SEMICONDUCTOR DEVICE INCLUDING INVERSELY TAPERED GATE ELECTRODE AND MANUFACTURING METHOD THEREOF
First Claim
1. A semiconductor device, comprising:
- a substrate;
source/drain regions formed in a main surface of said substrate with a channel region interposed therebetween;
a gate insulating film formed on said main surface of said substrate in an area in which said channel region is formed; and
an inversely tapered gate electrode formed on an upper surface of said gate insulating film.
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Accused Products
Abstract
An object is to obtain a semiconductor device in which channel length is reduced without increasing the gate resistance to realize higher operation speed and its manufacturing method. An MOSFET has a trench-type element isolation structure (2) formed in the main surface of a semiconductor substrate (1), a pair of extensions (3) and source/drain regions (4) selectively formed in the main surface of the semiconductor substrate (1) to face each other through a channel region (50), a silicon oxide film (5) formed on the trench-type element isolation structure (2) and on the source/drain regions (4) through a silicon oxide film (12), sidewalls (6) formed on sides of the silicon oxide film (5), a gate insulating film (7) formed on the main surface of the semiconductor substrate (1) in the part in which the channel region (50) is formed, and a gate electrode (8) formed to fill a recessed portion in an inversely tapered form formed by the sides of the sidewalls (6) and the upper surface of the gate insulating film (7).
10 Citations
20 Claims
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1. A semiconductor device, comprising:
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a substrate;
source/drain regions formed in a main surface of said substrate with a channel region interposed therebetween;
a gate insulating film formed on said main surface of said substrate in an area in which said channel region is formed; and
an inversely tapered gate electrode formed on an upper surface of said gate insulating film.
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2. A semiconductor device, comprising:
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a substrate;
source/drain regions formed in a main surface of said substrate with a channel region interposed therebetween;
a first insulating film formed on said main surface of said substrate in an area in which said source/drain regions are formed;
sidewalls composed of a second insulating film and formed on sides of said first insulating film;
a gate insulating film composed of a third insulating film and formed on said main surface of said substrate in an area in which said channel region is formed; and
a gate electrode formed to fill an inversely tapered recessed portion formed by sides of said sidewalls and an upper surface of said gate insulating film. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9)
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10. A method for manufacturing a semiconductor device, comprising the steps of:
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(a) forming a structure on a main surface of a substrate in an area in which a gate electrode is formed later;
(b) forming source/drain regions in said main surface of said substrate in an area in which said structure is not formed;
(c) forming a first insulating film on said main surface of said substrate in an area in which said structure is not formed;
(d) after said step (c), removing said structure;
(e) forming a second insulating film on the construction obtained by said step (d) and etching said second insulating film by an anisotropic etching whose etching rate is higher in depth direction of said substrate to form sidewalls on sides of said first insulating film;
(f) forming a gate insulating film composed of a third insulating film on said main surface of said substrate in an area in which said first insulting film and said sidewalls are not formed; and
(g) forming said gate electrode to fill an inversely tapered recessed part formed by sides of said sidewalls and an upper surface of said gate insulating film. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification