Delco Electronics Corporation

Paul E Stevenson

Ronald E Brown

Douglas J Yoder

Ronald K Leisure

Donald L Hornback

Nadeem S Alvi

A monolithic pressure sensitive silicon integrated circuit is formed by first providing a localized etch-stop layer on one surface of the silicon chip, then growing successive epitaxial layers of opposite conductivity types over this surface. In the upper of the two layers, there is formed a bridge of four piezoresistors overlying the periphery of the etch-stop layer and the conditioning circuitry for amplifying the output of the bridge including both lateral and vertical junction transistors. The back surface of the chip is etched anisotropically to form a cavity that leaves a thin diaphragm underlying the bridge of the four piezoresistors.

Monolithic pressure sensitive integrated circuit

A process for forming CMOS devices uses outdiffusion of implanted ions in a patterned refractory silicidable layer to form the source/drain regions of the device. Moreover, the oxidation of the sidewalls of openings formed in the layer serves to isolate the layer from the polysilicon gate electrode which is later formed in the openings in this layer.

Grown side-wall silicided source/drain self-align CMOS fabrication

A piezoresistive pressure transducer is formed in a silicon layer which has been grown over a monocrystalline silicon substrate, a central portion of which had been earlier coated with a silicon dioxide layer having a plurality of apertures under each of which had been formed a heavily doped etch resistant region. The silicon layer is grown epitaxially over the apertures to be monocrystalline but grows as polycrystalline material over the silicon dioxide. Then the silicon substrate is etched to remove its central portion under the silicon dioxide and the heavily doped regions, leaving a thick surrounding portion for support. Resistors are formed in the monocrystalline portions of the grown layer overlying the heavily doped regions.

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Kokomo, IN, United States of America

Paul E Stevenson