The purpose of paper is to investigate the impact of mask blank flatness on critical
dimension uniformity (CDU) and depth of focus (DOF) in the wafer printing process
with a test pattern designed for 65nm node technology. In this experiment we use 3
test masks with different flatness (0.3T, 0.5T and 1T), and the same test pattern array.
The mask flatness was measured with a Tropel® UltraFlatTM 200, and the focus error
is extracted from the CD data of the focus and energy matrix (FEM) analysis.
The goal of the study is to quantify the mask flatness influence on the high-numerical
aperture (NA) lithographic process.
Chemically amplified resists, CAR, and 50kV e-beam writers have been applied for the most advance mask manufacturing. To fulfill the requirement of 65nm generation a good performance resist played an important role. In this work, two advanced positive and negative CAR resist has been evaluated for 65nm photomask process with a 50kV e-beam pattern generator in an advanced process line. For 65nm node not only the resolution is needed to be improved but also the cirtical dimension(CD) control will be more critical than previous generation. So the evaluation is focus on the CD performance, resolution, profile, e-beam sensitivity, line edge roughness(LER), etc.