Park Hyo Mi, Joo Ki-Nam
Appl Opt. 2017 Nov 1;56(31):8592-8597. doi: 10.1364/AO.56.008592.
In this investigation, we describe a combined low-coherence interferometric technique to measure the surface and thickness profiles of wafers at once with high speed. The measurement system consists of a spectrally resolved interferometer to provide and monitor the optical path difference between two incident beams of the optical source part and a low-coherence scanning interferometer to measure the dimensions of wafers with significantly shortened scanning length. In the experiments, a silicon wafer and a sapphire wafer, of which both sides are polished, were used as targets of the measurement system for verification of the proposed system. As a result, the scanning length of the low-coherence scanning interferometer was reduced from a few millimeters to a few hundreds of micrometers approximately 10 times. In addition, surface profiles of both sides and thickness profiles were simultaneously measured to reconstruct 3D shapes of wafers.
在本研究中，我们描述了一种组合式低相干干涉测量技术，可高速一次性测量晶圆的表面轮廓和厚度轮廓。测量系统由一个光谱分辨干涉仪组成，用于提供和监测光源部分两束入射光束之间的光程差，以及一个低相干扫描干涉仪，用于以显著缩短的扫描长度测量晶圆尺寸。在实验中，使用双面抛光的硅晶圆和蓝宝石晶圆作为测量系统的目标，以验证所提出的系统。结果，低相干扫描干涉仪的扫描长度从几毫米减少到几百微米，大约减少了10倍。此外，同时测量了晶圆两面的表面轮廓和厚度轮廓，以重建晶圆的三维形状。
