JP2003254886A - Gas chromatograph scanning probe microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means capable of both securing higher spatial resolution than a method comprising a conventional scanning probe microscope in analysis of a microregion in the surface of matter and identifying the chemical constitution of the matter. <P>SOLUTION: The gas chromatograph scanning probe microscope comprises both a scanning probe microscope and a gas chromatograph mass analyzer. The scanning probe microscope is provided with both a means for heating, vaporizing, and decomposing a point of observation of a sample to be observed at the tip of a probe fixed to the side of one end of a cantilever and a gas introduction path communicating from an opening at the tip of the probe to an opening on the side of the other end of the cantilever through inside the cantilever. The gas chromatograph mass analyzer receives gases from the opening on the side of the other end of the cantilever via a gas conduit. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas chromatograph scanning probe microscope in which a scanning probe microscope and a gas chromatograph mass spectrometer are combined.

[0002]

2. Description of the Related Art Scanning probe microscope (SPM: Scanning)
Probe Microscope is a scanning tunneling microscope (ST
M: A general term for microscopes developed in various forms based on the Scanning Tunneling Microscope (AFM), and its representative is the atomic force microscope (AFM).
e). In the original STP, the observation object of the atomic force microscope was limited to conductive metals and semiconductors, but it was applied to inorganic, organic, and biological samples with or without conductivity. Therefore, it is used in various fields as a powerful means for observing the unevenness of the sample surface on the nm scale.

However, especially in the field of material development,
There is a demand for a means that can analyze not only the morphology of the sample surface but also the constituent components and chemical structures (bonding state of atoms) of minute parts.

As such means, X-ray photoelectron spectroscopy (XPS) and scanning near-field optical microscope (SNOM) are available.
A method using a vertical microscope is being studied.

However, in X-ray photoelectron spectroscopy, (1) the spatial resolution is as low as about 30 μmφ, (2) only observation in high vacuum is possible, (3) the obtained information is fragmentary, and the chemistry of the substance There was a limit that the structure could not be identified.

Even when a scanning near-field optical microscope is used,
(1) Spatial resolution is insufficient at around 200 nmφ, and (2)
There was a limit that the information obtained was fragmentary and the chemical structure of the substance could not be identified.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a method for analyzing a minute area of a material surface using a scanning probe microscope.
It is an object of the present invention to provide means for ensuring a higher spatial resolution and enabling identification of the chemical structure of a substance as compared with the conventional method.

[0008]

According to the present invention, the above object is to evaporate and decompose the observation point of an observation sample by heating the observation point of the observation sample with the tip of the probe fixed to one end side of the cantilever, and the probe tip. Scanning probe microscope having a gas conduit communicating from the opening of the cantilever through the probe and the cantilever to the opening on the other end of the cantilever, and a gas chromatograph that receives gas from the opening on the other end of the cantilever via a gas conduit. And a gas chromatograph scanning probe microscope.

The gas chromatograph scanning probe microscope of the present invention samples the sample surface substance in the form of gas from a minute region of 10 nmφ to 50 nmφ corresponding to the size of the probe tip of the scanning probe microscope, and directly samples this gas sample. It can be analyzed with a mass spectrometer. That is, the chemical structure of the sample surface can be analyzed with a high resolution of 10 nmφ to 50 nmφ.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the gas chromatograph scanning probe microscope of the present invention, the following two modes can be adopted as the observation point heating means for sampling the sample surface substance in the minute region as a gas.

Embodiment 1 A heater provided in a holder for holding a cantilever heats a probe tip through a cantilever and a probe, and radiant heat from the probe tip heats an observation point of an observation sample.

In a preferred embodiment, a heat transfer film is provided on the surfaces of the cantilever and the probe. As a result, heat transfer from the heater provided in the holder via the cantilever and the probe is promoted, and the heater efficiency is increased.

Embodiment 2 The observation sample is irradiated with the laser beam which is incident on the gas guide path in the probe through the semi-transparent and airtight window provided on the surface opposite to the probe fixing portion of the cantilever. This heats the observation point.

In a preferred embodiment, the laser beam is
It serves both for detecting the displacement of the cantilever and for heating.
This simplifies the structure of the device because only a single laser beam irradiation system is required. In that case, the laser beam emitted from the laser source to the cantilever is radiated to the observation sample through the gas passage in the probe at the part that has passed through the semi-transparent window, and the rest is reflected at the semi-transparent window. It is used for displacement detection. The translucent window is typically made of translucent glass.

Of course, separate laser beam irradiation systems may be provided for detecting the cantilever displacement and for heating the sample observation point.

[0016]

EXAMPLES Example 1 An example of the present invention according to the first embodiment will be described with reference to FIG.

The gas chromatograph scanning probe microscope 1 of the present invention comprises a scanning probe microscope 10 and a gas chromatograph mass spectrometer 20 connected by a capillary 30 as a gas conduit.

The scanning probe microscope 10 scans the surface A of an observation sample S placed and held on the piezo scanner 11 with a probe (probe) 14 fixed to the end of a cantilever 13 held by a holder 12. Is. A laser system for detecting the displacement of the cantilever 13 is not shown.

A gas conduit 15 passing through the cantilever 13.
And a gas conduit 1 that penetrates the probe 14 and opens at the tip
It communicates with 6. Gas conduit 15 of cantilever 13
Is a cavity filled with a polymer gel such as silicone resin, and the gas conduit 16 of the probe 14 is a cavity.
The cavity forming the conduit 16 has a diameter of 50 nm,
It is opened at the tip of the probe 14.

The holder 12 has a built-in heater 17 in the portion where the cantilever 13 is fixed.
The heat generated in 7 causes the cantilever 13 and the probe 14
Is radiated as radiant heat R from the tip of the probe 14 to heat the minute area of the sample surface A facing the tip of the probe 14. The surfaces of the cantilever 13 and the probe 14 are coated with a heat transfer film (not shown) such as gold or platinum so as to promote heat conduction from the heater 17 to the tip of the probe 14.

In the minute area of the heated sample surface A, the surface substance of the sample S is vaporized and decomposed by heating and released as gas G. The decomposition gas G rises in the gas conduit 16 of the probe 14, enters the gas conduit 15 of the cantilever 13, is guided to the capillary 30 connected to the gas conduit 15, and enters the gas chromatograph mass spectrometer 20. The capillary 30 is a tube filled with a polymer gel such as a silicone resin.

The gas chromatograph mass spectrometer 20 comprises a gas chromatograph 21 and a mass spectrometer 23. The decomposed gas that has entered the gas chromatograph mass spectrometer 20 is
After being separated in the capillary column 22 of the gas chromatograph 21, mass analysis is carried out in the mass analyzer 23.

As a result, the chemical structure of the surface substance at the analysis point on the sample surface A can be analyzed. By scanning the probe 14, the analysis point is confirmed on the surface shape image previously captured.

In this way, the chemical structure information of the sample surface can be obtained at a high resolution of 50 nmφ for each point of the surface observation image of the scanning probe microscope.

[Embodiment 2] Referring to FIG.
An embodiment of the present invention will be described.

The gas chromatograph scanning probe microscope 2 of the present invention comprises a scanning probe microscope 40 and a gas chromatograph mass spectrometer 20 connected by a capillary 30 as a gas conduit.

The scanning probe microscope 40 scans the surface A of the observation sample S placed and held on the piezo scanner 11 with the probe (probe) 14 fixed to the end of the cantilever 13 held by the holder 12. Is.

A gas conduit 15 passing through the cantilever 13.
And a gas conduit 1 that penetrates the probe 14 and opens at the tip
It communicates with 6. Gas conduit 15 of cantilever 13
Is a cavity filled with a polymer gel such as silicone resin, and the gas conduit 16 of the probe 14 is a cavity.
The cavity forming the conduit 16 has a diameter of 50 nm,
It is opened at the tip of the probe 14.

On the surface of the cantilever 13 opposite to the portion where the probe 14 is fixed, a semitransparent and airtight window 41 made of semitransparent glass is provided.

The laser beam L0 emitted from the laser source 18 is split into a transmitted laser beam L1 and a reflected laser beam L2 at the window 41. The reflected laser beam L2 is detected by the detector 1
The light is received at 9 and used for detecting the displacement of the cantilever 13. The semi-transmissive glass forming the window 41 is produced by thinly coating the glass surface with a metal, and the transmissive laser beam L1 is selected by selecting the type of the metal to be coated, the coating thickness, and the like.
The ratio of the reflected laser beam L2 can be adjusted.

The transmitted laser beam L1 passes through the probe 14 through a gas conduit 16 which is a cavity passing through the probe 14.
Radiation is emitted from the tip of the probe 4, and this heats a minute area of the sample surface A facing the tip of the probe 14. The emitted laser beam is narrowed down by the tip opening of the probe 14 to a diameter smaller than that at the time of incidence.

In the heated minute area of the sample surface A, the surface substance of the sample S is vaporized and decomposed by heating and released as a gas G. The decomposition gas G rises in the gas conduit 16 of the probe 14, enters the gas conduit 15 of the cantilever 13, is guided to the capillary 30 connected to the gas conduit 15, and enters the gas chromatograph mass spectrometer 20.

The gas chromatograph mass spectrometer 20 comprises a gas chromatograph 21 and a mass spectrometer 23. The decomposed gas that has entered the gas chromatograph mass spectrometer 20 is
After being separated in the capillary column 22 of the gas chromatograph 21, mass analysis is carried out in the mass analyzer 23.

As a result, the chemical structure of the surface substance at the analysis point on the sample surface A can be analyzed. By scanning the probe 14, the analysis point is confirmed on the surface shape image previously captured.

In this way, the chemical structure information of the sample surface can be obtained at a high resolution of 50 nmφ for each point of the surface observation image of the scanning probe microscope.

Further, in the case of the present embodiment, by capturing the Raman spectrum through the semi-transparent glass,
It is also possible to perform more detailed structural analysis.

[0037]

EFFECTS OF THE INVENTION According to the present invention, in microscopic area analysis of a material surface using a scanning probe microscope, it is possible to secure a higher spatial resolution and to identify the chemical structure of the material as compared with the conventional method. A gas chromatograph scanning probe microscope is provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a gas chromatograph scanning probe microscope according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a gas chromatograph scanning probe microscope according to a second embodiment of the present invention.

[Explanation of symbols]

1 ... Gas chromatograph scanning probe microscope 2 according to Embodiment 1 of the present invention ... Gas chromatograph scanning probe microscope 10 according to Embodiment 2 of the present invention ... Scanning probe microscope 11 used in Embodiment 1 ... Piezo scanner 12 ... Holder 13 ... Cantilever 14 ... Probe (probe) 15 ... Gas conduit (in cantilever) 16 ... Gas conduit (in probe) 17 ... Heater 18 ... Laser source 19 ... Laser beam detector 20 ... Gas chromatograph mass spectrometer 21 ... Gas chromatograph 22 ... Capillary column 23 ... Mass spectrometer 30 ... Capillary (gas conduit) 40 ... Scanning probe microscope 41 used in the second embodiment ... Window (semi-translucent / airtight) S ... Observation sample A ... Surface of observation sample S G ... Surface of observation sample S Decomposition gas L0 emitted from A ... Incident laser beam L1 ... Transmission ray Zabimu L2 ... reflected laser beam

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01N 30/16 G01N 30/16 K // G01N 1/22 1/22 E

Claims (5)

[Claims] 1. A means for heating and vaporizing and decomposing an observation point of an observation sample at the tip of a probe fixed to one end of the cantilever, and the other end of the cantilever passing through the probe tip and the cantilever from the opening of the probe tip. Gas chromatograph scanning probe, which comprises a scanning probe microscope having a gas conduit communicating with an opening on the side of the cantilever, and a gas chromatograph mass spectrometer which receives gas from the opening on the other end of the cantilever via a gas conduit. microscope. 2. The heater provided in a holder for holding the cantilever heats the probe tip through the cantilever and the probe, and the radiant heat from the probe tip heats the observation point of the observation sample. A gas chromatograph scanning probe microscope as described. 3. The gas chromatograph scanning probe microscope according to claim 2, wherein a heat transfer film is provided on the surfaces of the cantilever and the probe. 4. The observation sample is irradiated with a laser beam incident on a gas guide path in the probe through a semitransparent and airtight window provided on the surface of the cantilever opposite to the probe fixing portion. The gas chromatograph scanning probe microscope according to claim 1, wherein the observation point is heated by means of: 5. The gas chromatograph scanning probe microscope according to claim 4, wherein the laser beam serves both for displacement detection of the cantilever and for heating.