Fig. 1. Schematic of trajectory scanning system combined with closed-loop temperature control

Fig. 2. Schematic showing modulated processing beam spot

Fig. 3. Schematic of edge burn damage

Fig. 4. Parameter definitions for circular arc-linear trajectory

Fig. 5. Schematic of trajectory planning results and full power machining area

Fig. 6. Relationship between relative light intensity Iφ/I0 and trajectory azimuth angle φ

Fig. 7. Schematic of the Cartesian coordinate system O-xyz

Fig. 8. Relative amplitude of the processing light after orthogonal decomposition

Fig. 9. Relationship between Fresnel absorptance and azimuth angle

Fig. 10. Relationship between the relative absorbed power density Iside/Itop on the side and the azimuth angle φ

Fig. 11. Temperature variation curves of the silicon wafers during the laser scanning process at different azimuth angles (the first pass)

Fig. 12. Temperature variation curves of silicon wafers when the laser enters at different azimuth angles

Fig. 13. Variation of temperature peak at the edge of the silicon wafer during the first scanning with the trajectory azimuth angle

Fig. 14. The step temperature trajectory

Fig. 15. The second-order S-shape temperature trajectory. (a) Temperature curve; (b) temperature velocity curve; (c) temperature acceleration curve

Fig. 16. Comparison between temperature trajectory and the feedback temperature curve

Fig. 17. Scanning temperature curves before and after optimization of temperature control instructions