Gallium oxide: promise to provide more efficient life

Abstract

Despite being the long-time mainstream semiconductor for both logic and power devices, Silicon is now facing its dilemma and limitation of scalability and material potential. Especially for power devices, people are demanding escalating efficiency with higher blocking voltage while its power consumption and heat generation are less. Constrained by its narrow bandgap of 1.14 eV, Silicon only has a critical breakdown field (Ec) of 0.3 MV/cm, yielding a Baliga figure-of-merit (BFOM = ε × μ × Ec3) of unity when normalized to itself. It is hence required that the dominating factor Ec should be as high as possible such that the BFOM will be hundreds or even thousands of times when compared to Silicon so as to minimize the conduction loss. Beta-Gallium Oxide (β-Ga2O3) with decent μ of 250 cm2/Vs, ultra-wide bandgap of 4.8 eV and high critical Ec of 8 MV/cm, yielding a superior high BFOM of more than 3000. Therefore, system made with β-Ga2O3 can be thinner, lighter and capable of handling more power than the one with Silicon. In addition, low-cost and large size substrate through melt-grown method endows β-Ga2O3 more potentials as cost-effective power devices. After resolving the low thermal conductivity issue, unipolar devices made with ultra-wide bandgap β-Ga2O3 are promised to make power transition and our life more efficient.