Nanoimprint lithography (NIL) is an alternative lithographic method that offers a sub-10 nm feature size, high throughput, and low cost. It requires a mold which has a low fabrication cost and long life time. A mold is the material with various patterns to transfer on the plastic substrate. Materials such as Si, quartz, plastic and Ni have been widely used for micron or sub micron sized mold fabrication depending on its pattern size and application. Si and quartz are very easy to be broken, and plastic can be deformed easily during process. However, Ni has high enough hardness and life time as a mold material and can be fabricated from on Si micro to nano sized molds with a seed layer by a simple Ni electro-deposition. After electro-deposition, the sample is usually dipped in KOH solution to remove Si from Ni. The consumption of Si mold is necessary step to produce a Ni mold. In this study, a method was developed to fabricate a Ni mold without the consumption of Si mold. Vapor SAM (self assembled monolayer) method was used to deposit hydrophobic layer on Si mold. A low surface energy release layer on stamp surfaces not only helps to improve imprint qualities, but it also increases the stamp lifetime significantly by preventing surface contamination. Hydrophobic layer, which has a low surface energy, makes possible to separate Ni from Si substrate without causing any damages on Si mold. The characteristics of deposited hydrophobic layer were analyzed by measurements of the contact angle, its hysteresis, surface energy, thickness and lateral friction force. The stiction of Ni on Si mold was observed when the separation of Ni from Si was tried without the SAM deposition. The multiple duplication of Ni molds has been successfully developed without disposing costly Si mother mold. Duplicated patterns on Ni mold showed the same patterns as on Si mother mold when they were observed with optical microscope, 3D profiler, FE-SEM, and AFM (atomic force microscope).
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