SURFACE-ROUGHNESS ANALYSIS BY SCANNING TUNNELING MICROSCOPY AND ATOMIC FORCE MICROSCOPY

This report demonstrates the use of scanning tunneling microscopy and atomic force microscopy to obtain surface roughness parameters for semiconductor materials. Correlation between figures of merit and physical properties such as bondability and reflectivity has been demonstrated. Eutectic bond strength for silicon die attachment is shown to be inversely proportional to the roughness of the backside of the silicon die. Reflectivity of aluminum metallization has been shown to decrease with increasing roughness. We also illustrate that in some metal systems the surface structure is independent of the grain size as determined by planar transmission electron micrographs. Our work relies heavily on generating numerical data, which can be used to understand critical relationships and develop processing solutions.