Method of making a high breakdown active device structure with low series resistance
AssigneeHarris Corporation
InventorJames D. Beasom
Life of this patent
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Abstract
Series resistance in the low impurity portion of a high breakdown PN junction of a three or four layer device is reduced by providing an increased inpurity region at the junction of the same conductivity type as the low impurity portion and having an impurity profile such that the increased impurity region is depleted under reverse biasing before critical field is reached therein. The three layer devices include insulated gate field effect transistors and bipolar devices and the four layer device is a semiconductor controlled rectifier (SCR).
Claims16
A method of forming a three layer device, comprising:
- introducing a first conductivity type impurities into a substrate of said first conductivity type to form a first region;
- introducing a second conductivity type impurities into said first region to form a second region in and totally separated from said substrate by said first region;
- and
- introducing first conductivity type impurities into said second region to form a third region totally separated from said first region by said second region.
A method of forming a four layer device, comprising:
- introducing first conductivity type impurities in a substrate of said first conductivity type to form spaced first and second regions;
- introducing second conductivity type impurities into said first and second regions to form third and fourth regions separated from said substrate by said first and second regions respectively;
- and
- introducing first conductivity type impurities into said third region to form a fifth region separated from said first region by said third region.
A method of forming a two layer device, comprising:
- introducing a first conductivity type impurities into a substrate of said first conductivity type to form a first region having an impurity concentration profile which will deplete under reverse biasing before critical field is reached in said first region;
- and
- introducing a second conductivity type impurities to form a second region totally separated from said substrate by said first region.
A method of forming a three layer device, comprising:
- introducing a first conductivity type impurities into a substrate of said first conductivity type to form a first region having an impurity concentration profile which will deplete under reverse biasing before critical field is reached in said first region;
- introducing a second conductivity type impurities to form a second region totally separated from said substrate by said first region;
- and
- introducing first conductivity type impurities to form a third region totally separated from said first region by said second region.
A method of forming a four layer device, comprising:
- introducing first conductivity type impurities in a substrate of said first conductivity type to form spaced first and second regions having concentration profile which will deplete under reverse biasing before critical field is reached in said first region;
- introducing second conductivity type impurities to form third and fourth regions separated from said substrate by said first and second regions respectively;
- and
- introducing first conductivity type impurities to form a fifth region separated from said first region by said third region.
Dependencies are inferred from the claim text.