JPH08166342A - Raman microspectroscopic measuring apparatus - Google Patents

Abstract

PURPOSE: To easily execute Raman microspectroscopic measurements with a high spatial resolution. CONSTITUTION: An objective lens 2 is set to an airtight container 1. A sample- loading stage 3 is inside the container 1. The ambience in the container can be controlled by an ambience-introducing/discharging pipe 5. The temperature of a sample is adjustable by a temperature control layer 6 having a temperature- adjusting element. Every operation for the control and adjustment can be done with the ambience in the container maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the measurement of microscopic Raman spectra, and more particularly to the technique of measuring microscopic Raman spectra under a controlled atmosphere.

[0002]

2. Description of the Related Art Raman spectroscopy can be measured regardless of whether the sample is a gas, liquid, crystal, or amorphous solid, and the temperature can be either high or low. Unlike the conventional analysis method, it has the advantage of not requiring a special measurement atmosphere such as vacuum, and in addition, it does not require special pretreatment of the sample, and in-situ measurement can be used for measurement. Has been done. In the conventional measurement, compared to the measurement using the above advantages,
Various sampling methods tailored to individual sample forms have been proposed.

Further, by focusing the laser with an objective lens, measurement of a very small area having a minimum spot diameter of about 1 μm has been widely performed. It is widely used in the semiconductor and carbon related fields because it can evaluate the crystalline state.

[0004]

However, in the conventional measuring method, when an individual experimenter tried to control the measurement atmosphere, a glass cell containing a sample in which a specific atmosphere was injected was prepared and Although Raman measurement and the like have been attempted, in microscopic measurement, since a high-magnification objective lens is usually used, the working distance is small and it is difficult to focus on the sample. When using a lens with a small numerical aperture to increase the working distance,
Even if it is focused, the laser spot diameter becomes large, and the advantage of microscopic measurement is sacrificed.

[0005] In addition, the entire sample chamber is actually evacuated,
If nitrogen, an inert gas, a liquid, or the like is introduced into the sample chamber, the device becomes complicated, and there is a problem in that handling during installation and removal of the sample becomes inconvenient.
In addition, in order to control the temperature in such a situation, the device has to be more complicated.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide an apparatus capable of easily performing microscopic Raman spectroscopic measurement with high spatial resolution.

[0007]

One embodiment of the present invention for solving the above-mentioned problems is an apparatus for measuring a Raman spectrum of a microscope, which comprises: a container for holding a sample isolated from an external atmosphere; , An objective lens attached to the container, and an atmosphere introducing unit for changing the atmosphere in the container.

Another aspect of the present invention is an apparatus for measuring a microscopic Raman spectrum, which comprises a container for holding a sample isolated from the external atmosphere, and an objective attached to the container. It is characterized by comprising a lens and a means for moving the sample position in the container without destroying the atmosphere.

Another aspect of the present invention is an apparatus for measuring a microscopic Raman spectrum, which comprises a container for keeping a sample isolated from the external atmosphere, and an objective attached to the container. A lens and means for adjusting the temperature in the container are provided.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of the main part of a microscopic Raman spectroscopic measurement apparatus based on an embodiment of the present invention.

An objective lens 2 is attached to a container 1 which is a cell having a sample chamber inside. The objective lens 2 is provided with an attachment mechanism so that it can be directly connected to the microscope of the Raman spectrophotometer. Since the objective lens 2 is a normal objective lens, it can be directly connected to an existing Raman spectrophotometer.

A stage 3 for mounting and holding a sample 10 is provided in the container 1 so that it can be moved in the xy plane, rotated by θ, and moved in the z direction. The stage 3 is controlled by the stage controller 4. Reference numeral 5 denotes an atmosphere introduction / exhaust port for adjusting the atmosphere in the container 1. For temperature control, stage 3
A layer 6 in which a temperature adjusting element such as a heater or a Peltier element is embedded is provided on the upper surface of, and a thermocouple for monitoring the temperature is attached to the layer 6.
The temperature adjusting element and the thermocouple are connected to the temperature control device 7, and the sample 10 can be heated or cooled based on the temperature detected by the thermocouple.

The operation procedure is as follows. First, the stage 3 is moved up and down in the z direction by the control of the stage control device 4, and the measurement light such as laser light is focused on the sample 10. Next, sample stage 3
By xy movement or θ rotation to align the spot of the measurement light with the measurement point on the sample. After this, introduce the atmosphere
The discharge tube 5 is used to create a desired atmosphere in the sample chamber. The pressure in the sample chamber is monitored by a pressure gauge (not shown) after a sufficient time has elapsed. After the desired atmosphere is achieved, the laser spot adjustment (z direction) and the xy axis adjustment are performed again, and then the measurement is performed.

An example of measurement of palladium oxide prepared by irradiating a metal palladium film with laser light will be described below.

Sample 10 is a substrate having a palladium thin film. When a laser beam is made incident on this from the objective lens 2, an oxide is formed at the laser irradiation position in the oxidizing atmosphere when a certain power density is exceeded. By moving the substrate 10 in the xy plane by scanning with the stage 3, palladium oxide can be formed in a line shape.

The formation of palladium oxide can be confirmed by the appearance of a Raman line in the vicinity of 650 cm ^-1 in the Raman spectrum, as shown in FIG. 2, and this measurement was carried out using the scattered light of the laser light used to form palladium oxide. It can be conducted simultaneously with the formation of palladium oxide by introducing it into a spectroscope. Further, the amount of palladium oxide formed can be estimated from the intensity of the Raman line. In this embodiment,
The oxygen partial pressure dependence of the formed palladium oxide was investigated.

A more specific description will be given. The numerical aperture of the oscillation line of the excitation wavelength of 514.5 nm of the argon ion laser =
0.90, working distance = 0.30 mm, focal length = 1.8
mm, resolution = 0.37 μm, depth of focus = 0.73 μm
The palladium film having a film thickness of 150 A formed by burning palladium acetate on the glass substrate 10 is irradiated through the 100 × objective lens 2 having the optical performance of. At the same time, white light is made incident from the objective lens 2 and the surface image of the substrate 10 is transferred to an external CCD (Charge Coupled).
(Device) While monitoring with the camera, move the stage 3 up and down in the z direction to adjust the focus on the surface.
After that, the atmosphere inside the container 1 is controlled, and the stage 3 is set to 20 um / sec. While moving at the speed of
Palladium oxide formation and its Raman spectrum were measured simultaneously. At this time, the temperature of the sample was kept constant at 50 ° C. by the control of the temperature controller. The above measurement was repeated for each atmosphere 1 to 11 having N ₂ and O ₂ ratios as shown in Table 1.

[0018]

[Table 1]

FIG. 3 shows the atmosphere dependency of the Raman scattering intensity measured in this way. As can be seen from this graph, it was found that the amount of palladium oxide formed under the same conditions increased as the oxygen partial pressure increased.

For comparison, the same experiment as described above was tried by a method of irradiating a laser from the outside of the cell using an atmosphere control cell containing only a sample. It could not be squeezed and palladium oxide could not be formed.

An experiment was conducted in which the sample prepared in this example was put in a cell containing only the same sample and the Raman spectrum was measured under a controlled atmosphere. Because of this, the Raman spectrum of palladium oxide could not be obtained.

The present invention is not limited to the above embodiment. For example, what is introduced from the atmosphere introducing pipe may be an inert gas, nitrogen or the like, or an aqueous solution or the like. Further, the inside of the cell may be kept vacuum by connecting to a vacuum pump or the like.

[0023]

According to the first aspect of the present invention, it is possible to easily focus the measuring light on the surface of the sample and also to easily control the atmosphere.

According to the second aspect of the present invention, it is possible to easily focus the measuring light on the surface of the sample and also to easily position the sample.

According to the third aspect of the invention, it is possible to easily focus the measuring light on the surface of the sample and also to easily adjust the temperature of the sample.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a micro Raman spectroscopic measurement attachment according to an embodiment of the present invention.

FIG. 2 Example of general Raman spectrum of palladium oxide

FIG. 3 is a diagram showing the atmosphere dependence of Raman scattering intensity.

[Explanation of symbols]

 1 Container 2 Objective Lens 3 Stage 4 Stage Control Device 5 Atmosphere Introduction / Exhaust Pipe 6 Temperature Adjustment Layer 7 Temperature Control Device 10 Measurement Sample

Claims (3)

[Claims] 1. An apparatus for measuring a microscopic Raman spectrum, comprising a container for holding a sample in isolation from an external atmosphere, an objective lens attached to the container, and an atmosphere in the container. A Raman spectroscopic measurement device comprising: an atmosphere introducing unit for changing the temperature. 2. A device for measuring a microscopic Raman spectrum, which is a container for holding a sample in a manner separated from the external atmosphere, an objective lens attached to the container, and a sample in the container. And a means for moving the position without destroying the atmosphere. 3. A device for measuring a microscopic Raman spectrum, comprising a container for holding a sample in isolation from an external atmosphere, an objective lens attached to the container, and a temperature in the container. A Raman spectroscopic apparatus for microscopic observation, characterized by comprising means for adjusting.