JPH09166501A - Temperature measuring device and temperature measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely and easily measure the temperature of a semiconductor wafer. SOLUTION: A cellophane tape 20 is stuck to the surface of a thermolabel 10 where a color change area for temperature display is formed, placed on a silicon substrate 30, the temperature of which is to be measured, and further the substrate 30 is set on a substrate holder 40. The substrate holder 40 is inserted in a heating furnace for evaporation not shown in the figure. The cellophane tape 20 is used for removing an evaporation metal, and it is made of such a material as not to be melted at the metal evaporation temperature. Subsequently, by an electron beam evaporation method, aluminum(Al) is, for example, evaporated on the surface of the substrate 30 with a thickness of 1000 angstrom. After Al evaporation, when the cellophane tape 20 is separated, Al which is the evaporation metal is simultaneously removed from the color change area 11 of the thermolabel 10, so that the history temperature (highest temperature) of the substrate 30 in the evaporation process can be easily read.

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 a temperature measuring method for measuring a substrate temperature in a semiconductor process, and particularly to a simple measurement of a substrate temperature in a film forming process such as a vapor deposition process or a sputtering process. The present invention relates to a temperature measurement method that enables

[0002]

2. Description of the Related Art Conventionally, as a method of measuring the temperature of a semiconductor substrate during a semiconductor process, a method of attaching a thermocouple to the substrate is generally used, but a simpler method of measurement is a method of attaching a thermolabel. The thermo label is the highest temperature recorded by the semiconductor substrate during the process, and records it.
This is a temperature detection plate having a plurality of discolored areas, and since the thermolabel is directly attached to the substrate and the area corresponding to the maximum temperature in the process discolors (colors), the temperature history can be measured. Such a measurement method is only required to attach a thermo label to the target substrate, and since the label that has once discolored does not change in color even if the temperature subsequently decreases, compare with the method using a thermocouple. And simple. Therefore, it is often used for temperature measurement when the optimum film forming temperature in the semiconductor manufacturing process is experimentally confirmed.

[0003]

By the way, in the case where the maximum temperature history of the substrate in the heating furnace is to be measured by the above-mentioned thermolabel, when the thermolabel is attached to the surface of the substrate, a film forming process such as vapor deposition or sputtering is performed. Then, naturally, a film is also formed on the surface of the thermolabel. for that reason,
If the film is colored, it becomes difficult to confirm the presence or absence of discoloration in the discolored area, that is, to measure the display temperature. However, when a thermolabel is attached to the back surface of the board to be measured, a gap is created between the board and the board holder that holds the board in the heating furnace, so that heat conduction between the board and the thermolabel does not occur. It is incomplete and accurate temperature measurement is not possible. In addition to that, heat conduction between the substrate holder and the substrate is also hindered, and the temperature control such as cooling and heating of the semiconductor substrate by the substrate holder cannot be performed sufficiently.

As described above, in the conventional temperature measuring method using the temperature detecting plate, there is no problem in the case of measuring the temperature of the process not including the film forming process, but the history of the film forming process such as vapor deposition and sputtering is recorded. It was inconvenient to know.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a temperature measuring device and a temperature measuring method capable of surely and easily measuring the temperature of a semiconductor wafer or the like. It is a thing.

[0006]

According to a first aspect of the present invention, there is provided a temperature measuring device comprising: a temperature detecting plate having a plurality of color changing regions formed on its upper surface, the color changing regions changing in color at different temperatures; and a back surface of the temperature detecting plate. An adhesive means for adhering onto the object and a covering means for releasably covering at least the discolored area on the upper surface of the temperature detecting plate are provided.

A temperature measuring device according to a second aspect is the first aspect.
The coating means is made of a material having the same heat conductivity as the semiconductor wafer, and is adhered to the temperature detecting plate with a peelable adhesive.

A temperature measuring device according to claim 3 is the temperature measuring device according to claim 1.
The adhesive for bonding the coating means and the temperature detecting plate is a heat resistant adhesive.

The invention according to claim 4 to claim 6 is a temperature measuring method using the temperature measuring device according to claim 1 to claim 3.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described.

First Embodiment FIG. 1 is a process explanatory view showing a first embodiment of the present invention, and FIG. 2 is a plan view thereof. In addition, FIG.
(C) corresponds to a sectional view taken along the line I-I of FIG. 2.
Here, the thermo label 10 which is a temperature detection plate is Wahl
Thermolabel # 240 (TEMP-PLATE: registered trademark) manufactured by the company is used. First, a silicon (S) for measuring the temperature is applied to the thermo label 10 on which the cellophane tape 20 is attached on the surface side where the color change area for temperature display is formed.
i) It is placed on the substrate 30 at a substantially central portion thereof, and the substrate 3
0 is set in the substrate holder 40 ((a) in the figure). Reference numeral 41 is a substrate retainer for fixing the silicon substrate 30 to the substrate holder 40.

The substrate holder 40 is inserted into a heating furnace for vapor deposition (not shown). Here, the cellophane tape 20 is used to remove the vapor-deposited metal, and is a tape made of a material that does not melt at the metal vapor deposition temperature.

Next, the substrate 3 is formed by the electron beam evaporation method.
Aluminum (Al) 50, for example, is vapor-deposited at a thickness of 1000 [angstrom] on the 0 surface (FIG. 2B). When the cellophane tape 20 is peeled off after the vapor deposition of Al, the vapor deposited metal Al is removed from the discolored area 11 of the thermolabel 10 at the same time (FIG. 7C). Therefore, the history temperature (maximum temperature) of the substrate 30 in the vapor deposition process can be easily read. Note that the discolored area 11 is a plurality of circular areas as shown in FIG. 2, and each has a temperature difference (4
(0 to 70 ° C.) is detected and displayed.

As described above, according to the first embodiment, by removing the aluminum 50 which is the evaporated metal together with the cellophane tape 20 from the temperature display side of the thermo label 10, the display of the thermo label 10 can be performed easily and surely. The temperature can be read.

Second Embodiment In the first embodiment, the case where the cellophane tape 20 is used as the tape for removing the deposited metal has been described, but the same material as the silicon substrate 30 is used instead of the cellophane tape. A foil obtained by polishing a Si wafer to a thickness of several μm may be used. In this case, the silicon foil can be adhered to the surface of the thermolabel with a double-sided tape or an adhesive.

As described above, by using the silicon foil which is the same heat-conducting material as the substrate, the radiant heat from the vapor deposition source source in the portion where the thermolabel is adhered and the Si surface where the thermolabel is not adhered The difference in absorption can be reduced, and highly accurate temperature measurement becomes possible.
Especially when controlling the substrate temperature to a low level, considering that the radiant heat from the vapor deposition source has a great influence on the substrate temperature, the absorption of the radiant heat between the part where the thermolabel is affixed and the Si surface that is not affixed It is expected that the accuracy of measurement can be improved by reducing the difference between.

Embodiment 3 It is also possible to use an aluminum foil instead of the silicon foil in the second embodiment. An aluminum foil having the same size as or slightly smaller than the thermo label is prepared, and a Si thin film is further formed on the surface of this aluminum foil by a sputtering method or the like. Then, the surface of the foil on which the Si thin film is not formed is faced down and adhered to the thermolabel.

As a result, similarly to the second embodiment,
The difference in absorption between the substrate and the thermolabel with respect to radiant heat from the vapor deposition source can be reduced, and highly accurate temperature measurement becomes possible. Further, when compared with the method of polishing a Si wafer to form a silicon foil, it becomes easy to form a foil having a Si surface.

In each of the above-mentioned embodiments, the temperature measurement in the working process adopting the electron beam evaporation method as the film forming method has been exemplified, but the present invention is the temperature measurement in the general film forming method such as the sputtering method and the CVD method. Can be similarly implemented.

Further, in the first embodiment, the cellophane tape 20 is used as a covering means for the thermolabel 10 which is a temperature detecting plate, but generally the same effect can be obtained by covering the thermolabel with an adhesive tape or a thin film. Obtainable.

Further, in the third embodiment, the silicon thin film is formed on the aluminum foil to form the covering means. However, as long as the accuracy of the temperature measurement permits, a substrate such as titanium is generally used. It is also possible to form thin films of different materials by a sputtering method or the like and use it as a covering means.

In any of the embodiments, it is preferable to use an adhesive having heat resistance equal to or higher than the measurement temperature as an adhesive for adhering the coating means and the temperature detecting plate. This is because, unless the adhesive is unnecessarily hardened or burnt, the covering means such as the tape or the thin film can be easily peeled off, and the temperature display surface after peeling can be made easy to see. .

As an example of the above-mentioned heat-resistant adhesive, polyimide can be used for the temperature measurement of about 420 ° C. or lower.

[0024]

Since the present invention is constructed as described above, it has the following effects.

According to the invention described in claim 1, the temperature of the object to be measured can be easily measured by the temperature detecting plate.

According to the invention described in claim 2, accurate measurement can be performed.

According to the third aspect of the present invention, even if the temperature to be measured becomes high, the adhesive does not harden or burn, and the tape or thin film as the covering means is reliably peeled off. You can check the measurement results.

According to the fourth aspect of the present invention, the temperature detecting plate, the upper part of which is covered with the peelable film, is placed on the object to be measured, and the film is formed in this state. By peeling off the film, the temperature of the measured object recorded on the temperature detection plate can be surely known.

According to the invention described in claim 5, since the film is made of the same material as the object to be measured and is in contact with the thermolabel in a peelable manner, the difference in the absorption of radiant heat is Get smaller.

According to the invention described in claim 6, the temperature display surface can be easily seen by bonding the film and the temperature detection plate with a heat resistant adhesive.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

[Explanation of symbols]

10 thermo label, 20 cellophane tape, 30 silicon substrate, 40 substrate holder.

Claims (6)

[Claims] 1. A temperature detecting plate having a plurality of color changing regions on its upper surface that change colors at different temperatures, an adhesive means for sticking the back surface of the temperature detecting plate onto an object to be measured, and the temperature detecting plate. And a covering means for releasably covering at least the discolored region on the upper surface of the temperature measuring device. 2. The covering means is made of a material having the same heat conductivity as that of the semiconductor wafer, and is adhered to the temperature detecting plate with a peelable adhesive. Temperature measuring device. 3. The temperature measuring device according to claim 2, wherein the adhesive for adhering the coating means and the temperature detecting plate is a heat resistant adhesive. 4. A step of adhering a temperature detection plate, the upper part of which is covered with a peelable film, onto a semiconductor wafer to be measured, a step of forming a film on the semiconductor wafer in this state, and the film. And the step of confirming the temperature of the object to be measured from the temperature detection plate by peeling off. 5. The film is made of a material having the same heat conductivity as the semiconductor wafer and covers the temperature detection plate in a peelable state.
The method for measuring temperature according to. 6. The film and the temperature detection plate are bonded together by a heat resistant adhesive.
Alternatively, the temperature measuring method according to claim 5.