As feature sizes decrease and the demand for throughput increases, the semiconductor industry must concentrate on pattern positioning accuracy and process efficiency. Thermomechanical distortions induced in the photomask during fabrication may act to constrain the desired range of operating conditions to meet the manufacturing requirements for pattern placement accuracy and throughput. 3D finite element heat transfer and structural models have been developed to determine the global in-plane distortions induced in the photomask during e-beam patterning. Results obtained from these models show that the thermal-induced distortions, caused by global heating, are significant. Whereas, distortions due to the mechanical loading, caused by resist in situ stress relief, are minimal and can be neglected.
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