Particle beam device and method for processing and/or analyzing a sample

Abstract

A particle beam device and method for processing and / or for analyzing a sample are provided. A sample carrier is arranged at a first position, in which a sample surface is oriented parallel to a first beam axis of a first particle beam column. The sample carrier is rotatable from the first position into a second position, in which the sample surface is oriented perpendicular to a second beam axis of a second particle beam column. The first and second beam axes intersect at a coincidence point. In the first position a distance between the coincidence point and the first particle beam column is greater than a distance between the sample surface and the first particle beam column. In the second position a distance between the coincidence point and the second particle beam column is greater than a distance between the sample surface and the second particle beam column.

Description

TECHNICAL FIELD[0001]This application relates to a particle beam device and a method which are designed for processing and / or for analyzing (examining) a sample. In particular, this application relates to an electron beam device and / or an ion beam device.BACKGROUND OF THE INVENTION[0002]Electron beam devices, in particular a scanning electron microscope (SEM) or a transmission electron microscope (TEM), are used for examining samples in order to obtain insights with regard to the properties and behavior of said samples under specific conditions.[0003]In the case of an SEM, an electron beam (also called primary electron beam hereinafter) is generated using a beam generator. The electrons of the primary electron beam are accelerated to a predeterminable energy and focused by a beam guiding system, in particular an objective lens, onto a sample to be analyzed (that is to say an object to be analyzed). A high-voltage source having a predeterminable acceleration voltage is used for accel...

AI Technical Summary

Benefits of technology

[0016]The particle beam device according to the system described herein provides, then, for the sample surface of the sample to be processed using the first particle beam in the first position. By way of example, in the first position material is removed from the sample surface or material is applied to the sample surface. Afterward, the sample carrier is brought from the first position into the second position, in which the sample surface is oriented perpendicular to the second beam axis. This is done by rotation of the sample carrier about the rotation axis. In the second position the processed sample surface is analyzed using the second particle beam. In particular, provision is made for imaging the processed sample surface. Since the sample surface in the second position is oriented perpendicular to the second beam axis and, moreover, the second working distance is less than a comparable working distance in a particle beam device from the prior art (wherein the comparable working distance is basically the distance between the second end of the second particle beam column and the coincidence point), good imaging properties can be obtained. In this case, the system described herein has the advantage that, using a single movement of the sample carrier, namely the rotation of the sample carrier from the first position into the second position about the rotation axis, the sample surface of the sample can be oriented perpendicular to the second beam axis. Further movements are not absolutely necessary.

[0019]On account of the smaller working distances possible in comparison with the prior art, the system described herein makes it possible that in the first position and / or in the second position of the sample carrier imagings can be performed in which lower acceleration voltages than in comparison with the prior art can be used for particles of the first particle beam and / or particles of the second particle beam. By way of example, acceleration voltages of less than 750 V are provided in the system described herein. This is possible only with difficulty in the prior art, which likewise has the second particle beam column, for imagings of a sample surface arranged at the coincidence point. In order to obtain good imaging properties in said prior art, acceleration voltages of greater than 750 V should be used for the particles of the second particle beam. This has the following background. The known prior art has, for focusing purposes, an objective lens provided both with electrostatic elements and with magnetic elements. The electrostatic elements are always operated with a constant voltage, even if the acceleration voltage can vary in a specific range (for example in a range of 100 V to 20 kV). On account of the electrostatic elements, the second particle beam is focused to working distances that are less than 10 mm. Using the magnetic elements, it is then only possible to set the second particle beam to working distances even smaller than 10 mm. In the case of this particle beam device known from the prior art it has been found that the second particle beam, at acceleration voltages of less than 700 V, can be set only to working distances which are less than 5 mm. However, this is far below the coincidence point, which is arranged at a distance of approximately 5 mm from the second particle beam column in the case of the prior art. Consequently, the second particle beam in the case of the known particle beam device is no longer focused onto the sample surface arranged at the coincidence point. This causes poorer, that is to say no sharp, imagings of the sample surface. By comparison with this prior art, the system described herein has the advantage that in the first position and / or in the second position of the sample carrier imagings can be performed in which lower acceleration voltages than in comparison with the prior art can be used for particles of the first particle beam and / or particles of the second particle beam.

[0021]The system described herein is suitable, in particular, for a series examination on a sample. Consequently, the system described herein provides, after the conclusion of an analysis of the sample surface in the second position of the sample carrier, for the sample carrier to be brought into the first position again, such that the sample surface of the sample can be processed again. This is done by rotation of the sample carrier about the rotation axis from the second position into the first position. In the first position, using the first particle beam, by way of example, material is removed from the sample surface or material is applied to the sample surface. Afterward, the sample carrier is again brought into the second position, in which the sample surface that has been processed again is analyzed using the second particle beam. The system described herein has the advantage that a processing and an analysis of the sample in series is possible in a simple and rapid manner since the change between the first position and the second position can be effected only by a rotation of the sample carrier about the rotation axis.

Problems solved by technology

As a result of this, however, the series examination on the sample becomes time-consuming.