High-Performance 320 x 256 Long-Wavelength Infrared Photodetector Arrays Based on CdHgTe Layers Grown by Molecular Beam Epitaxy
A. V. Predein, Yu. G. Sidorov, I. V. Sabinina, V. V. Vasil’ev, G. Yu. Sidorov, I. V. Marchishin
Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, pr. Akademika Lavrent’eva 13, Novosibirsk, 630090 Russia
Keywords: cadmium–mercury–tellur, photodetector arrays, current-voltage characteristics, hybrid assembly
Abstract
This paper gives the parameters of 320 × 256 element long-wavelength infrared photodetectors fabricated by a new improved technology based on heteroepitaxial mercury–cadmium–tellur structures. In these photodetectors, the variation of the photodiode bias voltage over the area of the array is minimized; inefficient photodiode regions related to both hybridization and spike-shaped growth defects of epitaxial films are eliminated; the current-voltage characteristics of the diodes in the resulting photodetectors are homogeneous and are limited by the diffusion current component up to −400 mV. The dark current is 0.25–0.45 nA, and R0A = (0.6–3) · 102 Om · cm2. The voltage sensitivity, the threshold irradiance, and the average NETD at the maximum sensitivity are 11.8 · 108 V/W, 3.7 · 10−8 W/cm2, and 26.8 mK, respectively. The percentage of defective elements is 1.5%.
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