| 摘要 |
1,131,229. Semi-conductor devices. TEXAS INSTRUMENTS Inc. 11 Feb., 1966 [26 Feb., 1965 (2)], No. 6166/66. Heading H1K. Portions of mutually isolated low resistivity semi-conductor regions 12, 14 on a substrate 20 are removed through an insulating mask 22, and high resistivity material 30, 31 is epitaxially deposited in place of the removed material. Removal is preferably by vapour etching, the etching and re-deposition stages both being carried out in the same apparatus simply by changing the constitution of the vapours impinging on the substrate. The regions 12, 14 are isolated from the substrate 20 by insulating material 17, e.g. silicon oxide. Manufacture of the illustrated embodiment comprises initially forming an array of mesas (11-15), Fig. 1 (not shown), by masking and etching an N+ Si body (10). An insulating silicon oxide coating (16) is then grown over the surface including the mesas, and the parts of it not actually on the mesas are lapped or etched away to leave only the parts (17), Figs. 2, 3 (not shown) covering the mesas. A support layer (20) of epitaxial monocrystalline, polycrystalline or amorphous Si is grown over the mesas and their covering (17), and the Si body (10) is then lapped and polished away to leave only the mutually insulated and separated mesa regions (11-15) in a substrate (10). An oxide layer 22, Fig. 7, is deposited or grown and apertures 26, 27 are formed therein by etching. The process of vapour etching and redeposition is then effected, and discrete devices such as transistors, diodes and resistors are diffused or deposited in the resulting regions 30, 31. An integrated circuit is completed by the deposition of metal strips linking the devices. In one form layers of Mo or W are formed on the tops of the mesas initially, thereby providing a lowresistivity path lining the cavities in which the devices lie. The substrate surface on which the selective etching and redeposition occurs preferably lies in a plane other than a (111) plane. |
