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

• 作者: Bin Shu Bin Wang Hui-Yong Hu Peng Li Sheng Hu Yue Feng
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2020,（10）
• 所属期刊栏目: CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL,MAGNETIC,AND OPTICAL PROPERTIES
• 页码范围: 575-581
• 页数: 7页
• 语种: 英文
• DOI: 10.1088/1674-1056/ab99b5

摘要

Large threshold voltage and small on-state current are the main limitations of the normal tunneling field effect tran-sistor (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 Ion 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 Ion 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.