GB1153051A - Electrical Isolation of Semiconductor Circuit Components - Google Patents

Abstract

1,153,051. Semi-conductor devices. TEXAS INSTRUMENTS Inc. 23 June, 1966 [30 June, 1965], No. 28061/66. Heading H1K. A semi-conductor component, e.g. transistor T 1 , is formed adjacent one major surface of a semi-conductor body whose other major surface is attached to an insulating layer 11, the transistor being isolated from the surrounding semi-conductor material by channels 35, 36 extending through to the layer 11. In the integrated circuit shown, the transistor T 1 is connected to the other components such as resistor R 1 by metal interconnections 21, 26 which overlie an oxide coating 15 and which cross the channels 35, 36. The channels are etched through the oxide coating 15 and the underlying semi-conductor material after formation of the various components by diffusion into an N-type epitaxial Si layer 14 on an N+ -type Si wafer 10, and after deposition of the interconnections 21, 26, which may comprise successive evaporated layers of Mo and Au. Further Au may be electroplated on to the interconnections. As shown, the insulating layer 11 is an oxide coating applied to the wafer 10 and subsequently covered by a polycrystalline Si support 13. The integrated circuit may include diodes, field effect transistors and oxide dielectric capacitors. A second embodiment comprises a single transistor (40), Fig. 12 (not shown), formed in the same manner as that illustrated and similarly isolated from surrounding semi-conductor material which carries an oxide coating (57) on which are deposited contact pads (49, 52, 55) joined respectively to the emitter, collector and base regions by interconnections (48, 51, 56) bridging the channel (47) which surrounds the active part of the device.