ION GUN, ION MILLING DEVICE, AND ION MILLING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a Penning discharge type ion gun capable of using a low ion beam current at a low acceleration voltage, and also capable of narrowing a beam, an ion milling device having the same, and an ion milling method.SOLUTION: An ion milling device to control a half value width of a beam profile of an ion beam irradiated from an ion gun to a sample in a range from 200 μm to 350 μm has the ion gun for emitting ion beams by ionizing a gas supplied from outside, a gas flow rate varying part for varying a flow rate of the gas supplied to the ion gun, and a current measurement part for measuring a current value of the ion beams emitted from the ion gun. The gas flow rate varying part sets the gas flow rate at a gas flow rate larger than the gas flow rate by which the ion beam current becomes maximum, based on the gas flow rate determined in the gas flow rate varying part and the current value measured in the current measurement part.SELECTED DRAWING: Figure 5