Strain relaxation in IV-VI semiconductor layers grown on silicon (100) substrates
- Univ. of Oklahoma, Norman, OK (United States). School of Electrical Engineering
The large thermal expansion coefficient mismatch between IV-VI semiconductors and silicon results in significant tensile strain when structures are cooled down following growth at high temperatures. Molecular beam epitaxy (MBE) growth of PbSe on Si (100) at 280 C on BaF{sub 2}/CaF{sub 2} buffer layers results in high crack-density because of this strain. Interestingly, crack-free layers of PbSe can be grown by LPE on Si (100) by using MBE-grown PbSe/BaF{sub 2}/CaF{sub 2} buffer layer structures. Unlike LPE-grown PbSe layers, however, a high crack-density was observed in Pb{sub 1{minus}x}Sn{sub x}Se{sub 1{minus}y}Te{sub y} layers grown by LPE on Si (100) using similar buffer layer structures. It is hypothesized that the addition of tellurium, which is known to increase IV-VI material hardness, inhibits plastic deformation and thus crack formation becomes the thermal strain relief mechanism. Ternary Pb{sub 1{minus}x}Sn{sub x}Se layers grown by LPE exhibited much lower crack densities as compared to the quaternary layers and supported the conclusion that tellurium induced solid solution hardening occurs in the IV-VI materials system.
- Sponsoring Organization:
- National Science Foundation, Washington, DC (United States)
- OSTI ID:
- 305514
- Report Number(s):
- CONF-971201--
- Country of Publication:
- United States
- Language:
- English
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