Simulation study of biosensor based on germanium-based dual-source dopingless line-tunneling FET

In this paper, we propose and investigate a biosensor based on germanium-based dual-source dopingless line-tunneling FET, which uses dielectric modulation to detect biomolecules. Dual source and line-tunneling structure improves open state current of the biosensor. The trench gate structure facilitates biomolecules filling and cavity etching while enhancing the tunneling area. The dopingless structure prevents the formation of mutant junctions and minimizes the effects of random dopant fluctuations. Simulation results show that the proposed biosensor demonstrates excellent performance, with a high switching ratio of 5.9 × 10¹¹, a maximum threshold voltage sensitivity of 3.1 V, a maximum open state current sensitivity of 2.8 × 10⁶, a maximum average subthreshold swing (SS) sensitivity of 0.86, and the minimum average SS is 36.8 mv/decade. The proposed biosensor, exhibiting high sensitivity and low power consumption, holds significant application potential.