Self-heating effect analysis of a dual cavity AlGaN/GaN MOS-HEMT biosensor with AlN/diamond substrate

In this paper, we have designed and analysed the dual cavity AlGaN/GaN Metal oxide semiconductor high electron mobility transistor (MOS-HEMT) heterojunction biosensor for biomolecule detection. The proposed biosensor uses triple-metal work functions (M 1 , M 2 and M 3 ) to improve electric field distribution and electrostatic control. The proposed biosensor is evaluated using MCF-10 A (K = 4.5), Keratin(K = 8), Gelatin (K = 12), Hs578T (K = 22), MCF-7 (K = 27.5) and T47D (K = 32) biomolecules using Atlas Silvaco TCAD. The temperature dependent behaviour is examined at different temperatures (250 K, 300 K, 350 K and 400 K) to evaluate its electrical stability and sensing performance. In addition, Self-Heating Effect (SHE) is analysed using Sapphire and Diamonds substrate configurations. Self-heating increases the lattice temperature, leading to enhanced carrier scattering and reduced 2DEG mobility that can affect the electrical and sensing performance. A Diamond substrate AlN/Diamond substrate is used to improve heat dissipation and supress self-heating. The proposed device analyses the lattice temperature, DIBL, drain-current sensitivity and subthreshold swing (SS) sensitivity for different biomolecule effective dielectric constant. The Diamond substrate reduces the lattice temperature from 422 K to 324 K and increases the drain current sensitivity from 5.392 × 10 1 to 9.99 × 10 1 at K = 32. These results demonstrated that the proposed AlN/Diamond substrate device provides improved thermal management and sensing performance, making it suitable for biomedical applications.