High-quality high-throughput silicon laser milling using a 1 kW sub-picosecond laser

• DOI: 10.1364/ol.411412
• Publication Date: 2020-12-10T20:10:27Z
• Authors: Daniel Holder; Rudolf Weber; Christoph Röcker; Gerhard Kunz; David Bruneel; Martin Delaigue; Thomas Graf; Marwan Abdou Ahmed
• Keywords: 02 engineering and technology; 0210 nano-technology

We report on high-quality high-throughput laser milling of silicon with a sub-ps laser delivering more than 1 kW of average laser power on the workpiece. In order to avoid heat accumulation effects, the processing strategy for high-quality laser milling was adapted to the available average power by using five-pulse bursts, a large beam diameter of 372 µm to limit the peak fluence per pulse to approximately

0.7

J

/

c m

2

, and a high feed rate of 24 m/s. As a result, smooth surfaces with a low roughness of

S

a

≤ 0.6

µ

m

were achieved up to the investigated milling depth of 313 µm while maintaining a high material removal rate of

230

m m

3

/

min

.