SELECTIVE GROWTH-CONDITIONS OF ZNSE ZNS HETEROSTRUCTURES ON (001)GAASWITH METALORGANIC MOLECULAR-BEAM EPITAXY/

Selective growth of ZnSe and ZnS on (001) GaAs substrates partially co vered with SiOx was examined by metalorganic molecular-beam epitaxy. T he growth temperature was the key factor for the selective growth, and the minimum growth temperature of ZnS to achieve selective growth was 450 degrees C. On the other hand, the minimum growth temperature of Z nSe was 500 degrees C. This difference of temperature for the selectiv e growth made it difficult to grow high-quality ZnSe/ZnS heterostructu res. To overcome this problem, we used periodic supply epitaxy to lowe r the selective growth temperature of ZnSe. Supply interruption after short time supply of ZnSe enhances the desorption of precursors especi ally on SiOx surfaces and this suppresses the nucleation of ZnSe on Si Ox surfaces. The lower VI/II ratio also suppresses nucleation of ZnSe on SiOx. The selective growth of ZnSe was thus achieved at 430 degrees C with a VI/II ratio of 1. The minimum selective growth temperature r eported on ZnSe up to now is 600 degrees C, and this work demonstrated the selective growth of ZnSe at a considerably lower temperature. We have prepared a ZnSe/ZnS single quantum well (SQW) at 450 degrees C un der the selective growth condition and the bright band edge emission f rom the ZnSe well was observed by photoluminescence measurement at 13 K.