Plasmon Mediated Terahertz frequency response with AuGe Self-Assembled Hole-Arrays over Gallium Arsenide

Terahertz devices provide ample avenues for high-frequency information processing. Bulky THz detectors and generators are required to be synchronized with the presently established semiconductor industry. Settling terahertz native to GaAs and Silicon would enable on-chip highfrequency operations, THz imaging, THz Generation-Detection. This work demonstratesthe formation of Rapid Thermal Annealing (RTA) based hole arrays in AuGe deposited thin film over GaAs substrate for terahertz detection mechanism. Ultrafast transient spectroscopic excitation around the wavelength matching with the size of holes creates time-domain oscillations in the transient relaxation spectrum that lies in the THz frequency domain. This behavior depicts that the structure may be responsive to the THz detection, where incident radiation is mediated through the AuGe hole arrays; the charge density is excited and relaxed with phonon-phonon interaction in the THz frequency domain. By varying the hole diameter and thickness of the film, we can tune the THz frequency response over GaAs. The free charge carrier density on theGaAs surface is influenced with the hole-spacing and distributiondepending on the incident radiation. AuGe-GaAs interfacial properties are much influenced by thermal annealing,which induces intermixing of materials. The size of holes is not uniform throughout the film, which provides the broader response in the THz spectrum with higher pumping wavelengths. This method of THz detector fabrication is less complex and much feasible with batch processing. The THz response is available for tuning by changing the film thickness and RTA recipe. This work will contribute to a more accessible and efficient THz detector demonstration.