	US 11,855,194 B2
	Method for manufacturing semiconductor device
Shunpei Yamazaki, Setagaya (JP); Miyuki Hosoba, Isehara (JP); Kosei Noda, Atsugi (JP); Hiroki Ohara, Sagamihara (JP); Toshinari Sasaki, Atsugi (JP); and Junichiro Sakata, Atsugi (JP)
Assigned to Semiconductor Energy Laboratory Co., Ltd., Kanagawa-ken (JP)
Filed by Semiconductor Energy Laboratory Co., Ltd., Atsugi (JP)
Filed on Oct. 13, 2021, as Appl. No. 17/500,149.
Application 17/500,149 is a continuation of application No. 14/540,184, filed on Nov. 13, 2014, granted, now 11,152,493.
Application 14/540,184 is a continuation of application No. 12/832,329, filed on Jul. 8, 2010, granted, now 8,900,916, issued on Dec. 2, 2014.
Claims priority of application No. 2009-164134 (JP), filed on Jul. 10, 2009.
Prior Publication US 2022/0037153 A1, Feb. 3, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 29/786 (2006.01); H01L 21/477 (2006.01); H01L 29/66 (2006.01); H01L 27/12 (2006.01)

CPC H01L 29/66969 (2013.01) [H01L 21/477 (2013.01); H01L 29/7869 (2013.01); H01L 27/1225 (2013.01)]

17 Claims

1. A method of manufacturing a liquid crystal display comprising steps of:

forming a gate electrode over a substrate having an insulating surface;

forming a gate insulating film over the gate electrode;

forming an oxide semiconductor layer containing In, Ga, and Zn over the gate insulating film;

performing a first heat treatment on the oxide semiconductor layer in a first atmosphere;

cooling the oxide semiconductor layer in a second atmosphere after the first heat treatment;

forming a source electrode and a drain electrode over the oxide semiconductor layer after the step of cooling the oxide semiconductor layer;

forming an oxide insulating layer over the source electrode, the drain electrode and the oxide semiconductor layer;

performing a second heat treatment after forming the oxide insulating layer; and

forming a pixel electrode after the second heat treatment,

wherein the oxide insulating layer is in contact with the oxide semiconductor layer,

wherein the pixel electrode is electrically connected to the source electrode or the drain electrode, and

wherein each of the first atmosphere and the second atmosphere is formed by a gas that has been treated to reduce a concentration of moisture or a concentration of hydrogen.

6. A method of manufacturing a liquid crystal display comprising steps of:

forming a gate electrode over a substrate having an insulating surface;

forming a gate insulating film over the gate electrode;

forming an oxide semiconductor layer containing In, Ga, and Zn over the gate insulating film;

performing a first heat treatment on the oxide semiconductor layer in a first atmosphere;

cooling the oxide semiconductor layer in a second atmosphere after the first heat treatment;

forming a source electrode and a drain electrode over the oxide semiconductor layer after the step of cooling the oxide semiconductor layer;

forming an oxide insulating layer over the source electrode, the drain electrode and the oxide semiconductor layer;

performing a second heat treatment after forming the oxide insulating layer; and

forming a pixel electrode after the second heat treatment,

wherein the oxide insulating layer is in contact with the oxide semiconductor layer,

wherein the pixel electrode is electrically connected to the source electrode or the drain electrode, and

wherein moisture or hydrogen is removed from each of the first atmosphere and the second atmosphere.

10. A method of manufacturing a liquid crystal display comprising steps of:

forming a gate electrode over a substrate having an insulating surface;

forming a gate insulating film over the gate electrode;

forming an oxide semiconductor layer containing In, Ga, and Zn over the gate insulating film;

performing a first heat treatment on the oxide semiconductor layer;

cooling the oxide semiconductor layer after the first heat treatment;

forming a source electrode and a drain electrode over the oxide semiconductor layer after the step of cooling the oxide semiconductor layer;

forming an oxide insulating layer over the source electrode, the drain electrode and the oxide semiconductor layer;

performing a second heat treatment after forming the oxide insulating layer; and

forming a pixel electrode after the second heat treatment,

wherein the oxide insulating layer is in contact with the oxide semiconductor layer,

wherein the pixel electrode is electrically connected to the source electrode or the drain electrode, and

wherein the first heating and the cooling are performed in an atmosphere in which a concentration of moisture or a concentration of hydrogen is reduced by an apparatus for removing moisture or hydrogen.

14. A method of manufacturing a liquid crystal display comprising steps of:

forming a gate electrode over a substrate having an insulating surface;

forming a gate insulating film over the gate electrode;

forming an oxide semiconductor layer containing In, Ga, and Zn over the gate insulating film;

performing a first heat treatment on the oxide semiconductor layer;

cooling the oxide semiconductor layer after the first heat treatment;

forming a source electrode and a drain electrode over the oxide semiconductor layer after the step of cooling the oxide semiconductor layer;

forming an oxide insulating layer over the source electrode, the drain electrode and the oxide semiconductor layer;

performing a second heat treatment after forming the oxide insulating layer; and

forming a pixel electrode after the second heat treatment,

wherein the oxide insulating layer is in contact with the oxide semiconductor layer,

wherein the pixel electrode is electrically connected to the source electrode or the drain electrode, and

wherein the first heating and the cooling are performed in an atmosphere from which moisture or hydrogen has been removed by an apparatus for removing moisture or hydrogen.