Determination and analysis of minimum dose for achieving vertical sidewall in electron-beam lithography

Prior to carrying out the proximity effect correction by optimizing the spatial distribution of dose in electron beam lithography, one first needs to determine the minimum total dose required. A conventional method typically used to determine the minimum total dose is the trial-and-error approach, which can be unnecessarily costly and wasteful. In this paper, two new dose determination methods are described, which utilize the concept of a “critical path” without any proximity effect correction effort. Also, the dependency of the minimum total dose and dose distribution on the feature and lithographic parameters is investigated. The simulation results show that the proposed dose-determination methods can adaptively and efficiently determine the minimum total dose. Thus, they have the potential to provide a practical and effective alternative to the conventional trial-and-error approach.