Improvement of Gas Permeability of Gas Permeable Mold with Lattice Structure for Reduction of Transfer Failure in Photoimprint Lithography

In the nanoimprint process, the transfer failure due to the air involved from pressing the mold against the transfer material and the gas generated from the transfer material has been reported as a serious problem. We have investigated the relationship between the thickness of the mold and the gas permeation flow rate in a single-layer gas permeable mold with only a low density structure and a two-layer gas permeable mold with a low density structure and a lattice structure manufactured by a 3D printer. Furthermore, we imprinted the transfer material containing volatile solvents using two gas permeable molds, and investigated the presence of transfer defects due to gas. As a result, the gas permeation flow rate increased as the thickness of any gas permeable mold became thinner. In addition, when the gas permeable mold having a two-layer structure and the gas permeable mold having a single-layer structure are compared, the gas permeation flow rate of the two-layer structure is about 20 times as large as that of the single-layer structure. Furthermore, as a result of investigating the presence or absence of transfer failure due to gas in imprint molding, transfer failure due to gas occurred in the non-gas permeable mold, but transfer failure due to gas did not occur in the gas permeable mold having the two-layer structure. Therefore, the lattice structure designed for the gas passage can greatly improve the gas permeation flow rate, and it can be expected to reduce the transfer failure due to the gas at the time of imprint.