Tj. Delyon et al., CDZNTE ON SI(001) AND SI(112) - DIRECT MBE GROWTH FOR LARGE-AREA AGCDTE INFRARED FOCAL-PLANE ARRAY APPLICATIONS, Journal of the Electrochemical Society, 141(10), 1994, pp. 2888-2893
To facilitate the production of HgCdTe IR detectors on Si substrates,
epitaxial films of ZnTe and CdZnTe/ZnTe have been deposited by molecul
ar-beam epitaxy (MBE) onto both Si(001) and Si(112) substrates. On Si(
001) substrates misoriented from 0 to 8-degree toward [110], parallel
epitaxy of ZnTe(001) and CdZnTe(001)/ZnTe(001) has bene observed. Usin
g ZnTe initiation layers, high quality CdZnTe(001) films have been dem
onstrated with (004) reflection x-ray rocking curves as narrow as 158
arc-secs for Cd0.96Zn0.04Te and 78 arc-secs for CdTe. HgCdTe(001) film
s grown by liquid-phase epitaxy (LPE) on these MBE CdZnTe/ZnTe/Si(001)
substrates have x-ray rocking curves as low as 55 arc-secs and averag
e etch pit densities of 5 x 10(6) cm-2. IR detectors, fabricated from
LPE-grown p-on-n heterojunctions on CdZnTe/Si, are comparable in perfo
rmance to detectors on bulk CdZnTe substrates with R0A > 2 x 10(3) OME
GA-cm2 at 78 K for a 9.4 mum cutoff wavelength. On vicinal Si(112) sub
strates, ZnTe nucleates in either the (112) or twin (552) orientation,
depending on the Si misorientation. CdTe deposited on ZnTe/Si(112) nu
cleates in the same orientation as the ZnTe. X-ray rocking curves as n
arrow as 110 arc-secs have been obtained for CdTe(552) epitaxy.