Fluorine applications in Silicon, Silicon Germanium and Germanium

Fluorine has emerged as a critical element in the fabrication and optimization of silicon (Si), silicon–germanium (SiGe), and germanium (Ge) semiconductor technologies. Its unique chemical properties enable precise control over etching, surface passivation, defect engineering, and dopant activation, making it indispensable in advanced microelectronic and optoelectronic device manufacturing. In silicon-based devices, fluorine is widely employed in plasma etching processes, gate dielectric engineering, and the passivation of dangling bonds, resulting in enhanced electrical performance, reduced interface trap density, and improved device reliability. In SiGe heterostructures, fluorine plays a significant role in strain engineering, selective etching, diffusion suppression, and defect passivation, thereby improving carrier mobility and enabling the fabrication of high-performance transistors and photonic components. For germanium, fluorine-based surface treatments and plasma processes effectively mitigate native oxide formation, reduce interface defects, and enhance the quality of high-k dielectric integration, which is essential for next-generation CMOS and infrared photonic applications. Furthermore, fluorine incorporation has been shown to improve thermal stability, minimize leakage currents, and extend device lifetime across these material systems. This paper reviews the diverse applications of fluorine in Si, SiGe, and Ge technologies, highlighting its impact on material processing, interface engineering, point defects engineering and device performance while discussing recent advances and future prospects for fluorine-assisted semiconductor manufacturing in emerging nanoelectronic and quantum device architectures.