A New Experimental Approach to Evaluate Plasma-induced Damage in Microcantilever

Authors

Yuki Nishimori, Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, JapanFollow
Shinji Ueki, BEANS Project 3D BEANS Center, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
Masakazu Sugiyama, BEANS Project 3D BEANS Center, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
Seiji Samukawa, BEANS Project 3D BEANS Center, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
Gen Hashiguchi, Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan

Abstract

Plasma etching, during micro-fabrication processing is indispensable for fabricating MEMS structures. During the plasma processes, two major matters, charged ions and vacuum–ultraviolet (VUV) irradiation damage, take charge of reliability degradation. The charged ions induce unwanted sidewall etching, generally called as “notching”, which causes degradation in brittle strength. Furthermore, the VUV irradiation gives rise to crystal defects on the etching surface. To overcome the problem, neutral beam etching (NBE), which use neutral particles without the VUV irradiation, has been developed. In order to evaluate the effect of the NBE quantitatively, we measured the resonance property of a micro-cantilever before and after NBE treatment. The thickness of damage layer (δ) times the imaginary part of the complex Young's modulus (Eds) were then compared, which is a parameter of surface damage. Although plasma processes make the initial surface of cantilevers damaged during their fabrication, the removal of that damage by NBE was confirmed as the reduction in δEds. NBE will realize a damage-free surface for microstructures.

Bahasa Abstract

Pendekatan Eksperimental Baru untuk Mengevaluasi Kerusakan yang Disebabkan oleh Plasma pada Kantilever Mikro. Pengetsaan plasma selama proses fabrikasi-mikro adalah peristiwa yang tak terhindarkan dalam proses fabrikasi struktur-struktur MEMS. Selama proses plasma berjalan, dua materi utama, yaitu ion bermuatan dan kerusakan iradiasi vakum-ulraviolet (VUV), berperan penting dalam memastikan reliabilitas proses degradasi. Ion-ion bermuatan menyebabkan pengetsaan sisi-dinding yang tidak diharapkan, suatu peristiwa yang umumnya disebut “penotsaan” (“notching”), yang menyebabkan degradasi berkekuatan rapuh. Selanjutnya, iradiasi VUV menimbulkan kecacatan kristal pada permukaan etsa. Untuk mencegah hal ini, pengetsaan sinar netral (neutral beam etching atau NBE), yang menggunakan partikel-partikel netral tanpa iradiasi VUV, telah dikembangkan. Untuk dapat mengevaluasi efek dari proses NBE secara kuantitatif, kami mengukur properti resonansi dari kantilever mikro sebelum dan setelah proses NBE. Ketebalan lapisan rusak (δ) yang dikalikan dengan bagian imajiner dari modulus Young kompleks (Eds) kemudian dibandingkan; hasilnya menjadi parameter kerusakan permukaan. Meskipun proses plasma menyebabkan permukaan awal kantilever mengalami kerusakan selama proses fabrikasi, perbaikan kerusakan itu oleh proses NBE telah terbukti karena reduksi δEds. NBE dapat menghasilkan permukaan yang bebas-rusak pada struktur-struktur mikro.

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Recommended Citation

Nishimori, Yuki; Ueki, Shinji; Sugiyama, Masakazu; Samukawa, Seiji; and Hashiguchi, Gen (2013) "A New Experimental Approach to Evaluate Plasma-induced Damage in Microcantilever," Makara Journal of Technology: Vol. 17: Iss. 2, Article 4.
DOI: 10.7454/mst.v17i2.1948
Available at: https://scholarhub.ui.ac.id/mjt/vol17/iss2/4