Abstract:
The validity of a novel, direct and convenient method for
micromechanical property measurements by beam bending using a
nanoindenter is demonstrated. This method combines a very high
load resolution with a nanoemtric precision in the determination
of the microcantilever beam deflection. The method is described
clearly. In the deflection of microbeams, the influence of the
indenter tip pushing into the top of the microbeams and the
curvature across its width must be considered. The measurements
were made on single-layer, micro-thick, several kinds of width
and length polysilicon beams that were fabricated using
conventional integrated circuit (IC) fabrication techniques. The
elastic of a polysilicon microcantilever beam will vary linearly
with the force and the deformation is thought to be elastic.
Furthermore, it suggests that Young modulus of the beam can be
determined from the slope of this linear relation. From the
load-deflection data acquired during bending the mechanical
properties of the thin films were determined. Measured Young
Modulus is 137 Gpa with approximately a 2.9%~ 6.3% difference in
Young modulus.
Key words: Mechanical
properties Micromechanical devices Thin films Polysilicon
Nanoindentation
Manuscript received on
September 20, 1999; revised manuscript November 4, 1999 |