GROWTH-CHARACTERISTICS OF CDZNTE LAYERS GROWN BY METALORGANIC VAPOR-PHASE EPITAXY USING DIMETHYLZINC, DIMETHYLCADMIUM, DIETHYLTELLURIDE, AND DIMETHYLTELLURIDE AS PRECURSORS
K. Yasuda et al., GROWTH-CHARACTERISTICS OF CDZNTE LAYERS GROWN BY METALORGANIC VAPOR-PHASE EPITAXY USING DIMETHYLZINC, DIMETHYLCADMIUM, DIETHYLTELLURIDE, AND DIMETHYLTELLURIDE AS PRECURSORS, Journal of electronic materials, 27(8), 1998, pp. 948-953
Growth characteristics of (100)-oriented CdZnTe layers grown by atmosp
heric pressure metalorganic vapor phase epitaxy have been studied usin
g dimethylzinc (DMZn), dimethylcadmium (DMCd), diethyltelluride (DETe)
,and dimethyltelluride (DMTe) as precursors. Variations of Zn composit
ion and layer growth rate were examined by changing the DMZn supply ra
tio, defined as DMZn/(DMCd+DMZn), where the precursors are expressed i
n appropriate units of now rate, from 0 (no DMZn) to 1.0 (no DMCd), wh
ile keeping the total group II supply rate constant. The growth rate o
f CdZnTe layers was found to decrease monotonically with increase of t
he DMZn supply ratio. On the other hand, the Zn composition x of grown
layers increased gradually up to x = 0.04 with increase of the DMZn s
upply ratio from 0 to 0.8, beyond which the Zn composition increased a
bruptly to ZnTe. The abrupt transition of Zn composition was suppresse
d by increasing the VI/II ratio. The growth mechanism of CdZnTe layers
was studied based on the observed growth characteristics of CdTe and
ZnTe. A higher desorption rate from the growth surface for Zn species
than for Cd species, and a higher rate of CdTe formation than ZnTe for
mation are believed to cause the observed growth characteristics. CdZn
Te layers with high crystal quality were grown in a wide range of Zn c
ompositions. The full-width at half-maximum values for x-ray double-cr
ystal rocking-curve measurements were lower than 320 are-sec for x < 0
.3 and x > 0.75.