Semiconductor device and manufacturing method thereof
First Claim
1. A method for manufacturing a semiconductor device, comprising the steps of:
- forming a gate electrode layer over a substrate having an insulating surface;
forming a first oxide insulating layer which covers the gate electrode layer;
forming a first oxide semiconductor layer over the gate electrode layer and the first oxide insulating layer;
performing first heat treatment so as to form a crystal region in which c-axis is aligned in a direction substantially perpendicular to a surface of the first oxide semiconductor layer;
forming a second oxide semiconductor layer over the first oxide semiconductor layer;
performing second heat treatment so as to crystallize at least a part of the second oxide semiconductor layer by causing crystal growth from the crystal region;
forming a source electrode layer and a drain electrode layer over the second oxide semiconductor layer;
forming a second oxide insulating layer which covers the second oxide semiconductor layer, the source electrode layer, and the drain electrode layer;
performing third heat treatment so as to supply oxygen to the second oxide semiconductor layer;
forming a nitride insulating layer containing hydrogen over the second oxide insulating layer; and
performing fourth heat treatment so as to supply hydrogen at least to an interface between the first oxide semiconductor layer and the first oxide insulating layer.
1 Assignment
0 Petitions
Accused Products
Abstract
One embodiment of the present invention is to achieve high mobility in a device using an oxide semiconductor and provide a highly reliable display device. An oxide semiconductor layer including a crystal region in which c-axis is aligned in a direction substantially perpendicular to a surface is formed and an oxide insulating layer is formed over and in contact with the oxide semiconductor layer. Oxygen is supplied to the oxide semiconductor layer by third heat treatment. A nitride insulating layer containing hydrogen is formed over the oxide insulating layer and fourth heat treatment is performed, so that hydrogen is supplied at least to an interface between the oxide semiconductor layer and the oxide insulating layer.
-
Citations
11 Claims
-
1. A method for manufacturing a semiconductor device, comprising the steps of:
-
forming a gate electrode layer over a substrate having an insulating surface; forming a first oxide insulating layer which covers the gate electrode layer; forming a first oxide semiconductor layer over the gate electrode layer and the first oxide insulating layer; performing first heat treatment so as to form a crystal region in which c-axis is aligned in a direction substantially perpendicular to a surface of the first oxide semiconductor layer; forming a second oxide semiconductor layer over the first oxide semiconductor layer; performing second heat treatment so as to crystallize at least a part of the second oxide semiconductor layer by causing crystal growth from the crystal region; forming a source electrode layer and a drain electrode layer over the second oxide semiconductor layer; forming a second oxide insulating layer which covers the second oxide semiconductor layer, the source electrode layer, and the drain electrode layer; performing third heat treatment so as to supply oxygen to the second oxide semiconductor layer; forming a nitride insulating layer containing hydrogen over the second oxide insulating layer; and performing fourth heat treatment so as to supply hydrogen at least to an interface between the first oxide semiconductor layer and the first oxide insulating layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for manufacturing a semiconductor device, comprising the steps of:
-
forming a first oxide semiconductor layer; performing first heat treatment to the first oxide semiconductor layer so as to form a crystal region in which c-axis is aligned in a direction substantially perpendicular to a surface of the first oxide semiconductor layer; forming a second oxide semiconductor layer over the first oxide semiconductor layer; performing second heat treatment so as to crystallize at least a part of the second oxide semiconductor layer by causing crystal growth from the crystal region; forming an oxide insulating layer which covers the second oxide semiconductor layer; performing third heat treatment to the oxide insulating layer; forming a nitride insulating layer containing hydrogen over the oxide insulating layer; and performing fourth heat treatment to the nitride insulating layer containing hydrogen. - View Dependent Claims (11)
-
Specification