基于蓝光DVD光学读取头的纳米触发测头

Nano-trigger probe based on blue-ray DVD optical reader

基于光学读取头改装的非接触式微纳米测头已广泛应用于阶高、线宽和微小角度的测量。为了追求更高的精度与分辨力而提高聚焦透镜数值孔径(NA)则会使读取头内四象限传感器输出聚焦误差信号曲线的线性区间急剧减小,从而使测头系统的纵向可测量范围降低。为了在进一步提高纵向分辨力的情况下,扩大其纵向测量行程,基于蓝光DVD读取头研发了一种触发式非接触测头。既利用高NA值透镜测头的高精度和高分辨力,又通过触发测量的方式解除了高NA值带来低测量范围的限制,提高了测头的适用性。实验结果表明:该测头的纵向分辨力优于1 nm,重复性误差为18 nm,纵向测量范围可达10μm。

The non-contact micro-nano probe modified by optical reader has been widely used in the measurement of high-order, line width and small angle.In order to achieve higher precision and resolution, increasing the numerical aperture(NA) of the focusing lens will reduce the linear interval of the output focus error signal curve of the four-quadrant sensor in the reader, so that the longitudinal measurement range of the probe system will be reduced.In order to further improve the longitudinal resolution and expand the longitudinal measuring stroke, a trigger type non-contact probe is developed based on the blue-ray DVD reader.It not only makes use of the high precision and high resolution of the lens probe with high NA value, but also lifts the limitation of low measuring stroke caused by high NA value by triggering the measurement, and improves the applicability of the probe.The experimental results show that the longitudinal resolution of the probe is better than 1 nm, the repeatability error is 18 nm, and the longitudinal measurement range is up to 10 μm.