Semiconductor device including semiconductor film with outer end having tapered shape
First Claim
Patent Images
1. A semiconductor device comprising:
- a first conductive film over an insulating surface;
a first insulating film over the first conductive film;
a semiconductor film over the first conductive film with the first insulating film interposed between the first conductive film and the semiconductor film, wherein the semiconductor film comprises a channel formation region, a first impurity region, and a second impurity region;
a second insulating film over the semiconductor film;
a second conductive film on the semiconductor film; and
a third conductive film on the semiconductor film with the second insulating film interposed between the second conductive film and the third conductive film,wherein at least an outer end of the semiconductor film has a tapered shape.
0 Assignments
0 Petitions
Accused Products
Abstract
The present invention has an object to provide an active-matrix liquid crystal display device that realizes the improvement in productivity as well as in yield. In the present invention, a laminate film comprising the conductive film comprising metallic material and the second amorphous semiconductor film containing an impurity element of one conductivity type and the amorphous semiconductor film is selectively etched with the same etching gas to form a side edge of the first amorphous semiconductor film 1001 into a taper shape. Thereby, a coverage problem of a pixel electrode 1003 can be solved and an inverse stagger type TFT can be completed with three photomask.
-
Citations
20 Claims
-
1. A semiconductor device comprising:
-
a first conductive film over an insulating surface; a first insulating film over the first conductive film; a semiconductor film over the first conductive film with the first insulating film interposed between the first conductive film and the semiconductor film, wherein the semiconductor film comprises a channel formation region, a first impurity region, and a second impurity region; a second insulating film over the semiconductor film; a second conductive film on the semiconductor film; and a third conductive film on the semiconductor film with the second insulating film interposed between the second conductive film and the third conductive film, wherein at least an outer end of the semiconductor film has a tapered shape. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A semiconductor device comprising:
-
a first conductive film and a second conductive film over an insulating surface; a first insulating film formed over the first conductive film and the second conductive film; a semiconductor film over the first conductive film and the second conductive film with the first insulating film interposed between the first conductive film and the semiconductor film, wherein the semiconductor film comprises a channel formation region, a first impurity region, and a second impurity region; a second insulating film over the semiconductor film; a third conductive film on the semiconductor film; and a fourth conductive film on the semiconductor film with the second insulating film interposed between the third conductive film and the fourth conductive film, and over the second conductive film with the first insulating film interposed between the second conductive film and the fourth conductive film. - View Dependent Claims (8, 9, 10, 11)
-
-
12. A semiconductor device comprising:
-
a first conductive film and a second conductive film over an insulating surface; a first insulating film formed over the first conductive film and the second conductive film; a semiconductor film over the first conductive film and the second conductive film with the first insulating film interposed between the first conductive film and the semiconductor film, wherein the semiconductor film comprises a channel formation region, a first impurity region, and a second impurity region; a second insulating film over the semiconductor film; a third transparent conductive film on the semiconductor film; and a fourth transparent conductive film on the semiconductor film with the second insulating film interposed between the third transparent conductive film and the fourth transparent conductive film, and over the second conductive film with the first insulating film interposed between the second conductive film and the fourth transparent conductive film, wherein at least an outer end of the semiconductor film has a tapered shape. - View Dependent Claims (13, 14, 15, 16, 17, 18)
-
-
19. A semiconductor device comprising:
-
a first conductive film and a second conductive film over an insulating surface; a first insulating film formed over the first conductive film and the second conductive film; a first semiconductor film over the first conductive film and the second conductive film with the first insulating film interposed between the first and second conductive films and the first semiconductor film, wherein the first semiconductor film comprises a first channel formation region over the first conductive film, and a second channel formation region over the second conductive film; a second semiconductor film, a third semiconductor film, and a fourth semiconductor film, which contain an impurity element of one conductivity type, over the first semiconductor film; a fourth conductive film on the second semiconductor film; a fifth conductive film on the fourth semiconductor film; and a pixel electrode on the fifth conductive film, wherein the first channel formation region is provided between the second semiconductor film and the third semiconductor film, wherein the second channel formation region is provided between the third semiconductor film and the fourth semiconductor film, wherein at least outer ends of the first semiconductor film are tapered, wherein at least an outer end of the second semiconductor film opposite to the third semiconductor film is tapered, and wherein at least an outer end of the fourth semiconductor film opposite to the third semiconductor film is tapered. - View Dependent Claims (20)
-
Specification