Performance and Modeling of the MWIR HgCdTe Electron Avalanche Photodiode

• Published in: Journal of electronic materials Vol. 38; no. 8; pp. 1579 - 1592
• Main Authors: Beck, Jeffrey, Scritchfield, Richard, Sullivan, Billy, Teherani, Jamie, Wan, Chang-Feng, Kinch, Mike, Ohlson, Martha, Skokan, Mark, Wood, Lewis, Mitra, Pradip, Goodwin, Mike, Robinson, Jim
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Boston Springer US 01.08.2009; Springer; Springer Nature B.V
• Subjects: Applied sciences; Bandwidths; Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: structure, mechanical and thermal properties; Density; Diffusion; Diffusion in solids; Electronics; Electronics and Microelectronics; Electrons; Exact sciences and technology; Instrumentation; Materials Science; Optical and Electronic Materials; Optoelectronic devices; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solid State Physics; Transport properties of condensed matter (nonelectronic); spectral; avalanche photodiode; dark current; capacitance; cylindrical; bandwidth; excess noise; gain; point spread function; HgCdTe; diffusion length; spot scan; fill factor; collection efficiency; Spectral response; Diode; Mid infrared radiation; Background noise; Modeling; Time dependence; Unit cell; Cadmium tellurides; Bandwidth; Avalanche photodiodes; Dark current; Mercury tellurides; Diffusion; Diffusion length; Voltage capacity curve; Electron injection; Theoretical study; Two dimensional model; Doping profile; Photodetector; Steady state; II-VI semiconductors; Capacitance; Current gain
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-009-0684-8

The operation of the mid-wave infrared (MWIR) HgCdTe cylindrical electron injection avalanche photodiode (e-APD) is described. The measured gain and excess noise factor are related to the collection region fill factor. A two-dimensional diffusion model calculates the time-dependent response and steady-state pixel point spread function for cylindrical diodes, and predicts bandwidths near 1 GHz for small geometries. A 2  μ m diameter spot scan system was developed for point spread function and crosstalk measurements at 80 K. An electron diffusion length of 13.4  μ m was extracted from spot scan data. Bandwidth data are shown that indicate bandwidths in excess of 300 MHz for small unit cells geometries. Dark current data, at high gain levels, indicate an effective gain normalized dark density count as low as 1000 counts/ μ s/cm 2 at an APD gain of 444. A junction doping profile was determined from capacitance–voltage data. Spectral response data shows a gain-independent characteristic.