Computer Simulation of Laser Induced Temperatures for the Laser Direct Writing technique

Abstract

ABSTRACTLaser induced temperatures in substrates irradiated with a scanning gaussian laser beam were calculated by the finite element method. A quartz substrate of a given thickness and covered with a one - micron - thick silicon coating was assumed to be either placed on a heat sink or thermally insulated. The maximum temperature in the center of the laser spot was found to be proportional to the laser power for a spot size larger than the silicon thickness. Furthermore at a given laser power, the temperature decreased with increasing laser spot diameter and the time to reach the equilibrium temperature increases with the spot radius for radii less than the substrate thickness. The laser induced temperature was found to be affected by laser - scan speeds for speed values above the heat diffusion rate.