Process control for 32 nm imprint masks using variable shape beam pattern generators

摘要

Step and Flash Imprint Lithography (S-FIL~®) is a unique method that has been designed from the beginning to enable precise overlay for creating multi-level devices. However, since the technology is 1X, it is critical to address the infrastructure associated with the fabrication of templates (imprint masks).rnFor device manufacturing, one of the major technical challenges remains the fabrication of full-field 1X templates with commercially viable write times. Recent progress in the writing of sub-40 nm patterns using commercial variable shape e-beam tools and non-chemically amplified resists has demonstrated a very promising route to realizing these objectives, and in doing so, has considerably strengthened imprint lithography as a competitive manufacturing technology for the sub-32 nm node. Here we report the critical dimension (CD) uniformity and process latitude of dense 32 nm patterns from templates written with variable shape beam pattern generators. Uniformity on the template and in the imprinted field was 3.22 and 3.45 nm, 3σ. Process latitude during the writing of the template was improved by increasing both feature bias and exposure dose. As an example, the slopes for the 36 and 32 nm features are approximately 0.30 and 0.25 nm/μC/cm~2, respectively, indicating a substantial process window for exposure dose.