JP2534193Y2 - Temperature measuring device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature measuring device, and more particularly, to a temperature measuring device for measuring a temperature distribution in a wafer surface in a furnace tube.

[0002]

2. Description of the Related Art In general, as the diameter of a wafer becomes larger and the elements become finer, it is important to grasp the detailed thermal history of the wafer during heat treatment. This is because it has become clear that the thermal history of the wafer affects the generation of defects and precipitates in the wafer.

A conventional most common temperature measuring device will be described with reference to the drawings. In FIG. 3, reference numeral 19 denotes a furnace core tube, and heaters 2 are provided above and below the furnace core tube 19 respectively.
0 and 21 are provided. An external thermocouple 18 is provided between the furnace core tube 19 and the lower heater 21, and the temperature inside the furnace core tube 19 is measured inside the furnace core tube 19.
Internal thermocouples 17 are fixed at several places.

In the temperature measuring apparatus thus constructed, the temperature in the furnace core tube 19 and the heater 21 are measured by the internal thermocouple 17 and the external thermocouple 18 for measuring the in-plane temperature of the wafer.
Was measured by measuring the temperature of each.

[0005] As shown in FIG. 4, an infrared monitor 22 is provided outside the furnace core tube 19,
2, there is a method of measuring the temperature distribution in the wafer 15 surface. In this method, the heaters 20, 2
When the wafer 15 mounted on the wafer board 16 is carried into the furnace core tube 19 in which the wafer 1 is provided, infrared rays emitted from the wafer 15 by the infrared monitor 22 provided outside the furnace core tube 19 Is monitored, and the temperature distribution in the surface of the wafer 15 is measured.

[0006]

In the above-described temperature measuring apparatus for measuring the temperature in the plane of the wafer 15, the wafer 15 is connected to the furnace core tube 19.
The heat capacity inside the furnace core tube 19 changes greatly when it is loaded into the furnace, and the temperature inside the furnace core tube 19 changes due to the influence of air entrainment and the like, and the temperature distribution in the surface of the wafer 15 changes. is expected. Therefore, in order to recover the temperature change in the furnace core tube 19 in as short a time as possible, efforts are made to improve the temperature response by a method of controlling the PID control and the feedback ratio of the internal thermocouple 17 and the external thermocouple 18. ing. However, when the internal thermocouple 17 and the external thermocouple 18 are fixed to the furnace core tube 19, there has been a problem that it is not possible to accurately grasp the thermal history of the wafer 15.

The infrared monitor 22 controls the wafer 1
According to the method of measuring the temperature distribution in five planes, the temperature in the plane of the wafer 15 at the time of loading can be measured, but only one wafer 15 in front of the infrared monitor 22 can measure the temperature distribution. was there.

The present invention has been devised in view of such a problem, and in a heat treatment process using a furnace core tube,
It is an object of the present invention to provide a temperature measuring device capable of accurately monitoring the thermal history of a wafer.

[0009]

In order to achieve the above object, a temperature measuring apparatus according to the present invention is a temperature measuring apparatus for measuring a temperature distribution in a wafer plane in a furnace core tube. In addition, a plurality of thermocouples are embedded inside a jig having the same heat capacity.

[0010]

According to the above construction, in a temperature measuring device for measuring a temperature distribution in a wafer surface in a furnace tube, a plurality of thermoelectric devices are placed inside a jig having the same planar shape as a wafer and the same heat capacity. Since the pair is buried, the thermocouple for measuring the temperature distribution in the wafer plane is carried into the furnace core tube together with the wafer, and the jig in which the thermocouple is buried has the same temperature as the wafer. By showing the change in the distribution, the thermal history of the wafer is accurately monitored not only during the heat treatment but also when the wafer is carried into the furnace core tube.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the temperature measuring device according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a temperature measuring device 10, in which 11 indicates a jig made of quartz glass. The jig 11 has the same planar shape as the silicon wafer 15, and has a plurality of thermocouples 12 embedded therein. The thermocouple 12 has a lead wire 14 through a quartz tube 13 so that the output voltage of the thermocouple 12 can be monitored.
Is derived.

When the jig 11 made of quartz glass is carried into the furnace core tube, it exhibits a temperature change similar to that of the silicon wafer 15 and is measured as the temperature within the surface of the silicon wafer 15. Therefore, it is necessary to make the heat capacity of the jig 11 and the silicon wafer 15 equal, and it is necessary to calculate the thickness of the jig from the relationship of heat capacity = specific heat × volume × density based on the data shown in Table 1.

[0013]

[Table 1]

Here, the area of the 6-inch wafer is S, the thickness of the quartz glass jig 11 is d _SiO2 , and the silicon wafer 15 is
The following equation 1 is established when the thickness of the substrate is d _Si .

[0015]

(Equation 1)

Here, if d _Si = 625 μm, d _SiO2
= 482 μm. That is, when the thickness of the silicon wafer 15 is 625 μm, the thickness of the jig 11 is set to 482 μm.
m.

FIG. 2 shows a temperature measuring device 10 mounted on a quartz board 16.
An example is shown above. In order to more accurately measure the thermal history of the silicon wafer 15, the temperature measurement device 1
0 may be arranged before and after the silicon wafer 15 so as to sandwich the silicon wafer 15. In addition, when the carrying-in speed of the silicon wafer 15, the temperature rising rate, the number of processed wafers, and the like are not changed, the temperature history may be measured in advance by mounting the temperature measuring devices 10 at all positions on the quartz board 16. It is possible.

In this embodiment, the jig 11 made of quartz glass is described. However, the jig 11 has the same planar shape as the silicon wafer 15 and
The jig 11 can be processed into a form having the same heat capacity as that of the quartz glass, and the jig 11 is not limited to quartz glass as long as it does not become a contamination source of the wafer 15.

As described above, according to the above embodiment, the thermocouple 12 for measuring the temperature distribution in the surface of the silicon wafer 15 is used.
Can be carried into the furnace core tube together with the silicon wafer 15, and the jig 11 in which the thermocouples 12 are embedded exhibits the same temperature change as the silicon wafer 15, so that the silicon wafer 15 is carried into the furnace core tube. Also, the thermal history of the silicon wafer 15 can be accurately monitored, and the prediction and control of defects and precipitates can be performed accurately.

[0020]

As described above in detail, the temperature measuring device according to the present invention is a temperature measuring device for measuring a temperature distribution in a wafer surface in a furnace core tube, which has the same planar shape as a wafer. In addition, since a plurality of thermocouples are buried inside a jig having the same heat capacity, the thermocouple for measuring the temperature distribution in the wafer surface can be carried into the furnace core tube together with the wafer. At the same time, the jig in which the thermocouple is embedded shows the same change in temperature distribution as the wafer, so that the wafer is not only loaded during the heat treatment but also when the wafer is loaded into the furnace core tube. The thermal history can be accurately monitored, and prediction and control of defects and precipitates can be performed accurately.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a temperature measuring device according to the present invention.

FIG. 2 is a schematic cross-sectional view showing an arrangement example of a temperature measuring device.

FIG. 3 is a schematic sectional view showing a conventional temperature measuring device.

FIG. 4 is a side sectional view when an infrared monitor is arranged as a temperature measuring device.

[Explanation of symbols]

 Reference Signs List 10 Temperature measuring device 11 Jig 12 Thermocouple 15 Wafer

Claims (1)

(57) [Scope of request for utility model registration] 1. A temperature measuring apparatus for measuring a temperature distribution in a wafer surface in a furnace tube, wherein a plurality of thermocouples are embedded in a jig having the same planar shape as the wafer and having the same heat capacity. A temperature measuring device.