GaN‐on‐Si Wafers for HEMTs with High Power‐driving Capability

By means of our patented strain engineering technology, we achieved high crystal quality and near zero wafer bow on our 150 mm GaN-on-Si wafers. To show the feasibility of our wafers for HEMTs with large gate periphery, we investigated the buffer breakdown(V-BR) yield on device test structures with different periphery. To reduce the processing complexity, we used comb-shaped structures with only source and drain contacts and N+ implant isolation in between the contacts. The V-BR was defined at buffer leakage of 1 mu A/mm. For a typical source-drain distance of 14 mu m, the V-BR yield specification is 600 V. Then we demonstrated over 80% V-BR yield for 100 mm device test structures on our 150 mm GaN-on-Si wafers. This high yield for large periphery test structures shows that our 150 mm GaN-on-Si wafers are very suitable for fabricating large HEMT devices. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim