Surface studies on benzophenone doped PDMS microstructures fabricated using KrF excimer laser direct write lithography

Autor: Madhushree Bute Kant, K. P. Adhi, Kashinath R. Patil, Dhananjay Bodas, S.D. Shinde, Suresh W. Gosavi, Vasant Sathe
Rok vydání: 2014
Předmět:
Zdroj: Applied Surface Science. 314:292-300
ISSN: 0169-4332
DOI: 10.1016/j.apsusc.2014.06.054
Popis: This paper discusses microfabrication process for benzophenone doped polydimethylsiloxane (PDMS) using laser lithography. KrF excimer laser of 248 nm with 20 ns pulse width at repetition rate of 1 Hz was used for microfabrication of undoped and benzophenone doped PDMS. The doped-PDMS shows sensitivity below 365 nm, permitting processing under ambient light. The analysis of etch depth revealed that doped PDMS shows self developable sensitivity at lower fluence of ∼250 mJ/cm 2 . The unexposed and exposed surface was studied using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and Scanning electron microscopy (SEM). Spectrocopic analysis indicated increase in C O, C O, Si O 3 and Si O 4 bonding at the expense of Si C and Si O 2 bonds of PDMS. In case of laser exposed doped-PDMS, removal of benzophenone from probe depth of spectroscopy was observed. Whereas the surface morphology of exposed and unexposed doped-PDMS was observed to be same, indicating clean development of PDMS micropatterns. The present study indicates that addition of 3.0 wt.% benzophenone in PDMS enhance self development sensitivity of PDMS. The self developable results on doped-PDMS are quite encouraging for its potential use in point of care Lab-On-Chip applications, for fabricating micropatterns using direct write laser lithography technology.
Databáze: OpenAIRE
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