Sub-1nm Patterning Accuracy via Spatial-Phase Locking

摘要

Scanning-electron-beam lithography (SEBL) is an essential tool for creating patterns of arbitrary geometry at feature sizes below 100 nm, even down to 15 nm dimensions. Aside from the slow writing speed, the most outstanding problem of SEBL is its inability to achieve pattern-placement accuracy that is compatible with its resolution. For example, commercial SEBL systems, costing several millions of dollars, can under the most ideal conditions achieve placement accuracy of about 20 nm. To solve this problem MIT invented and has pursued a novel approach called spatial-phase locking. The objective of this grant was to demonstrate the efficacy of spatial-phase-locked e-beam lithography (SPLEBL) in achieving 1-nm level placement accuracy. SPLEBL replaces the normally open-loop approach to scanning-electron-beam lithography (SEBL) with a closed-loop approach.