Method for making thin-film transistors
First Claim
1. A method for making a thin-film transistor which comprises the steps of forming a first metal layer of Ta, which ultimately becomes a gate electrode, on an insulative substrate, forming a second metal layer of Nb on said first metal layer, simultaneously oxidizing said first and second metal layers by the use of an anodization technique to form first and second oxide layers of Ta2 O5 and Nb2 O5, respectively, said first oxide layer being formed on said first layer of Ta and said second oxide layer being formed on said first oxide layer, and effecting a selective etching to remove only the second oxide layer of Nb2 O5, thereby leaving the first oxide layer of Ta2 O5 to form the gate insulating layer for the Ta gate electrode.
1 Assignment
0 Petitions
Accused Products
Abstract
A method for making a thin-film transistor wherein a gate insulating layer is formed by anodizing two oxide layers on the substrate and then etching the assembly to completely remove the uppermost one of these layers to leave the lowermost layer so as to serve as the gate insulating layer.
46 Citations
1 Claim
-
1. A method for making a thin-film transistor which comprises the steps of forming a first metal layer of Ta, which ultimately becomes a gate electrode, on an insulative substrate, forming a second metal layer of Nb on said first metal layer, simultaneously oxidizing said first and second metal layers by the use of an anodization technique to form first and second oxide layers of Ta2 O5 and Nb2 O5, respectively, said first oxide layer being formed on said first layer of Ta and said second oxide layer being formed on said first oxide layer, and effecting a selective etching to remove only the second oxide layer of Nb2 O5, thereby leaving the first oxide layer of Ta2 O5 to form the gate insulating layer for the Ta gate electrode.
Specification
-
- Resources
-
Current AssigneeSharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Japan Electronic Industry Development Association
-
Original AssigneeSharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Japan Electronic Industry Development Association
-
InventorsKato, Hiroaki, Takafuji, Yutaka, Kishi, Kohhei
-
Primary Examiner(s)Weisstuch, Aaron
-
Assistant Examiner(s)Schiavelli, Alan E.
-
Application NumberUS06/446,046Time in Patent Office643 DaysField of Search29/571, 29/589, 29/591, 156/655, 357/4, 357/23 TF, 357/23 I, 204/42, 204/38 A, 204/56 R, 204/35 RUS Class Current205/162CPC Class CodesH01L 21/28008 Making conductor-insulator-...H01L 29/4908 for thin film semiconductor...Y10S 148/043 Dual dielectricY10S 148/117 Oxidation, selectiveY10S 148/118 Oxide films
