SEM画像復元における劣化関数推定技術

抄録

In the semiconductor device manufacturing there has been a pressing need for inspection and measurement by using high-resolution images of scanning electron microscopes (SEMs). The SEM spatial resolution is mainly determined by the beam spot size at the specimen's surface and the spreading of the beam electrons in the specimen. Image restoration sharpens an observed image by the process of removing blur, which is represented by a point spread function (PSF), from the image. In this paper we address the problem of identifying the parameter of the PSF, the so-called blind deconvolution problem. The proposed method estimates the parameter from both the Fourier spectrum of the observed image and the diameter of the electron beam calculated by electro-optics simulator. Extensive experiments on real image data indicate significant improvements in image quality compared with conventional methods. The estimation error of the PSF parameter by the proposed method was about half that of the conventional one.