Integrated Electrostatic RMS-to-DC Converter: Fabricated in a BIFET-CompatibleSurface-Micromachining Process (Geientegreerde Elektrostatische RMS-naar-DC Omzetter, Gefabriceerd in een BIFET-Compatibel Oppervlakte-Microfabricageproces)

摘要

This thesis desribes the design of a surface-micromachined electrostatic RMS-to-DC converter and the development of a fabrication process, which is compatible with a standard BIFET process. In chapter 2, an overview of RMS conversion techniques is given, the characteristics of the most important integrated RMS converters are summarized, resulting in the proposed electrostatic RMS converter. Chapter 3 starts with considerations about structure geometry, dimensions and detection principle. The resulting parallel-plate actuator, with capacitive read-out system is modeled and the mechanical, damping and electrostatic behavior of the complete structure is examined. Chapter 4 provides an overview of the micromachining techniques. Chapter 5 examines in detail the compatibility considerations when merging a standard bipolar eletronic process (DIMES01) with a surface-micromachining process. The chapter concludes with measurements of the electrical characteristics of the standard transistors before and after the processing of the surface micromachining. In chapter 6, stress measurement techniques are discussed. A rotating-pointer structure is presented, which is used to develop a low-stress polysilicon deposition process. Finally, in Chapter 7, general conclusions are drawn.