Motorola Corporation

Judith L Sutor

Stephen P Robb

Lewis E Terry

Gary V Fay

David M Susak

Dennis L Welty

John Bliss

Lloyd H Hayes

Chi-Sung Chang

An object of the present invention is to provide an LD-MOS transistor with a reduced device real estate and high breakdown strength. An extended drain region doped with phosphorus is formed in contact with an underside of an insulation layer and a drain diffusion region, respectively. The insulation layer is deposited over a conductive gate layer and a drain diffusion region, respectively.

LD-MOS transistor

A transient protection circuit provides protection from high voltage transients appearing along a transmission line by sensing a predetermined threshold of the voltage developed thereon and opening the conduction path through first and second switching circuits in the transmission line. The switching circuits are implemented with first and second serially coupled transistors sharing a common drain and enabled by a control signal during normal operation. The first and second transistors each have a diode oriented to conduct from the source to the drain for bi-directional operation. During high voltage transient conditions, a sensing circuit detect a predetermined threshold of the potential on the transmission line and disables one of the first and second transistors which opens the conduction path through the first and second switching circuits thereby suppressing the surge currents flowing therethrough.

Transient protection circuit using common drain field effect transistors

MOSFET devices or circuits incorporating an improved substrate temperature sensing element are obtained by forming a PN junction directly on a thin (gate) dielectric region. The temperature sense junction is desirably formed in a poly layer. By mounting it directly on thin (gate) dielectric its thermal response to temperature changes in the substrate is improved while still being electrically isolated from the substrate. It is desirable to provide over-voltage protection elements coupled to the junction to avoid rupture of the underlying thin dielectric. Because the sense diode and all the over-voltage protection devices may be made of poly with junctions perpendicular to the substrate, the structure is particularly compact and simple to fabricate.

Process for forming a semiconductor structure with closely coupled

Semiconductor structure with closely coupled substrate temperature sense

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Chandler, AZ, United States of America

Judith L Sutor