HEMT for Biosensing Applications

Among various types of biological sensors, the semiconductor biosensors gathered attraction due to their superior advantage in the process of integration, multifunction, and miniaturization. ISFET’s based sensor has been processed for the very same as they deliver faster response, higher sensitivity, higher resolution, and label-free detection. The major drawback of these types of sensors it lacks because of its material degradation of the gate insulators and longer-term drift performance which possess instability in solution. Field-Effect Transistors (FET) based biosensors provide easy signal read-out capabilities, lower detection limit, and higher sensitivity. At the same time, the occurrence of Debye or Charge screening when exposed in high salt concentration suchlike as physiological fluids restrict in ground of clinical applications as assay requirements that includes expansive sample pre-treatment process steps, this technology suffer from noise signals which restrict their detection limit. Upon the introduction of a few external change around surface conditions, i.e., linking of biomolecules in the underlap area of gate region results in significant variation in the piezoelectric-induced carrier density inside channel region of the device results in variation in drain current. Henceforth, comparatively HEMT-based biosensor facilitates higher sensitivity upon immobilization of biomolecules. Therefore these demerits could be overcome by implementation of GaN HEMT biosensor that bears the built-in properties like stability in aqueous solutions, biocompatibility, and are more sensitive to surrounding surface charge as the 2DEG channel concentration at the heterointerface layer which changes due to its existing surface charge variations by capacitive coupling.