| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a marking accuracy as high as the one obtained through a dry processing, by forming on a compound semiconductor substrate containing As a mask pattern for exposing to the external the region scheduled to form therein a mask-alignment mark, and by heating the substrate to bring the surface of exposed region into the state of a thermal alteration. SOLUTION: By a plasma CVD, an SiN film 6 is deposited on a GaAs substrate 1, and a selective etching of the region scheduled to form therein a mask- alignment mark is applied to the SiN film 6 to remove the etched one therefrom. Thereafter, by a lamp annealing, the intermediate is heated to a high temperature of 850-1000 deg.C to bring the exposed portion of the substrate 1 into a thermal alteration state 7. That is, since GaAs is exposed to the external in the portion of the SiN film 6 being absent, an As-separation is generated selectively in the portion by heating the portion to subject its surface to a rough thermal alteration. The SiN film 6 is a surface protecting film for protecting active regions on the substrate 1, also protecting the generations of cracks caused by thermal stresses, etc., at a heat treatment.</p> |
