JP2003309077A - Method for measuring temperature of vertical furnace and method for heat treating and boat used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for measuring the temperature of a vertical furnace having high temperature detecting accuracy, and to provide a method for heat treating and a boat used therefor. <P>SOLUTION: The method for measuring the temperature of the vertical furnace comprises: a step of mounting a plurality of materials 63A to be treated and a temperature detector 65 in the boat 60, and setting the materials and the detector at treating positions in a vertical reaction tube 18; a step of setting in the tube 18 to a predetermined temperature by a heater 16; and a step of measuring a temperature distribution of a boat atmosphere by the detector 65 mounted in the boat 60. Thus, the temperature can be detected near the material 63A mounted in the boat 60, and hence the accuracy of the detecting temperature is raised. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature measuring method and heat treatment method for a vertical furnace, and a boat used therefor.

[0002]

BACKGROUND ART In a vertical furnace used for oxidation, diffusion, etc., a plurality of processed pairs mounted on a boat are batch processed at once. In order to ensure the processing uniformity among the plurality of objects to be processed, it is extremely important to ensure the temperature uniformity in the processing zone in the vertical furnace.

Conventionally, in order to measure the temperature distribution in a vertical furnace, a temperature detecting part such as a thermocouple is arranged in a space between a vertical reaction vessel (process tube) and a heater around the vertical reaction vessel to perform processing. The temperature distribution in the vertical reaction vessel was measured throughout, and the temperature of each zone-divided heater was controlled based on the measurement result.

An object of the present invention is to provide a vertical furnace temperature measuring method and heat treatment method capable of realizing more accurate heater control, and a boat used therefor.

[0005]

According to one embodiment of the present invention, there is provided a vertical furnace temperature measuring method, in which a boat is provided with a plurality of objects to be processed and a temperature detecting portion, and the temperature is set at a processing position in a vertical reaction tube. And a step of setting the inside of the vertical reaction tube to a predetermined temperature with a heater, and a step of measuring a temperature distribution of the boat atmosphere by a temperature detection unit mounted on the boat.

The temperature can be detected in the vicinity of the object to be processed mounted on the boat, and the detection accuracy can be improved to set the temperature more accurately.

To measure the temperature distribution of the boat atmosphere,
At least one temperature detecting element provided in the temperature detecting unit may be moved along the vertical axis direction, or the temperature may be detected by each of the plurality of temperature detecting elements provided along the vertical axis direction.

In a boat used for temperature measurement, an object to be processed is supported by a plurality of columns connecting flanges at both ends. The temperature detecting portion may be arranged in a hollow portion provided in at least one of the plurality of columns, or in a hollow portion provided in another at least one column having no function of supporting the object to be processed. It may be provided.

In the temperature measurement of the vertical furnace according to one aspect of the present invention, a dummy object to be processed can be mounted on the boat. In this case, the temperature distribution of the boat atmosphere is preliminarily measured before the actual processing. At this time, the inert gas can be introduced into the vertical reaction tube at substantially the same supply amount as the gas introduced during the actual treatment. Since the temperature changes depending on the gas flow rate, the flow rates are substantially the same, but an inert gas can be used because the process gas is not required during the preliminary temperature measurement.

In a heat treatment method according to another aspect of the present invention, the above-mentioned temperature preliminary measurement step using a dummy object to be processed and a plurality of objects to be processed are mounted on an actual processing boat, The step of setting the actual processing boat at the processing position, the step of setting the process temperature in the reaction tube by the heater, the step of introducing a process gas to heat-treat the plurality of objects, and the heater. The step of measuring the temperature to be raised outside the reaction tube, the temperature measured outside the reaction tube are corrected based on the temperature distribution measured in the temperature preliminary measurement step, and the heater is controlled. And a step of performing.

Even when the temperature rise of the heater is measured outside the vertical reaction tube during actual processing, the temperature can be corrected based on the temperature measurement data in the vicinity of the object to be processed, so that more accurate heater control is possible. .

A boat according to still another aspect of the present invention is
It defines a structure that has both the function of supporting the object to be processed and the function of mounting the temperature detector.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

(Description of Vertical Heat Treatment Furnace and Actual Treatment Boat) FIG. 1 is a sectional view showing an example of a vertical heat treatment furnace used in an embodiment of the present invention. In FIG. 1, this vertical heat treatment furnace 10 is provided with a heat insulating material 14 inside an outer shell 12, and the heat insulating material 14 has a plurality of zones, for example, 3
A heater 16 divided into zones is provided. A process tube (vertical reaction tube) 18 made of quartz is arranged in a region surrounded by the heater 16. A gas introduction pipe 20 and an exhaust pipe 22 are connected to the process tube 18.

The boat 30, which is a heat treatment jig to be inserted into and removed from the process tube 18, is erected and supported on a heat retaining cylinder 34 arranged in the boat elevator 32. In this boat 30, a plurality of objects to be processed, for example, semiconductor wafers 36
Are horizontally supported, and a plurality of semiconductor wafers 36 are batch processed at one time. The boat 30 has flanges 30A and 30B at both ends and columns 30C connecting them, and each column 30C is provided with a groove (not shown) for supporting the semiconductor wafer 36.

In the space between the process tube 18 and the heater 16, there is provided a first temperature detector 40, which is permanently installed in the vertical heat treatment furnace 10 and formed by, for example, a thermocouple. The first temperature detector 40 is arranged outside the process tube 18 so that the process is not adversely affected. This first temperature detector 40
This is because, when is placed in the process tube 18, the detected temperature changes with time due to, for example, contamination of the surface thereof.

The first temperature detector 40 detects the temperature at each position in the vertical axis direction of the vertical heat treatment furnace 10 and measures the temperature distribution in the treatment zone during the heat treatment. The measured temperature distribution is corrected by the temperature control unit 52 based on the correction temperature data stored in the memory 50 in advance, and the heater 16 is independently provided for each zone based on the corrected temperature distribution. Have control.

A temperature measuring boat 60 used for measuring the correction temperature data stored in the memory 50 shown in FIG.
An example is shown in FIG. The boat 60 shown in FIG. 2 also has flanges 61 at both ends, similar to the processing boat 30 shown in FIG.
62 and a plurality of, for example, five support columns 63 connected to each other. The flange 62 on the side mounted on the heat retaining cylinder 34 is provided with a locked portion 62A that is locked to the heat retaining cylinder 34. As shown in FIG. 3, the four pillars 63 have a solid structure, and like the processing boat 30 of FIG. ing. The remaining one pillar 63 does not have a function of supporting the semiconductor wafer 36, and has a hollow portion 64 as shown in FIGS. 3 and 4. In the hollow portion 64, as shown in FIG. 4, a second temperature detecting portion 65 for measuring the correction temperature data is arranged. The second temperature detecting section 65 has temperature detecting elements such as thermocouples at a plurality of positions in the vertical axis direction.

(Step of Measuring Temperature Correction Data) The correction temperature data stored in the memory 50 of FIG. 1 is measured every time the process tube is replaced for cleaning, for example.
For this purpose, instead of the actual processing boat 30 shown in FIG.
The temperature measurement boat 60 shown in FIGS. 2 to 4 is used.

As shown in FIG. 2, dummy wafers 36A are mounted on the temperature measuring boat 60 in the same number as in the actual processing.

The temperature measuring boat 60 is erected on the heat retaining cylinder 34 shown in FIG. 1 and the boat elevator 32 is raised. As a result, like the actual processing boat 30 shown in FIG. 1, the temperature measuring boat 6 is placed at the processing position of the vertical heat treatment furnace 10.
0 is placed (see FIG. 5).

Thereafter, while introducing gas from the gas introducing pipe 20, the gas is exhausted through the gas exhaust pipe 22 and the heater 16 is heated in the same manner as in the actual processing. As the gas introduced from the gas introduction pipe 20, the same gas may be introduced at the same flow rate as in the actual processing, but only the inert gas may be introduced. This is because it is not necessary to perform heat treatment when measuring the correction temperature data. However, it is preferable that the flow rate of the inert gas is substantially the same as the total flow rate of all the gases introduced during the actual treatment. This is because the atmospheric temperature of the boat 60 changes depending on the gas flow rate, and it is preferable to set the same conditions as in actual processing (difference in gas type and dummy wafer) when measuring the correction temperature. Is.

Under the above conditions, the temperature at each position in the vertical axis direction of the vertical heat treatment furnace is controlled by the first temperature detecting section 40 arranged outside the process tube 18 and the first temperature detecting section 40 mounted on the boat 60. The temperature detector 65 and the temperature detector 65 of FIG.

As shown in FIG. 5, the second temperature detector 65 mounted on the boat 60 is disposed in the process tube 18, and the temperature is set in the immediate vicinity of the dummy wafer 36A also mounted on the boat 60. It can be detected.
On the other hand, the first temperature detection unit 40 is arranged outside the process tube 18, so that the first temperature detection unit 40 is not affected by the gas in the process tube 18 and is closer to the heater 16 than the second temperature detection unit 65. It is located in. Therefore,
Even at the same position in the vertical axis direction, there is a difference between the temperatures detected by the first and second temperature detectors 40 and 65. Originally, it is desirable to measure the temperature in the vicinity of the wafer to be heat-treated, so that the temperature detected by the first temperature detection unit 40 should be corrected by the temperature detected by the second temperature detection unit 65. It is possible to detect the temperature with high accuracy.

In the present embodiment, the temperature is detected by the temperature detecting elements of the first and second temperature detecting portions 40 and 65 located at the same position in the vertical axis direction. Then, for example, the temperature control unit 52 obtains a difference between two types of detected temperatures at the same height position, and the difference is stored in the memory 50 of FIG. 1 as correction temperature data for each position. If necessary, heater 1
The above temperature detection is performed every predetermined time from the start of the temperature rise of 6,
At every predetermined time, the first and second temperature detecting units 40, 65
The temperature control unit 52 may obtain the difference between the respective detected temperatures and the difference may be stored in the memory 50.

(Actual Processing Step) In this actual processing step, as shown in FIG.
The semiconductor wafer 36 is mounted on the actual processing boat 30 shown in FIG. 1, is set upright on the heat insulating cylinder 34, and the boat 30 is carried into the process tube 18 by the boat elevator 32.

Thereafter, the process gas is introduced through the gas introduction pipe 20 to raise the temperature of the heater 16. At this time, the first temperature detection unit 40 detects the temperature at each position in the vertical axis direction. The temperature controller 52 shown in FIG. 1 corrects the detected temperature to a temperature near the semiconductor wafer 36 based on the correction temperature data in the memory 50. Then, the heater 16 is controlled based on the corrected temperature data, and feedback control is performed so that the temperature of the processing zone during the heat treatment becomes substantially uniform as the set process temperature.

(Modified Example of Temperature Measuring Boat) The temperature measuring boat 70 shown in FIG. 6 has, for example, a second temperature detecting element movable in the longitudinal direction within the hollow portion 64, such as one temperature detecting element such as a thermocouple. The temperature detecting section 71 is provided. In addition,
A plurality of thermocouples may be provided in the second temperature detector 71.
The second temperature detecting section 71 can be moved up and down by a vertical movement mechanism 72.

When the temperature compensating boat 70 is used in place of the boat 60 of FIG. 5, the vertical movement mechanism 72 moves the second temperature detecting portion 71 in the vertical axis direction, and at least one thermocouple couples it to a plurality of locations. The temperature at is detected. Other operations are exactly the same as in the case of FIG. This temperature detection may be performed every time the second temperature detection unit 71 is stopped, or may be performed during continuous movement at a relatively low speed.

(Other Modifications) In FIGS. 2 to 4, in addition to the four columns 63 for supporting the dummy wafer 36A, another column 63 having a hollow structure is provided. In addition, at least one of the four columns 63 supporting the dummy wafer 36A may have a hollow structure, and the second temperature detector 65 or 71 may be mounted therein. That is, the dummy wafer 36
The support function of A and the mounting function of the second temperature detection units 65 and 71 may be combined by at least one support column 63.

Although the above-mentioned temperature measuring step for correction is carried out before the actual processing step, it may be carried out simultaneously during the actual processing step. In this case, the above-mentioned boats 60 and 70 are used as actual processing boats. At this time, the first temperature detection unit 40 and the memory 50 of FIG. 1 are unnecessary. Second during actual processing
The temperature detector 65 or 71 may detect the temperature, and the temperature controller 52 may control the heater 16 based on the detected temperature.

The heat treatment method of the present invention can be applied not only to atmospheric pressure treatment such as oxidation or diffusion treatment, but also to reduced pressure treatment. The hollow portion 64 in which the second temperature detecting portion 65 or 71 is arranged may be vacuum-sealed from the reduced pressure atmosphere. Even if the quartz pieces are joined together, the vacuum resistance strength of the joined portion can be ensured, and the pillar 6 in which the hollow portion 64 is formed is formed.
The thickness of 3 may be set in consideration of vacuum resistance.

As described above, according to the present embodiment, it becomes possible to detect the temperature in the vicinity of the object to be processed with high accuracy in the vertical furnace in which the process requiring more strict temperature control is carried out. . Therefore, it is possible to carry out a process having strict requirements for processing characteristics under strict temperature control, and it is possible to improve the process yield.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, the first temperature detector 4 shown in FIG.
The position of 0 may be outside the process tube 18,
The position is not necessarily set to the position shown in FIG.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a vertical heat treatment furnace according to an embodiment of the present invention.

FIG. 2 is a schematic explanatory view of a boat for measuring temperature data.

FIG. 3 is a schematic explanatory view for explaining a supporting state of dummy wafers in the boat shown in FIG.

FIG. 4 is a schematic explanatory view showing a second temperature detection unit arranged in one column of the boat shown in FIG.

5 is a schematic cross-sectional view showing a state in which the boat for temperature data measurement shown in FIG. 2 is carried into a vertical heat treatment furnace.

FIG. 6 is a schematic explanation showing a modified example of the temperature data measuring boat.

[Explanation of symbols]

10 Vertical heat treatment furnace 12 Outer shell 14 Insulation 16 heater 18 Process tube (vertical reaction tube) 20 gas introduction pipe 22 Exhaust pipe 30 Boats for actual processing 32 boat elevator 34 Insulation tube 40 First temperature detector 50 memory 52 Temperature control unit 60 Temperature measuring boat 61,62 Flange 63 props 64 hollow 65 Second temperature detector 70 Temperature Measuring Boat 71 Second temperature detector 72 Vertical movement mechanism

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // C23C 16/52 C23C 16/52

Claims (11)

[Claims] 1. A step of mounting a plurality of objects to be processed and a temperature detection unit on a boat and setting the processing position in a vertical reaction tube, and a step of setting a predetermined temperature in the vertical reaction tube by a heater. And a step of measuring a temperature distribution of the boat atmosphere by a temperature detection unit mounted on the boat, the method for measuring temperature in a vertical furnace. 2. The temperature distribution of the boat atmosphere according to claim 1, wherein at least one temperature detection element provided in the temperature detection unit is moved along a vertical axis direction. Vertical furnace temperature measurement method. 3. The temperature detection unit according to claim 1, wherein the temperature detection unit measures the temperature distribution of the boat atmosphere by detecting the temperature with each of a plurality of temperature detection elements provided along the longitudinal axis thereof. Measuring method for vertical furnace temperature. 4. The hollow boat according to claim 1, wherein the boat is supported by a plurality of columns that connect flanges at both ends, and the processing target is supported by at least one of the columns. A temperature measuring method for a vertical furnace, characterized in that the temperature detecting section is disposed in the section. 5. The object to be processed according to claim 1, wherein the object to be processed is supported by a plurality of columns that connect the flanges on both ends, and the at least one column other than the plurality of columns is provided. A temperature measuring method for a vertical furnace, wherein the temperature detecting unit is disposed in the hollow portion. 6. The boat according to claim 1, wherein the plurality of dummy objects to be processed are mounted on the boat, and the temperature distribution of the boat atmosphere is preliminarily measured before actual processing. Vertical furnace temperature measurement method. 7. The inert gas according to claim 6, wherein the inert gas is introduced into the vertical reaction tube at a supply amount substantially the same as that of the gas introduced during the actual treatment during the preliminary measurement step. And a method for measuring the temperature of a vertical furnace. 8. The temperature preliminary measurement step according to claim 6 or 7, wherein a plurality of objects are mounted on an actual processing boat, and the actual processing boat is set at a processing position in the vertical reaction tube. The step of setting the inside of the reaction tube to the process temperature by the heater and introducing the process gas to heat-treat the plurality of objects to be processed, and the temperature raised by the heater is set to the temperature outside the reaction tube. And a step of controlling the heater by correcting the temperature measured outside the reaction tube based on the temperature distribution measured by the temperature preliminary measurement step. Heat treatment method. 9. A flange at both ends, a plurality of pillars connecting the flanges at both ends, a support portion provided on each of the plurality of pillars and supporting a plurality of objects to be processed, and at least one of the plurality of pillars. A boat having a hollow portion provided in a book and a temperature detecting portion arranged in the hollow portion. 10. A flange at both ends, a plurality of pillars connecting the flanges at both ends, a hollow portion provided in at least one of the plurality of pillars, and at least one of the plurality of pillars other than the at least one pillar. A boat, comprising: a support portion that is provided on each of the other columns and that supports a plurality of objects to be processed; and a temperature detection portion that is disposed inside the hollow portion. 11. The boat according to claim 10, wherein the temperature detection unit has at least one temperature detection element movable in the hollow portion.