An Experimental Analysis of Residual Stress Measurements in Porous Silicon Using Micro-Raman Spectroscopy

Micro-Raman spectroscopy of porous silicon films of micrometers and on silicon bulk substrates is carried out. The practical information is given for applications of stress measurements in the films which were obtained with electrochemical etching technique. Higher residual stress (reached GPa) in the etched area falls continuously through the transitional area to the un-etched area of the sample. However, the stress gradient is smaller in the etched or un-etched area and increases in the transitional area between the two areas. Using atomic force microscopy to investigate surface appearance of porous silicon films, micro-cavity structure is expected to relate to the distribution of residual stress.