US 7,888,732 B2 · Lateral drain-extended MOSFET having channel along sidewall of drain extension dielectric

Abstract

An integrated circuit (200) includes one of more transistors (210) on or in a substrate (10) having semiconductor surface layer, the surface layer having a top surface. At least one of the transistors are drain extended metal-oxide-semiconductor (DEMOS) transistor (210). The DEMOS transistor includes a drift region (14) in the surface layer having a first dopant type, a field dielectric (23) in or on a portion of said surface layer, and a body region of a second dopant type (16) within the drift region (14). The body region (16) has a body wall extending from the top surface of the surface layer downwards along at least a portion of a dielectric wall of an adjacent field dielectric region. A gate dielectric (21) is on at least a portion of the body wall. An electrically conductive gate electrode (22) is on the gate dielectric (21) on the body wall. A source region (18) of the first doping type is in the body region (16), a drain region (20) of the first doping type is in the drift region (14), and interconnects (521) are operable to electrically connect the one or more transistors to each other on the integrated circuit (200).

Claims24

Dependent claims

An integrated circuit including at least one drain extended metal oxide semiconductor (DEMOS) transistor, comprising:

a drift region in a surface layer having a first dopant type;
a field dielectric in or on a portion of the surface layer;
a body region of a second dopant type within the drift region, the body region having a body wall extending from a top surface of the surface layer downwards along at least a portion of a dielectric wall of the field dielectric region;
a gate dielectric on at least a portion of the body wall;
a gate electrode on the gate dielectric on the body wall;
a source region of the first doping in the body region;
and
a drain region of the first doping type in the drift region.

5 more elements

An integrated circuit including a drain extended metal-oxide-semiconductor (DEMOS) transistor, comprising:

a substrate having a semiconductor surface;
a drift region of first dopant type formed in the surface;
a field dielectric formed in a portion of the drift region;
a body region of second dopant type formed in the drift region;
a gate electrode having a portion formed with a vertical component depending into the drift region between the body region and the field dielectric;
a gate dielectric having a portion formed with a vertical component depending into the drift region between the vertical component of the gate electrode and the body region;
a source region of the first dopant type formed in the body region proximate a side facing the body region of the vertical component of the gate dielectric;
a drain region of the first dopant type formed in the surface proximate a side of the field dielectric opposite the vertical component of the gate electrode and in electrical communication with the drift region;
whereby a channel region is defined in the body region with a vertical component corresponding to at least a portion of the vertical components of the gate dielectric and gate electrode between the source region and a part of the drift region located below the body region.

6 more elements

Dependencies are inferred from the claim text.

Lateral drain-extended MOSFET having channel along sidewall of drain extension dielectric

Life of this patent

Lateral drain-extended MOSFET having channel along sidewall of drain extension dielectric

Life of this patent

Abstract

Claims24