Single Source Heterojunction Metal-Oxide-Semiconductor Transistors for Quasi-Ballistic Devices: Optimization of Source Heterostructures and Electron Velocity Characteristics at Low Temperature

摘要

We have experimentally studied the electron velocity behavior of single source heterojunction metal-oxide-semiconductor field-effect transistor (SHOTs) without a drain energy spike fabricated by optimizing the source heterostructures. The electron velocity V_E of SHOTs with source conduction band offset △E_C strongly depends on the source heterojunction position, and the enhancement of V_E for SHOTs relative to that for single drain-heterojunction transistors (DHOTs) and strained-Si-on-insulator devices (SSOIs) slightly increases with decreasing lattice temperature T. We have also found that V_E for SHOTs, DHOTs, and SSOIs has a power law dependence on low-field electron mobility μ_(EFF), that is, the mean free path of electrons A at various T. Thus, the electron kinetic energy △E_K converted by the source band offset in SHOTs increases with increasing mean free path of electrons at lower T. Using V_E α κ~α(α: constant), we can also estimate V_E for both SHOTs and DHOTs at the ballistic transport limit.