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Theoretical Insights Into the Interface Properties of Hydrogen-Terminated and Oxidized Silicon-Terminated Diamond Field-Effect Transistors With h-BeO Gate Dielectric

MetadataDetails
Publication Date2023-10-04
JournalIEEE Transactions on Electron Devices
AuthorsQingzhong Gui, Wei Yu, Chunmin Cheng, Hailing Guo, Xiaoming Zha
InstitutionsWuhan University, University of Cambridge
Citations10

Diamond surfaces provide an innovative platform for the exploitation of electronic devices. In this work, we investigate the structural and electronic properties of hexagonal beryllium oxide (h-BeO)/hydrogen, fluorine, oxygen, and oxidized silicon (H, F, O, O-Si)- terminated diamond (100) heterostructures by first-principles calculations. The results indicate that the h-BeO /(H, O-Si)-diamond heterostructures demonstrate lower binding energies and higher interfacial charge transfer compared to the h-BeO /(F, O)-diamond systems. Furthermore, the h-BeO /H-diamond heterostructure shows semiconducting characteristics with a direct bandgap of 4.80 eV, where the h-BeO layer forms a Type-II band alignment with the H-diamond surface. The resultant band offsets are 2.75 and 1.42 eV, indicating that h-BeO can be considered a high-quality gate dielectric material for 2-D hole gas (2DHG) H-diamond field-effect transistors (FETs). A low electron affinity is established on the (H, O-Si)-diamond surfaces and the h-BeO /(H, O-Si)-diamond interfaces form a downward band bend, which contributes to the formation of normally- OFF diamond FETs. This study provides an in- depth theoretical understanding of the normally- OFF characteristics for 2DHG diamond FETs and demonstrates the excellent potential of h-BeO on (H, O-Si)-diamond surface for diamond devices.