| 摘要 |
1,099,846. Semi-conductor devices. STANDARD TELEPHONES & CABLES Ltd. Dec. 30, 1966 [Jan. 4, 1966], No. 277/66. Heading H1K. In the manufacture of a semi-conductor device silicon is epitaxially deposited to form a PN junction with a polycrystalline silicon substrate which has been melted by R.F. heating and resolidified in a hollow-walled crucible through which coolant can be circulated, the crucible being constructed of metals such as silver having a thermal conductivity of at least 0À49 gramme calories/sec.(cm./‹ C. and a resistivity of not more than 2À665 microhms per cm.<SP>3</SP> at 0‹ C. In a typical case the substrate is prepared by zone refining silicon and then introducing phosphorus into it by zone levelling to give a resistivity of 0À01 ohm. cm. N-type, both processes being carried out in a copper crucible in a stream of argon. A 12-thou. slice is cut from the resulting polycrystalline ingot and placed in an epitaxial deposition apparatus after its surface has been ground, polished, and cleaned. Boron-doped silicon is then deposited on it to a thickness of 10Á to form a Zener junction, the area of which is finally reduced by conventional photolithographic masking and etching steps.
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