1. Field of the Invention
The present invention relates to an ion-beam processing system for preparing a sample observed with a transmission electron microscope or other instrument and also to a sample holder used in the ion-beam processing system.
2. Description of Related Art
Ion-beam processing equipment described in Japanese Patent Laid-Open No. 2003-173754 is known for preparing a thin film sample observed with a transmission electron microscope (TEM). This equipment, shown in FIG. 1 of the patent reference, has a shielding material disposed over a sample. An ion beam is directed at both the shielding material and the sample from above the shielding material. The sample portion that is not shielded by the shielding material is ion-etched. In this equipment, a sample holder (13) on which a sample is set is spaced from a shielding material support device (23) holding the shielding material. The position of the shielding material is so adjusted that the shielding material is located in the center of the sample.
In the conventional system, the sample holder (13) is not formed integrally with the shielding material support device (23) as described previously but they are disposed in a spaced relationship to each other. Therefore, if external vibrations, for example, are transmitted to the system during processing of the sample, the shielding material and sample will be vibrated with different amplitudes in different directions. This will vary the positional relationship between the shielding material and the sample. Where the position of the shielding material relative to the sample is varied by an external perturbation during processing of the sample in this way, a good sample adapted for TEM observation cannot be prepared.
Furthermore, in the conventional system, the position of the shielding material must be adjusted to place it in the center of the sample as described previously. Normally, this operation is performed by the operator. That is, the operator makes the adjustment while watching through an optical microscope. Such an adjustment must be made whenever a sample is processed, which is greatly annoying to the operator.