Highly Sensitive Ga<sub>2</sub>O<sub>3</sub>-Face Tunnel Field Effect Phototransistor for Deep UV Detection
Manisha Khurana, Upasana, Manoj Saxena, Mridula Gupta
Abstract
In this article, a Technology Computer-Aided Design (TCAD)-based study has been done for gallium oxide (Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) gated UV phototransistor with face tunneling architecture and magnesium silicide (Mg <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Si) substrate using ATLAS-2-D device simulator, in which Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> has been used as a photoabsorber layer over the complete channel. The photon absorption inside the Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> has been utilized to modulate the silicon channel conduction (tunneling at the source channel junction), where the advantage of face tunneling over the conventional tunnel field-effect transistor (TFET) architectures has been shown. The device operation has been studied in the wavelength spectrum of deep UV (DUV) (solar blind) and outside this range to analyze the application of the proposed architecture for DUV radiation detection and rejecting others. From the dark and illuminated characterization, transient response, and spectral response, Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> of thickness 50 nm is the best concluded candidate with a response time of 11.5 ms, sensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.1\times 10^{7}$ </tex-math></inline-formula> , responsivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.59\times 10^{4}$ </tex-math></inline-formula> A/W, and detectivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.15\times 10^{15}$ </tex-math></inline-formula> Jones, which makes it a suitable candidate for its application as DUV photodetector.