A comparative study on the production of ohmic contacts on Si by pulsed laser irradiation and by furnace heating

Ohmic contacts on Si has been realised by either Nd:glass pulsed laser irradiation or furnace heating of metal coated Si surfaces. The ohmic qualities of the contacts were studied by measuring the I-V characteristics of the samples. It was found that in order to obtain good ohmic contacts with the pulsed laser technique, the laser energy density E/sub l/ had to be large enough to transiently melt the Si surface. However, too large an E/sub l/ would produce excessive damage and deteriorate the contact. Although the pulsed laser technique for ohmic contact formation was simpler and faster than the furnace heating technique, the contacts I-V characteristics were less stable and usually had slightly larger contact resistances. These were attributed to the much more severe surface damages as a result of the transient formation process