein the gate insulating layer comprises an amorphous region and a cavity,

17. The semiconductor device according to claim 16, wherein the gate insulating layer further comprises yttrium.

18. A semiconductor device comprising:

an oxide semiconductor layer;

a gate insulating layer wherein the gate insulating layer is the insulating film according to claim 9;

a gate electrode;

a source electrode layer; and

a drain electrode layer,

wherein the gate insulating layer is provided in contact with the oxide semiconductor layer.

19. The semiconductor device according to claim 18, wherein the oxide semiconductor layer is provided over the gate electrode with the gate insulating layer interposed therebetween.

20. The semiconductor device according to claim 18, wherein the gate electrode is provided over the oxide semiconductor layer with the gate insulating layer interposed therebetween.