A Highly Sensitive and Robust GaN Ultraviolet Photodetector Fabricated on 150-mm Si (111) Wafer
Ravindra S. Pokharia, Ritam Sarkar, Shivam Singh, Swarup Deb, Sami Suihkonen, Jori Lemettinen, Subhabrata Dhar, Dinesh Kabra, Apurba Laha
Abstract
In this work, we demonstrate the potential of a gallium nitride (GaN)-based visible-blind ultraviolet (UV) photodetector (PD) on a commercially viable 150-mm Si wafer. The influence of thermionic field emission (TFE) and Poole-Frenkel (PF) mechanisms on the current transport of the PD has been analyzed. Conduction due to the TFE mechanism dominates in the moderate electric fields (1.25 kV/cm <; E <; 10 kV/cm), while the influence of PF is prominent at higher electric fields. A bulk trap energy level of 0.374 eV is obtained with PF conduction analysis. A high responsivity of 33.3 A/W at 15 V with a 362-nm incident wavelength has been achieved in the presence of an internal gain. The internal gain of the PD is also assisted by TFE and PF mechanisms. The PD exhibits a low dark current of 4.7 nA as well as high detectivity of 4.6×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> Jones at the abovementioned bias. The demonstrated robustness and high performance show the promise of III-nitride PDs for commercial applications.