A METHOD FOR FABRICATING A MICRO STRUCTURE ON SILICON SUBSTRATE WITH A CMOS CIRCUIT, AND A MEMS DEVICE COMPRISING THE MICRO STRUCTURE FABRICATED BY THE SAME METHOD

摘要

A method for forming a micro structure on a silicon substrate integrated with a CMOS circuit and an MEMS(Micro-Electro-Mechanical System) device with the micro structure manufactured thereby are provided to prevent the damage of the CMOS circuit due to a micro structure forming process by enclosing the CMOS circuit integrated portion using a protection layer. A first protection layer(24) is formed on a single crystal silicon substrate(110) to enclose a CMOS circuit portion of the substrate. A mask pattern is formed on the resultant structure. A trench is formed on the resultant structure by patterning selectively the substrate using the mask pattern as an etch mask. A second protection layer is formed at sidewalls of the trench. The second protection layer is selectively removed from a bottom portion of the trench. An additional etching process is performed on the substrate by using the second protection layer as an etch mask. A cavity is formed on the bottom portion of the trench by a wet etching process. At this time, a micro structure floats from the bottom portion of the trench. Then, the remaining second protection layer is removed.