International Business Machines Corporation

Roger Andrew Verhelst

David V Horak

Toshiharu Furukawa

Mark Charles Hakey

Harold Pilo

Steven Harley Lamphier

Archibald John Allen

Edward F O'Neil

Ronald DeSales Rossi

Kevin George Petrunich

Paul Stafford Zerr

The present invention overcomes the difficulties found in the background art by providing a direct low resistive contact between devices on a semiconductor chip without excessive current leakage. Current leakage is prevented in the preferred design by using silicon on insulator (SOI) construction for the chip. By constructing the direct contact over an insulator, such as silicon dioxide, current leakage is minimized. The preferred embodiment uses silicide to connect a polysilicon gate to a doped region of the substrate. An alternative embodiment of the present invention provides for the use of conductive studs to electrically connect devices. An increased density of approximately twenty percent may be realized using the present invention.

Device contact structure and method for fabricating same

Circuit and method are presented for activating/deactivating a special operational mode at power-on of an integrated circuit device having no industry defined test state and/or dedicated test pin. The operational mode is enabled upon powering on the integrated circuit combined with detection of a predefined pattern of a first logic state and a second logic state clocked in successive cycles within a first standard input signal, such as an output enable signal, for a normal operating mode of the device. Special non-functional processing is then performed, such as reading prestored identification data from the integrated circuit and/or testing the integrated circuit via embedded test circuitry including boundary scan or other diagnostic circuitry. This special operational mode is deactivated upon receipt at the integrated circuit device of a second standard input signal, such as a write signal for a random access memory (RAM) device, of a predefined logic state (e.g., write enable state). Deactivating of the special operating mode is transparent to the normal response of the integrated circuit device to the second standard input signal.

Special mode enable transparent to normal mode operation

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Colchester, VT, United States of America

Roger Andrew Verhelst