Dislocation Reduction of HgCdTe/Si Through Ex Situ Annealing

作者：Brill G^*; Farrell S; Chen Y P; Wijewarnasuriya P S; Rao Mulpuri V; Benson J D; Dhar N

来源：Journal of Electronic Materials, 2010, 39(7): 967-973.

DOI：10.1007/s11664-010-1142-3

• Mercury
• cadmium
• telluride
• HgCdTe
• thermal cycle annealing
• (112)
• etch pit density (EPD)
• dislocations
• MBE
• silicon
• Si
• composite substrates

Current growth methods of HgCdTe/Cd(Se)Te/Si by molecular-beam epitaxy (MBE) result in a dislocation density of mid 10(6) cm(-2) to low 10(7) cm(-2). Although the exact mechanism is unknown, it is well accepted that this high level of dislocation density leads to poorer long-wavelength infrared (LWIR) focal-plane array (FPA) performance, especially in terms of operability. We have conducted a detailed study of ex situ cycle annealing of HgCdTe/Cd(Se) Te/Si material in order to reduce the total number of dislocations present in as-grown material. We have successfully and consistently shown a reduction of one half to one full order of magnitude in the number of dislocations as counted by etch pit density (EPD) methods. Additionally, we have observed a corresponding decrease in x-ray full-width at half-maximum (FWHM) of ex situ annealed HgCdTe/Si layers. Among all parameters studied, the total number of annealing cycles seems to have the greatest impact on dislocation reduction. Currently, we have obtained numerous HgCdTe/Si layers which have EPD values measuring similar to 1 x 10(6) cm(-2) after completion of thermal cycle annealing. Preliminary Hall measurements indicate that electrical characteristics of the material can be maintained.

• 出版日期2010-7