Delta Doping in Silicon by Argon Ion Preimplantation and Nanosecond Laser Annealing

Delta doping (δ-doping) has extensive applications in advanced metal oxide semiconductor field effect transistors, quantum devices, and deep ultraviolet (DUV) photodetectors. In this work, we demonstrate a novel method for high-concentration phosphorus δ-doping in silicon using pulsed laser annealing assisted with argon preimplantation. The δ-doping layer has a peak phosphorus concentration of 1.44 × 1020 cm–3. Low-temperature Hall measurements reveal that the δ-doping layer is in a metallic state and exhibits a weak localization phenomenon, which implies the formation of a two-dimensional electron gas. As a demonstration, a highly sensitive deep UV photodetector is fabricated by forming an n-type δ-doping layer on a p-type Si substrate. The photoresponsivity of our δ doping PN junction photodiodes is 0.124 A/W, more than 2 times higher than that of the commercial photodiode. This finding offers a promising route for the realization of a highly doped δ-doping layer in silicon, with potential applications in a variety of electronic and optoelectronic devices.