Performance and Modeling of the MWIR HgCdTe Electron Avalanche Photodiode
- 149 Downloads
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 μm diameter spot scan system was developed for point spread function and crosstalk measurements at 80 K. An electron diffusion length of 13.4 μm 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/μs/cm2 at an APD gain of 444. A junction doping profile was determined from capacitance–voltage data. Spectral response data shows a gain-independent characteristic.
KeywordsHgCdTe avalanche photodiode gain excess noise cylindrical spot scan diffusion length point spread function bandwidth fill factor collection efficiency dark current capacitance spectral
Unable to display preview. Download preview PDF.
- 5.M. Goodwin, J. Beck, L. Wood, C. Rau, R. Scritchfield, M. Skokan, M. Ohlson, M. Woodall, P. Mitra, and J. Robinson (2008 MSS Specialty Group Meeting on Detectors, Nellis AFB, NV, 4–7 February 2008)Google Scholar
- 6.M.A. Kinch, Proc. SPIE 4369, 566 (2001). doi:10.1117/12.445316
- 8.G. Perrais, L. Mollard, J.-P. Chamonal, G. Destefanis, and J. Rothman, J. Electron. Mater. (2009, to be published)Google Scholar