Author(s)

Caitlin R. Philippi^1*, John W. Zeller², Nibir K. Dhar³, Priyalal Wijewarnasuriya⁴, Ashok K. Sood², Harry Efstathiadis¹

¹State University of New York Polytechnic Institute, Albany, NY, USA.
²Magnolia Optical Technologies Inc., Woburn, MA, USA.
³US Army Night Vision & Electronic Sensors Directorate, Fort Belvoir, VA, USA.
⁴US Army Research Laboratory, Adelphi, MD, USA.

Germanium offers many benefits over groups III-V materials when used for infrared detection. Most importantly, germanium is compatible with Complementary Metal Oxide Semiconductor (CMOS) manufacturing which allows for a low-cost, high-throughput device, and it does not require cooling, which many III-V devices do. With the deposition of germanium directly on silicon, there will be a thermally induced strain due to the difference in thermal expansion coefficients between the two materials. When a biaxial tensile strain is present, the direct bandgap of germanium is lowered to ~0.77 eV and is capable of absorbing longer wavelengths. We have used a two-step deposition process to create a strained germanium film in order to fabricate a photodetector device. Our device has a dark current of 1.35 nA and a photocurrent of 22.5 nA at 1570 nm wavelength. Next, we developed a model in order to compare theoretical results with experimental results. The results indicate that the model is in close agreement with our measured data, and we are therefore able to use it to model future devices.

Infrared Detection, Germanium, Photodetector, Model, TCAD

Philippi, C. , Zeller, J. , Dhar, N. , Wijewarnasuriya, P. , Sood, A. and Efstathiadis, H. (2018) Model Development of p-i-n Germanium Devices for Infrared Detection. Optics and Photonics Journal, 8, 201-211. doi: 10.4236/opj.2018.86018.