Ion beam sample preparation apparatus and methods

A method of operating an ion beam sample preparation apparatus having a tilting ion beam irradiating means to prepare a sample, the sample durably adhered to a shield, the method comprising the steps of:

• a) receiving the shield into a rotating shield retention stage, the rotating shield retention stage being further characterized as having a first datum feature, a second datum feature, a rotation axis located substantially in the plane of the first datum feature, and a rotation drive for rotating the rotating shield retention stage around the rotation axis, the shield being further characterized as having a third datum feature and a fourth datum feature;
• b) retaining said shield in the rotating shield retention stage with a shield retention means such that:
• i) the first datum feature of the rotating shield retention stage abuts the third datum feature of the shield, and,
• ii) the second datum feature of the rotating shield retention stage abuts the fourth datum feature of the shield;
• iii) a first shielding surface of the shield is disposed in the path of the ion beam and positioned to shield a portion of the ion beam directed at the first shielding surface when said shield is held in the rotating shield retention stage;
• c) operating a tilt drive such that the tilting ion beam irradiating means is disposed at a first tilt angle with respect to the shield;
• and,
• d) operating the tilting ion beam irradiating means at the first tilt angle to project an ion beam toward the first shielding surface;
• e) operating the rotation drive such that the rotating shield retention stage rotates at least a portion of one rotation while the ion beam prepares the sample.