| 摘要 |
1,113,287. Etching. MOTOROLA Inc. 12 July, 1966 [17 Aug., 1965], No. 31298/66. Heading B6J. [Also in Division H1] Semi-conductor material, such as silicon, germanium or gallium arsenide, is etched in the vapour of a halide of the material (in the case of a compound such as gallium arsenide, a halide of either element) mixed with an inert diluent such as helium, argon, neon, xenon, krypton or nitrogen, the halide comprising 0À01-25% by volume of the mixture, at a temperature above 700‹ C. Wafers 21 on a quartz slab 22 resting on a graphite or molybdenum susceptor 23 heated by an induction coil 24 are etched in a quartz chamber 26 to which gas is admitted through a pipe 28. Silicon tetrachloride in liquid form is contained in a saturator 30. Inert gas from a source 58 is used to flush the chamber. Inert gas from 31 is passed through the liquid, and the proportions are controlled by admitting inert gas from 43. After etching, the chamber may be flushed with hydrogen from 63, and thereafter hydrogen from 48 is passed through the liquid and the mixture is passed together with hydrogen from 53 to cause epitaxial growth. The temperature for etching is 800‹-1400‹ C. for silicon and 700‹-930‹ C. for germanium.
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