A new nonpoisonous polishing slurry used in ultra-flat InP substrates production

InP is a very important III-V compound semiconductor, which is a material for increasing applications in opto-electronic fiber communications, opto-electronic integrated circuits (OEICs) and high frequency devices,such as HEMTs, HBTs and MISFETs. Most of these devices are fabricated by using epitaxial growth technologies, such as LPE, MBE, MOCVD and CBE. Epi-layer duality is key problem for them. Bromine-methanol polishing technology (1) for InP substrate is commonly used, but said bromine-methanol is not a good polishing solution, because of its severe corrosion, poison and unsatisfied flatness of the polished surface. These situations require a further development of InP polishing slurry to replace the bromine-methanol solution. Bromine-methanol polishing technology is basically a chemical polishing,not a mechano-chemical polishing. In this paper, we will mainly report a new nonpoisonous polishing slurry, H₃PO₄ -based slurry. Mechano-chemical polishing for InP can be carried out by H₃PO₄-based slurry and ultra-flat LnP wafers have been obtained