US5300446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making staggered gate MOSTFT
Assignee: Yamaha Corp
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Filing: 1993-05-05
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Granted: 1994-04-05
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Expires: 2013-05-05
Abstract
Abstract On an insulating film (12) covering the surface of a semiconductor substrate (10), a gate electrode layer (14), a gate insulating film (16), and a semiconductor layer (18) such as silicon are sequentially deposited to form an under-gated MOS transistor. A flat coating film such as resist is formed covering the semiconductor layer (18). The coating film is then etched back to expose the surface of the semiconductor layer (18) at the area above the gate electrode layer (14). The left coating film is used as the mask for the selective growth of a mask material layer (24) such as tungsten on the exposed surface of the semiconductor layer (18) with a side-projection. After removing the left coating film, impurity ions such as BF2 are selectively injected in the semiconductor layer (18) using the mask material layer (24) as the mask to form a source region (18S) and a drain region (18D).
Inventors
- 👤 Toshio Fujioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:04
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0316; H10D30/0321; Y; Y10; Y10S; Y10S148/00; Y10S148/105; Y10S148/106; Y10S148/15
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
167 words
A method of manufacturing an under-gated semiconductor device comprising the steps of: forming a gate electrode layer on an insulating surface of a substrate; forming a gate insulating film covering said gate electrode layer; forming a semiconductor layer on said gate insulating film to overlie said gate electrode layer; forming a flat coating film covering said semiconductor layer; etching back said coating film to partially expose a surface of said semiconductor layer at an area overlying said gate electrode layer and to leave said coating film at two side areas of the exposed surface; selectively growing a mask material layer on the exposed surface of said semiconductor layer with a side-projection, by using said left coating film as a mask; and removing said left coating film and selectively injecting impurity ions in said semiconductor layer to form an impurity doped source region and an impurity doped drain region at opposite sides of said gate electrode region, by using said mask material layer as an ion injection mask.
Claim 2
Independent Claim
167 words
A method of manufacturing an under-gated semiconductor device comprising the steps of: forming a gate electrode layer on an insulating surface of a substrate; forming a gate insulating film covering said gate electrode layer; forming a semiconductor layer on said gate insulating film to overlie said gate electrode layer; forming a flat coating film covering said semiconductor layer; etching back said coating film to partially expose a surface of said semiconductor layer at an area overlying said gate electrode layer and to leave said coating film at two side areas of the exposed surface; selectively growing a mask material layer on the exposed surface of said semiconductor layer with a side-projection, by using said left coating film as a mask; and removing said left coating film and selectively injecting impurity ions in said semiconductor layer to form an impurity doped source region and an impurity doped drain region at opposite sides of said gate electrode region, by using said mask material layer as an ion injection mask.
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein said mask material layer is made of tungsten.
Claim 4
Dependent Claim
21 words
A method according to claim 1, wherein the selective growth of said mask material layer is performed by chemical vapor deposition.
Claim 5
Dependent Claim
23 words
A method according to claim 3, wherein said chemical vapor deposition is performed by using a reduction reaction of tungsten hexafluoride with silicon.
Claim 6
Dependent Claim
18 words
A method according to claim 3, wherein said chemical vapor deposition is performed under an application of light.
Claim 7
Dependent Claim
14 words
A method according to claim 1, wherein said injected ions are BF 2 ions.
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