Thomas M Herman

US Patent:

45352518, Aug 13, 1985

Filed:

Dec 21, 1982

Appl. No.:

6/451792

Inventors:

Thomas Herman - Redondo Beach CA
Oliver Williams - Camarillo CA

Assignee:

International Rectifier Corporation - Los Angeles CA

International Classification:

G02B 2700

US Classification:

250551

Abstract:

A solid state a. c. relay has two separate and indentical power thyristors connected in anti-parallel arrangement. The power thyristors are optically switched, lateral conduction devices with anode and cathode electrodes on the same surface. Both are switched by illuminating their surface by reflected illumination from an LED. Each thyristor is provided with a respective control circuit which includes a MOSFET transistor for clamping its respective thyristor gate wherever the voltage across the thryistor exceeds a given absolute value or whenever there is a high dV/dt transient across the thyristor. The control circuit for the control transistor includes a capacitance divider, one element of which is the distributed capacitance of the control transistor. The control circuit components can be integrated into the same semiconductor chip which contains the respective power thyristor. Each of the two identical power chips and the LED chip are spaced from one another and mounted on an alumina substrate.

US Patent:

47791268, Oct 18, 1988

Filed:

Sep 12, 1986

Appl. No.:

6/908867

Inventors:

Thomas Herman - Redondo Beach CA

Assignee:

International Rectifier Corporation - Los Angeles CA

International Classification:

H01L 2974

US Classification:

357 38

Abstract:

An optically triggered lateral thyristor consists of a plurality of individual lateral thyristor elements connected in parallel. Each element has an active base region which contains a respective cathode region. Each of the base regions is carried in a common conductivity type body. Extending fingers of a continuous anode electrode partly enclose each individual base region to enable the parallel connection of the individual devices. The thyristor base and emitter zones are surrounded by an auxiliary P region which is resistively connected to a field plate and the cathode electrode to improve emitter collection efficiency. The cathode electrode and anode electrode are interdigitated. The cathode electrode is connected to spaced, parallel, generally rectangular emitter regions which are disposed in respective bases between loops of the cathode electrode. Radiation applied to the surface of the device by a noncritical photo source produces the effect of a gate current in order to turn on the device.

US Patent:

44122420, Oct 25, 1983

Filed:

Nov 17, 1980

Appl. No.:

6/207123

Inventors:

Thomas Herman - Redondo Beach CA
Alexander Lidow - Manhattan Beach CA

Assignee:

International Rectifier Corporation - Los Angeles CA

International Classification:

H01L 2934

US Classification:

357 52

Abstract:

Two gaps are placed in the reflowed phosphorus-doped silicon dioxide material overcoating of a planar high voltage semiconductor device to prevent polarization of the reflowed silox. The invention is applicable to any device using a polarizable glassy coating which will be exposed to a high electric field extending along its surface and is shown applied to a high voltage diode, a high voltage MOSFET and a high voltage TRIMOS-type device which is a semiconductor switching device using spaced MOS transistors having a common drain region.

US Patent:

43994490, Aug 16, 1983

Filed:

Nov 17, 1980

Appl. No.:

6/207124

Inventors:

Thomas Herman - Redondo Beach CA
Alexander Lidow - Manhattan Beach CA

Assignee:

International Rectifier Corporation - Los Angeles CA

International Classification:

H01L 2940

US Classification:

357 53

Abstract:

A field plate structure is provided to terminate the electrode of a semiconductor device in a manner to reduce curvature of electric field within the body of the semiconductor device underlying the electrode and surrounding the electrode. A stepped electrode outer rim is provided in effect through the use of an underlying polysilicon which drapes over an underlying oxide. The main contact metal, typically aluminum, overlies the polysilicon but is upwardly displaced above the relatively thin polysilicon by a relatively thick oxide layer over the polysilicon. The composite effect of the thin polysilicon layer at one level and the heavier metallizing at a higher level but overlapping the polysilicon is that of a metal electrode deposited atop an insulation layer having two steps therein.