A theoretical approach to study the frequency dependent dielectric behavior of breast cancer cells using AlN buffer-based AlGaN/GaN HEMT

The present study reports the detection of healthy (MDA-10) and malignant cells (MDA-MB-231) associated with breast cancer using high-quality AlN buffer AlGaN/GaN HEMT with dual cavity structure formed by etching out the gate metal from source and drain sides under the gate region. The AlN buffer AlGaN/GaN HEMT provides better 2DEG confinement and large conduction band offset than GaN buffer. The proposed design is analysed at frequencies of 900 MHz and 10 GHz, as breast cells have distinct dielectric properties at different microwave frequencies. The variation in dielectric constant of the cavity region corresponding to biomolecular species will change the device's electrical characteristics and hence can be used to detect breast cancer cells. In this work, the device sensing parameters considered for analysis are shift in threshold voltage and drain current sensitivity. The device performance has also been analyzed by optimizing cavity thickness and length to select the best design for the sensing. The effect of non-ideal conditions such as steric hindrance and probing is also studied by emulating these real time effects in simulation. The device shows a maximum drain current sensitivity of 29.94% for 20 nm of cavity thickness and 1 mu m of the cavity length. The results depict that the proposed device design exhibits a highly sensitive response and can be promising alternate for future biosensing applications.