Texas Instruments Corporation

Chin-yu Tsai

Imran Khan

Xiaoju Wu

Guruvayurappan Mathur

Shaoping Tang

An integrated circuit includes an extended drain MOS transistor. The substrate of the integrated circuit has a lower layer with a first conductivity type. A drain well of the extended drain MOS transistor has the first conductivity type. The drain well is separated from the lower layer by a drain isolation well having a second, opposite, conductivity type. A source region of the extended drain MOS transistor is separated from the lower layer by a body well having the second conductivity type. Both the drain isolation well and the body well contact the lower layer. An average dopant density of the second conductivity type in the drain isolation well is less than an average dopant density of the second conductivity type in the body well.

Extended drain MOS with dual well isolation

A p-channel drain extended metal oxide semiconductor (DEPMOS) device includes a doped surface layer at least one nwell finger defining an nwell length and width direction within the doped surface layer. A first pwell is on one side of the nwell finger including a p+ source and a second pwell is on an opposite side of the nwell finger including a p+ drain. A gate stack defines a channel region of the nwell finger between the source and drain. A field dielectric layer is on a portion of the doped surface layer defining active area boundaries including a first active area having a first active area boundary including a first active area boundary along the width direction (WD boundary). The nwell finger includes a reduced doping finger edge region over a portion of the WD boundary.

P-channel DEMOS device

An n-channel DEMOS device a pwell finger defining a length and a width direction formed within a doped surface layer. A first nwell is on one side of the pwell finger including a source and a second nwell on an opposite side of the pwell finger includes a drain. A gate stack is over a channel region the pwell finger between the source and drain. A field dielectric layer is on the surface layer defining a first active area including a first active area boundary along the width direction (WD boundary) that has the channel region therein. A first p-type layer is outside the first active area at least a first minimum distance from the WD boundary and a second p-type layer is doped less and is closer to the WD boundary than the first minimum distance.

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Allen, TX, United States of America

Chin-yu Tsai