SUBSTRATE-QUALITY, SINGLE-CRYSTAL ZNSE FOR HOMOEPITAXY USING SEEDED PHYSICAL VAPOR TRANSPORT

We describe the results of optical and electrical characterization of seeded physical vapor transport (SPVT) ZnSe suitable for use as substrates in homoepitaxy. Photoluminescence, Hall measurements, C-V data and thermally simulated conductivity and luminescence (TSC/TL) results are described. As-grown SPVT wafers are of very high crystallinity and of high resistivity. N-type conductivity can be induced by post-growth Zn-extraction, producing wafers with room temperature resistivities as low as 3.82 OMEGA cm and free carrier densities of approximately 1.5 x 10(15) cm-3. The conductivity is limited by the presence of unwanted acceptors due to Cu and Li impurities. Deep level analysis reveals various electron and hole states within the as-grown specimens. Trap depths and capture cross-sections are evaluated for the major centers.