Semiconductor device comprising a void portion in an insulation film and method for manufacturing a semiconductor device comprising a void portion in an insulating film

• US 9,184,297 B2
• Filed: 07/15/2013
• Issued: 11/10/2015
• Est. Priority Date: 07/20/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koezuka, Junichi, Sasaki, Toshinari, Tochibayashi, Katsuaki, Yamazaki, Shunpei
• Primary Examiner(s): Valentine, Jami M
• Application Number:
  US13/942,504
• Publication Number:
  US 20140021467A1
• Time in Patent Office: 848 Days
• Field of Search: 257/43, 438/104
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• 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: G06F 3/0412 Digitisers structurally integrated in a display
• 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 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/14612 involving a transistor
• CPC Class Codes: H01L 27/14616 characterised by the channel of the transistor, e.g. channel having a doping gradient
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 29/66742 Thin film unipolar transistors
• 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: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/124 Insulating layers formed between TFT elements and OLED elements

Abstract

A change in electrical characteristics of a semiconductor device including an interlayer insulating film over a transistor including an oxide semiconductor as a semiconductor film is suppressed. The structure includes a first insulating film which includes a void portion in a step region formed by a source electrode and a drain electrode over the semiconductor film and contains silicon oxide as a component, and a second insulating film containing silicon nitride, which is provided in contact with the first insulating film to cover the void portion in the first insulating film. The structure can prevent the void portion generated in the first insulating film from expanding outward.

Claims

1. A semiconductor device comprising:

an oxide semiconductor film;

a conductive film on and in contact with the oxide semiconductor film;

a first insulating film covering the conductive film, a side end surface of the conductive film, and the oxide semiconductor film; and

a second insulating film on and in contact with the first insulating film,

wherein the first insulating film comprises a void portion due to a step of the side end surface of the conductive film, and

wherein the second insulating film covers the void portion of the first insulating film.

2. The semiconductor device according to claim 1,

wherein the first insulating film comprises silicon and more oxygen than nitrogen, and

wherein the second insulating film comprises silicon and more nitrogen than oxygen.

3. The semiconductor device according to claim 1,

wherein the first insulating film is a silicon oxynitride film, and

wherein the second insulating film is a silicon nitride film.

4. The semiconductor device according to claim 1,

wherein the first insulating film is a silicon oxide film, and

wherein the second insulating film is a silicon nitride film.

5. The semiconductor device according to claim 1,

wherein the first insulating film has a thickness larger than the second insulating film.

6. The semiconductor device according to claim 1,

wherein the first insulating film has a density higher than or equal to 2.26 g/cm³ and lower than or equal to 2.50 g/cm³.

7. A display device comprising the semiconductor device according to claim 1.

8. A semiconductor device comprising:

an oxide semiconductor film;

a conductive film on and in contact with the oxide semiconductor film;

a first insulating film covering the conductive film, a side end surface of the conductive film, and the oxide semiconductor film; and

a second insulating film on and in contact with the first insulating film,

wherein the first insulating film comprises a void portion due to a step of the side end surface of the conductive film,

wherein the second insulating film covers the void portion of the first insulating film, and

wherein the first insulating film comprises a stack of a first oxide insulating film and a second oxide insulating film.

9. The semiconductor device according to claim 8,

wherein the first oxide insulating film and the second oxide insulating film are silicon oxynitride films, and

wherein the second insulating film is a silicon nitride film.

10. The semiconductor device according to claim 8,

wherein the second oxide insulating film is interposed between the first oxide insulating film and the second insulating film,

wherein the second oxide insulating film has a thickness larger than the first oxide insulating film, and

wherein the first insulating film has a thickness larger than the second insulating film.

11. The semiconductor device according to claim 8,

wherein the first insulating film has a density higher than or equal to 2.26 g/cm³ and lower than or equal to 2.50 g/cm³.

12. The semiconductor device according to claim 8,

wherein the second oxide insulating film is denser than the first oxide insulating film.

13. A display device comprising the semiconductor device according to claim 8.

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

forming an oxide semiconductor film;

forming a conductive film on and in contact with the oxide semiconductor film;

forming a first insulating film covering the conductive film, a side end surface of the conductive film, and the oxide semiconductor film; and

forming a second insulating film on and in contact with the first insulating film,

wherein the first insulating film comprises a void portion due to a step of the side end surface of the conductive film, and

wherein the second insulating film covers the void portion of the first insulating film.

15. The semiconductor device according to claim 14,

wherein the first insulating film comprises a stack of a first oxynitride film and a second oxynitride film on and in contact with the first oxynitride film,

wherein the first oxynitride film is formed by a plasma CVD method under a first pressure and with a first high-frequency power, and

wherein the second oxynitride film is formed by a plasma CVD method under a second pressure higher than the first pressure and with a second high-frequency power higher than the first high-frequency power.

16. The semiconductor device according to claim 14,

wherein the first insulating film comprises a stack of a first oxynitride film and a second oxynitride film on and in contact with the first oxynitride film,

wherein the first oxynitride film is formed by a plasma CVD method under a first pressure, a first substrate temperature, and with a first high-frequency power, and

wherein the second oxynitride film is formed by a plasma CVD method under a second pressure higher than the first pressure, a second substrate temperature equal to the first substrate temperature, and with a second high-frequency power higher than the first high-frequency power.

17. The semiconductor device according to claim 14,

wherein the second insulating film is a silicon nitride film.

18. The semiconductor device according to claim 14,

wherein the first insulating film has a thickness larger than the second insulating film.

19. The semiconductor device according to claim 14,

wherein the first insulating film has a density higher than or equal to 2.26 g/cm³ and lower than or equal to 2.50 g/cm³.

20. The semiconductor device according to claim 15,

wherein the second oxynitride film is denser than the first oxynitride film.

21. The semiconductor device according to claim 16,

wherein the second oxynitride film is denser than the first oxynitride film.

22. A display device comprising the semiconductor device according to claim 14.