Investigations of activation energy of porous silicon oxidation using calorimetric methods

The oxidation of porous silicon has been studied using differential scannin g calorimeter. The oxidation was found to consist of two parts with differe nt activation energies. This indicates the existence of two different react ion mechanism. The results from the hydrogen desorption measurements have b een used to study the different oxidation behaviour of the n- and p(+)-type porous silicon. The results show that the dihydride structure dominates on the surface of the n-type porous silicon, contrary to p(+)-type porous sil icon, where the monohydride is the major structure. Explanations of these f eatures are discussed. Using the activation energy, the surface termination effects are investigated. The best improvement in the activation energy wa s observed in the sample, whose surface was partially stabilized by ammoniu m groups.