Investigation of the activation and diffusion of ion-implanted p-type and n-type dopants in germanium using high-pressure annealing

Abstract

In this study, we investigate the effectiveness of high-pressure annealing (HPA) compared to microwave annealing (MWA) in activating n-type and p-type dopants in germanium. For phosphorus dopants, HPA at 500 °C significantly enhances the activation level, resulting in a reduction of sheet resistance to 120.1 ohms sq.⁻¹ and a maximum active concentration of up to 5.76 × 10¹⁹ P cm⁻³. Similarly, for boron dopants, HPA at 800 °C reduces the sheet resistance to 80.6 ohms sq.⁻¹ and achieves a maximum active concentration that maintains effective doping profiles. Transmission electron microscopy images reveal that the amorphous layers implanted with phosphorus and boron are significantly reduced, indicating that HPA is more effective in achieving solid-phase epitaxial regrowth compared to MWA. HPA demonstrates superior performance in minimizing dopant diffusion and reducing sheet resistance for both phosphorus and boron dopants, making it a preferable method for high-temperature annealing in germanium-based devices.