It was found, using deep-level transient spectroscopy, that chemical etching induced 2 isolated point defects, E1(0.26-0.31) and E2(0.20), into the near-surface region of n-type ZnSe single crystals. The etching effect on the traps in Br-doped ZnSe bulk crystals was studied by using 5%Br-methanol solution, and then the E1 trap density increased with the chemical etching time, and reached to maximum value of 5.3 x 1013/cm3. The E1 trap was obtained in the samples etched in some kinds of acid solutions, Br-methanol solution, HCl, and HBr, but did hardly in NaOH alkali etchant. These results suggested that the E1 trap was induced during the chemical etching and diffuse into the interior of the crystals. From above etching effects, the tentative identification was proposed that E1 and E2 traps arose from 2 kinds of H-related defects.

Chemical Etching-Induced Defects in n-Type ZnSe Crystal Grown by Physical Vapor Transport. M.Yoneta, H.Kato, K.Yoshino, M.Ohishi, H.Saito, K.Ohmori: Physica Status Solidi C, 2003, 0[2], 635-9