JPH01163594A - High-temperature observation furnace by infrared image heating - Google Patents

Abstract

PURPOSE: To ensure sufficient observation in vacuum even at a temperature of 1100 deg.C or above by locating a transparent partitioning quartz plate at a position of low infrared density in a light source room and providing an observation window at a furnace part where the optical axis of the objective lens of a microscope passes. CONSTITUTION: An observation window 6 is fixed at a part of a furnace chamber 2 where the optical axis of the objective lens 8 of a microscope passes and a gas introduction port 15 provided on the outside of the furnace body 1 communicates with a passage 13. A sample holder 12 is inserted through the passage 13 into a heating chamber 2b and a sample 16 is set at a specified position. The heating chamber 2b is evacuated through an evacuation passage 14 and introduced with a required gas through the port 15 and the passage 13. When infrared rays are emitted from a ring- like light source 10 disposed in a light source chamber 2d, a part of the infrared rays passes through a partitioning quartz plate 11 and impinges directly on the sample 16 in the chamber 2b and the remainder reflects on the inner wall of a light source chamber 2a and the chamber 2b toward the sample 16 which is thereby heated up quickly to a desired temperature from the entire surface. Vacuum atmosphere is thereby produced at 1100 deg.C or above and a high resolution image can be observed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-temperature observation furnace using infrared image heating, which is used, for example, in semiconductor manufacturing technology and high-temperature observation of various materials.

[Prior Art] As a heating device for a conventional high-temperature microscope, a so-called internal heating type is known. Usually, a heater is provided on the sample bolt around the periphery and bottom of the sample, and this heater is attached to a refractory material. Alternatively, the sample may be housed in an electrically insulating material, and a thermocouple for temperature measurement may be provided in the refractory or electrically insulating material to heat the sample from below. The assembly thus constructed is then covered with a quartz glass or pyrex glass enclosure to enclose it in a specific atmosphere to prevent contamination and oxidation of the sample surface.

However, in such an internal heating type heating device, the distance to the sample surface is about 10 + nIr1 even with the latest objective lenses with ultra-long working distances, so the heater and temperature measurement equipment must be installed in a very limited space. It is necessary to install a thermocouple, which requires a complicated structure, and since it is possible to heat only from the bottom of the sample, the temperature gradient and distribution that affect the sample is poor, and the sample material that evaporates due to heating is poor. Other substances (for example, materials from the heater or its holster) can contaminate the inner surface of the quartz or pyrex crow enclosure, interfering with measurements.

Furthermore, this type of heating device is suitable for a reflection type microscope, but in the case of a transmitted light type from below the power plate, it is necessary to make a hole in the heating section, making the structure increasingly complicated.

In order to solve these drawbacks, the present applicant first filed a patent application in 1983.
No. 1-296609, a lamp housing is provided adjacent to the objective lens of a microscope and surrounding its front axis.
This lamp housing is provided with a heating chamber containing an infrared lamp for heating therein, and also provides protection against a sample that passes through the heating chamber of the lamp housing and is positioned relative to the objective lens and whose interior can be evacuated. We propose a high-temperature observation furnace using infrared image heating, in which the inner wall of the heating chamber of the lamp housing is configured such that the infrared rays from an infrared lamp installed in the heating chamber enter the sample through the protective tube. .

In this device, a part of the infrared rays emitted from the infrared lamp heating the sample is directly incident on the sample to be heated through the protection tube, and the remaining part is reflected by the inner wall of the heating chamber of the lamp housing, substantially reducing the temperature of the sample. The sample was made to be incident from all directions, and as a result, the sample could be uniformly heated from the outside by infrared rays from the infrared lamp, and the above-mentioned drawbacks could be solved.

[Problems to be Solved by the Invention] By the way, in the high-temperature observation furnace proposed above, a quartz protection tube is inserted into the furnace, and a sample can be inserted into this protection tube, and a part of the protection tube, i.e. The part through which the optical axis of the microscope passes is made flat to serve as the observation window, but at high temperatures of over 1100°C, the quartz changes color and loses its transparency.
Under vacuum at temperatures above 100°C, quartz begins to soften and deform. Therefore, there is a problem that it is impossible to satisfy both the conditions for creating an atmosphere at a high temperature of 1100° C. or higher and the optical conditions for observation.

Furthermore, it is relatively difficult to form a thin observation window in the quartz protective tube as described above that satisfies the optical conditions, that is, it is homogeneous, parallel, and flat, and has as little chromatic aberration as possible. There is also a problem in terms of degree.

Furthermore, since the infrared lamps placed in the furnace are exposed to high temperatures, there is a problem in terms of lamp life. There is a technical issue in that it should be cooled down to a certain temperature.

Therefore, the object of the present invention is to provide a high-temperature observation furnace using infrared image heating that solves the problems and technical problems associated with the previously proposed high-temperature observation furnace and can be used and observed satisfactorily under vacuum even at temperatures of 1100° C. or higher. It is in.

[Means for Solving the Problems] In order to achieve the object 1 above, in the high temperature observation furnace using infrared image heating according to the present invention, a protection made of quartz with an observation window in the previously proposed device is used. Instead of using a tube, the inside of the furnace is divided into a light source chamber and a heating chamber by a transparent partitioning quartz plate, and the heating chamber is made airtight. It is characterized by being positioned at a location with low infrared density, and by providing an observation window in the furnace wall section through which the optical axis of the microscope objective lens passes.

[Function] In the high-temperature observation furnace using infrared image heating of the present invention, the transparent partitioning quartz plate that partitions the inside of the furnace into the light source chamber and the heating chamber is located at a position where the infrared density is low, so that the temperature remains low. It is made so that it does not become dark. In addition, the infrared light source can be protected by exhausting hot air from the light source chamber or suppressing a temperature rise in the light source chamber by using a cooling caspage. Furthermore, since the observation window is in contact with the outside, it has the effect of suppressing temperature rise, and since it is located adjacent to the objective lens of the microscope, the aperture can be made small and the window can be made as thin as possible. Furthermore, by constructing the observation window with an eccentric rotating disk, it is possible to always use the observation window surface in a clean state.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 schematically shows a high-temperature observation furnace using infrared image heating according to an embodiment of the present invention, where 1 is the furnace body;
The furnace body 1 can be made of aluminum, for example, and has a furnace chamber 2 in the shape of a rotating body whose axis of rotation is a line that passes through one focal point of the ellipse and intersects with the long axis of the ellipse. , its inner walls are decorated with gold plating. In addition, a cooling medium flow path 3.4 is provided in the furnace body 1 surrounding the furnace chamber 2.
-t, and these cooling medium channels 3.4 are connected to a suitable cooling medium supply source (not shown) to cool the furnace body 1.

The central part of the upper wall of the furnace chamber 2 is formed into a planar shape, and an observation window 6 made of quartz is attached to the center opening 5 of the furnace chamber 2 airtightly from the outside by a member 7.
As shown in the figure, it is rotatably positioned opposite to the objective lens 8 of the microscope and eccentrically relative to the optical axis of the microscope. and a central opening 5 in the central part of the upper wall.
A heat exhaust port 9 extending to the outside is provided in the center of the upper wall on the opposite side.

A ring-shaped infrared light source 10 is arranged in the lower part of the furnace chamber 2 on a locus drawn by the other focal point of the ellipse. Then, infrared rays are incident on the sample from all directions, which will be explained later.

A transparent partitioning quartz plate 11 is inserted directly above the infrared light source 10 and perpendicular to the optical axis of the microscope, and the furnace chamber 2 is divided into a light source chamber 2a where the infrared light source 10 is placed and a heating chamber 2b above. It's in charge. In this case, the cutting quartz plate 11 is preferably positioned at a position where the density of infrared rays from the infrared light source 10 is low. Furthermore, the partitioning quartz plate 11 is naturally designed to withstand the differential pressure that may occur when the heating chamber 2b is evacuated.

Further, in the furnace body 1, a passage 13 for passing the sample boulder 12 into the heating chamber 2b and a vacuum exhaust passage 14 for evacuating the inside of the heating chamber 2b are provided along an axis perpendicular to the optical axis of the microscope. .

A waste inlet 15 is provided on the outside ff1l of the furnace body 1, and the waste inlet 15 communicates with the passage 13 so that the heating chamber 21 can be filled with the required waste.

The sample holter 12 holds the sample fl16 to be observed at its tip, and is configured to be able to be inserted into the heating chamber 2b through the passage 13 and pulled out from the heating chamber 2b. Further, the sample holder 12 is dimensioned so that the sample 16 is located on the optical axis of the microscope when inserted into the heating chamber 2b. Additionally, a thermocouple (not shown) is attached to the tip of the sample holder 12 that supports the sample 16.
The temperature of the sample f11G is measured, and the output signal of this thermocouple is the temperature of the infrared light source 10 in the light source chamber 2a (=
It can be used to control the f-force.

In the operation of the illustrated apparatus constructed in this way, first, the sample holder 12 is inserted into the heating chamber 21) through the passage 13, and the sample 16 is placed at a predetermined position within the heating chamber 21].

The inside of the heating chamber 2b is evacuated via a vacuum exhaust passage 14 by a vacuum exhaust system (not shown). After evacuation, a required amount of waste is introduced into the heating chamber 21) through the waste introduction port 15 and the passage 13.

A link-shaped infrared light source 10 arranged in the light source chamber 2a is supplied with power from the outside and emits infrared rays. In this case, a part of the infrared rays passes through the partitioning quartz plate 11 and directly into the heating chamber 2b.
The remaining portion is reflected by the inner walls of the light source chamber 2a and the heating chamber 2b and enters the sample 16. This allows the sample 16 to be uniformly and rapidly heated to the desired temperature from substantially its entire surface. In this case, it can be used up to about 1300°C. The hot air accumulated in the light source chamber 2a is exhausted through the heat exhaust port 9.

FIG. 2 shows another embodiment of the invention, in which parts corresponding to the apparatus of FIG. 1 are designated by the same reference numerals as used in FIG.

In the embodiment shown in FIG. 2, the furnace chamber 2 is formed into an elliptical spherical shape, and the partitioning quartz plate 11 is provided at a position that divides the spheroidal furnace chamber 2 into approximately one section vertically. In this embodiment, a spot type infrared light source 17 is arranged in the lower light source chamber 2a at the lower focal point of the elliptical sphere, and is connected to an external power source (not shown).

A number of holes (one of which is indicated by reference numeral 18 in the drawing) for introducing cooling gas are provided in the lower part of the furnace body 1 along the surface of the partitioning quartz plate 11 on the side of the light source chamber 2a. These cooling gas introduction holes are connected to a suitable cooling gas source (not shown) via a cooling gas supply pipe 19.

In addition, in FIG. 2, 20 passes through the passage 13 to the heating chamber 2.
21 is a scum introduction port for introducing scum into the interior of b, and 21 is a rotary shutter mounted above the rotary observation window 6.

The operation of the illustrated apparatus is also substantially the same as that of the apparatus of the embodiment shown in FIG. It has good reflection efficiency and can reach higher temperatures, up to about 1700°C.

Incidentally, in the illustrated embodiment, the observation window is made of quartz, but other than quartz, optical glasses such as Pyrex and Vycor may also be used.

[Effects of the Invention] As explained above, in the high-temperature observation furnace according to the present invention, the furnace chamber is partitioned into a heating chamber and a light source chamber by a partitioning quartz plate, and a sample placed in the heating chamber is placed in the light source chamber. Since the light source is externally heated using an infrared light source, it is possible to keep the temperature of the light source chamber lower than that of the heating chamber by cooling or other means, thereby reducing the lifespan of the light source. Moreover, a vacuum atmosphere can be created at a temperature of 1100° C. or higher. In addition, the observation window can be made relatively small (1 diameter), and the window material can be made thin, and since it is in contact with the outside, temperature rise can be suppressed, preventing deterioration and deformation of the window material due to high temperatures. This enables high-resolution observation.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing the main parts of a high temperature observation furnace according to one embodiment of the present invention, and FIG. 2 is a schematic sectional view showing the main parts of a high temperature observation furnace according to another embodiment of the invention. Figure Middle 1: Furnace body 2: Furnace chamber 2a: Light source chamber 2b = Heating chamber 3: Coolant flow path 4: Coolant flow path 6: Observation window 8:
Objective lens 9: Heat exhaust port 10: Infrared light source 1
1: Quartz plate for partition 12: Sample holder 13: Passage
14: Vacuum exhaust passage 15: Gas inlet
16: Sample 17: Infrared light source '18: Cooling waste introduction hole 19: Cooling waste supply pipe 20: Waste introduction port 21: Rotating shutter

Claims (1)

[Claims] 1. A sample is placed in a furnace formed adjacent to the objective lens of the microscope and surrounding its optical axis, and infrared rays from an infrared light source provided in the furnace are focused toward the sample. In a high-temperature observation furnace that allows light to enter and performs high-temperature observation of a sample by infrared image heating, the inside of the furnace is divided into a light source chamber and a heating chamber by a transparent partitioning quartz plate, and the heating chamber is made into an airtight structure. , an infrared image characterized in that the above-mentioned transparent partitioning quartz plate is positioned at a position in the light source chamber where the density of infrared rays from the infrared light source is low, and an observation window is provided in the furnace wall portion through which the optical axis of the objective lens of the microscope passes. High temperature observation furnace by heating. 2. A high-temperature observation furnace using infrared image heating according to claim 1, wherein the infrared light source disposed in the light source chamber in the furnace is annular. 3. A high-temperature observation furnace using infrared image heating according to claim 1, wherein the infrared light source disposed in the light source chamber in the furnace is a spot-shaped infrared light source. 4. A high-temperature observation furnace using infrared image heating according to claim 1, wherein a heating chamber in the furnace in which a sample is placed is connected to a vacuum exhaust system. 5. A high-temperature observation furnace using infrared image heating according to claim 1, wherein the light source chamber in the furnace is provided with an outlet for discharging hot air accumulated inside. 6. A high-temperature observation furnace using infrared image heating according to claim 1, wherein the observation window provided in the furnace wall portion adjacent to the objective lens of the microscope comprises an eccentric rotating disk.