After an analysis of the factors that causes critical dimension (CD) variation in the lithography process of the LLE (Litho-Litho-Etch) double-patterning technology that employs the freezing process, an optimum process for freezing the resist patterns to reduce the CD variation, which occurs after the 2nd litho process, was achieved. By optimizing the track parameters of freezing process, CD variation is likely to be reduced not only in the 1st resist pattern but also in the 2nd resist pattern. The optimum conditions were adopted to form patterns of 40 nm resist lines and spaces in the evaluations conducted in this paper. The formation result showed improvement of 3 sigma of the within-wafer CD uniformity of both the 1st resist pattern and the 2nd resist pattern, by about 13% and 46% respectively.