Simulation study of device physics and design of GeOI TFET with PNN structure and buried layer for high performance

【摘要】 Large threshold voltage and small on-state current are the main limitations of the normal tunneling field effect transistor（TFET）.In this paper,a novel TFET with gate-controlled P⁺N⁺N⁺ structure based on partially depleted GeOI（PD-GeOI） substrate is proposed.With the buried P⁺-doped layer（BP layer） introduced under P⁺N⁺N⁺ structure,the proposed device behaves as a two-tunneling line device and can be shut off by the BP junction,resulting in a high on-state current and low threshold voltage.Simulation results show that the on-state current density I_on of the proposed TFET can be as large as 3.4×10^-4 A/μm,and the average subthreshold swing（SS） is 55 mV/decade.Moreover,both of I_on and SS can be optimized by lengthening channel and buried P+layer.The off-state current density of TTP TFET is 4.4×10^-10 A/μm,and the threshold voltage is 0.13 V,showing better performance than normal germanium-based TFET.Furthermore,the physics and device design of this novel structure are explored in detail.更多还原

【Abstract】 Large threshold voltage and small on-state current are the main limitations of the normal tunneling field effect transistor（TFET）.In this paper,a novel TFET with gate-controlled P⁺N⁺N⁺ structure based on partially depleted GeOI（PD-GeOI） substrate is proposed.With the buried P⁺-doped layer（BP layer） introduced under P⁺N⁺N⁺ structure,the proposed device behaves as a two-tunneling line device and can be shut off by the BP junction,resulting in a high on-state current and low threshold voltage.Simulation results show that the on-state current density I_on of the proposed TFET can be as large as 3.4×10^-4 A/μm,and the average subthreshold swing（SS） is 55 mV/decade.Moreover,both of I_on and SS can be optimized by lengthening channel and buried P+layer.The off-state current density of TTP TFET is 4.4×10^-10 A/μm,and the threshold voltage is 0.13 V,showing better performance than normal germanium-based TFET.Furthermore,the physics and device design of this novel structure are explored in detail.更多还原