Quench rate dependence of the center formation in Er-implanted Si

Er-implanted Si (Er:Si) is a promising candidate for scalable planar quantum memory (QM) applications. In Er:Si, Er has a preference to coordinate with O impurities, and multiple types of Er center are typically formed after a post-implant anneal. Intrinsic Si was implanted with 10 18 cm −3 Er, then annealed using a rapid quench annealing technique at 950°C for 10 min with quench rates of 5°C, 23°C, 46°C, 93°C, 185°C, and 400°C/s. The evolution of photoluminescence (PL) peaks and their associated Er centers was tracked as a function of quench rate. Across all samples, five distinct Er centers were identified. Two centers, one with mixed Si/O coordination and one with Si-only coordination, exhibited fully resolved crystal-field splitting of the 4 I 15/2 ground state together with 2–3 hot lines from the 4 I 13/2 excited state; fitting crystal-field parameters for both was consistent with C 2v symmetry. The mixed Si/O coordinated center was suppressed at quench rates above 185°C/s, while the Si-only coordinated center was progressively enhanced with increasing quench rate up to the maximum of 400°C/s. These results indicate that rapid quench annealing can favor the formation of Si-coordinated Er centers in Er:Si, which is required for QM applications.