GB1288278A - - Google Patents

Abstract

1288278 Semi-conductor device TEXAS INSTRUMENTS Inc 20 Nov 1969 [31 Dec 1968] 56861/69 Heading H1K The (110) surface of a semi-conductor body has a recess therein which is bounded by {111} planes which form walls perpendicular to the {110} planes. In one embodiment (Figs. 7 to 16, not shown) dielectrically isolated circuits components are formed by epitaxially depositing N- type Si 36 on an N<SP>+</SP>-type Si layer 21, forming a silicon oxide layer 37 thereon and growing a high resistivity polycrystalline Si supporting layer 38 on the oxide layer 37, (Fig. 9, not shown). The layer 21 is lapped and polished and a photo mask 50 formed thereon, Fig. 11. The layer 21 and epitaxial layer 36 are etched using an aqueous solution of ethylenediamine and pyrocatechol to give isolated semi-conductor portions shaped as parallelepipeds (Figs. 12 and 16, not shown). The mask 50 is removed and a silicon oxide layer 46 formed over the isolated portions (Fig. 13, not shown) and a thick supporting layer 47 of polycrystalline Si formed over the oxide layer 46. The body is inverted and the supporting layer 38 removed by lapping and polishing to expose the oxide layer 37. The devices may be separated by scribing and breaking. In another embodiment (Figs. 1 to 6, not shown) parallelepiped pockets (29, 30) of epitaxially deposited semiconductor material are formed in semi-conductor body (21).