Analysis of MEMS Structure Sidewalls for Carbon and Fluorinated Residue with SEM, EDS and TSA

摘要

The transition of MEMS and MOEMS devices from the laboratory to laminate-based (PCB) highvolumernmanufacturing is challenging. Devices now must be manufactured with low defect rates and highrnreliability. Micromanufacturing techniques used for deep reaction ion etching (DRIE) typically use fluorinernplasma chemistries and can leave fluorinated sidewall residues that may release in the form of flakes.rnSidewall residues that release as flakes can interfere with moving parts in fluidic and optical pathways,rnrendering the devices useless.rnAnalysis of fluorine and other contamination can be quantified using Scanning Electron Microscopyrn(SEM) equipped with Electron Dispersive Spectroscopy (EDS). New EDS techniques, using fast DSPrn(Digital Signal Processor) controlled systems, add additional power to conventional EDS, capturing andrnanalyzing significantly more X-Ray CPS (counts per second) than the older systems. Digital systemsrncontrolled by software provide additional analytical capability through post-processing. Trace ElementrnSensitivity Analysis (TSA), a new post-processing technique for chemical mapping of surfaces, enablesrndetection of low level contamination that formerly would have been lost in the noise. It is capable ofrndetermining individual particle chemistry with excellent accuracy and traceability.