Simple fabrication scheme for sub-10 nm electrode gaps using electron-beam lithography

An innovative and simple method, based on electron-beam (e-beam) overlapping and overexposure techniques, is developed to fabricate sub-10 nm electrode gaps with very good electrical properties. Gaps with 4 to 10 nm spacing can be fabricated using a proper e-beam dose and pattern-developing time. The fabrication yield is nearly 100% for 8–9 nm gaps, but significantly smaller for 3–4 nm gaps. The gap leakage resistance is around $1012–1013 Ω,$ implying very good isolation. As an example, we present a transport study on a single 8 nm Co particle junction using a 10 nm gap.