摘要
157nm是对硬脆材料进行激光表面微加工的理想波段。构建数学模型以探讨激光抛光材料时工艺参数对表面粗糙度Ra的影响,使用最小二乘法推导出粗糙度的计算式。利用157nm激光对GaN外延片进行了抛光微加工的基础实验。通过比较多组模拟与实验粗糙度值,发现理论粗糙度值与实际的测量值之间有一定误差,但相对误差都在15%以下,最小的相对误差为4%。以低于15Hz的脉冲频率和高于0.7mm/min的扫描速度进行激光扫描刻蚀时,可以获得较低的表面粗糙度。数学模型合理地解释了抛光后底面沟壑的形成,为今后改善加工质量提供了理论依据。
As one of the ultra-precision machining tools, 157 nm laser is an ideal means of surface micro-machining for hard and brittle materials. By establishing the mathematical model, the effects of the process parameters on the etched surface roughness （Ra） are discussed for laser polishing of materials. The roughness calculation formula is derived by using the least squares method. Experimental studies on polishing micro-processing of LED-GaN semiconductor films have been performed using excimer laser with 157 nm wavelength. Through the comparison of multiple sets of theoretical and experimental roughness values, there is an error between them, but the relative errors are all below 15 %, and the smallest relative error is only 4 %. For 157 nm laser spanning, the ablated surface with lower roughness can be obtained when the laser repetition rate is lower than 15 Hz and the scanning velocity is higher than 0.7 mm/min. The mathematical model can reasonably explain the groove formation mechanism of the etched GaN surface, which provides a theoretical basis to improve the processing quality.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2013年第6期162-166,共5页
Chinese Journal of Lasers
基金
国家自然科学基金(51175393)
湖北省自然科学基金(2011CDA055)资助课题
作者简介
徐刚（1985-），男，博士研究生，主要从事激光微加工方面的研究。E-mail：xugang524@163.com
导师简介：戴玉堂（1964-），男，博士，教授，主要从事激光微加工方面的研究。E-mail：daiyt68@163.com
