JP2003042927A - Scanning probe microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent lowering in lightness and contrast of a sample, generated by an optical element, when the sample is observed in prior art, and change in color information therein to shorten a measuring time. SOLUTION: The optical element OD is moved from an observation optical path L, when the sample is observed, and light from the sample 6 is made to reach an observation point VP without passing through the optical element OD. Disturbance to observation light is not generated thereby by the optical element OD in the observation, to prevent the lowering in the lightness and contrast of the sample 6, and changes in of the color information therein.

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a scanning probe microscope which scans a sample surface with a probe and enlarges and displays the surface information. 2. Description of the Related Art Conventionally, a scanning probe microscope has been used as an apparatus for analyzing a fine surface shape. Scanning probe microscopes include a scanning tunneling microscope that uses a tunnel current flowing between the probe and the sample surface and an atomic force microscope that uses an atomic force acting between the probe and the sample surface. The scanner generates a position change that compensates for a fine tunnel current change or an atomic force change that acts on the probe in response to fine irregularities or the like, and detects and displays the position change. In addition, although the said position change also depends on the change of the physical property of the sample surface in addition to the unevenness of the sample surface, hereinafter, in the present specification, the unevenness of the sample surface and the change of the physical property of the sample surface are referred to as unevenness. Call. An optical detection mechanism mainly using laser light is used for detecting a minute change in tunnel current or a change in atomic force acting on the probe. The basic configuration of a conventional scanning probe microscope will be described below with reference to FIG. 3, focusing on an optical detection mechanism.
The laser light emitted from the laser 1 is reflected at right angles by the beam splitter 3, reflected by an optical reflection surface (not shown) provided in advance near the tip of the probe 5, and further reflected by the mirror 4. Probe 5 with detector 8
Is converted to a position signal output. The sample 6 is placed on a scanner 7 and moved in a three-dimensional direction by a three-dimensional driving mechanism of the scanner 7. In the three-dimensional drive mechanism, a known structure using a piezoelectric element or the like has been widely used, and thus illustration and detailed description thereof are omitted. In preparation for the measurement, first, the sample 6 is roughly moved in the three-dimensional direction while observing the sample 6 from the observation point VP along the observation optical path L to roughly determine the sample position, and the scanner 7 is finely moved in the z direction in FIG. Adjust the distance between 5 and sample 6 to an appropriate position. Therefore, the observation of the sample 6 at the observation point VP is performed by the light passing through the optical element OD including the beam splitter 3 and the filter 2. Filter 2
Has a function of blocking laser light scattered by the probe 5 or the sample 6 before the observation point VP. At the time of measurement, the sample 6 is moved by the scanner 7 to x, y
In the scanning direction, the position signal output of the detector 8 is fed back to the scanner 7, and the sample 6 is controlled by the scanner 7 so that the output is always kept constant during measurement, that is, the position of the probe 5 is always kept constant. Is slightly moved in the z direction in the figure. In accordance with the three-dimensional position information of the sample position from the scanner 7, a display such as unevenness on the surface of the sample 6 is displayed on an appropriate display device (not shown). [0006] The structure of the conventional scanning probe microscope is as described above. In the prior art, the observation of the sample 6 is performed by the optical system including the beam splitter 3 and the filter 2 as described above. This is performed by light passing through the element OD. For this reason, the brightness and contrast of the sample 6 are remarkably reduced, the color information is changed, and it is difficult to discriminate and distinguish the colors, thus causing a problem in measurement. An object of the present invention is to provide a scanning probe microscope that solves such a problem. In order to solve the above-mentioned problems, a scanning probe microscope provided by the present invention provides a filter and a beam inserted in the middle of a sample observation optical path for detecting the position of a probe. A moving mechanism for moving an optical element including a splitter forward and backward is provided. Therefore, when the sample is observed, the optical element is moved and light from the sample can be directly observed without passing through the optical element. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a sectional view showing a configuration of a scanning probe microscope provided by the present invention, and FIG. 2 is a perspective view showing an example of a moving structure of an optical element OD. 1 and 2
In FIG. 7, components denoted by the same reference numerals as those shown in FIG. 3 are the same as the components shown in FIG. 3, and a detailed description of these functions will be omitted. In FIG. 1, an optical element OD comprising a filter 2 and a beam spiriter 3 has a moving structure. FIG. 2 shows an example of a specific moving structure at the time of observation by a direct observation system. In FIG. 2, the optical element OD is set on a movable optical element table M. At the same time, the optical element table M is mounted on a rail R via wheels S, and is moved by a drive system including a wire W and pulleys P1, P2.
That is, the pulse motor PM is directly connected to the pulley P1, and when a switching signal is input, the optical element table M moves in the moving direction D by driving the pulse motor PM. Then, the optical element OD is moved outside the observation optical path L, and the observation of the sample 6 in FIG. When measuring the irregularities of the sample 6, the optical element table M is moved along the moving direction D in the direction of the rail R, and the optical element OD is returned into the observation optical path L. The structure shown in FIG. 2 is an example, and the present invention is not limited to the structure and the direction of the movement. That is, for example, means for adopting a screw feed mechanism and rotating the screw rod by a motor or the like and automatically moving the same may be provided. In addition, the method of observing the sample 6 at the observation point VP is not limited to visual observation, and an auxiliary device may be used as necessary, such as a method using an optical fiber, a magnifying lens system, or a CCD (charge coupled device). Encompasses all of these observation methods. Since the present invention has been described in detail above, the light from the sample reaches the observation point without passing through the optical element. No obstruction occurs, the brightness and contrast of the sample at the time of observation are prevented from lowering, color information is prevented from changing, observation is performed with high sensitivity, sample positioning can be performed accurately and accurately, and measurement preparation time is reduced. Including measurement time is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a configuration of a scanning probe microscope according to the present invention. FIG. 2 is a perspective view showing an example of an optical element moving mechanism of the scanning probe microscope according to the present invention. FIG. 3 is a cross-sectional view showing a structure of a scanning probe microscope according to the related art. [Explanation of Symbols] 1 laser 2 filter 3 beam splitter 5 probe 6 sample 7 scanner OD optical element L observation optical path VP observation point

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Claims (1)

Claims: 1. A scanning probe microscope for analyzing a sample surface, comprising: a probe disposed close to the surface of the sample and an optical system for detecting the position of the probe. A filter inserted in the middle of the sample observation optical path to be detected, a moving mechanism for moving the optical element consisting of a beam splitter is provided, and the light from the sample moves without moving the optical element when observing the sample by moving the optical element. A scanning probe microscope characterized by enabling direct observation.