HgCdTe MWIR back-illuminated electron-initiated avalanche photodiode arrays

• Published in: Journal of electronic materials Vol. 36; no. 8; pp. 1059 - 1067
• Main Authors: REINE, M. B, MARCINIEC, J. W, WONG, K. K, PARODOS, T, MULLARKEY, J. D, LAMARRE, P. A, TOBIN, S. P, GUSTAVSEN, K. A, WILLIAMS, G. M
• Format: Conference Proceeding Journal Article
• Language: English
• Published: New York, NY Institute of Electrical and Electronics Engineers 01.08.2007; Springer Nature B.V
• Subjects: Applied sciences; Cadmium telluride; Cross-disciplinary physics: materials science; rheology; Electric properties; Electronics; Exact sciences and technology; Infrared radiation; Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids); Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Molecular beam epitaxy; Optoelectronic devices; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sensors; LPE; Voltage dependence; avalanche photodiode; Infrared detector; Photodiode; Empirical model; Photodetector; Thin film; Bias voltage; APD; Cadmium tellurides; Avalanche photodiodes; Illumination; Mercury tellurides; Diode array; HgCdTe; Donor center; Voltage capacity curve
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-007-0172-y

This paper reports data for back-illuminated planar n-on-p HgCdTe electron-initiated avalanche photodiode (e-APD) 4 X 4 arrays with large unit cells (250 X 250 mum). The arrays were fabricated from p-type HgCdTe films grown by liquid phase epitaxy (LPE) on CdZnTe substrates. The arrays were bump-mounted to fanout boards and characterized in the back-illuminated mode. Gain increased exponentially with reverse bias voltage, and the gain versus bias curves were quite uniform from element to element. The maximum gain measured was 648 at -11.7 V for a cutoff wavelength of 4.06 mum at 160 K. For the same reverse-bias voltage, the gains measured at 160 K for elements with two different cutoff wavelengths (3.54 mum and 4.06 mum at 160 K) show an exponential increase with increasing cutoff wavelength, in agreement with Beck's empirical model for gain versus voltage and cutoff wavelength in HgCdTe e-APDs. Spot scan data show that both the V = 0 response and the gain at V = -5.0 V are spatially uniform over the large junction area. To the best of our knowledge, these are the first spot scan data for avalanche gain ever reported for HgCdTe e-APDs. Capacitance versus voltage data are consistent with an ideal abrupt junction having a donor concentration equal to the indium concentration in the LPE film.