Doi Tomotaka, Yamamoto Takatoki
Department of Mechanical Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan.
Materials (Basel). 2020 May 11;13(9):2206. doi: 10.3390/ma13092206.
We proposed and demonstrated an optical dry etching method for transferring a pattern on a photomask to a surface of plastics by decomposing the irradiated area using the high energy of vacuum ultraviolet light (VUV) at room temperature and pressure. Two kinds of wavelengths of 160 nm and 172 nm were used as the vacuum ultraviolet light, and the patterning performances for polymethyl methacrylate (PMMA) and polycarbonate (PC) were compared. As a result, it was revealed that proportional relationships were obtained between the etching rate and the irradiation dose for both wavelengths, and the cross-sectional profiles were anisotropic. In addition, both PMMA and PC were etched at a wavelength of 160 nm, whereas PC could not be etched at a wavelength of 172 nm, suggesting that it correlates with the bond dissociation energies of the molecular bonds of the materials and the energies of the photons. Furthermore, by combining this method with the optical bonding method that we had previously developed to bond surfaces irradiated with VUV, we have demonstrated a method for fabricating microfluidic devices by irradiating only with VUV. This paper shows that this technique is a new microfabrication method suitable for simple and mass production of plastic materials.
我们提出并演示了一种光学干法蚀刻方法，该方法通过在室温和常压下利用真空紫外光（VUV）的高能分解照射区域，将光掩膜上的图案转移到塑料表面。使用160 nm和172 nm两种波长的真空紫外光，并比较了聚甲基丙烯酸甲酯（PMMA）和聚碳酸酯（PC）的图案化性能。结果表明，两种波长下蚀刻速率与辐照剂量均呈正比关系，且横截面轮廓呈各向异性。此外，PMMA和PC在160 nm波长下均能被蚀刻，而PC在172 nm波长下不能被蚀刻，这表明这与材料分子键的键解离能和光子能量有关。此外，通过将该方法与我们之前开发的用于粘结VUV照射表面的光学粘结方法相结合，我们展示了一种仅通过VUV照射来制造微流控装置的方法。本文表明，该技术是一种适用于塑料材料简单大规模生产的新型微制造方法。
