EP0414400A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
MOSFET depletion device
Assignee: Delco Electronics LLC
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Filing: 1990-08-06
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Granted: —
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Expires: 2010-08-06
Abstract
Abstract A p-channel depletion device (10) in a MOSFET is formed and preferably comprises a silicon substrate (12), an N-well region (14), P+ source (16) and drain (18) regions, and a polysilicon gate (20) which has been appropriately doped to be of a P- conductivity type. The resulting structure performs analogously to a depletion device formed in accordance with conventional methods wherein a depletion mask and implant are utilized, and is characterized by having a threshold voltage of approximately +250 millivolts.
Inventors
- 👤 Mark F. Henderson
- 👤 John R. Schlais
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 02:13
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/80; H10D84/82; H10D84/83; H10D84/84; H10D30/00; H10D30/60; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01306; H10D64/60; H10D64/66; H10D64/661; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0165; H10D84/0172; H10D84/0177; H10D84/02; H10D84/03; H10D84/038; H10D84/85; H10D84/857; H10D84/83135
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
62 words
A p-channel depletion device (10) in an MOSFET comprising the following: an N-well region (14) of conductivity type within an appropriate substrate (12); source (16) and drain (18) regions of P+ conductivity type within said N-well region (14); and a polysilicon gate region (20) of P- conductivity type; characterised in that the threshold voltage of said device (10) is approximately +250 millivolts.
Claim 2
Dependent Claim
62 words
A p-channel depletion device (10) in an MOSFET comprising the following: an N-well region (14) of conductivity type within an appropriate substrate (12); source (16) and drain (18) regions of P+ conductivity type within said N-well region (14); and a polysilicon gate region (20) of P- conductivity type; characterised in that the threshold voltage of said device (10) is approximately +250 millivolts.
Claim 3
Dependent Claim
96 words
A method for forming a p-channel depletion device (10) according to claim 1, in an MOSFET, which method comprises the following steps: forming an N-well region (14) of conductivity type within an appropriate substrate (12); forming a polysilicon gate (40) over said N-well region (14) which is characterized by a N-- conductivity type; and implanting boron into said N-well region (14) to form source (16) and drain (18) regions of P+ type conductivity whilst concurrently counter-doping said gate (40), so that said gate (40) is changed into a gate (20) characterized by a P- type conductivity.
References Cited (Backward Citations)
No citation records indexed.
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