DMOS transistors with schottky diode body structure
First Claim
1. A DMOS transistor for an IC circuit, comprising:
- an epitaxial layer of a first conductivity type formed over a substrate;
a deep barrier region formed within adjoining surface portions of the substrate and the epitaxial layer;
a deep drain region extending from a surface of the epitaxial layer to outer peripheral regions of the deep barrier region to define a well region within the epitaxial layer;
a body region of a second conductivity type formed within the well region;
first and second source regions of the first conductivity type positioned at a surface of the well region and within the body region;
first and second portions of gate electrodes positioned above the first and second source regions, respectively, the body region, and the well region;
a conductive drain contact coupled to the deep drain region; and
a metallic source contact coupled to the first and second source regions and to a central portion of the well region.
2 Assignments
0 Petitions
Accused Products
Abstract
A DMOS device in a complex integrated circuit having a well region defined by a buried isolation region and an overlapping deep drain region within an epitaxial layer formed over a substrate, a body region having two source regions within the well region, insulated gates over the two source regions, and a Schottky contact over a central portion of the well region and spaced from the body region. The Schottky contact defines a Schottky diode within the epitaxial layer for diverting current from the substrate in the event of a below ground effect or an oversupply effect. The invention reduces or eliminates altogether the effects of parasitic transistors in the complex integrated circuit.
60 Citations
13 Claims
-
1. A DMOS transistor for an IC circuit, comprising:
-
an epitaxial layer of a first conductivity type formed over a substrate; a deep barrier region formed within adjoining surface portions of the substrate and the epitaxial layer; a deep drain region extending from a surface of the epitaxial layer to outer peripheral regions of the deep barrier region to define a well region within the epitaxial layer; a body region of a second conductivity type formed within the well region; first and second source regions of the first conductivity type positioned at a surface of the well region and within the body region; first and second portions of gate electrodes positioned above the first and second source regions, respectively, the body region, and the well region; a conductive drain contact coupled to the deep drain region; and a metallic source contact coupled to the first and second source regions and to a central portion of the well region. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A DMOS device for reducing the effects of parasitic devices in an IC circuit driving an inductive load, the device comprising:
-
an epitaxial layer formed on a substrate; a well region formed by a deep drain region extending from a surface of the epitaxial layer and over a peripheral area of a deep barrier region located within the epitaxial layer and the substrate; a body region within the well region, the body region containing first and second source regions; a plurality of insulated gate electrodes formed over outer portions and inner central portions of the first and second source regions, respectively, the body region, and the well region; a guard ring in a central surface portion of the well region and surrounded by the body region; a first metallic contact coupled to the deep drain region; and a Schottky metallic contact coupled to the source regions and to the central surface portion of the well region between the insulated gate electrodes and contacting the guard ring.
-
-
7. A DMOS device for reducing operational effects of parasitic devices associated with IC circuits, the device comprising:
-
a well region defined by a buried isolation region having an overlapping deep drain region within an epitaxial layer; a body region containing first and second source regions within the well region; insulated gates formed over a portion of the first and second source regions; and a Schottky contact coupled to a central portion of the well region and spaced from the body region, the Schottky contact defining a portion of a Schottky diode within the epitaxial layer having operational characteristic means for reducing operational characteristics of parasitic devices associated with IC circuits. - View Dependent Claims (8)
-
-
9. A DMOS transistor in an IC circuit, comprising:
-
an epitaxial layer of a first conductivity type formed over a substrate of a second conductivity type; a drain region of a first conductivity type formed within the epitaxial layer; a body region of the second conductivity type formed within the epitaxial layer; a source region of the first conductivity type formed within the body region; a gate electrode positioned above the source region, the body region, and the epitaxial layer; a conductive drain contact coupled to the drain region; and a metallic source contact coupled to the source region and to the epitaxial layer. - View Dependent Claims (10, 11, 12, 13)
-
Specification