Fishing – trapping – and vermin destroying
Patent
1989-04-03
1991-03-19
Chaudhuri, O.
Fishing, trapping, and vermin destroying
437 62, H01L 21331
Patent
active
050010751
ABSTRACT:
Improved dielectrically isolated semiconductor structures especially suited for very high frequency bipolar transistors are produced. Recesses are formed in a (e.g., N.sup.+) single crystal semiconductor wafer, the wafer surface is coated with a dielectric, and a thick polycrystalline semiconductor layer is deposited thereon to provide a support. The single crystal wafer is back-lapped to expose dielectrically isolated N.sup.+ islands located between the original recesses. Depressions are etched in the N.sup.+ islands and the exposed surface is covered by a more lightly doped (e.g., N.sup.-) semiconductor layer which is, generally, single crystal above the N.sup.+ islands and non-single crystal therebetween, and which at least fills the depressions. The structure is then planarized (e.g., by lapping and etching) to remove this non-single crystal material and give isolated single crystal islands having a surrounding N.sup.+ periphery and an N.sup.- central epi region of well controlled thickness and a smooth outer surface suitable for device formation. Bipolar transistors of excellent properties are formed by providing a nested base and emitter within the central region. Other types of devices may also be formed. The surrounding N.sup.+ periphery automatically provides a buried layer and buried layer contact.
REFERENCES:
patent: 3407479 (1965-06-01), Fordemwalt et al.
patent: 3431468 (1967-04-01), Huffman
patent: 3457123 (1969-07-01), Van Pal
patent: 3461003 (1969-08-01), Jackson, Jr.
patent: 3508980 (1970-04-01), Jackson, Jr. et al.
patent: 3876480 (1975-04-01), Davidsohn et al.
patent: 3902936 (1975-09-01), Price
patent: 3929528 (1975-12-01), Davidson et al.
patent: 4566914 (1986-01-01), Hall
patent: 4649630 (1987-03-01), Boland et al.
Paul Sanders, "An Inexpensive Silicon Monolithic IC Process for Microwave Low and Medium Power Circuits", Proceedings RF Expo-West, Feb. 15, 1989, pp. 353-357.
Boland Bernard W.
Sanders Paul W.
Chaudhuri O.
Fourson George R.
Handy Robert M.
Motorola
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