Sains Malaysiana
40(1)(2011): 71–74
Fabrication Effects
on Polysilicon-based Microcantilever Piezoresistivity for Biological Sensing
Application
(Kesan Proses
Fabrikasi Terhadap Piezorintangan Microkantilever Berasaskan Bahan Polisilicon
untuk Aplikasi Penderiaan Biologi)
Nina Korlina Madzhi1, *, Anuar Ahmad2, Balkish Natra1, Mastura Sidek1 & Lee Yoot Khuan1
1Faculty of Electrical Engineering, Universiti Teknologi MARA
40450 Shah Alam, Selangor, Malaysia
2Faculty of Engineering, Universiti Industri Selangor
Jalan Zirkon A7/A, Seksyen 7, 40000 Shah Alam, Selangor,
Malaysia
Diserahakan: 7 Disember 2009 / Diterima: 16 Julai 2010
ABSTRACT
In principle, adsorption
of biological molecules on a functionalized surface of a microfabricated
cantilever will cause a surface stress and consequently the cantilever bending.
In this work, four different type of polysilicon-based piezoresistive
microcantilever sensors were designed to increase the sensitivity of the
microcantilevers sensor because the forces involved is very small. The design
and optimization was performed by using finite element analysis to maximize the
relative resistance changes of the piezoresistors as a function of the
cantilever vertical displacements. The resistivity of the piezoresistivity
microcantilevers was analyzed before and after dicing process. The maximum
resistance changes were systematically investigated by varying the
piezoresistor length. The results show that although the thickness of
piezoresistor was the same at 0.5 μm the resistance value was varied.
Keywords: Biological
sensing; piezoresistive; microcantilever; resistivity
ABSTRAK
Pada prinsipnya, jerapan
molekul biologi pada permukaan yang fungsikan oleh kantilever yang telah
difabrikasi akan menyebabkan tegangan permukaan dan akibatnya lenturan pada
kantilever. Dalam kajian ini, empat jenis sensor piezorintangan mikrokantilever
berasakan bahan polisilicon direka untuk meningkatkan sensitiviti sensor mikrokantilever
memandangkan tekanan yang terlibat adalah sangat kecil. Reka bentuk dan
pengoptimuman dilakukan dengan menggunakan analisis elemen hingga memaksimumkan
perubahan pertahanan relatif daripada piezorintangan sebagai fungsi perpindahan
menegak kantilever. Ukuran rintangan dari piezorintangan mikrokantilever
dianalisis sebelum dan selepas proses ‘dicing’. Perubahan maksimum nilai
rintangan diselidiki secara sistematik dengan mengubah ukuran panjang
piezorintangan. Keputusan kajian menunjukkan bahawa walaupun ketebalan
piezorintangan adalah sama iaitu sebanyak 0.5 μm tetapi nilai rintangan
adalah berbeza.
Kata kunci: Mikrokantilever;
penderiaan biologi; piezorintangan; rintangan
RUJUKAN
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Korlina Madzhi, Anuar Ahmad & Lee Yoot Khuan. 2008. Design and Fabrication
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*Pengarang untuk surat-menyurat; email: ninak654@salam.uitm.edu.my
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