Doping and Defect Co-Engineering Strategy to Overcome Gain-Speed Dilemma of Ga 2 O 3 Thin Film Grown by Mist-CVD Technique

Abstract

Modern intelligent electronic systems are required to be of high gain or fast speed, to enhance the system power efficiency and reliability. Apart from geometrical design in devices, doping profile is a key factor affecting device performances, especially for ultra-wide bandgap (UWBG) semiconductors. However, controllable doping in UWBG material is hard to implement due to the large bandgap, complex crystal structure, and deep impurity level, resulting in low doping efficiency and carrier mobility. Especially, gallium oxide (Ga2O3), as a promising UWBG semiconductor is facing more vital challenge in doping due to the complicated physicochemical process. To overcome such difficulty and investigate doping mechanism, in this work, we take the mist chemical vapor deposition (mist-CVD) grown tin (Sn(IV)) doped α-phase Ga2O3 (Sn:α-Ga2O3) as an example, and its properties are novelly modulated by changing the hydrochloric acid (HCl) concentration in the precursor, and the crystallinity, chemical valance distribution, along with relation between n-type conductivity and response speed are discussed. These results explain a gain-speed dilemma in UWBG semiconductor in view of material physics, and suggest great significance of material growth in designing a semiconductor device with demand of high gain and fast speed electronic devices.