Semiconductor device and manufacturing method thereof
First Claim
1. A semiconductor device comprising:
- a gate electrode over an insulating surface;
a gate insulating film over the gate electrode;
a semiconductor film over the gate insulating film;
a first insulating film over the semiconductor film, the first insulating film having an opening;
a first conductive film over the first insulating film, the first conductive film being in contact with the semiconductor film through the opening of the first insulating film;
a second insulating film over the first conductive film, the second insulating film being in contact with side surfaces of the gate electrode, the gate insulating film, the semiconductor film, the first insulating film and the first conductive film, the second insulating film having an opening; and
a second conductive film over the second insulating film, the second conductive film being in contact with the first conductive film through the opening of the second insulating film,wherein outer circumferences of the gate electrode, the gate insulating film, and the semiconductor film are substantially aligned.
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Accused Products
Abstract
A conductive film to be a gate electrode, a first insulating film to be a gate insulating film, a semiconductor film in which a channel region is formed, and a second insulating film to be a channel protective film are successively formed. With the use of a resist mask formed by performing light exposure with the use of a photomask which is a multi-tone mask and development, i) in a region without the resist mask, the second insulating film, the semiconductor film, the first insulating film, and the conductive film are successively etched, ii) the resist mask is made to recede by ashing or the like and only the region of the resist mask with small thickness is removed, so that part of the second insulating film is exposed, and iii) the exposed part of the second insulating film is etched, so that a pair of opening portions is formed.
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Citations
24 Claims
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1. A semiconductor device comprising:
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a gate electrode over an insulating surface; a gate insulating film over the gate electrode; a semiconductor film over the gate insulating film; a first insulating film over the semiconductor film, the first insulating film having an opening; a first conductive film over the first insulating film, the first conductive film being in contact with the semiconductor film through the opening of the first insulating film; a second insulating film over the first conductive film, the second insulating film being in contact with side surfaces of the gate electrode, the gate insulating film, the semiconductor film, the first insulating film and the first conductive film, the second insulating film having an opening; and a second conductive film over the second insulating film, the second conductive film being in contact with the first conductive film through the opening of the second insulating film, wherein outer circumferences of the gate electrode, the gate insulating film, and the semiconductor film are substantially aligned. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a first conductive film, a first insulating film, a semiconductor film, and a second insulating film over an insulating surface in this order; applying a first resist over the second insulating film; exposing the first resist to light with the use of a first photomask which is a multi-tone mask and developing the first resist to form a first resist mask comprising a region with a first thickness and a region with a second thickness; etching the second insulating film, the semiconductor film, the first insulating film, and the first conductive film with the use of the first resist mask; reducing a size of the first resist mask by plasma treatment to remove the region with the first thickness, so that a second resist mask is formed; etching the second insulating film with the use of the second resist mask to expose part of the semiconductor film; removing the second resist mask; forming a second conductive film for covering the insulating surface, the first conductive film, the first insulating film, the semiconductor film, and the second insulating film; applying a second resist over the second conductive film; exposing the second resist to light with the use of a second photomask and developing the second resist to form a third resist mask; etching the second conductive film with the use of the third resist mask to form a first electrode which is in contact with the exposed part of the semiconductor film; removing the third resist mask; forming a third insulating film for covering the insulating surface, the first conductive film, the first insulating film, the semiconductor film, the second insulating film, and the first electrode; applying a third resist over the third insulating film; exposing the third resist to light with the use of a third photomask and developing the third resist to form a fourth resist mask; etching the third insulating film with the use of the fourth resist mask to expose part of the first electrode; removing the fourth resist mask; forming a third conductive film for covering the first electrode and the third insulating film; applying a fourth resist over the third conductive film; exposing the fourth resist to light with the use of a fourth photomask and developing the fourth resist to form a fifth resist mask; etching the third conductive film with the use of the fifth resist mask to form a second electrode which is in contact with the exposed part of the first electrode; and removing the fifth resist mask. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification