A flexible 300 mm integrated Si MOS platform for electron- and hole-spin qubits exploration

TL;DR

This paper presents a versatile 300 mm silicon platform for fabricating both electron- and hole-spin qubits, featuring precise control, design flexibility, and promising quantum device performance at millikelvin temperatures.

Contribution

It introduces a flexible, high-precision silicon process integrating optical and electron beam lithography for scalable qubit fabrication with on-the-fly design modifications.

Findings

Successful fabrication of well-defined quantum dots

Demonstration of tunable tunnel couplings

Coherent spin control achieved at 10 mK

Abstract

We report on a flexible 300 mm process that optimally combines optical and electron beam lithography to fabricate silicon spin qubits. It enables on-the-fly layout design modifications while allowing devices with either n- or p-type ohmic implants, a pitch smaller than 100 nm, and uniform critical dimensions down to 30 nm with a standard deviation ~ 1.6 nm. Various n- and p-type qubits are characterized in a dilution refrigerator at temperatures ~ 10 mK. Electrical measurements demonstrate well-defined quantum dots, tunable tunnel couplings, and coherent spin control, which are essential requirements for the implementation of a large-scale quantum processor.