CoMSaT: a single-chip fabrication technique for three-dimensional integrated fluid systems

Abstract

A new micromachining process, i.e., Cover- on- Meshes technique for Single-chip f abrication of Three-dimensional structures (CoMSaT), is proposed and used for the fabrication of micro integrated-fluid systems (IFS). In this technique, a two-stage etching process, including quick sacrificial layer etching and silicon anisotropic etching, is applied to the fabrication. Both use the etching holes (meshes) on the anti-etching membranes through which the etchant can pass freely. After the etching, an LTO layer is deposited using low pressure chemical vapor deposition (LPCVD) to cover the opened meshes. Real three dimensional structures with membranes suspended on deep cavities can be formed by use of such an single-chip fabrication. The technique makes it possible to produce 3D structures without wafer/chip bonding and alignment, resulting in an easy integration of on-chip electric-circuits and an easy miniaturization of the 3D systems. Various micro-pumps, micro-valves with pressure sensors, temperature sensors and micro-actuators have been on-chip integrated with electric-circuits within an area of 5.9 mm×6.4 mm. The primary experiments show that this technique is promising in the fabrication of miniature integrated fluid systems.