| 摘要 |
1,223,707. Etching. TEXAS INSTRUMENTS Inc. 12 June, 1968 [11 Dec., 1967], No. 27938/68. Heading B6J. [Also in Division C1] A single crystal Si body is vapour etched by heating it to 1075-1420‹ C., preferably 1250- 1350‹ C. and passing the following gases over the body in sequence: (1) H2, (2) HX+H 2 for ¢-5 mins. in a vol. ratio of 2 : 10 to 3 : 10, (3) H 2 for more than 1 min., (4) HX+H 2 for 5-30 mins. in a vol. ratio of 0À5 : 10 to 1À5 : 10. Steps 1 and 2 may then be repeated twice more. Si is then deposited on the body by increasing the H 2 flow rate, adding a stream of SiHCl 3 and H 2 such that the concentration of SiHCl 3 is 2-10 vol. per cent, reducing the HX concentration to less than 2%, and reducing the temperature, e.g. to 1200‹ or 1250‹ C. HX is preferably HCI or HBr, but HI and HF are mentioned.
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