Design and Optimization of AlGaN/GaN Graded Barrier MOS-HEMT Biosensor for Breast Cancer Biomolecule detection

In this paper, we have designed and simulated an AlGaN/GaN graded barrier metal oxide semiconductor high electron mobility transistor (MOS-HEMT) heterojunction biosensor for detection of Breast Cancer biomolecules. A graded AlGaN barrier layer is utilized to enhance polarization-induced charges, thus increasing the density of 2DEG and improving carrier mobility in the channel. The proposed device uses Triple Metal Gate (TMG) with different work functions (M1, M2, M3) for controlling the electric field profile along the channel and improves the electrostatic control of the proposed biosensor. AlGaN graded barrier MOS-HEMT heterojunction biosensor was evaluated using Silvaco TCAD. The performance of proposed device analyzed using healthy Breast Cancerous biomolecules (K = 4.5(MCF-10)) and non-healthy Breast Cancerous biomolecules (K = 22(Hs578T), 27.5(MCF-7), 32(T47D)). The device characteristics are evaluated through transfer characteristics (I_d-V_gs), output characteristics (I_d-V_ds), electron (e^-) mobility and surface potential. Moreover, the effect of different positions for cavity fillings on I_on/I_off ratio sensitivity and V_th sensitivity is examined under different conditions. The sensitivity of the device is 0.147 × 10², subthreshold swing (SS) value is 60 mV/dec, I_on/I_off ratio sensitivity is 3.67 × 10⁵ at K = 32. The results reveal that the sensitivity of the biosensor is based on the number of biomolecules rather than their position. The proposed biosensor has a relatively higher sensitivity compared to existing biosensors, making it a promising device for detecting Breast Cancer biomolecules.