SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME
First Claim
Patent Images
1. A semiconductor device including a thin film transistor, the thin film transistor comprising:
- a gate electrode layer;
a gate insulating layer over the gate electrode layer;
a source electrode layer and a drain electrode layer over the gate insulating layer;
a first buffer layer having n-type conductivity over the source electrode layer;
a second buffer layer having n-type conductivity over the drain electrode layer; and
an oxide semiconductor layer over the first and second buffer layers,wherein the oxide semiconductor layer overlapping with the gate electrode layer is partly over and in contact with the gate insulating layer and is provided between the source electrode layer and the drain electrode layer,wherein a carrier concentration of the first buffer layer and the second buffer layer is higher than a carrier concentration of the oxide semiconductor layer, andwherein the oxide semiconductor layer and the source electrode layer are electrically connected to each other with the first buffer layer interposed therebetween, andwherein the oxide semiconductor layer and the drain electrode layer are electrically connected to each other with the second buffer layer interposed therebetween.
1 Assignment
0 Petitions
Accused Products
Abstract
One of the objects of the present invention is to provide a thin film transistor using an oxide semiconductor film containing indium (In), gallium (Ga), and zinc (Zn), in which the contact resistance between the oxide semiconductor layer and a source and drain electrodes is reduced, and to provide a method for manufacturing the thin film transistor. An ohmic contact is formed by intentionally providing a buffer layer having a higher carrier concentration than the IGZO semiconductor layer between the IGZO semiconductor layer and the source and drain electrode layers.
-
Citations
15 Claims
-
1. A semiconductor device including a thin film transistor, the thin film transistor comprising:
-
a gate electrode layer; a gate insulating layer over the gate electrode layer; a source electrode layer and a drain electrode layer over the gate insulating layer; a first buffer layer having n-type conductivity over the source electrode layer; a second buffer layer having n-type conductivity over the drain electrode layer; and
an oxide semiconductor layer over the first and second buffer layers,wherein the oxide semiconductor layer overlapping with the gate electrode layer is partly over and in contact with the gate insulating layer and is provided between the source electrode layer and the drain electrode layer, wherein a carrier concentration of the first buffer layer and the second buffer layer is higher than a carrier concentration of the oxide semiconductor layer, and wherein the oxide semiconductor layer and the source electrode layer are electrically connected to each other with the first buffer layer interposed therebetween, and wherein the oxide semiconductor layer and the drain electrode layer are electrically connected to each other with the second buffer layer interposed therebetween. - 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 gate electrode layer over a substrate; forming a gate insulating layer over the gate electrode layer; forming a source electrode layer and a drain electrode layer over the gate insulating layer; forming a buffer layer having n-type conductivity over the source electrode layer and the drain electrode layer; and forming an oxide semiconductor layer over the buffer layer, wherein a carrier concentration of the buffer layer is higher than a carrier concentration of the oxide semiconductor layer, and wherein the oxide semiconductor layer and the source electrode layer are electrically connected to each other with the buffer layer interposed therebetween. - View Dependent Claims (11, 12, 13, 14, 15)
-
Specification