Low Pressure Vapor Phase Epitaxy of High Purity ZnSe Using Metallic Zinc and Selenium as Source Materials

High-purity ZnSe layers have been grown on GaAs(100) substrates at 420°C by low pressure (∼21 kPa) vapor phase epitaxy using metallic zinc and selenium as starting source materials. Zinc vapor and H2Se gas produced by a reaction between selenium and hydrogen are transported into a crystal growth region by H2 carrier gas. Growth rates are 0.05∼0.3 µm/h, and dependent on source transport rates. When the source transport rates are controlled at Zn=Se=1∼3 µmol/min, free exciton emissions dominate 4.2 K photoluminescence spectra, and emissions due to donor-bound excitons and deep level defects become very weak.