PROCESSING OF SEMICONDUCTOR SUBSTRATE

摘要

PURPOSE:To remove residual In securely and protect an epitaxial growth surface from damage by a method wherein after a III-V compound semiconductor layer is formed on a semiconductor substrate by epitaxial growth in a solution whose solvent is In the substrate is immersed in metal Ga at low temperature. CONSTITUTION:An InP substrate 4 on which an epitaxial growth layer is formed is immersed in melted metal Ga kept in a carbon crucible at the temperature 200 deg.C and the temperature is kept at 200 deg.C about 30min. By this process, a small amount of In remained on the substrate produces Ga-rich In-Ga solution with the metal Ga. Then the crucible is cooled to the room temperature and an In-Ga alloy layer is formed on the substrate 4. Because a eutectic temperature of the In-Ga alloy is approximately as low as 15.7 deg.C, it isn't necessary to heat the substrate 4 to the temperature higher than 156 deg.C, a melting point of pure In, to remove the residual In. The In-Ga solution on the substrate can be easily wiped off by soft textile such as a cotton ball after immersed in warm water approximately 40 deg.C so that damage or cracking which occurs when the substrate is heated to high temperature for removing In by conventional method.