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EP0179196A2
Expired / Lapsed
EP
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A method of forming a semiconductor device using a mask
Assignee: International Business Machines Corp
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Filing: 1985-06-13
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Granted: —
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Expires: 2005-06-13
Abstract
Abstract A semiconductor device, particularly an ultra-short gate MOSFET, is formed by depositing a mask (6) at a low angle with respect to a planar surface and then performing an angular conductivity conversion operation, such as ion implantation, so that the converted region extends (9) partially under the mask. The mask is then removed and a gate electrode (12) is deposited in its place, the gate being smaller than the channel length (11) from the source (7) to the point (9) where the conversion extended under the mask. Straggle location change is accommodated by arranging that the mask has a dimension along a line parallel to the planar surface which is greater than the desired channel length.
Inventors
- 👤 Frank Fu Fang
- 👤 Bertrand M. Grossman
- 👤 Wei Hwang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 04:33
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0221; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01326; H10D64/0133; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/517; H10D64/518; H10P; H10P30/00; H10P30/20; H10P30/22; H10P30/221; H10P30/222; H10P76/00; H10P76/40; H10P76/408; H10P76/4085; H10D64/017; Y; Y10; Y10S; Y10S148/00; Y10S148/082
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
123 words
A method of forming a semiconductor device comprising the successive steps of depositing material at a low angle with respect to a planar surface of a semiconductor crystal in order to form a mask against a locating face lying perpendicular to said planar surface, the height of the locating face being such that the mask has a dimension along a line parallel to said planar surface which is equal to the sum of a desired device dimension and an increment to compensate for dopant movement during subsequent processing, and performing a conductivity converting operation at such an angle to said planar surface that the conductivity of the surface region of the semiconductor crystal is converted up to a point lying under the mask.
Claim 2
Independent Claim
123 words
A method of forming a semiconductor device comprising the successive steps of depositing material at a low angle with respect to a planar surface of a semiconductor crystal in order to form a mask against a locating face lying perpendicular to said planar surface, the height of the locating face being such that the mask has a dimension along a line parallel to said planar surface which is equal to the sum of a desired device dimension and an increment to compensate for dopant movement during subsequent processing, and performing a conductivity converting operation at such an angle to said planar surface that the conductivity of the surface region of the semiconductor crystal is converted up to a point lying under the mask.
Claim 3
Dependent Claim
17 words
A method as claimed in claim 1, in which the conductivity-converting operation is an ion implantation operation.
Claim 4
Dependent Claim
18 words
A method as claimed in claim 1 or 2, in which the mask is deposited by vacumn deposition.
Claim 5
Independent Claim
61 words
A method as claimed in any preceding claim, which includes the subsequent steps of removing the mask and depositing an electrode against said locating face, the electrode having a dimension along a line parallel to said planar surface which is less than the distance from the locating surface to said point upto which the conductivity of the surface region was converted.
Claim 6
Dependent Claim
16 words
A method as claimed in claim 4, in which the electrode is deposited by vacumn deposition.
Claim 7
Dependent Claim
20 words
A method as claimed in claim 4 or claim 5, including performing an annealing operation before the electrode is deposited.
Claim 8
Independent Claim
50 words
A method as claimed in any of claims 4 to 6, including forming, prior to depositing the mask material, a gate oxide layer on said planar surface so that the gate oxide layer abuts the locating face whereby a MOSFET device is produced, said electrode serving as its gate electrode.
References Cited (Backward Citations)
No citation records indexed.
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