Stress measurement technique to monitor porous silicon processing

Macroscopic stress measurements are used to monitor Porous Silicon processi ng. Silicon wafer of 1 Omega cm resistivity, n-type and < 1 0 0 > orientati on were used as starting material. Porous Silicon layers with a porosity of 57% and a thickness of 85 mu m, fabricated by electrochemical anodisation, were differently dried, then the evolution of the wafer deflection has bee n followed with storage time in air. Thermal treatments both in inert and o xidant atmosphere have been performed up to 1000 degrees C. The stress beha viour vs. temperature allows to estimate the hydrogen desorption activation energy.