Fabrication of patterned substrate by wet process for biochip

Hydrophobic/hydrophilic patterned substrates were fabricated on a glass substrate by a liquid phase deposition (LPD) method. Hydrophobic surface was obtained by modifying ZnO thin films with a rough surface using a fluoroalkyltrimethoxysilane (FAS) and hydrophilic surface was prepared by decomposing FAS on an exposed to UV light. The hexagonal ZnO rods were perpendicularly grown by LPD method on glass substrates with a ZnO seed layer. The diameter and thickness of hexagonal ZnO rods were increased as a function of increases of immersion time. The surface morphology, thickness, crystal structure, transmittance and contact angle of prepared ZnO thin films were measured by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV-visible spectrophotometer (UV-vis) and contact angle measurement. Hydrophilic ZnO thin films with a contact angle of $20^{\circ}{\sim}30^{\circ}$ were changed to a hydrophobic surface with a contact angle of $145^{\circ}{\sim}161^{\circ}$ by a FAS surface treatment. Prepared hydrophobic surface was pattered by an irradiation of UV light using shadow mask with $300\;{\mu}m$ or 3 mm dot size. Finally, the hydrophobic surface exposed to UV light was changed to a hydrophilic surface.

습식 공정법에 의한 바이오칩 용 패터닝 기판 제조

LPD법을 이용하여 유리 기판 위에 발수/친수 패터닝 기판을 제조하였다. 발수 표면은 거친 표면을 갖는 ZnO 박막을 FAS를 이용한 표면 개질에 의하여 만들어졌고, 친수 표면은 자외선을 조사하여 FAS를 제거함으로써 만들어졌다. Hexagonal ZnO rod는 LPD법에 의하여 ZnO seed 층이 코팅된 유리 기판 위에 수직으로 성장되었다. 침적시간이 증가함에 따라 ZnO rod의 직경과 두께는 증가하였다. 제조된 ZnO 박막의 표면구조, 두께, 결정구조, 투과율과 접촉각은 FE-SEM, XRD, UV-vis와 contact angle meter를 이용하여 측정하였다. $20^{\circ}{\sim}30^{\circ}$의 접촉각을 갖는 친수 ZnO 박막은 FAS 표면 처리에 의해 $145^{\circ}{\sim}161^{\circ}$의 접촉각을 갖는 표면으로 바뀌었다. 제조된 발수 표면은 $300\;{\mu}m$, 3 mm의 dot size를 갖는 shadow mask를 이용하여 자외선을 조사하여 패터닝 되었다. 최종적으로 자외선이 조사된 발수 표면은 친수 표면으로 바뀌었다.