In a semiconductor manufacturing process, miniaturization of a circuit pattern formed on a semiconductor substrate (wafer) has been rapidly progressing, and importance of process monitoring for monitoring whether or not the pattern is formed as designed is more and more increased. For example, measurement and inspection of a circuit pattern and the like on a wafer are performed at completion of each manufacturing process in order to detect abnormality and failures (defects) in the semiconductor manufacturing process early or in advance.
At time of the above-mentioned measurement or inspection, in a measurement and inspection device such as an electron microscope device (SEM) using a method of a scanning electron beam, an electron beam (electron ray) is irradiated onto an object wafer (sample) while being scanned, and energy such as secondary electrons thus generated are detected. Then an image (a measurement image or an inspection image) is generated by signal processing or image processing or the like based on the detection. Then measurement and inspection are performed based on the image.
For example, if the device is a device which performs inspection of defects in a circuit pattern (an inspection device), images of the same circuit pattern are compared with each other using inspection images, and a part where a difference between the images is large is determined or detected as having defects. Moreover, if the device is a device which performs measurement in a circuit pattern (a measurement device), since a generation amount of secondary electrons or the like changes depending on unevenness (surface shape) of the sample, changes or the like of the surface shape of the sample can be perceived through an evaluation process of a signal of the secondary electrons. In particular, by utilizing the fact that the signal of secondary electrons abruptly rises or falls at edge portions of the circuit pattern, edge positions within the image of the circuit pattern are estimated so that a dimension value or the like of the circuit pattern can be measured. Then, based on the measurement result, quality of the processing of the circuit pattern can be evaluated.
When performing blanking of an electron beam B while shooting the electron beam B towards a sample in an electron beam drawing device, distribution of an energy amount inclines in a blanking movement direction within one shot, thus a desired shot shape is not maintained, and CD accuracy and positional accuracy aggravates. A method for solving such a problem is disclosed in Patent Literature 1. In Patent Literature 1, in order to solve the problem, voltages of opposite polarities are applied to two blanking deflectors. Blanking by a first blanking deflector and blanking by a second blanking deflector are repeatedly performed in one shot of the electron beam B towards the sample, so that bias of distribution of the energy amount is canceled out, and an electron beam B shot having a flat energy amount distribution without inclination is realized. The CD accuracy and the positional accuracy of electron beam drawing are thus improved.
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