基于157nm深紫外激光的蓝宝石基片微加工

Micromachining technology of sapphire substrate based on 157nm DUV laser

为了探索157nm深紫外激光对蓝宝石材料的微加工技术,采用157nm激光微加工系统,对蓝宝石基片进行了扫描刻蚀和打孔加工,以研究激光工艺参量与刻蚀深度、表面形貌的关系,分析了157nm深紫外激光对蓝宝石材料的作用机理,并利用扫描刻蚀法在蓝宝石基片上加工了一个2维图形。由实验结果可知,157nm深紫外激光作用于蓝宝石材料是一个光化学作用与光热作用并存的加工过程,适合扫描刻蚀的加工参量为能量密度3.2J/cm^2,重复频率10Hz～20Hz,扫描速率0.15mm/min;在能量密度2.5J/cm^2下的刻蚀率为0.039μm/pulse。结果表明,通过对激光重复频率和扫描速度的控制可实现蓝宝石材料的精细微加工。

In order to probe micromachining technology of sapphire material, the ablation characteristics of 157nm deep ultraviolet laser were studied. The effect of laser process parameters on etching efficiency and surface quality was studied by scanning ablation and drilling on sapphire substrate. Moreover, the etching mechanism of 157nm laser on sapphire was analyzed. And then, a 2-D pattern was ablated onto the sapphire substrate by scanning approach. Both analysis and experimental results indicate that micromachining process that 157nm deep ultraviolet laser reacts on sapphire includes photochemical reactions and photothermolysis, and that a set of proper parameters about scanning etching were obtained, i. e. , scanning velocity at 0.15 mrn/ min with fluence of 3.2J/cm2, repetition frequency at 10Hz -20Hz; etching rate of drilling at 0. 039txm/pulse with fluenee of 2.5J/cm2. Precise micromachining could be realized under control of laser repetition rate and scanning velocity.