Performance evaluation and characterization of an Al0.30Ga0.70As/GaAssuperlattice-based MOSFET structure for biosensing application

Introduction: The present work explores how the variations in lattice temperature influence carrier mobility in MOSFETs with arsenide-based superlattice structures, taking into account various lattice scattering mechanisms. Methods: An analytical model of AlGaAs/GaAs superlattice MOSFET is developed, incorporating multiple scattering mechanisms, including polar optical phonon, acoustic phonon background impurity, remote impurity, and interface roughness scattering. The three-dimensional AlGaAs/GaAs superlattice MOSFET is theoretically modeled using MATLAB software. The structure is designed and simulated to evaluate transfer drain and output characteristics across a range of temperatures. The results are validated by comparison of measured mobility values of two-dimensional electrons in Al0.30Ga0.70As/GaAs superlattice systems. Results: The results reveal that electron mobility remains high at cryogenic temperatures but decreases significantly above 30K due to OPT polar scattering, which becomes the dominant factor limiting carrier transport. The MOSFET exhibits a nearly linear ID-VGS relationship across a wide gate voltage range, with the maximum transconductance estimated at approximately 470 mS/mm. Discussion: The analysis confirms that low-temperature operation enhances carrier mobility, enabling higher drain current and stronger transconductance, while the influence of scattering mechanisms provides insights into device limitations at elevated temperatures. The device characteristics closely resemble those of nanoscale MOSFETs, reinforcing its potential applicability in highperformance electronic systems. Conclusion: The study demonstrates the dual significance of AlGaAs/GaAs superlattice-based MOSFETs: from a theoretical perspective, it enriches understanding of scattering-dominated transport phenomena, while from an applied standpoint, it highlights promising opportunities for designing high-speed, low-power, and stable biosensing devices.