Study of "on-chip" measurement methods of thin film mechanical properties for micromachining

Four methods for on-chip determining the thin-film stress in silicon micromachining are studied both theoretically and experimentally. For two new methods, i.e., beam pull-in voltage (V/sub PI/) and long beam deflection (LBD) methods, a detailed description is given. For other two known methods, i.e., beam buckling and rotating methods, some improvements are made. Experimental results of the four methods show reasonable consistence. Finally, a general comparison of these methods are given.