Thin film transistor, method for manufacturing the same, and semiconductor device
First Claim
1. A method for manufacturing a semiconductor device, comprising the steps of:
- forming a gate electrode including copper over a substrate;
forming a gate insulating layer over the gate electrode;
forming an oxide semiconductor layer over the gate insulating layer;
forming a conductive layer including titanium over the oxide semiconductor layer; and
performing a thermal treatment, whereby oxygen in the oxide semiconductor layer is diffused into the conductive layer.
0 Assignments
0 Petitions
Accused Products
Abstract
In a thin film transistor, an increase in off current or negative shift of the threshold voltage is prevented. In the thin film transistor, a buffer layer is provided between an oxide semiconductor layer and each of a source electrode layer and a drain electrode layer. The buffer layer includes a metal oxide layer which is an insulator or a semiconductor over a middle portion of the oxide semiconductor layer. The metal oxide layer functions as a protective layer for suppressing incorporation of impurities into the oxide semiconductor layer. Therefore, in the thin film transistor, an increase in off current or negative shift of the threshold voltage can be prevented.
-
Citations
15 Claims
-
1. A method for manufacturing a semiconductor device, comprising the steps of:
-
forming a gate electrode including copper over a substrate; forming a gate insulating layer over the gate electrode; forming an oxide semiconductor layer over the gate insulating layer; forming a conductive layer including titanium over the oxide semiconductor layer; and performing a thermal treatment, whereby oxygen in the oxide semiconductor layer is diffused into the conductive layer. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A method for manufacturing a semiconductor device, comprising the steps of:
-
forming a gate electrode including copper over a substrate; forming a gate insulating layer over the gate electrode; forming an oxide semiconductor layer over the gate insulating layer; forming a conductive layer including titanium and copper over the oxide semiconductor layer; and performing a thermal treatment, whereby oxygen in the oxide semiconductor layer is diffused into the conductive layer. - View Dependent Claims (7, 8, 9, 10)
-
-
11. A method for manufacturing a semiconductor device, comprising the steps of:
-
forming a gate electrode including titanium and copper over a substrate; forming a gate insulating layer over the gate electrode; forming an oxide semiconductor layer over the gate insulating layer; forming a conductive layer including titanium and copper over the oxide semiconductor layer; and performing a thermal treatment, whereby oxygen in the oxide semiconductor layer is diffused into the conductive layer. - View Dependent Claims (12, 13, 14, 15)
-
Specification