LASER-PULSE INDUCED CHANGE OF COSI2-SIO2-SI STRUCTURE

The Q-switched YAG: Nd and CO2 laser initiated formation has been stud ied of thin CoSi2 crystalline layers deposited by coevaporation of the Co+Si mixture on SiO2/Si substrates. The electrical and optical prope rties of the CoSi2 layers were also determined. High quality resistive crystalline CoSi2 films were obtained by treating the layer with CO2 laser radiation of 2 MW/cm(2) to 8 MW/cm(2) intensity. The electrical resistance of the layer decreased by a factor of 9. When this layer is subjected to a Q-switched YAG: Nd laser radiation of the intensity of 20 MW/cm(2) to 35 MW/cm(2), the magnitude of the resistance increases by a factor of 3 due to clusters of vacancies in the CoSi2. The phase of the CoSi2 and the build-up of the concentration of vacancies were determined by the X-ray diffraction. A correlation between changes in the optical and electrical properties as well as structural changes of the silicide layer was found. It is shown that change in the optical parameters of the resistive films subjected to laser treatment can be used for both remote resistivity control and quality check. (C) 1998 E lsevier Science Ltd. All rights reserved.