Measuring and testing – Surface and cutting edge testing – Roughness
Reexamination Certificate
1999-04-21
2002-06-18
Larkin, Daniel S. (Department: 2856)
Measuring and testing
Surface and cutting edge testing
Roughness
C073S001860
Reexamination Certificate
active
06405583
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to a correlation sample for scanning probe microscope and to a method of processing the sample, and, more particularly, to a correlation sample for a scanning probe microscope for use as a measurement standard while measuring a state of a surface of a sample, and to a method of processing the correlation sample.
In recent years, am irregular shape of the surface of a sample can be observed at an atomic level. That is, in an atomic force microscope for resolving atomic structure, a cantilever having a tip at the head portion thereof is used as a scanning probe. When the tip is scanned across the surface of a sample serving as a measured surface, attraction or reaction based on atomic forces between the surface of the sample and the tip are generated, and the atomic forces can be measured by detecting deflection of the cantilever.
The scanning probe microscope includes a magnetic force microscope for detecting a magnetic force of a measured surface developed by application of the above-mentioned atomic force microscope (hereinafter, AFM), a scanning Maxwell stress microscope for detecting voltage and electrostatic force of the measured surface, and a Kelvin probe force microscope, and each can detect a force which can not be obtained from the irregular data of the measured surface. The magnetic force microscope (hereinafter, MFM), the scanning Maxwell stress microscope (hereinafter, SMM), and the scanning Kelvin force microscope (hereinafter, KFM) can obtain the irregular data of the measured data in high resolution similarly to the AFM, and irregular data and magnetic image data can be observed in the same domain and at the same time in the MFM for example.
Therefore, when comparing the conventional measuring and observing method, the above-mentioned MFM, SMM, and KFM have various advantages such as high resolution, capability of observation of shapes of any surface at the same time, and ease of data acquisition. Therefore, the application field of these microscopes is spreading in domain analysis of magnetic media, analysis of magnetic material, analysis of electric characteristics and failure analysis of semiconductors, and estimation of work function in material.
However, although a relative comparing image of each force (N pole and S pole in magnetic force for example) can be obtained in the conventional scanning type probe microscope because of object of observation, there has been a problem in obtaining absolute strength (magnetic strength for example) because of the lack of a measurement standard.
A recent AFM is capable of measuring absolutely and is not limited only to observation by preparing a correlation sample of standard height. However, there has been a problem in that measured value varies at replacement of microscopes and samples because the sample is one kind and the measured surface is measured with respect to the sample used as a standard. No correlation sample of force performing as a standard has been prepared for MFM, SMM, and KFM performing as scanning probe microscope except for the above-mentioned AFM. Accurate detection of force of a measured surface using these microscopes requires measurement in a state in which distance between the measured surface and the tip is always kept constant. However, it is difficult to detect force distribution of a real correlation sample because the influence of irregularity appears in a measurement result when the surface is irregular even if a correlation sample is made. For example, an object (a magnetic body and the like) generating a force (a magnetic force, for example) serving as a certain standard is located at a surface of a silicon or glass substrate so as to make a correlation sample and is used for the correlation sample performing as a measurement standard of high density magnetic media. However, a real force distribution of the sample can not be measured accurately because it is difficult to accurately keep the distance between the tip and the surface of sample constant if measurement is attempted while moving the tip up and down so that the distance is kept constant.
For compensation of the above problem, it has been considered that the result of force measurement of a sample surface may be corrected based on irregular data of a correlation sample previously obtained. However, force measurement by the cancellation system is not in practical use yet so as to obtain an accurate measurement value.
The present invention has been made in view of the above-mentioned inconvenience in the prior art. A first object of the present invention is to provide a scanning probe microscope in which each force performing as a standard is accurately detected without influence of irregular data of surface and strength value of each force at measurement can be determined (absolute measurement) correlating the microscope using the detection and a method of processing the correlation sample. A second object of the present invention is to provide a scanning probe microscope in which absolute measurement can be accurately carried out based on the irregular data and a method of processing the correlation sample.
SUMMARY OF THE INVENTION
To achieve the above-mentioned objects, the present invention in a first aspect includes a correlation sample of a scanning probe microscope for measuring the state of a surface of a sample, comprising foreign domain where material having physical constant differing from material of a substrate is buried with certain thickness toward in-plane direction of the substrate performing as a sample, wherein surface of said substrate is flat.
As foreign domain where material having physical constant differing from material of a substrate is buried with constant thickness toward in-plane direction of the substrate performing as a sample and surface of the substrate is flat, the present invention is not influenced by irregular data, and can purely and correctly detect each force performing as a standard so as to be possible to carry out absolute measurement in various kinds of scanning probe microscopes. Here, a material having a physical constant differing from the material of the substrate means, for example, a magnetic body generating magnetic strength performing as a standard in the case of MFM and material generating voltage and electrostatic force performing as a standard. These materials are buried in the substrate with a certain thickness in order to obtain enough thickness to detect force depending on the materials because the materials could not detect force enough if thickness of buried material is thin.
The present invention in a second aspect includes a method of processing a correlation sample of a scanning probe microscope for measuring a state of a surface of a sample comprising steps of, forming holes of certain depth having a vertical wall face in the surface of a substrate at a predetermined domain of the substrate performing as a sample, burying material having a physical constant differing from material of the substrate into the holes formed in the forming process, and flattening the surface of the domain where the material differing in physical constant from the substrate is buried and the surface of the substrate.
According to the present invention, holes of a certain depth having a vertical wall face in the surface of a substrate at a predetermined domain of the substrate are formed, a material having a physical constant differing from the material of the substrate is buried in the holes, and the surface of the domain where the substrate is buried and the surface of the substrate are flattened. Therefore, the present invention is not influenced by irregular data, and can purely and correctly detect each force to perform as a standard so as to be possible to carry out absolute measurement in various kinds of scanning probe microscopes.
The present invention in a third aspect includes a correlation sample of a scanning probe microscope for measuring the state of a surface of a sample, comprising at least one of domains
Shimizu Nobuhiro
Shirakawabe Yoshiharu
Takahashi Hiroshi
Yamaoka Takehiro
Adams & Wilks
Larkin Daniel S.
Seiko Instruments Inc.
LandOfFree
Correlation sample for scanning probe microscope and method... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Correlation sample for scanning probe microscope and method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Correlation sample for scanning probe microscope and method... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2934076