SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME
First Claim
1. A semiconductor device comprising:
- a gate electrode layer;
a first insulating layer in contact with the gate electrode layer;
an oxide semiconductor layer in contact with the first insulating layer; and
a second insulating layer in contact with the oxide semiconductor layer,wherein the oxide semiconductor layer has a wurtzite crystal structure and has a concentration gradient in which a nitrogen concentration is increased as a distance from the first insulating layer becomes shorter.
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Accused Products
Abstract
An object to provide a material suitably used for used for a semiconductor included in a transistor, a diode, or the like, with the use of a sputtering method. Specifically, an object is to provide a manufacturing process an oxide semiconductor film having high crystallinity. By intentionally adding nitrogen to the oxide semiconductor, an oxide semiconductor film having a wurtzite crystal structure that is a hexagonal crystal structure is formed. In the oxide semiconductor film, the crystallinity of a region containing nitrogen is higher than that of a region hardly containing nitrogen or a region to which nitrogen is not intentionally added. The oxide semiconductor film having high crystallinity and having a wurtzite crystal structure is used as a channel formation region of a transistor.
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Citations
20 Claims
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1. A semiconductor device comprising:
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a gate electrode layer; a first insulating layer in contact with the gate electrode layer; an oxide semiconductor layer in contact with the first insulating layer; and a second insulating layer in contact with the oxide semiconductor layer, wherein the oxide semiconductor layer has a wurtzite crystal structure and has a concentration gradient in which a nitrogen concentration is increased as a distance from the first insulating layer becomes shorter.
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2. A semiconductor device comprising:
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a gate electrode layer; a first insulating layer in contact with the gate electrode layer; a first oxide semiconductor layer in contact with the first insulating layer; a second oxide semiconductor layer in contact with the first oxide semiconductor layer; and a second insulating layer in contact with the second oxide semiconductor layer, wherein the first oxide semiconductor layer and the second oxide semiconductor layer each have a wurtzite crystal structure, and wherein the first oxide semiconductor layer has a higher nitrogen concentration than the second oxide semiconductor layer. - View Dependent Claims (3, 4)
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5. A method for manufacturing a semiconductor device, comprising the steps of:
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forming an insulating film containing nitrogen over a substrate including an insulating surface; introducing the substrate over which the insulating film containing nitrogen is formed, into a vacuum chamber; forming a first oxide semiconductor film containing nitrogen by sputtering in a nitrogen containing atmosphere under a first deposition condition that a substrate temperature is higher than or equal to 150°
C. and lower than or equal to 450°
C.; andforming a second oxide semiconductor film containing nitrogen by sputtering in a nitrogen containing atmosphere under a second deposition condition that a substrate temperature is higher than or equal to 150°
C. and lower than or equal to 450°
C. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12)
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13. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a gate electrode layer over a substrate including an insulating surface; forming an insulating film containing nitrogen over the gate electrode layer; introducing the substrate over which the gate electrode layer and the insulating film containing nitrogen are formed, into a vacuum chamber; forming a first oxide semiconductor film containing nitrogen by sputtering in a nitrogen containing atmosphere under a first deposition condition that a substrate temperature is higher than or equal to 150°
C. and lower than or equal to 450°
C.; andforming a second oxide semiconductor film containing nitrogen by sputtering in a nitrogen containing atmosphere under a second deposition condition that a substrate temperature is higher than or equal to 150°
C. and lower than or equal to 450°
C. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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Specification