| 摘要 |
PURPOSE:To form a grown layer of superior quality and to improve yield rate by a method wherein a protective plate, whose surface is etched by mixed liquid with hydrochloric acid, hydrobronic and hydrogen peroxide, is used in case that a protective plate of gallium arsenic for protecting a substrate until raw material solution is made the substrate contact. CONSTITUTION:A protective plate 4a is constituted by GaAs and is etched by mixed liquid with e.g. HCl 36%, HBr 47% and H2O2 31% at the ratio, whose volume rate is 40:1:1, prior to protect a substrate. Thereby, a surface layer, which is removed together with a polluting substance, is almost uniform and a peripheral section does not become taper state as usual but flatten. Besides, existence of P is not observed even through P is contained in the polluting substance. Consequently, if protecting the substrate is performed by the protective plate 4a, adhesion with surroundings of the retaining section 2a of the substrate is improved and the substrate 1 is able to be isolated sufficiently, then the above-mentioned pollution of the raw material 3 by P before contact with the substrate 1 is eliminated and also the fine growth layer is obtained. |
