微小尺寸测量中的图像处理技术

Image processing technique for microstructure measurement system

图像质量是影响光学显微系统微小尺寸测量精度的一个重要原因。介绍了测量系统的组成和工作原理 ,以及光学系统设计上保证成像质量的一些措施 ,探讨了提高图像质量和测量精度的方法。采用小波进行图像去噪 ,很好地去除了图像传输和存储过程中引入的高频噪声 ;为了进一步提高测量精度 ,采用同相累加平均的方法 ,滤除随机信号的影响。实验结果表明可满足超大规模集成电路线宽测量的要求 ,测量重复精度达到了 0 .0 1μm。

Image quality has an important effect on the micro structure measurement accuracy of optical microscopic systems. Some methods are given to improve image quality in optical systems with the image processing algorithms discussed in detail. Wavelet transform in two dimensions was used to filter the noise which was introduced during the transmission and storage of images. To improve the calculating accuracy, the line width values at different positions were accumulated in phase to reduce the random noise. The result can be used for large scale integrated circuit line width measurements. The repetitive precision is no more than ±0.01μm.