JPH0224951A - Correction method for drift of specimen position - Google Patents

Abstract

PURPOSE:To enhance the drift correction accuracy and shorten the measuring time by sensing drift of the specimen position with a tunnel current measuring means on the specimen holder side, and controlling a specimen position micro- movement mechanism. CONSTITUTION:In an analyzing device with possibility of analysis of a specimen 1 in its heated condition, a tunnel current measuring means due to a location sensing chip 6 and a reference position meter 7 installed on a specimen holder 3 senses the tunnel current corresponding to the position drift of the specimen 1 originating from thermal drift of specimen stage 6. This current is fed back through a drift correction circuit 8, and a specimen position micro-movement adjusting mechanism 4 consisting of piezo ceramic element is controlled, and thus the specimen position drift correction accuracy is enhanced and possible drift variation during correction is prevented to lead to shortening of the measuring time for analysis.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an analyzer that is capable of analyzing a sample in a heated state, and particularly relates to an analyzer that enables analysis of a sample in a heated state. This paper relates to a drift correction method.

(Prior art) In SEM (scanning electron microscope), AES (Auger electron spectroscopy), and scanning RHEED (reflection high-speed diffraction) devices, for example, a sample such as steel is heated.
It is possible to analyze how the particles blow out and spread. For such analysis, the sample holder is equipped with a heating device. Normally, the sample holder is mounted on a sample stage and the analysis position is determined by moving the sample stage. However, if the sample stage is also heated when the sample is heated, the analysis position may move due to thermal expansion. arise. For this purpose, the thermal insulation around the sample is improved so that only the sample is heated and no heat is transmitted to the sample stage or the like.

[Problem to be solved by the invention]

However, when a sample is heated to a high temperature of about 600° C., the radiant heat generated during heating results in a thermal drift of the sample stage, resulting in a drift in the sample position during analysis. Particularly when the analysis region is narrow, 1 μm or less, the drift cannot be ignored, so it is necessary to wait until the thermal drift stops or becomes constant before analysis, which requires a long time for analysis. If the drift reaches a certain speed, the stage can correct the position, but it will take a long time to do so.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a sample position drift correction method that can accurately perform sample position drift correction when analyzing the heating state of a sample.

[Means to solve the problem]

To this end, the present invention provides an analyzer capable of analyzing a sample in a heated state, which is equipped with a sample position fine movement mechanism between the sample holder and the sample stage, and a tunnel current measuring means on the sample holder side. The present invention is characterized in that the position drift is detected by a tunnel current measuring means, and the sample position is corrected by controlling the sample position fine movement mechanism.

[Effect]

In the sample position drift correction method of the present invention, when the sample position changes due to heating of the sample, the tunnel current changes, so the sample position is corrected by controlling the sample position fine movement mechanism so that the tunnel current remains constant. Ru. Since the drift of the sample position is detected using the tunnel current in this way, the amount of drift can be suppressed to about 5 to 10 people.

[Example] Examples will be described below with reference to the drawings.

FIG. 1 shows a sample position drift correction method according to the present invention.
1 is a diagram showing an example, 1 is a sample, 2 is a sample heating device,
3 is a sample holder, 4 is a piezoelectric ceramic, 5 is a sample stage, 6 is a position detection chip, 7 is a reference position meter, and 8 is a drift correction circuit.

In FIG. 1, a sample heating device 2 is assembled inside a sample holder 3, and a sample 1 is placed in the sample heating device 2.
and then placed on the sample stage 5. A position detection chip 6 is attached to the sample holder 3, and a base (seven position meter 7) is arranged opposite to this position detection chip 6.The reference position meter 7 is a sample holder with a built-in sample heating device 2 3 and are thermally independent, and after the analysis position is determined, it is brought close to the sample holder 3 and used as the reference position.These position detection chip 6 and reference position meter 7 /Nias is applied between the sample holder 3 and the sample stage 5, and when the two are brought close together (approximately 5 to 10 people), a so-called tunnel current flows. The space is connected by a piezoelectric ceramic (piezo element) 4. Then, the thermal drift of the sample holder 3 is detected by the position detection chimper and the reference position meter 7, and the drift of the sample holder 3 is corrected using the piezoelectric ceramic 4 as a fine position control mechanism. This is carried out by the drift correction circuit 8. Therefore, this drift correction circuit 8 detects and amplifies the tunnel current flowing through the position detector knob 6, and feeds it back to the piezoelectric ceramic 4 so that the tunnel current becomes constant. It is.

With the above configuration, when a sample is to be analyzed in a heated state, an analysis position is first selected by operating the X, Y, and Z movement mechanisms of the sample stage 5. After that, the Vi quasi-position meter 7 is attached to the position detection chip 6 attached to the sample holder 3.
get closer to When the two approaches to about 5 to 10 people and a tunnel current flows, the reference position meter 7 is fixed with that position as the reference position. In this state, the sample heating device 2 is operated to heat the sample 1. Then, a predetermined temperature, for example 600
The analysis begins when the temperature reaches ゛C. When a drift appears in the sample holder 2 due to heating, the line between the position detecting tipper and the reference position meter 7 changes, and the tunnel current changes. Due to this change in tunnel current, the drift correction circuit 8 operates and feeds back to the piezoelectric ceramic 4 so that the tunnel current becomes constant, thereby correcting the drift in the piezoelectric ceramic 4.

Note that the present invention is not limited to the above embodiments, and various modifications are possible. For example, if a position detection means using tunnel current is provided in both the X and 7 directions, and a fine movement position control mechanism using a piezo rod can be driven in both the X and 7 directions, no matter which direction the trift is moved, it will be two-dimensional. This can be corrected, but since the direction in which the drift occurs is usually determined to be one direction due to the structure, it is of course possible to configure the structure so that the correction can be performed only in that direction.

[Effects of the Invention] As is clear from the above description, according to the present invention, the tunnel current is monitored and fed back to the fine position control mechanism composed of piezo ropes to achieve positional accuracy, which eliminates the conventional thermal drift. It is possible to significantly reduce the number of people involved to about 5 to 10 people, and it is also possible to improve the accuracy of drift correction. Therefore,
Even when analyzing a sample in a heated state, the analysis can be performed without waiting until the thermal drift stops, so the analysis time can be shortened.

[Brief explanation of the drawing]

FIG. 1 shows a sample position drift correction method according to the present invention.
It is a figure showing an example. l...sample, 2...sample heating device, 3...sample holder, 4...piezoelectric ceramics, 5...sample stage, 6...position detection chip, 7...reference position meter , 8
...Drift correction circuit. Applicant: JEOL Ltd.

Claims (2)

[Claims] (1) In an analyzer that is capable of analyzing a sample in a heated state, it is equipped with a sample position fine movement mechanism between the sample holder and the sample stage, as well as a tunnel current measuring means on the sample holder side, to prevent drift of the sample position. A sample position drift correction method, characterized in that the sample position is detected by a tunnel current measuring means, and the sample position is corrected by controlling a sample position fine movement mechanism. (2) The sample position drift correction method according to claim 1, wherein the sample position fine movement mechanism is constituted by a piezoelectric element.