Evaluation of Thermal Resistance Reduction by Thinning Substrate of β-Ga2O3 SBD

Wide-bandgap semiconductor is key material for advanced power device. Higher critical electric field of wide-bandgap semiconductor improves trade-off between high voltage durability and low resistance. Ga2O3 has wider bandgap than SiC and GaN. Especially, β-Ga2O3 single crystal is easy to produce and expected as material for high voltage and large current power devices. However, thermal conductivity of βGa2O3 is much lower than other semiconductor materials. This limits maximum power dissipation in power devices. Thermal resistance reduction is key factor to put β-Ga2O3 into practical use. This paper thins the substrate layer of β-Ga2O3 SBD to reduce thermal resistance. Two different substrate layer thickness samples are compared with their transient thermal resistance. This paper shows that thinning the substrate layer substantially reduces thermal resistance. However, halving the substrate thickness does not halve the thermal resistance.