Atomic-Precision Placement of Single Donors in Silicon Quantum Devices with 100% Yield

Quantum devices such as qubits and analog quantum simulators fabricated out of individual or small clusters of donors in silicon are highly sensitive to the precise atomic arrangement of those donors relative to one another and surrounding control electrodes. A variation of +/- 1 atom at a key site within a device alters the potential landscape and therefore device behavior significantly. Until recently, attempts to fabricate true single-atom precision P in Si devices using the scanning probe hydrogen depassivation lithography (HDL) technique have met with failure rates of 30% - 40% per intended single-atom site. We present here a modification of HDL in which STM tip-based molecular manipulation enables a dramatic increase in yield with 100% success when incorporating P into Si. We discuss the details of this technique as well as 2x2 donor array devices where each array site is gated that have been fabricated with single-atom precision.