| 摘要 |
PURPOSE:To make it possible to carry out the titled etching extremely precisely controlled, by repeating a process wherein a halogen gas or a hydrogen halide gas adsorbed on substrate crystal and a process wherein an element of group III is vaporized as a halide of the element of group III of III-V compound semiconductor. CONSTITUTION:In gaseous-phase etching method for III-V compound semiconductor such as GaAs, etc., as a first process, a halogen gas such as Cl2, etc., or a hydrogen halide gas such as HCl, etc., is adsorbed on substrate crystal. For example, after HCl is adsorbed, feed of HCl is stopped and, as a second process, temperature of the substrate crystal is raised and Ga is removed as GaCl from crystal surface. By this first and second processes, a monomolecular layer on the surface of the substrate crystal is etched. Consequently, the depth of etching depends only on number of repetition of the first and the second processes and can be controlled in unit of the monomolecular layer. Further, since absorption of HCl does not depend on temperature if temperature is <=a fixed substrate temperature and absorption uniformly occurs in the whole surface of the substrate, depth of etching is completely made uniform.
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