Measurement of buried undercut structures in microfluidic devices by laser fluorescent confocal microscopy

Journal Article · Fri Nov 20 00:00:00 EST 2009 · Applied Optics

DOI:https://doi.org/10.1364/AO.48.006432· OSTI ID:22036424

Shiguang, Li; Jing, Liu; Nguyen, Nam-Trung; Zhongping, Fang; Yoon, Soon Fatt

Measuring buried, undercut microstructures is a challenging task in metrology. These structures are usually characterized by measuring their cross sections after physically cutting the samples. This method is destructive and the obtained information is incomplete. The distortion due to cutting also affects the measurement accuracy. In this paper, we first apply the laser fluorescent confocal microscopy and intensity differentiation algorithm to obtain the complete three-dimensional profile of the buried, undercut structures in microfluidic devices, which are made by the soft lithography technique and bonded by the oxygen plasma method. The impact of material wettability and the refractive index (n) mismatch among the liquid, samples, cover layer, and objective on the measurement accuracy are experimentally investigated.

• OSTI ID: 22036424
• Journal Information: Applied Optics, Vol. 48, Issue 33; Other Information: (c) 2009 Optical Society of America; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6935
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCURACY
ALGORITHMS
CROSS SECTIONS
EQUIPMENT
EXTRACTION
FLUORESCENCE
HEIGHT
IMAGE PROCESSING
LASER RADIATION
LAYERS
MICROSCOPY
MICROSTRUCTURE
OXYGEN
REFRACTIVE INDEX
SURFACES
THREE-DIMENSIONAL CALCULATIONS
WETTABILITY