JPH049284B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spectroscopic microscope apparatus that uses optical fibers for projecting and condensing light and is equipped with a light scanning mechanism.

Generally, a density meter, a flying spot scanner, or a spectroscopic microscope has been developed and put into practical use as a means for quantitatively measuring optical information in a minute area. These meters, devices, instruments, etc. scan the sample mechanically,
This device collects two-dimensional information by scanning the focused laser beam with a mirror, but the mechanical scanning accuracy of the sample stage directly becomes the surface resolution of the device, and the laser scanning This method requires a complicated optical mechanism, which has the drawback of problems in measurement accuracy and durability.

This invention was made in order to eliminate the above-mentioned drawbacks.It is equipped with an observation eyepiece, irradiates the sample with light from a light source through an objective lens, and collects the reflected light from the sample to analyze it into spectroscopy. In a spectroscopic microscope, the light emitting fiber guides the light from the light source to a point on the real image plane of the sample in the objective lens, and the condensing optical fiber collects the reflected light from the sample and guides it to the spectrometer. The optical fiber is provided with an end portion of an optical fiber that is integrated with the end portion of the optical fiber, and a scanning mechanism that holds the end portion of the optical fiber and scans the real image plane in the X and Y directions. This invention will be explained below.

FIG. 1 is an explanatory diagram showing the principle of this invention.
In this figure, 1 is a light projection fiber, 1a is an output end, 2 is a condensing fiber, 2 is an entrance end, 3 is a real image plane, 4 is a deflection lens, 5 is an objective lens, and 6 is a sample.

A light source (not shown) is guided onto a real image plane 3 by a projection optical fiber 1, and the light from its output end 1a is reduced and projected by an objective lens 5 via a deflection lens 4, and is projected onto a sample 6. The image is focused on a minute area on the surface of the The diameter of this image is equal to the diameter of the projection optical fiber 1 divided by the magnification of the objective lens 5. The reflected light or photoluminescence light on the surface of the sample 6 is focused by the objective lens 5, and is passed from the input end 2a of the focusing optical fiber 2 installed in front of the real image plane 3 to the spectroscope (Fig. (not shown). The focal point of the deflection lens 4 is set at the pupil point of the objective lens 5, and the optical path from the projecting optical fiber 1 to the surface of the sample 6 coincides with the optical path from the surface of the specimen 6 to the condensing optical fiber 2. . Two-dimensional information is transmitted through each optical fiber 1,
2 manually or by a step motor (not shown) with the optical neutral line N of the objective lens 5 as the axis.
The data are collected by scanning in the Y-axis and Y-axis directions.

FIG. 2 shows the configuration of an optical fiber in an embodiment of the present invention, and FIGS. 3, 4, and 5 show details of the ends of each optical fiber.

In FIG. 2, the number of strands used for the light emitting optical fiber 1 and the condensing optical fiber 2 is determined by the wavelength used,
It can be selected depending on the area of the area to be analyzed.
In this example, the core diameter is 80 μm and the cladding diameter is 125 μm.
One low-loss quartz fiber for light emission,
Six lights are used for condensing light. These quartz fibers are assembled into a mechanically strong seven-core optical fiber cable 7, and guided to a spectrometer 8 and a light projecting laser 9, which are several meters to several hundred meters away.

FIGS. 3a and 3b are an enlarged view and a partial sectional view of the microscope-side end surface of the seven-core optical fiber cable 7 shown in FIG. 2. FIGS. To explain FIG. 3 with reference to the principle diagram of FIG. 1, the output end 1a of the light projection fiber 1 is placed on the real image plane 3 of the objective lens 5, and the excitation light is designed to be focused as much as possible. There is. The input end 2a of the condensing optical fiber 2 is installed around the light projecting optical fiber 1 in front of the real image plane 3. The end portions of the light projecting optical fiber 1 and the condensing optical fiber 2 are integrated to form an optical fiber end portion. By increasing the number of light collecting optical fibers 2, light collecting efficiency can be improved.

FIG. 4 shows the end face of the condensing optical fiber 2 on the spectrometer 8 side. By arranging them in a line along the entrance slit 8a of the spectrometer 8, the coupling efficiency with the spectrometer 8 can be improved.

FIGS. 5a and 5b are an enlarged view and a partial sectional view of the light source side end face of the light projecting optical fiber 1. FIG. A connector 10 is connected to the end face of the light-emitting optical fiber 1 on the light source side, so that the type of light source can be easily changed according to the needs of the experiment.

In the above, the in-plane distribution of the light emitters can be detected using only the condensing optical fiber 2. Furthermore, it is also possible to construct a two-dimensional optical probe in the X-axis and Y-axis directions using only the light projecting optical fiber 1.

FIG. 6 is a schematic diagram showing an embodiment of the spectroscopic microscope apparatus of the present invention using the optical fiber shown in FIG.
An example of application to photoluminescence at extremely low temperatures is shown. In this figure, the same symbols as in Figure 1 indicate the same components, 11 is a spectroscopic microscope, 12 is
XY stage, 13 is a light source for epi-illumination, 14 is a condensing lens, 15 and 16 are removable semi-transparent mirrors for observation and semi-transparent mirrors for illumination, 17 is an eyepiece, 18 is a special environment holding device, A cooling device for low temperatures, a heating device for high temperatures, a vacuum device, etc. are used.

In this embodiment, since the light emitting optical fiber 1 and the condensing optical fiber 2 are incorporated into the spectroscopic microscope 11, the observer can observe the optically excited region with the naked eye as a bright spot in the microscope image. I can do it.

After the measurement point is confirmed, the spectroscopic microscope 1
By removing each of the semi-transparent mirrors 15 and 16 from the optical path within the optical system 1, the loss of light amount can be eliminated. Further, scanning of the measurement point is performed by driving each optical fiber 1, 2 using a manual or electric XY stage 12.

As an example, a case will be described in which a crystal defect image of a semiconductor sample is observed. A laser beam is introduced into the light projection optical fiber 1, and the output end 1 of the light projection optical fiber 1 is
A is placed on the camera port of the spectroscopic microscope 11 exactly on the plane where the film is placed. When the exit surface 1a is swept on this plane using a stepping motor stage, the laser beam is reduced by the reciprocal of the magnification of the objective lens 5 and moves on the surface of the semiconductor sample.
Therefore, the light reflected from the position of each laser spot is introduced into a spectroscope 8, photoelectrically converted into an electrical signal, and this electrical signal is digitized and sent to a computer as a signal corresponding to the position of each laser spot. A two-dimensional topography of the measured physical quantity can be created by recording the measured physical quantity on the screen, normalizing it appropriately, and displaying it on a display.

As explained above, the present invention includes a projection optical fiber that guides light from a light source to a point on the real image plane of a sample in an objective lens, and a condensing optical fiber that collects reflected light from the sample and guides it to a spectrometer. It is equipped with an optical fiber end that is integrated with the fiber, and a scanning mechanism that holds this optical fiber end and scans the real image plane in the X and Y directions. effective.

Operation is simple because the laser spot position can be confirmed and focused while observing the optical microscope image through the eyepiece.

Since optical fibers are used for projecting and focusing light, it is easy to replace and attach/detach the light source, and it is also easy to change the type of light source.

The output end or fiber end of the light projection optical fiber is scanned by a scanning mechanism using its flexibility.
Since scanning can be performed in the Y direction and the output end of the light projection optical fiber can be scanned on the enlarged real image plane, mechanical precision for scanning is not required much, and precise optical axis alignment is unnecessary.

Since there is no need to mechanically drive the sample to be measured, it can be used without mechanical limitations even for samples held in special environment holding equipment such as low temperature, high temperature, and vacuum.

Further, since the end portion of the optical fiber that integrates the light emitting optical fiber and the condensing optical fiber is scanned in the X and Y directions by the scanning mechanism, light emitting and condensing can be performed simultaneously.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the principle of the invention, FIG. 2 is a perspective view showing the configuration of an optical fiber in an embodiment of the invention, and FIGS. An enlarged view and a partial sectional view of the end face, FIG. 4 is an end view of the condensing optical fiber, FIGS. 2 is a schematic diagram showing an embodiment of the present invention using the optical fiber of FIG. 2. FIG. In the figure, 1 is an optical fiber for light projection, 1a is an output end,
2 is a condensing optical fiber, 2a is an incident end, 3 is a real image plane, 5 is an objective lens, and 6 is a sample.

Claims (1)

[Claims] 1 In a spectroscopic microscope equipped with an observation eyepiece, which irradiates a sample with light from a light source through an objective lens, and collects the reflected light from the sample and supplies it to a spectrometer, the light from the light source is Light that integrates the ends of a projecting optical fiber that guides the objective lens to a point on the real image plane of the sample and a condensing optical fiber that collects reflected light from the sample and guides it to the spectrometer. 1. A spectroscopic microscope device using an optical fiber, characterized in that it is equipped with a fiber end and a scanning mechanism that holds the optical fiber end and scans the real image plane in the X and Y directions.