The epitaxial growth and structure of Films of CdTe evaporated onto Ge

Abstract

Films of CdTe were grown by focussed electron beam evaporation in vacua in the 10−5 to 10−6 Torr range on Ge substrates with (100), (110), and (111) surface orientations. For (100) substrates the epitaxial growth range of substrate temperature was 250 to 470°C, whereas for both (110) and (111) substrates it was 200 to 470°C. On (100) substrates the films grew with the cubic sphalerite structure in parallel orientation with the substrate. The diffraction patterns of these (100) films were streaked in the 〈111〉 directions indicating the presence of high densities of {111} planar defects. The films grown on (111) substrates had the hexagonal wurtzite structure in the epitaxial orientation relationship: (0001) CdTe parallel to (111) Ge with [1120] CdTe parallel to [110] Ge. The (0001) films grown at substrate temperatures throughout the epitaxial range had diffraction patterns that contained neither streaks nor satellite spots. Thus the films contained neither three dimensional defects such as included grains of second phase material nor planar defects in high densities. The films grown on (110) substrates had basically the sphalerite structure in parallel alignment. However, the diffraction patterns of (110) films grown throughout the epitaxial range were streaked in the two 〈111〉 directions at 35.3°C to [110] normal to the plane of the film. This was due to faulting on the two corresponding {111} planes in a striking domain‐form transformed structure.

Epitaxial Growth and Structure of CdSe Evaporated in Vacuum onto Ge

“…Similar deposition cut-off temperatures were observed to occur in all previously investigated II-VI/IV combinations (1)(2)(3)(4)6). Similar deposition cut-off temperatures were observed to occur in all previously investigated II-VI/IV combinations (1)(2)(3)(4)6).…”

“…Dn-p,r --Ig.-p,rl-{ (dl --d2) 2 + afdldf} 1/2 [4] This is the expression quoted in Ref. (10) but not that originally quoted by Bassett et al (11).…”

“…4(b). This form of contrast in dark and bright areas of jig-saw-puzzle shape, led to this type of structure being termed a domain-form faulted structure in previous cases (2,4). 5(a).…”

“…Previous work in this program has dealt with the growth and structure of films of CdS on Ge (1,2), ZnTe on Ge (3), and CdTe on Ge (4). Previous work in this program has dealt with the growth and structure of films of CdS on Ge (1,2), ZnTe on Ge (3), and CdTe on Ge (4).…”

“…Previous work in this program has dealt with the growth and structure of films of CdS on Ge (1,2), ZnTe on Ge (3), and CdTe on Ge (4). A domain-form {111} faulted structure was found in the CdTe films grown on (110) surfaces (2,4). A domain-form {111} faulted structure was found in the CdTe films grown on (110) surfaces (2,4).…”