A Study of Front-Side Etching Technology in the Fabrication of Vacuum Sealed Absolute Micro Pressure Sensor

Abstract

A study on front side etching technology in the fabrication of membrane newlinetype absolute micro pressure sensor newlineFabrication of thin membranes has been an important aspect in common newlinemicromechanical devices owing to its numerous industrial applications. The pressure newlinesensing technology that provides a multiple-measurement and multiple-range capability newlineis also based on a thin diaphragm or membrane fabrication process. This thesis describes newlinethe experimental details of the fabrication of a thin membrane over a conical V-shaped newlinecavity using front side lateral etching technology and the results obtained are discussed. newlineIn the reported work, front side lateral etching technology has been studied. This newlinestudy proposes a novel front side etching fabrication process for silicon based newlinepiezoresistive pressure sensor. As far as the fabrication process is concerned, this newlinetechnique successfully accomplished a front side etching process laterally to replace the newlineconventional back-side bulk micromachining. This novel structure pressure sensor can newlineachieve the distinguishing features of the chip size reduction and fabrication costs newlinedegradation. newlineThe study presented in this thesis is divided into six chapters as follows, each newlinestarting with an introduction and ending with references together with the seventh chapter newlineon summary and conclusions. newlineII newlineChapter 1: Introduction newlineChapter 2: Thin Film Materials newlineChapter 3: Anisotropic Etching newlineChapter 4: Fundamental Theory and Design of Micro Pressure Sensor newlineChapter 5: Fabrication of Absolute Micro Pressure Sensor using Front-Side-Lateral newlineEtching Technology newlineChapter 6: In-Process Observations and Discussions newlineChapter 7: Summary and Conclusions newlineChapter 1 on Introduction describes micromachining and micro fabrication newlinetechnologies (e.g., submicron photolithography, thermal oxidation, thin film deposition newlineand chemical etching etc.) to construct the three dimensional micro-electro-mechanical newline(MEMS) devices such as the fabricated device- absolute micro pressure sensor.