Semiconductor device comprising an insulating layer including a void

• US 9,548,393 B2
• Filed: 09/22/2015
• Issued: 01/17/2017
• 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:
  US14/861,289
• Publication Number:
  US 20160013324A1
• Time in Patent Office: 483 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 first insulating film covering the oxide semiconductor film; and

a second insulating film covering the first insulating film,

wherein, when seen in a cross-sectional view, a lateral extension of the oxide semiconductor film is comprised within a lateral extension of the first insulating film and within a lateral extension of the second insulating film,

wherein the first insulating film comprises steps with concave edges and convex edges,

wherein the first insulating film comprises a void portion within external boundaries of the first insulating film, the void portion being localized in a vicinity of one of the concave edges and the convex edges, 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 void portion is localized in a vicinity of one of the convex edges of the first insulating film.

3. The semiconductor device according to claim 1,

wherein the steps are due to an end portion of a layer located under the first insulating film.

4. The semiconductor device according to claim 1,

wherein the steps are due to end portions of a layer located under the first insulating film, and

wherein the layer located under the first insulating film is a conductive layer.

5. The semiconductor device according to claim 1,

wherein the first insulating film comprises silicon and oxygen, and

wherein the second insulating film comprises silicon and nitrogen.

6. 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.

7. 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.

8. 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.

9. The semiconductor device according to claim 1,

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

10. 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.

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

25. The semiconductor device according to claim 1,

wherein the void portion is generated as a structural defect within the first insulating film.

12. A semiconductor device comprising:

an oxide semiconductor film;

a first insulating film over the oxide semiconductor film; and

a second insulating film over the first insulating film,

wherein a portion of the first insulating film comprises a void portion,

wherein the second insulating film overlaps with the 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.

13. The semiconductor device according to claim 12,

wherein the portion is adjacent to a step of the first insulating film.

14. The semiconductor device according to claim 12,

wherein the portion is adjacent to with a step of the first insulating film, the step being due to an end portion of a layer located under the first insulating film.

15. The semiconductor device according to claim 12,

wherein the portion is adjacent to a step of the first insulating film, the step being due to an end portion of a layer located under the first insulating film, and

wherein the layer located under the first insulating film is a conductive layer.

16. The semiconductor device according to claim 12,

wherein each of the first oxide insulating film and the second oxide insulating film comprises silicon and oxygen, and

wherein the second insulating film comprises silicon and nitrogen.

17. The semiconductor device according to claim 12,

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.

18. The semiconductor device according to claim 12,

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.

19. The semiconductor device according to claim 12,

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 12,

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

21. A display device comprising the semiconductor device according to claim 12.

26. The semiconductor device according to claim 12,

wherein the void portion is generated as a structural defect within the first insulating film.

22. A semiconductor device comprising:

an oxide semiconductor film;

a first insulating film over the oxide semiconductor film; and

a second insulating film over the first insulating film,

wherein a portion of the first insulating film comprises a void portion within external boundaries of the first insulating film, and

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

wherein the portion is adjacent to a step of the first insulating film, the step being due to an end portion of a layer located under the first insulating film,

wherein the layer located under the first insulating film is a conductive layer,

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.

23. The semiconductor device according to claim 22,

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

24. The semiconductor device according to claim 22,

wherein the first insulating film has a density higher than or equal to 226 g/cm³ and lower than or equal to 2.50 g/cm³.

27. The semiconductor device according to claim 22,

wherein the void portion is generated as a structural defect within the first insulating film.