PHASE-SEPARATION IN ZNSE1-XSX AND ZN1-YMGYSE1-XSX LAYERS GROWN BY MOLECULAR-BEAM EPITAXY

The occurrence of phase separation in (100) ZnSe1-xSx and Zn1-yMgySe1- xSx layers grown by molecular beam epitaxy was found by transmission e lectron microscopy. The direction of the phase separation is [011], an d the period of the composition modulation ranges from 300 to 500 angs trom. X-ray microanalysis of the two regions resulting from the phase separation showed one to be sulfur-rich and the other sulfur-deficient . The one-to-one correspondence of the wavy surface structure and the composition modulation suggests that the phase separation occurs via n onuniform incorporation of sulfur atoms into the wavy growth plane of the epilayer.