CW Laser Induced Chemical Reactions with Integrated Circuits,

By focussing a CW laser on the surface of an integrated circuit, the temperature can be locally increased if the laser wavelength is adsorbed by the silicon of the circuit. This is the case when using visible or UV wavelengths. When turning on the laser beam power, the laser induced temperature increases and reaches an equilibrium temperature in less than a tenth of a microsecond for a one micron laser spot diameter. The equilibrium temperature strongly depends on the optical and thermal properties of the irradiated area and is lower when irradiating a metal, which has high lateral heat losses and high reflectivity, than a semiconductor, which has low thermal conductivity and low reflectivity.