ABSTRACT
There have been considerable interests about the fabrication of the submicron size hole due to the potential application of the near field optical sensor or liquid metal ion source. In this report, the various anisotropic processes, such as anisotropic Si etching, anisotropic oxidation, and anisotropic etching by Cl2 plasma, were utilized for submicron aperture fabrication. The 2-micron size dot array was photo lithographically patterned on the Si (100) wafer. After formation of the V-groove shape utilized by anisotropic KOH etching, the orientation dependent oxide growth at 1000C was performed to have an etch-mask for dry etching. The reactive ion etching by 100 watt, 9 mtorr, 40 sccm Cl2 feed gas using inductively coupled plasma (ICP) system was performed in order to etch 90nm SiO2 layer on the bottom of the etch stop and to etch the Si on the bottom. The negative on energy would enhance the directional anisotropic etching of the Cl2 RIE. After etching, the remaining thickness of the oxide on the Si (111) plane was measured to be 130nm by scanning electron microscopy. The fabricated hole is measured to be ~100nm in diameter.
