| 摘要 |
PURPOSE:To curtail image pick-up period of electron beam delineator by improving response speed of a digital-analog converter (DAC). CONSTITUTION:When digital data of which analog voltage corresponds to E1 volt is output to an output line 16 from a data control system 2 at the time to, a latch register 4 holds it, and a DAC5 outputs an analog voltage of E1 volt as an output 17 after the time tD. Meanwhile, when the switch S1 is set to the side B after tc seconds from the time to and simultaneously the switch S2 is set to the side A, an output (E1 volt) of the DAC5 having the characteristic A appears on the line 15 and thereby the electron beam 12 moves by the corresponding distance on a sample 13. Thereafter, the data control circuit outputs an instruction for making ON the electron beam to the line 14 and thereby a blanking up 3 is driven and the electron beam 12 is shot on the sample 13 for exposure. On the other hand, the data control system 2 outputs, after tC seconds, a digital data of which analog voltage corresponds to E2 volt onto the output line 16. Accordingly, the DAC7 outputs an analog voltage of E2 volt to the output 18 after tD seconds. |
