Method for manufacturing semiconductor device
First Claim
Patent Images
1. A semiconductor device comprising:
- a gate electrode;
a gate insulating film which covers the gate electrode;
a semiconductor film comprising an oxide semiconductor, wherein a region of the semiconductor film overlaps with the gate electrode;
a source electrode and a drain electrode which are in contact with the semiconductor film;
a metal oxide film which is in contact with the semiconductor film and covers the source electrode and the drain electrode;
an insulating film which covers the metal oxide film;
a conductive film over the insulating film, wherein the conductive film overlaps with the region of the semiconductor film;
a liquid crystal element comprising a pixel electrode, wherein the pixel electrode is electrically connected to one of the source electrode and the drain electrode; and
a storage capacitor,wherein a hydrogen concentration of the semiconductor film is less than or equal to 5×
1018 atoms/cm3, andwherein a thickness of the metal oxide film is larger than a thickness of the semiconductor film, andwherein a capacitance of the storage capacitor is equal to or less than one third of a capacitance of the liquid crystal element.
1 Assignment
0 Petitions
Accused Products
Abstract
In a transistor including an oxide semiconductor film, a metal oxide film which has a function of preventing electrification and covers a source electrode and a drain electrode is formed in contact with the oxide semiconductor film, and then, heat treatment is performed. Through the heat treatment, impurities such as hydrogen, moisture, a hydroxyl group, or hydride are intentionally removed from the oxide semiconductor film, whereby the oxide semiconductor film is highly purified. By providing the metal oxide film, generation of a parasitic channel on the back channel side of the oxide semiconductor film in the transistor can be prevented.
-
Citations
20 Claims
-
1. A semiconductor device comprising:
-
a gate electrode; a gate insulating film which covers the gate electrode; a semiconductor film comprising an oxide semiconductor, wherein a region of the semiconductor film overlaps with the gate electrode; a source electrode and a drain electrode which are in contact with the semiconductor film; a metal oxide film which is in contact with the semiconductor film and covers the source electrode and the drain electrode; an insulating film which covers the metal oxide film; a conductive film over the insulating film, wherein the conductive film overlaps with the region of the semiconductor film; a liquid crystal element comprising a pixel electrode, wherein the pixel electrode is electrically connected to one of the source electrode and the drain electrode; and a storage capacitor, wherein a hydrogen concentration of the semiconductor film is less than or equal to 5×
1018 atoms/cm3, andwherein a thickness of the metal oxide film is larger than a thickness of the semiconductor film, and wherein a capacitance of the storage capacitor is equal to or less than one third of a capacitance of the liquid crystal element. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A semiconductor device comprising:
-
a gate electrode; a gate insulating film over the gate electrode; a semiconductor film comprising an oxide semiconductor, wherein a region of the semiconductor film overlaps with the gate electrode; a source electrode and a drain electrode which are in contact with the semiconductor film; a metal oxide film which is in contact with the semiconductor film and overlaps with the source electrode and the drain electrode; an insulating film over and in contact with the metal oxide film; a conductive film over the insulating film, wherein the conductive film overlaps with the region of the semiconductor film; a liquid crystal element comprising a pixel electrode, wherein the pixel electrode is electrically connected to one of the source electrode and the drain electrode; and a storage capacitor, wherein a hydrogen concentration of the semiconductor film is less than or equal to 5×
1018 atoms/cm3, andwherein a thickness of the metal oxide film is larger than a thickness of the semiconductor film, and wherein a capacitance of the storage capacitor is equal to or less than one third of a capacitance of the liquid crystal element. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 20)
-
-
15. A method for manufacturing a semiconductor device comprising a liquid crystal element and a storage capacitor, comprising the steps of:
-
forming a gate electrode over a substrate; forming a gate insulating film which covers the gate electrode; forming a semiconductor film comprising an oxide semiconductor over the gate electrode with the gate insulating film interposed therebetween, wherein a region of the semiconductor film overlaps with the gate electrode; forming a source electrode and a drain electrode over the semiconductor film; forming a metal oxide film which covers the semiconductor film, the source electrode, and the drain electrode; forming an insulating film which covers the metal oxide film; forming a conductive film over the insulating film, wherein a region of the semiconductor film; and performing heat treatment on the semiconductor film, wherein a hydrogen concentration of the semiconductor film is less than or equal to 5×
1018 atoms/cm3, andwherein a thickness of the metal oxide film is larger than a thickness of the semiconductor film, and wherein a capacitance of the storage capacitor is equal to or less than one third of a capacitance of the liquid crystal element. - View Dependent Claims (16, 17, 18, 19)
-
Specification