METHOD AND APPARATUS FOR THE MONITORING OF SAMPLE MILLING IN A CHARGED PARTICLE INSTRUMENT

摘要

An apparatus for monitoring sample milling in a charged-particle instrument has a variable-tilt specimen holder (130) attached to the instrument tilt stage (120). The variable-tilt specimen holder (130) includes a first pivoting plate (260) having a slot (280) for holding a specimen (290) rotatably supported in the variable-tilt specimen holder (130). The first pivoting plate (260) has a range of rotation sufficient to move the preferred axis of thinning of the specimen (290) from a first position where the tilt stage (120) is placed at its maximum range of tilt and the angle between the preferred axis of thinning of the specimen (290) and the axis of the ion beam column (110) of the instrument is greater than zero, to a second position where the preferred axis for thinning of the specimen (290) is substantially parallel to the axis of the ion-beam column (110). A light detector (250) is positioned to intercept light passing through the specimen (290) as it is thinned by ion-beam milling. The intensity of the light passing through the specimen (290) may be compared to the intensity recorded for previous stages of milling to determine an endpoint for milling