Hybrid EB-writing technique with 100 kV-SB and 50 kV-VSB writers: Use of the former for outlines and the latter for bodies after pattern data splitting

A new technique of hybrid use of a 100 kV-SB (spot beam) EB writer and a 50 kV-VSB (variable shaped beam) EB writer, based on an outline-and-body method, is proposed and examined for making nano-imprint molds. Here an original layer is split into an outline layer and a body layer, which the 100 kV writer and the 50 kV writer, respectively, take care of. This outline-and-body method is compared with a normal method (using only the 100 kV writer) in terms of CD linearity, pattern fidelity, and writing time. The CD linearity is similar. The pattern fidelity is satisfactory because no disconnected, shortened, or largely distorted features of the resist pattern are observed. A silicon mold with two layers of a 36 nm-rule logic/gate circuit was fabricated. The writing time for the 100 kV writer was reduced by 34%–64%. In conclusion, the outline-and-body method is effective to reduce the writing time without sacrificing fidelity.