| 摘要 |
An imprint template is provided with a shallower field bordering the patterned region. The shallower field can be formed with additional lithography/etch steps after (or before) the formation of the features in the patterned region. The template is used to establish a thin film pattern with a field thickness that is shallower than the pattern. A shallower field bordering the patterned region alleviates sidewall re-deposition during ion mill. In a planarization/etch-back process, a thinner field helps to achieve a flat top surface by compensating for the thickness variation caused by different filling ratios. Fabrication of the recessed field template comprises a multi-step patterning process. The initial patterns are formed using a convention fabrication process. A second patterning step is used to reduce the height of the field region, which can be applied by coating the “half-finished” template with a suitable resist pattern and patterning the resist using a second lithography step that is aligned to the original pattern. Template material in the field region is then etched with the resist as a mask, forming a template with a recessed field region after the remaining resist is removed. It should be appreciated that the order of these etch steps can be reversed to obtain the same result.
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