Development and fabrication of extended short wavelength infrared HgCdTe sensors grown on CdTe/Si substrates by molecular beam epitaxy

作者：Simingalam Sina^*; VanMil Brenda L; Chen Yuanping; DeCuir Eric A Jr; Meissner Greg P; Wijewarnasuriya Priyalal; Dhar Nibir K; Rao Mulpuri V

来源：Solid-State Electronics, 2014, 101: 90-94.

DOI：10.1016/j.sse.2014.06.037

• HgCdTe
• Short-wavelength infrared
• Shunt current
• Passivation

The development and fabrication of extended short-wavelength infrared (SWIR) HgCdTe (MCT) sensors grown on CdTe/Si substrates is reported. The MCT epilayers were grown on CdTe/Si substrates by molecular beam epitaxy (MBE). The epilayers were evaluated using Fourier transform infrared spectroscopy (FTIR), X-ray double crystal rocking curve (DCRC), Van der Pauw Hall measurements, dislocation defect-decoration etching and Nomarski microscopy. The FTIR analysis revealed a cutoff wavelength of 2.25 mu m at 300 K which corresponds to a cadmium composition of 47%. As-grown epilayers have void defect densities less than 10(3) cm(-2) and etch pit densities of similar to 1 x 10(7) cm(-2). The Hall mobilities of annealed MCT samples are on the order of 1500 cm(2)/Vs and have carrier concentrations of similar to 1 x 10(16) cm(-3) at 300 K. Samples were doped in situ with indium (donor) and ion-implanted with arsenic (acceptor) to fabricate p-n diodes with sizes ranging from 15 mu m to 250 mu m diameter. We present the results and analysis of temperature dependent current-voltage (I-V) and quantum efficiency/responsivity measurements on the p-n diodes. In our analysis, we found that the I-V characteristics of small devices were dominated by shunt currents and quantum efficiency is limited by Shockley-Read-Hall (SRH) mechanisms.

• 出版日期2014-11