A perspective on β -Ga2O3 micro/nanoelectromechanical systems

Beta gallium oxide (β-Ga2O3) is an emerging ultrawide bandgap (∼4.8 eV) semiconductor with attractive properties for future power and radio frequency (RF) electronics, optoelectronics, and sensors for detecting gases and solar-blind ultraviolet radiation. Beyond such promises, β-Ga2O3 crystal possesses excellent mechanical properties, making it pertinent as a material for micro/nanoelectromechanical systems (M/NEMS). Here, we present an overview and perspective on the emerging β-Ga2O3 M/NEMS and their roles in supplementing Ga2O3 power and RF electronics. We review the development of β-Ga2O3 micro/nanomechanical devices and precise extraction of mechanical properties from these devices. We evaluate the design for frequency scaling up to over 4 GHz by tuning the device geometry and dimensions. Toward technological applications, β-Ga2O3 M/NEMS are analyzed in two aspects: β-Ga2O3 vibrating channel transistors for potential integration with β-Ga2O3 power and RF electronics with operating frequency beyond 1 GHz, and β-Ga2O3 resonant transducers for photon radiation detection with scaling of responsivity and response time. With analytical prediction, we envision challenges and propose strategies and schemes in efficient electromechanical transduction engineering, frequency scaling, and design and fabrication for future development of β-Ga2O3 M/NEMS.