| 摘要 |
<p>PURPOSE:To prevent the increase of the thickness of an oxide film on the surface of a GaAlAs layer or substrate or the occurrence of etch pits by etching the layer or substrate with an etching soln. having a specified compsn. consisting of H2O2, H3PO4 end H2O. CONSTITUTION:A mixed H2O2-H3PO4 soln. having <=2.3 volume ratio of 30% H2O2 to 85% H3PO4 and contg. >=50% H2O is prepd. as an etching soln. at room temp. and a Ga1-XAlXAs (0<x<1.0) layer or substrate is etched with the etching soln. A satisfactory etched surface free from etch pits is obtd. without increasing the thickness of a natural oxide film. Since the etching soln. has no selectivity to GaAs, the mesa etching of a substrate having GaAs/ GaAlAs heterostructure can be properly carried out with the etching soln.</p> |
