Method for manufacturing transistor

• US 9,601,601 B2
• Filed: 08/07/2014
• Issued: 03/21/2017
• Est. Priority Date: 12/19/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Sakata, Junichiro
• Primary Examiner(s): Ahmad, Khaja
• Application Number:
  US14/454,126
• Publication Number:
  US 20150037912A1
• Time in Patent Office: 957 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02554 Oxides
• 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 21/02664 Aftertreatments planarisation in general H01L21/304
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14
• 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 29/41733 for thin film transistors with insulated gate
• 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 29/78618 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

A hydrogen barrier layer is selectively provided over an oxide semiconductor layer including hydrogen and hydrogen is selectively desorbed from a given region in the oxide semiconductor layer by conducting oxidation treatment, so that regions with different conductivities are formed in the oxide semiconductor layer. After that, a channel formation region, a source region, and a drain region can be formed with the use of the regions with different conductivities formed in the oxide semiconductor layer.

Claims

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

forming a source electrode and a drain electrode over a substrate;

forming an oxide semiconductor layer over the substrate;

forming a layer over the oxide semiconductor layer;

etching the layer selectively so as to leave a part of the layer overlapping with a source region and a drain region of the oxide semiconductor layer, and so as to expose a channel formation region of the oxide semiconductor layer; and

performing an oxidizing treatment to the oxide semiconductor layer having the channel formation region exposed and the source region and the drain region overlapped with the part of the layer so as to desorb hydrogen from the channel formation region of the oxide semiconductor layer,

wherein the channel formation region after performing the oxidizing treatment includes hydrogen at a lower concentration than the source region and the drain region, and

wherein the layer comprises any one of silicon nitride, silicon nitride oxide, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride, titanium oxide, tantalum oxide, and tantalum nitride.

2. The method for manufacturing a semiconductor device according to claim 1, further comprising the steps of:

forming a gate insulating layer over the oxide semiconductor layer; and

forming a gate electrode over the gate insulating layer,

wherein the gate electrode overlaps with the channel formation region.

3. The method for manufacturing a semiconductor device according to claim 1, wherein the oxide semiconductor layer comprises indium.

4. The method for manufacturing a semiconductor device according to claim 1, wherein concentration gradient of hydrogen is formed between the channel formation region and the source region and the drain region.

5. The method for manufacturing a semiconductor device according to claim 1, wherein the layer is a hydrogen barrier layer.

13. The method for manufacturing a semiconductor device according to claim 1, wherein a concentration of hydrogen included in the channel formation region of the oxide semiconductor layer and a concentration of hydrogen included in the source region and the drain region of the oxide semiconductor layer are measured by secondary ion mass spectrometry.

15. The method for manufacturing a semiconductor device according to claim 1, wherein a concentration of hydrogen included in the channel formation region of the oxide semiconductor layer is greater than or equal to 1×

10¹⁶ atoms/cm³ and less than or equal to 1×

10²¹ atoms/cm³.

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

forming a source electrode and a drain electrode over a substrate;

forming an oxide semiconductor layer over the substrate;

forming a first layer over the oxide semiconductor layer;

etching the first layer selectively so as to leave a part of the first layer overlapping with a source region and a drain region of the oxide semiconductor layer, and so as to expose a channel formation region of the oxide semiconductor layer;

forming a second layer so as to be in contact with the channel formation region of the oxide semiconductor layer; and

performing an oxidizing treatment to the oxide semiconductor layer having the channel formation region in contact with the second layer and the source region and the drain region overlapped with the part of the first layer so as to desorb hydrogen from the channel formation region of the oxide semiconductor layer,

wherein the channel formation region after performing the oxidizing treatment includes hydrogen at a lower concentration than the source region and the drain region, and

wherein the first layer comprises any one of silicon nitride, silicon nitride oxide, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride, titanium oxide, tantalum oxide, and tantalum nitride.

7. The method for manufacturing a semiconductor device according to claim 6, further comprising the steps of:

forming a gate insulating layer over the oxide semiconductor layer; and

forming a gate electrode over the gate insulating layer,

wherein the gate electrode overlaps with the channel formation region.

8. The method for manufacturing a semiconductor device according to claim 6, wherein the oxide semiconductor layer comprises indium.

9. The method for manufacturing a semiconductor device according to claim 6, wherein concentration gradient of hydrogen is formed between the channel formation region and the source region and the drain region.

10. The method for manufacturing a semiconductor device according to claim 6, wherein the first layer is a hydrogen barrier layer.

11. The method for manufacturing a semiconductor device according to claim 6, wherein the second layer comprises a material selected from the group consisting of an amorphous silicon, a polycrystalline silicon and a tungsten oxide.

12. The method for manufacturing a semiconductor device according to claim 6, wherein the second layer is a hydrogen adsorption layer which adsorbs hydrogen included in the oxide semiconductor layer in the oxidizing treatment.

14. The method for manufacturing a semiconductor device according to claim 6, wherein a concentration of hydrogen included in the channel formation region of the oxide semiconductor layer and a concentration of hydrogen included in the source region and the drain region of the oxide semiconductor layer are measured by secondary ion mass spectrometry.

16. The method for manufacturing a semiconductor device according to claim 6, wherein a concentration of hydrogen included in the channel formation region of the oxide semiconductor layer is greater than or equal to 1×

10¹⁶ atoms/cm³ and less than or equal to 1×

10²¹ atoms/cm³.

17. The method for manufacturing a semiconductor device comprising the steps of:

forming a source electrode and a drain electrode over a substrate;

forming an oxide semiconductor layer over the substrate;

forming a layer over the oxide semiconductor layer;

etching the layer selectively so as to leave a part of the layer overlapping with a source region and a drain region of the oxide semiconductor layer; and

performing an oxidizing treatment to the oxide semiconductor layer having the channel formation region exposed and the source region and the drain region overlapped with the part of the layer so as to desorb hydrogen from the channel formation region of the oxide semiconductor layer,

wherein the channel formation region after performing the oxidizing treatment includes hydrogen at a lower concentration than the source region and the drain region, and

wherein the oxidizing treatment is at least one of heat treatment in an oxygen atmosphere, heat treatment in a nitrogen atmosphere, and oxygen plasma treatment.