Semiconductor device and display device including the same

Patent metadata

Field	Value
Publication number	US-10236306-B2
Application number	US-201815963141-A
Country	US
Kind code	B2
Filing date	Apr 26, 2018
Priority date	Mar 22, 2016
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

To improve field-effect mobility and reliability in a transistor including an oxide semiconductor film. A semiconductor device includes a transistor including an oxide semiconductor film. The transistor includes a region where the maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 40 and smaller than 150; a region where the threshold voltage is higher than or equal to minus 1 V and lower than or equal to 1 V; and a region where the S value is smaller than 0.3 V/decade.

First claim

The invention claimed is:

1. A method for manufacturing a semiconductor device comprising:
forming a first oxide semiconductor layer over a substrate at a room temperature;
forming an insulating film over the first oxide semiconductor layer; and
performing a heat treatment after forming the insulating film in an atmosphere comprising nitrogen,
wherein the first oxide semiconductor layer is formed by a sputtering apparatus using a deposition gas comprising at least oxygen,
wherein a proportion of oxygen in the deposition gas is higher than 0% and lower than or equal to 30%, and
wherein a partial pressure of gas molecules corresponding to m/z=18 in a deposition chamber in a standby mode of the sputtering apparatus is lower than or equal to 1×10 −4 Pa.

2. The method for manufacturing a semiconductor device according to claim 1 ,
wherein the proportion of oxygen is higher than or equal to 7% and lower than or equal to 15%.

3. The method for manufacturing a semiconductor device according to claim 1 ,
wherein a dew point of the deposition gas is −40° C. or lower.

4. The method for manufacturing a semiconductor device according to claim 1 , further comprising steps of:
etching the insulating film; and
forming a second oxide semiconductor layer over the insulating film.

5. The method for manufacturing a semiconductor device according to claim 1 ,
wherein the semiconductor device is a transistor, and
wherein a maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 40 cm 2 /Vs and smaller than 150 cm 2 /Vs.

6. The method for manufacturing a semiconductor device according to claim 5 ,
wherein a threshold voltage of the transistor is higher than or equal to −1 V and lower than or equal to 1 V,
wherein an S value of the transistor is smaller than 0.3 V/decade,
wherein an off-state current of the transistor is lower than 1×10 −12 A/cm 2 , and
wherein μ FE (max)/μ FE (V g =2V) is larger than or equal to 1 and smaller than 1.5, where μ FE (max) represents the maximum value of the field-effect mobility of the transistor and μ FE (V g =2V) represents a value of the field-effect mobility of the transistor at a gate voltage of 2 V.

7. A method for manufacturing a semiconductor device comprising:
forming a first oxide semiconductor layer over a substrate at a room temperature;
forming an insulating film over the first oxide semiconductor layer; and
performing a heat treatment after forming the insulating film in an atmosphere comprising nitrogen,
wherein the first oxide semiconductor layer is formed by a sputtering apparatus using a deposition gas comprising at least oxygen,
wherein a proportion of oxygen in the deposition gas is higher than 30% and lower than 70%, and
wherein a partial pressure of gas molecules corresponding to m/z=18 in a deposition chamber in a standby mode of the sputtering apparatus is lower than or equal to 1×10 −4 Pa.

8. The method for manufacturing a semiconductor device according to claim 7 ,
wherein a dew point of the deposition gas is −40° C. or lower.

9. The method for manufacturing a semiconductor device according to claim 7 , further comprising steps of:
etching the insulating film; and
forming a second oxide semiconductor layer over the insulating film.

10. The method for manufacturing a semiconductor device according to claim 7 ,
wherein the semiconductor device is a transistor, and
wherein a maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 40 cm 2 /Vs and smaller than 150 cm 2 /Vs.

11. The method for manufacturing a semiconductor device according to claim 10 ,
wherein a threshold voltage of the transistor is higher than or equal to −1 V and lower than or equal to 1 V,
wherein an S value of the transistor is smaller than 0.3 V/decade,
wherein an off-state current of the transistor is lower than 1×10 −12 A/cm 2 , and
wherein μ FE (max)/μ FE (V g =2V) is larger than or equal to 1.5 and smaller than 3, where μ FE (max) represents the maximum value of the field-effect mobility of the transistor and μ FE (V g =2V) represents a value of the field-effect mobility of the transistor at a gate voltage of 2 V.

12. A method for manufacturing a semiconductor device comprising:
forming a first oxide semiconductor layer over a substrate at a room temperature;
forming an insulating film over the first oxide semiconductor layer; and
performing a heat treatment after forming the insulating film in an atmosphere comprising nitrogen,
wherein the first oxide semiconductor layer is formed by a sputtering apparatus using a deposition gas comprising at least oxygen,
wherein a proportion of oxygen in the deposition gas is higher than or equal to 70% and lower than or equal to 100%, and
wherein a partial pressure of gas molecules corresponding to m/z=18 in a deposition chamber in a standby mode of the sputtering apparatus is lower than or equal to 1×10 −4 Pa.

13. The method for manufacturing a semiconductor device according to claim 12 ,
wherein the proportion of oxygen is 100%.

14. The method for manufacturing a semiconductor device according to claim 12 ,
wherein a dew point of the deposition gas is −40° C. or lower.

15. The method for manufacturing a semiconductor device according to claim 12 , further comprising steps of:
etching the insulating film; and
forming a second oxide semiconductor layer over the insulating film.

16. The method for manufacturing a semiconductor device according to claim 12 ,
wherein the semiconductor device is a transistor, and
wherein a maximum value of field-effect mobility of the transistor at a gate voltage of higher than 0 V and lower than or equal to 10 V is larger than or equal to 10 cm 2 /Vs and smaller than 100 cm 2 /Vs.

17. The method for manufacturing a semiconductor device according to claim 16 ,
wherein a threshold voltage of the transistor is higher than or equal to −1 V and lower than or equal to 1 V,
wherein an S value of the transistor is smaller than 0.3 V/decade,
wherein an off-state current of the transistor is lower than 1×10 −12 A/cm 2 , and
wherein μ FE (max)/μ FE (V g =2V) is larger than or equal to 3 and smaller than 10, where μ FE (max) represents the maximum value of the field-effect mobility of the transistor and μ FE (V g =2V) represents a value of the field-effect mobility of the transistor at a gate voltage of 2 V.

Assignees

• Semiconductor Energy Lab

Inventors

• Yamazaki Shunpei
• Koezuka Junichi
• Okazaki Kenichi
• Shima Yukinori
• Matsuda Shinpei
• Baba Haruyuki
• Honda Ryunosuke

Classifications

• H10P14/3434

  being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424) · CPC title

• H01L27/127

  Electricity · mapped topic

• H01L29/7782

  Electricity · mapped topic

• H01L29/78696

  Electricity · mapped topic

• H01L29/66969

  Electricity · mapped topic