Magnetron sputter and phase change optimization of wafer-level GeTe films for RF switch

Abstract With the rapid advancement of 5G communication technology, increasingly stringent demands are placed on the performance and functionality of phase change switches. Given that RF and microwave signals exhibit characteristics of high frequency, high speed, and high precision, it is imperative for phase change switches to possess fast, accurate, and reliable switching capabilities. Moreover, wafer-level compositional homogeneity and resistivity uniformity during semiconductor manufacturing are crucial for ensuring the yield and reliability of RF switches. By controlling magnetron sputter of GeTe through from four key parameters (pressure, power, Ar flow, and post-annealing) and incorporating elemental proportional compensation in the target, we achieved effective modulation over GeTe uniformity. Finally, we successfully demonstrated the process integration of GeTe phase-change RF switches on 6-inch scaled wafers.