Performance enhancement of a scanning electron microscope using a deep convolutional neural network

Abstract

We report noise reduction and image enhancement in scanning electron microscope (SEM) imaging while maintaining a fast scan rate during imaging, using a deep convolutional neural network (D-CNN). SEM images of non-conducting samples without a conducting coating always suffer from charging phenomenon, giving rise to SEM images with low contrast or anomalous contrast and permanent damage to the sample. One of the ways to avoid this effect is to use fast scan mode, which suppresses the charging effect fairly well. Unfortunately, this also introduces noise and gives blurred images. The D-CNN has been used to predict relatively noise-free images as obtained from a slow scan from a noisy, fast scan image. The predicted images from D-CNN have the sharpness of images obtained from a slow scan rate while reducing the charging effect. We show that by using the proposed method it is possible to increase the scanning rate by a factor of about seven with an output of image quality comparable to that of slow scan mode. We present experimental results in support of the proposed method.