Semiconductor device and method for manufacturing

• US 8,519,387 B2
• Filed: 07/19/2011
• Issued: 08/27/2013
• Est. Priority Date: 07/26/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Endo, Yuta, Noda, Kosei, Sasaki, Toshinari
• Primary Examiner(s): PRENTY, MARK V
• Application Number:
  US13/185,779
• Publication Number:
  US 20120018727A1
• Time in Patent Office: 770 Days
• Field of Search: 257/43, 257/57, 257/E29.296, 438/104
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02367 Substrates
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• 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 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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

An insulating layer which releases a large amount of oxygen is used as an insulating layer in contact with a channel region of an oxide semiconductor layer, and an insulating layer which releases a small amount of oxygen is used as an insulating layer in contact with a source region and a drain region of the oxide semiconductor layer. By releasing oxygen from the insulating layer which releases a large amount of oxygen, oxygen deficiency in the channel region and an interface state density between the insulating layer and the channel region can be reduced, so that a highly reliable semiconductor device having small variation in electrical characteristics can be manufactured. The source region and the drain region are provided in contact with the insulating layer which releases a small amount of oxygen, thereby suppressing the increase of the resistance of the source region and the drain region.

Claims

1. A semiconductor device comprising:

an insulating layer including a first region and a second region;

an oxide semiconductor layer provided in contact with the first region and the second region;

a gate insulating layer provided in contact with the oxide semiconductor layer; and

a gate electrode provided in contact with the gate insulating layer,

wherein the oxide semiconductor layer includes a channel region, a source region, and a drain region,

wherein the channel region is provided in contact with the first region,

wherein the source region and the drain region are provided in contact with the second region, and

wherein a composition of the first region is different from a composition of the second region.

2. The semiconductor device according to claim 1,

wherein the first region comprises silicon oxide, and

wherein the second region comprises silicon oxide, silicon nitride, silicon nitride oxide, silicon oxynitride, aluminum oxide, aluminum nitride, or aluminum oxynitride.

3. The semiconductor device according to claim 1, wherein the amount of oxygen released from the first region which is converted into oxygen atoms is greater than or equal to 1×

10¹⁸ atoms/cm³ in thermal desorption spectroscopy.

4. The semiconductor device according to claim 1, wherein the source region and the drain region are obtained by reducing resistance of the oxide semiconductor layer.

5. The semiconductor device according to claim 1, wherein oxygen is released from the first region and the gate insulating layer by heating.

6. The semiconductor device according to claim 1, wherein the first region and the gate insulating layer comprise silicon oxide in which the number of oxygen atoms is more than twice the number of silicon atoms per unit volume.

7. The semiconductor device according to claim 1, further comprising:

an interlayer insulating layer provided over the gate electrode, and

a wiring provided over the interlayer insulating layer and in contact with the oxide semiconductor layer through an opening provided in the interlayer insulating layer.

8. The semiconductor device according to claim 1, wherein a surface of the first region and a surface of the second region are coplanar with each other.

9. The semiconductor device according to claim 2, wherein the number of oxygen atoms in silicon oxide or silicon oxynitride for the second region is smaller than the number of oxygen atoms of the first region per unit volume.

10. The semiconductor device according to claim 1, wherein an amount of oxide deficiency in the channel region is lower than in the source region and the drain region.

11. The semiconductor device according to claim 1, wherein the first region contains oxygen at a higher concentration than the second region.

12. A semiconductor device comprising:

an insulating layer selectively provided on an insulating surface;

an oxide semiconductor layer provided over the insulating layer;

a gate insulating layer provided in contact with the oxide semiconductor layer; and

a gate electrode provided in contact with the gate insulating layer,

wherein the oxide semiconductor layer includes a channel region, a source region, and a drain region,

wherein the channel region is provided in contact with the insulating layer,

wherein the source region and the drain region are provided in contact with the insulating surface, and

wherein the oxide semiconductor layer extends beyond side surfaces of the insulating layer.

13. The semiconductor device according to claim 12, wherein the insulating layer comprises silicon oxide.

14. The semiconductor device according to claim 12, wherein the amount of oxygen released from the insulating layer which is converted into oxygen atoms is greater than or equal to 1×

10¹⁸ atoms/cm³ in thermal desorption spectroscopy.

15. The semiconductor device according to claim 12, wherein the source region and the drain region are obtained by reducing resistance of the oxide semiconductor layer.

16. The semiconductor device according to claim 12, wherein oxygen is released from the insulating layer and the gate insulating layer by heating.

17. The semiconductor device according to claim 12, wherein the insulating layer and the gate insulating layer comprise silicon oxide in which the number of oxygen atoms is more than twice the number of silicon atoms per unit volume.

18. The semiconductor device according to claim 12, further comprising:

an interlayer insulating layer provided over the gate electrode, and

a wiring provided over the interlayer insulating layer and in contact with the oxide semiconductor layer through an opening provided in the interlayer insulating layer.

19. The semiconductor device according to claim 12, wherein an amount of oxide deficiency in the channel region is lower than in the source region and the drain region.