Journal of Basrah Researches ((Sciences)) Volume 37.Number 2 15 April ((2011)) 11 Reactive Ion Etching (RIE) for Micro and Nanogap Fabrication 1 Th. S. DHAHI, 2 U. HASHIM and 3 N. M. AHMED Nano Biochip Research Group 1,2 Institute of Nano Electronic Engineering, University Malaysia Perlis (UniMAP) Lot 106, 108 & 110, Tingkat 1 Block A, Taman Pertiwi Indah, Jalan Kangar-Alor Setar, Seriab, 01000 Kangar, Perlis, Malaysia. 3 School of Microelectronic Engineering, UniMAP. sthikra@yahoo.com ISSN ــ1817 ــ2695 (Received 6 April 2010; Accepted 3 March 2011) Abstract To understand the important relationship between the biosensor and micro and nanostructures we introduce this proposal about the fabrication of micro and nanostructure by using one of the most important dry etching processes in micro and nanostructures, reactive ion etching (IC-RIE) has been applied and developed as a method for etching micro and nanogap semiconductors. PolySi material is used to fabricate micro and nanogap structure and gold as electrodes. The fabrication and preparation methods to fabricate micro and nanogaps using RIE properties are discussed along with their advantages towards the nanotechnology and biodetection. In this study, 2 masks design are proposed. The first mask is the lateral micro and nanogap and the second mask is for gold pad electrode pattern. Lateral micro and nanogaps are introduced in the fabrication process using polysilicon and gold as an electrode. Conventional photolithography and dry etching techniques are used to fabricate these micro and nanogaps based on the standard CMOS technology. As a result we need to deposit Al layer over the polysilicon semiconductor before coating a photoresist to protect the polysilicon layer during the etching (IC-RIE) for using the Al material as a hard mask. The requirement time to etch 1m polysilicon layer completely by using IC-RIE to fabricate the micro and nanogap structure it takes approximately 40sec. These results are better than those using wet anisotropic etching techniques. KEY WORDS: Micro &nanogap, photolithography, reactive ion etching (RIE). INTRODUCTION In the past two decades, the biological and medical fields have seen great advances in the development of biosensors and biochips capable of characterizing and quantifying biomolecules. The RIE equipment used in these experiments was a Vacutech parallel-plate system. The lower electrode is powered by a 13.56 MHz-RF generator coupled through an automatic tuning network. Each electrode is 200 mm in diameter and the distance between them is 23 mm. The RF electrodes are made of anodised aluminium. The chamber volume is 131 and the system is pumped by a 350 l/rain lurbomolecular pump backed by a mechanical rotary vane pump. The base pressure before each run was less than 5 x 10 -2 Torr. A two-level factorial design of experiments was used to find the main and interaction effects governing etch rate and sidewall slope. Even through the RIE process performance is influenced by the interaction effects between different factors, such as, oxygen content, power density, pressure and loading, at a chosen set of etching parameters.