研究目的
Investigating the influence of the pulse duration in a range of 200 fs up to 10 ps on the cutting process of thin silicon.
研究成果
The cutting kerf geometry strongly depends on the fluence level or pulse energy. A higher fluence leads to deeper grooves, but also to an increased width. The progress of the depth is logarithmically shaped with a saturation level determined by the particular fluence. The experiments show a significant influence of the pulse duration on the cutting geometry, with the shortest pulse duration leading to much deeper and narrower grooves compared to a pulse duration of 10 ps. This behavior is independent from pulse energy and pulse overlap, explained by the higher pulse peak intensity and therefore less heat conduction in the surrounding material and a very selective ablation process.
研究不足
The study is limited to the investigation of pulse durations between 200 fs and 10 ps on the cutting process of thin silicon. The influence of other parameters such as different materials or laser wavelengths is not explored.
1：Experimental Design and Method Selection:
The experiments are carried out with a Light Conversion Pharos laser with various pulse durations between 190 fs and 10 ps, operated at the second harmonic wavelength of 515 nm and a repetition rate of 200 kHz. A raw beam diameter of 5 mm and a focussing optics with 100 mm focussing length leads to a focal spot diameter of 15 μm. The beam deflection is realized by a Scanlab IntelliScan 14DE galvo scanner. The polarization of the beam is linear with a contrast ratio of 1:300. The direction of the polarisation is set perpendicular to the cutting / scanning direction by means of a half-wave-plate.
2：The direction of the polarisation is set perpendicular to the cutting / scanning direction by means of a half-wave-plate.
Sample Selection and Data Sources:
2. Sample Selection and Data Sources: 500 μm thick boron doped silicon wafers are grooved with certain experimental parameters and afterwards cleaved perpendicularly to measure the cutting width and depth.
3：List of Experimental Equipment and Materials:
Light Conversion Pharos laser, Scanlab IntelliScan 14DE galvo scanner, half-wave-plate, 500 μm thick boron doped silicon wafers.
4：Experimental Procedures and Operational Workflow:
The silicon wafers are grooved with different parameters and afterwards cleaved perpendicularly. The cutting width and depth are measured, and possible material damage next to the cutting kerf is observed.
5：Data Analysis Methods:
The ablation threshold is determined with the method of Liu. The cutting geometry is analyzed based on pulse duration, pulse energy, peak fluence, scanning speed, pulse spacing, and passes.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
