This SPIE paper by Handel and Morkoç examines piezoelectric quantum 1/f noise in AlGaN HFETs and reliability. The research investigates the relationship between piezoelectric-induced quantum 1/f noise and device reliability in aluminum gallium nitride heterostructure field-effect transistors, demonstrating that noise analysis provides insights into degradation mechanisms, defect dynamics, and failure modes, enabling reliability prediction and quality assessment for GaN-based RF and power electronic devices in demanding military and commercial applications.