Laser annealing plays a significant role in the fabrication of scaled-down semiconductor devices by activating dopant ions and rearranging silicon atoms in ion-implanted silicon wafers, thereby improving material properties. Precise temperature control is crucial in wafer annealing, particularly for repeated processes where repeatability affects uniformity. In this study, we employ a three-dimensional time-dependent thermal simulation model to numerically analyze the multiple static laser annealing processes based on a CO₂ laser with a center wavelength of 9.3 μm and a pulse repetition rate of 10 kHz. The heat transfer equation is solved using a multiphysics coupling approach to accurately simulate the effects of different numbers of CO₂ laser pulses on wafer temperature rise and repeatability. Additionally, a pyrometer is used to collect and convert the surface temperature of the wafer. Radiation intensity is converted to temperature via Planck’s law for real-time monitoring. Post-processing is performed to fit the measured temperature and the actual temperature into a linear relationship, aiding in obtaining the actual temperature under small beam spots. According to the simulation conditions, a wafer annealing device using a CO₂ laser as the light source was independently built for verification, and a stable and uniform annealing effect was realized.

A frequency-tunable and single-longitudinal-mode master oscillator power amplifier system based on a radio-frequency (RF)-excited waveguide CO ₂ laser with three-stage amplification was demonstrated. The continuous tuning range of 0.29 GHz within one longitudinal mode spacing of the RF-excited waveguide CO ₂ laser was realized by adjusting the cavity length in closed loop. The linewidth of the CO ₂ laser was 3.9 MHz, and the maximal output power was 23.7 W at the center frequency of 9P (20) (9.56 μm). An amplification factor of 17 was obtained by adopting three RF-excited seven-channel folded-waveguide CO ₂ amplifiers. This laser system will be a good candidate for coherent detection lidar.

In this study, we analyzed the spatiotemporal distribution of annealing temperature using a dual-beam dynamic scanning annealing technique based on a CO₂ laser (10.6 μm) and a 785 nm laser, and the effects of laser energy density, scanning speed, and preheating temperature on the resulting temperature. We systematically examined the influence of key process parameters, including laser energy density, scanning speed, and preheating temperature, on the annealing temperature. Our aim was to optimize annealing conditions to enhance the electrical properties of the materials, as indicated by reduced sheet resistance, controlled diffusion depth of doped ions, and higher activation rates. This approach ensured high activation rates of doped ions while limiting dopant re-diffusion to merely 3.6 nm in the depth direction, as confirmed by concentration profile analysis. Furthermore, based on temperature distribution, deformation of the wafer surface was analyzed. The results indicate that under the employed process parameters, no significant adverse effects on wafer flatness or structural integrity were observed.