LAUSR

Silicon chips containing arrays of single dopant atoms could be the material of choice for both classical and quantum devices that exploit single donor spins. For example, group-V-donors implanted in isotopically purified 28 Si crystals are attractive for large-scale quantum computers. Useful attributes include long nuclear and electron spin lifetimes of 31 P, hyperfine clock transitions in 209 Bi or electrically controllable 123 Sb nuclear spins. Promising architectures require the ability to fabricate arrays of individual near-surface dopant atoms with high yield. Here we employ an on-chip detector electrode system with 70 eV r.m.s. noise (∼ 20 electrons) to demonstrate near room temperature implantation of single 14 keV 31 P+ ions. The physics model for the ion-solid interaction shows an unprecedented upper-bound single ion detection confidence of 99.85±0.02% for near-surface implants. As a result, the practical controlled silicon doping yield is limited by materials engineering factors including surface gate oxides in which detected ions may stop. For a device with 6 nm gate oxide and 14 keV 31 P+ implants we demonstrate a yield limit of 98.1%. Thinner gate oxides allow this limit to converge to the upper-bound. Deterministic single ion implantation can therefore be a viable materials engineering strategy for scalable dopant architectures in silicon devices. This article is protected by copyright. All rights reserved.