Micropits MEMS

Abstract

Three sized Micropits were developed. Micropits were designed and fabricated using wet etching. MEMS fabrication consists of thin film deposition and patterned of several geometric structures. For Si substrate etching three layers SiO2/ Si3N4/ SiO2 were deposited and patterned. They were used as a mask. Micropit pattern was transferred by lift off technique. SiO2, Si3N4 layers and Si substrate were etched by HF, H3PO4 and KOH solutions. Si substrate has 7mm/h etching rate. Micropit micrographs were obtained by scanning electronic microscopy (SEM). Micropits are MEMS widely used in gas sensors, because they provide thermal isolation, Micropits will be used for gas microsensors, polisilicon microheater and gas sensor thin film will be deposited later. Today gas sensors have several applications in manufacturing & industry, such as, automotive, medicine/biomedical, consumer products, aerospace, chemical, optical displays, fluidics, wireless and optical communications.