| 摘要 |
<p>A method for acquiring settling time according to an embodiment of the present invention uses a deflector which deflects a charged particle beam by a deflection signal from a digital-to-analog converter (DAC) amplifier to set settling time of the DAC amplifier to be a first time period to deflect the charged particle beam to a specimen with the deflector by a deflection movement amount smaller than an evaluation deflection movement amount for evaluating the settling time of the DAC amplifier to form a reference pattern written by two shots of the beam having a width dimension whose both ends are different and set the settling time of the DAC amplifier to be variable by using a plurality of second time periods which are different from each other to deflect the charged particle beam to the specimen with the deflector by a deflection movement amount of the two consecutive shots equal to the evaluation deflection movement amount for evaluating the settling time of the DAC amplifier for each second time period set as variable to form an evaluation pattern written by the two consecutive shots on both ends of the width dimension designed to be equal to the reference pattern, calculate a difference between the width dimension of the evaluation pattern and the width dimension of the reference pattern for each second time period set as variable, and acquire the settling time of the DAC amplifier required for a deflection by the deflection movement amount by using the difference for each second time period set as variable.</p> |
