JP2020174098A - Conductive type determination device and conductive type determination method for semiconductor product - Google Patents

Abstract

To provide a conductive type determination device for a semiconductor product which can determine the conductive type with high accuracy even when the electrical resistivity of the semiconductor product is high.SOLUTION: A conductive type determination device 1 includes a first probe 2 and a second probe 3 in contact with a silicon wafer W, a cooling unit 4 that cools a silicon wafer W, a heating unit 5 that heats the second probe 3, and a determination unit 8 that determines the conductive type of a silicon wafer W on the basis of thermoelectromotive force generated by a temperature difference between a first contact P1 with a first probe 2 and a second contact P2 with a second probe 3 in the silicon wafer W.SELECTED DRAWING: Figure 2

Description

The present invention relates to a conductive type discriminating device and a conductive type discriminating method for semiconductor products.

Radio-frequency (RF) circuits are widely used in mobile terminals. A high-resistance silicon wafer is used for the support substrate of the RF circuit for the purpose of reducing the current loss from the back surface side. The resistivity standard for silicon wafers for RF circuits is gradually increasing, for example, the resistivity standard for p-type wafers is 8000 Ωcm or more. With this demand, the accuracy of distinguishing the conductive type is also important.
As a method for discriminating the conductive type, a thermoelectromotive force discriminating method as described in Patent Document 1 is known.
In the method of Patent Document 1, one of the pair of probes is kept at room temperature and the other probe is heated to 60 ° C. or higher, so that a sufficient thermoelectromotive force is generated by the temperature difference between the two, and the conductive type is discriminated. The variation of is suppressed.

Japanese Unexamined Patent Publication No. 2012-253216

However, in the method as in Patent Document 1, when the electrical resistivity of the silicon wafer is high (when the dopant concentration is low), the number of carriers generated at the contact point with the heated probe is reduced, and the absolute electromotive force is absolute. The value becomes small. Therefore, in order to increase the carrier density, it is conceivable to raise the heating temperature of the probe further, but there is a limit to raising the heating temperature, and there is a possibility that the conductive type cannot be discriminated with high accuracy.

An object of the present invention is to provide a conductive type discriminating device for a semiconductor product and a conductive type discriminating method capable of discriminating the conductive type with high accuracy even if the electrical resistivity of the semiconductor product is high.

The conductive type discriminating device for a semiconductor product of the present invention includes a first probe and a second probe that come into contact with the semiconductor product, a cooling unit that cools at least one of the first probe and the semiconductor product, and the first probe. Based on the thermoelectromotive force generated by the temperature difference between the heating unit that heats the 2 probes and the first contact between the first probe and the second contact of the second probe in the semiconductor product. It is characterized by including a discriminating unit for discriminating the conductive type of the semiconductor product.
The method for determining the conductive type of a semiconductor product of the present invention includes a cooling step of cooling the first contact between the semiconductor product and the first probe, and heating for heating the second contact between the semiconductor product and the second probe. It is characterized in that the step and the discrimination step of discriminating the conductive type of the semiconductor product based on the thermoelectromotive force generated by the temperature difference between the first contact and the second contact are carried out.

In the present invention, when the temperature is not clearly defined, "heating" means a process of raising the temperature of the object to be heated to a temperature exceeding the temperature (room temperature (23 ° C.)) under the installation environment of the conductive type discriminator. However, "cooling" means a process of lowering the temperature of the object to be cooled to less than room temperature.
According to the present invention, by cooling the first contact, the carrier concentration in the vicinity thereof is lowered, and by heating the second contact, the carrier density in the vicinity thereof is increased, so that the electrical resistivity is increased. Even in a semiconductor product having a high dopant concentration and a low dopant concentration, the difference in carrier concentration in the vicinity of both contacts can be increased. As a result, a thermoelectromotive force having a large absolute value can be generated as compared with the conventional method as in Patent Document 1, and the conductive type can be discriminated with high accuracy.
Examples of semiconductor products include semiconductor wafers and semiconductor single crystals.

In the method for determining the conductive type of a semiconductor product of the present invention, the semiconductor product contains an n-type dopant and has an electrical resistivity of 20000 Ωcm or more, and the cooling step and the heating step are performed by the first probe. It is preferable to perform cooling and heating so that the temperature difference between at least one of the semiconductor products and the second probe is 175 ° C. or more.
In the method for determining the conductive type of a semiconductor product of the present invention, the semiconductor product contains a p-type dopant and has an electrical resistivity of 50,000 Ωcm or more, and the cooling step and the heating step are performed by the first probe. It is preferable to perform cooling and heating so that the temperature difference between at least one of the semiconductor products and the second probe is 160 ° C. or more.
According to the present invention, it is possible to provide a high resistance semiconductor product in which the conductive type is appropriately determined.

In the method for determining the conductive type of a semiconductor product of the present invention, the semiconductor product has an electrical resistivity of 80,000 Ωcm or more, and the cooling step and the heating step include at least one of the first probe and the semiconductor product and the above. It is preferable to perform cooling and heating so that the temperature difference from the second probe is 210 ° C. or more.
In the method for determining the conductive type of a semiconductor product of the present invention, the semiconductor product has an electrical resistivity of 80,000 Ωcm or more, and the cooling step and the heating step include at least one of the first probe and the semiconductor product and the above. It is preferable to perform cooling and heating so that the temperature difference from the second probe is 180 ° C. or more.
According to the present invention, it is possible to appropriately determine the conductive type of a semiconductor product of 80,000 Ωcm or more, which is practically important.

In the method for determining the conductive type of a semiconductor product of the present invention, the semiconductor product has an electrical resistivity of 180,000 Ωcm or more, and the cooling step and the heating step include at least one of the first probe and the semiconductor product and the above. It is preferable to perform cooling and heating so that the temperature difference from the second probe is 240 ° C. or more.
In the method for determining the conductive type of a semiconductor product of the present invention, the semiconductor product has an electrical resistivity of 180,000 Ωcm or more, and the cooling step and the heating step include at least one of the first probe and the semiconductor product and the above. A method for determining a conductive type of a semiconductor product, which comprises cooling and heating so that the temperature difference from the second probe is 220 ° C. or more.
According to the present invention, it is possible to appropriately determine the conductive type of a semiconductor product having a maximum resistance level of 180,000 Ωcm or more.

In the method for determining the conductive type of a semiconductor product of the present invention, the semiconductor product is preferably a silicon wafer or a silicon single crystal.

The graph which shows the temperature dependence of the carrier density of an intrinsic semiconductor. The schematic diagram which shows the structure of the conductive type discriminating apparatus of the semiconductor product which concerns on one Embodiment of this invention. The graph which shows the relationship between the temperature difference of a silicon wafer and a 2nd probe and the electrical resistivity of a semiconductor product in the case where the conductive type which concerns on the Example of this invention can be discriminated.

[Temperature dependence of carrier density of semiconductor products]
The carrier density of an intrinsic semiconductor containing almost no dopant has a temperature dependence as shown in FIG. For example, when the intrinsic semiconductor is n-type Si (silicon) and the dopant concentration is 1.45 × 10 ¹⁰ atoms / cm ³ , the carrier density decreases as the temperature decreases. Similarly, when the intrinsic semiconductor is n-type GaAs (gallium arsenide) and the dopant concentration is 1.79 × 10 ⁶ atoms / cm ³ , or when it is n-type Ge (germanium) and the dopant concentration is 2.4. Even in the case of × 10 ¹³ atoms / cm ³ , the carrier density decreases as the temperature decreases. In the graph of FIG. 1, for example, the expression “Si, 1.45 × 10 ¹⁰ ” means Si having a dopant concentration of 1.45 × 10 ¹⁰ atoms / cm ³ .
Even when the intrinsic semiconductor is a p-type, it is considered that it has a characteristic that the carrier density decreases as the temperature decreases, as shown in FIG.
Since the n-type or p-type semiconductor product to be determined as the conductive type in the present embodiment is a high-resistance product, the dopant content is almost the same as that of the above-mentioned n-type or p-type intrinsic semiconductor. It can be considered that the carrier density decreases as the temperature decreases.

[Construction of conductive type discriminator for semiconductor products]
As shown in FIG. 2, the conductive type discriminating device 1 discriminates between the first probe 2, the second probe 3, the cooling unit 4, the heating unit 5, the voltmeter 6, and the dew condensation suppressing unit 7. A unit 8 and a notification unit 9 are provided, and the conductive type of the silicon wafer W as a semiconductor product is discriminated by using a thermoelectromotive force discriminating method.

The cooling unit 4 includes a cooling plate 41 on which a silicon wafer W as a cooling target is placed, a cryopump 42 that cools the cooling plate 41 from below, and a cooling adjustment unit 43 that adjusts the cooling temperature of the cryopump 42. I have. By cooling the back surface of the silicon wafer W, the first contact point P ₁ and the first probe 2 with the first probe 2 in the silicon wafer W are cooled.

The heating unit 5 includes a heater 51 that heats the second probe 3 and a heating adjustment unit 52 that adjusts the heating temperature of the heater 51.

The voltmeter 6 is electrically connected to the first probe 2 and the second probe 3, and has a first contact P ₁ with the first probe 2 on the silicon wafer W and a second contact P ₁ on the silicon wafer W. The voltage value of the thermoelectromotive force generated by the temperature difference between the probe 3 and the second contact P ₂ is measured.

The dew condensation suppressing portion 7 is formed in a box shape having an opening on the lower surface, and the closed space forming portion 71 forming the closed space S by closing the opening by the cooling plate 41 and the inside of the closed space S are evacuated. It includes a suction unit 72. The first and second probes 2 and 3 are fixed inside the closed space forming portion 71. The first and second probes 2 and 3 are fixed so as to come into contact with the silicon wafer W when the lower end 71A of the closed space forming portion 71 is in close contact with the cooling plate 41 to form the closed space S. ..
The first and second probes 2 and 3 are preferably fixed so that the distance from the _first contact P ₁ to the second contact P ₂ is 15 mm or more and 50 mm or less.

When the voltage value measured by the voltmeter 6 is equal to or greater than the _first threshold value (positive value) V ₁ , the determination unit 8 determines that the silicon wafer W is p-type, and determines that the silicon wafer W is p-type, and determines that the silicon wafer W is a p-type, and the second threshold value (negative value). ) When V ₂ or less, it is determined that the silicon wafer W is n-type. The absolute value of the _first threshold value V _{1 and} the absolute value of the second threshold value V ₂ may be the same or different.
The notification unit 9 notifies the operator of the discrimination result of the discrimination unit 8 by displaying or sounding.

[Method for determining the conductive type of semiconductor products]
First, the operator prepares a silicon wafer W for semiconductors containing boron, gallium, indium or the like as a p-type dopant, or a silicon wafer W for semiconductors containing phosphorus, arsenic, antimony or the like as an n-type dopant. The electrical resistivity (hereinafter abbreviated as resistivity) is not particularly limited, but in the conductive type discriminator 1 of the present embodiment, the silicon wafer W having a dopant concentration of 20000 Ωcm or more (dopant concentration is less than 1 × 10 ¹¹ atoms / cm ³ ). Can be discriminated against.
Next, if necessary, a pretreatment for appropriately performing the conductive type discrimination process is performed. Examples of the pretreatment include mirror etching, donor killer heat treatment, polishing, cleaning, and drying.

After that, as shown by the alternate long and short dash line in FIG. 2, the operator places the silicon wafer W on the cooling plate 41 in a state where the closed space forming portion 71 is separated from the cooling plate 41. Next, an operator or a transport unit (not shown) moves the closed space forming portion 71 from the position indicated by the alternate long and short dash line to the position indicated by the solid line, and brings the lower end 71A of the closed space forming portion 71 into close contact with the cooling plate 41. A closed space S is formed, and the first and second probes 2 and 3 are brought into contact with the measurement surface W1 of the silicon wafer W.

After that, the suction unit 72 evacuates the closed space S. The degree of vacuum of the closed space S may be such that dew condensation does not occur on the silicon wafer W when the silicon wafer W is cooled by the cooling unit 4.
Next, the cooling unit 4 cools the silicon wafer W to cool the first contact P ₁ (cooling step), and the heating unit 5 heats the second probe 3 to cool the second contact P ₂ (Heating process).

In the cooling step and the heating step, the cooling temperature and the heating temperature of each are adjusted so that the temperature difference between the first contact P ₁ and the second contact P ₂ becomes the target temperature difference. The target temperature difference is preferably selected according to the dopant and resistivity contained in the silicon wafer W so that a sufficient thermoelectromotive force can be obtained. For example, in the case of a silicon wafer W containing an n-type dopant, the target temperature difference is preferably 175 ° C. or higher when the resistivity is 20000 Ωcm or higher, and 210 ° C. or higher when the resistivity is 80,000 Ωcm or higher. It is preferable, and when the resistivity is 180,000 Ωcm or more, it is preferably 240 ° C. or more. Further, in the case of a silicon wafer W containing a p-type dopant, the target temperature difference is preferably 160 ° C. or higher when the resistivity is 20000 Ωcm or higher, and 180 ° C. or higher when the resistivity is 80,000 Ωcm or higher. It is preferable, and when the resistivity is 180,000 Ωcm or more, it is preferably 220 ° C. or more.
The heating temperature is preferably 150 ° C. or lower from the viewpoint of the heating capacity and cost of the heater 51.

When the silicon wafer W is n-type, electrons as carriers are generated in the vicinity of the first and second contacts P ₁ and P _2, and when the silicon wafer W is p-type, holes as carriers are generated. By cooling the first contact P ₁ to a temperature lower than room temperature, the carrier density in the vicinity of the first contact P ₁ becomes lower than in the case of room temperature. On the other hand, by heating the second contact P ₂ to a temperature higher than room temperature, the carrier density in the vicinity of the second contact P ₂ becomes higher than that at room temperature.
Therefore, the difference in carrier density between the vicinity of the _first contact P ₁ and the vicinity of the second contact P ₂ becomes larger than that in the case where the first contact P ₁ is not cooled. For example, as shown in FIG. 1, the difference D in carrier density when the first contact P ₁ is cooled to −51 ° C. and the second contact P ₂ is heated to 140 ° C. at room temperature of 23 ° C. ₁ is larger than the difference in carrier density D ₂ when the _second contact P ₂ is heated to 140 ° C. while the first contact P ₁ is maintained at room temperature without being cooled. As a result, the voltage value measured by the voltmeter 6 tends to be equal to or higher than the first threshold value V ₁ or lower than the second threshold value V ₂ .

After that, the discriminating unit 8 determines that the silicon wafer W is p-type when the voltage value measured by the voltmeter 6 is equal to or greater than the _first threshold value V ₁ , and n when the voltage value is equal to or less than the _second threshold value V _2. It is determined that it is a type (discrimination step), and the determination result is notified using the notification unit 9.

[Action and effect of the embodiment]
According to the above embodiment, since the first contact P ₁ is cooled and the second contact P ₂ is heated, even if the silicon wafer W has a high resistivity and a low dopant concentration, the first and second contacts P ₂ are heated. The difference in carrier concentration in the vicinity of the contacts P ₁ and P ₂ can be made larger than that in the case where the first contact P ₁ is not cooled. Therefore, the absolute value of the voltage value measured by the voltmeter 6 can be increased, and the conductive type of the silicon wafer W can be discriminated with high accuracy.

Condensation suppression unit 7, by condensation of when the silicon wafer W is cooled, first, prevents the second contact P _1, moisture P ₂ is attached. Therefore, the measurement error of the voltage value can be eliminated, and the step of removing water from the silicon wafer W after determining the conductive type becomes unnecessary.

In the cooling step, the first contact P ₁ is cooled by cooling the object in contact with the first contact P _1, and in the heating step, the second contact is heated by heating the object in contact with the second contact P _2. P ₂ can be heated. As a result, the temperature difference between the first contact P ₁ and the second contact P ₂ becomes large, a large thermoelectromotive force is generated, and the conductive type of the semiconductor product having a high electrical resistivity can be discriminated.

[Modification example]
The present invention is not limited to the above-described embodiment, and various improvements and design changes can be made without departing from the gist of the present invention.
For example, as the cooling unit, a mechanism for directly cooling the first probe 2 may be used in place of or in combination with the cryopump 42 for cooling the silicon wafer W.
Regardless of the type of dopant in the silicon wafer W, the minimum temperature during cooling at the _first contact P ₁ may be the same temperature, or the maximum temperature during heating at the _second contact P ₂ may be the same temperature. Good.

An advance / retreat mechanism for advancing / retreating the first and second probes 2 and 3 with respect to the silicon wafer W is provided between the first and second probes 2 and 3 and the upper surface or the inner peripheral surface of the sealed space forming portion 71. At the time when the closed space S is formed, the first and second probes 2 and 3 are not brought into contact with the silicon wafer W, and the advance / retreat mechanism is driven at a predetermined timing thereafter to drive the first and second probes 2. , 3 may be brought into contact with the silicon wafer W.
After the silicon wafer W is placed in the container and cooled, the silicon wafer W is taken out of the container, and at a timing when the temperature of the silicon wafer W does not rise significantly, the uncooled first probe 2 and the heated second probe 2 are used. 3 may be brought into contact with the silicon wafer W to determine the conductive type. In this case, as a method of cooling the silicon wafer W, a method of immersing in liquid nitrogen in a container can be exemplified.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these examples.

[Comparative Example 1]
First, a silicon single crystal containing an n-type dopant was produced using the Czochralski method. A silicon wafer having a thickness of 1.3 mm was cut out from the straight body portion of this silicon single crystal. Then, both sides of the silicon wafer W were mirror-etched with a removal allowance of 300 μm, and a donor killer heat treatment was performed. Next, the measurement surface W1 was polished with an alumina abrasive having a particle size of 600 or more and 1200 or less, thoroughly washed with degreasing water, and dried. Next, the resistivity of the silicon wafer W was measured. The resistivity was 18,000 Ωcm.

As a conductive type discriminator, a device having a _first threshold value V ₁ of +56 mV and a second threshold value V ₂ of −56 mV was prepared. Then, the silicon wafer is placed in a room temperature (23 ° C.) environment, the second probe is heated to 150 ° C. with a heater, and the second probe and the first probe that has not been heated or cooled are transferred. The conductive type was discriminated by contacting the silicon wafer with a distance of 15 mm. That is, as shown in Table 1 below, the discrimination process was performed under the conditions that the cooling temperature of the silicon wafer was room temperature (23 ° C.), the heating temperature of the second probe was 150 ° C., and the temperature difference between the two was 127 ° C. ..
As a result, the discriminating unit was able to discriminate that it was an n-type (displayed as "OK" in the "discrimination result" column of Table 1 (hereinafter, the same applies)).

[Comparative Example 2]
When the discrimination process was performed under the same conditions as in Comparative Example 1 except that a silicon wafer containing an n-type dopant and having a resistivity of 20000 Ωcm was prepared, the discriminant unit could not discriminate the conductive type (“Discrimination” in Table 1). "NG" is displayed in the "Result" column (hereinafter, the same applies).
[Comparative Example 3]
When the discrimination process was performed under the same conditions as in Comparative Example 1 except that a silicon wafer containing an n-type dopant and having a resistivity of 36000 Ωcm was prepared, the discriminant unit could not discriminate the conductive type.
[Comparative Example 4]
When the discrimination process was performed under the same conditions as in Comparative Example 1 except that a silicon wafer containing an n-type dopant and having a resistivity of 45,000 Ωcm was prepared, the discrimination unit could not discriminate the conductive type.
[Comparative Example 5]
When the discrimination process was performed under the same conditions as in Comparative Example 1 except that a silicon wafer containing an n-type dopant and having a resistivity of 80,000 Ωcm was prepared, the discrimination unit could not discriminate the conductive type.
[Comparative Example 6]
When the discrimination process was performed under the same conditions as in Comparative Example 1 except that a silicon wafer containing an n-type dopant and having a resistivity of 180,000 Ωcm was prepared, the discrimination unit could not discriminate the conductive type.

[Comparative Example 7]
When the discrimination process was performed under the same conditions as in Comparative Example 1 except that a silicon wafer containing a p-type dopant and having a resistivity of 55,000 Ωcm was prepared, the discrimination unit could not discriminate the conductive type.
[Comparative Example 8]
When the discrimination process was performed under the same conditions as in Comparative Example 1 except that a silicon wafer containing a p-type dopant and having a resistivity of 80,000 Ωcm was prepared, the discrimination unit could not discriminate the conductive type.
[Comparative Example 9]
When the discrimination process was performed under the same conditions as in Comparative Example 1 except that a silicon wafer containing the p-type dopant and having a resistivity of 180,000 Ωcm was prepared, the discrimination unit could not discriminate the conductive type.

[Example 1]
A silicon wafer having the same dopant and resistivity as in Comparative Example 2 (n-type, 20000 Ωcm) was prepared, and the silicon wafer was cooled to −25 ° C. In addition, the second probe was heated to 150 ° C. with a heater. The second probe and the first probe that had not been heated or cooled were brought into contact with the silicon wafer at a distance of 15 mm, and the conductive type was discriminated. That is, the discrimination process was performed under the conditions that the cooling temperature of the silicon wafer was −25 ° C., the heating temperature of the second probe was 150 ° C., and the temperature difference between the two was 175 ° C.
As a result, the discriminating unit was able to discriminate that it was an n-type.

[Example 2]
The discrimination process was performed under the same conditions as in Example 1 except that a silicon wafer having the same dopant and resistivity as in Comparative Example 3 (n-type, 36000 Ωcm) was prepared and the cooling temperature was set to −40 ° C. As a result, the discriminating unit was able to discriminate the conductive type.
[Example 3]
The discrimination process was performed under the same conditions as in Example 1 except that a silicon wafer having the same dopant and resistivity as in Comparative Example 4 (n-type, 45,000 Ωcm) was prepared and the cooling temperature was set to −50 ° C. As a result, the discriminating unit was able to discriminate the conductive type.
[Example 4]
The discrimination process was performed under the same conditions as in Example 1 except that a silicon wafer having the same dopant and resistivity as in Comparative Example 5 (n-type, 80000 Ωcm) was prepared and the cooling temperature was set to -60 ° C. As a result, the discriminating unit was able to discriminate the conductive type.
[Example 5]
The discrimination process was performed under the same conditions as in Example 1 except that a silicon wafer having the same dopant and resistivity as in Comparative Example 6 (n-type, 180,000 Ωcm) was prepared and the cooling temperature was set to −90 ° C. As a result, the discriminating unit was able to discriminate the conductive type.

[Example 6]
The discrimination process was performed under the same conditions as in Example 1 except that a silicon wafer having the same dopant and resistivity as in Comparative Example 7 (p-type, 55000 Ωcm) was prepared and the cooling temperature was set to −10 ° C. As a result, the discriminating unit was able to discriminate the conductive type.
[Example 7]
The discrimination process was performed under the same conditions as in Example 1 except that a silicon wafer having the same dopant and resistivity as in Comparative Example 8 (p-type, 80000 Ωcm) was prepared and the cooling temperature was set to −30 ° C. As a result, the discriminating unit was able to discriminate the conductive type.
[Example 8]
The discrimination process was performed under the same conditions as in Example 1 except that a silicon wafer having the same dopant and resistivity as in Comparative Example 9 (p-type, 180,000 Ωcm) was prepared and the cooling temperature was set to −70 ° C. As a result, the discriminating unit was able to discriminate the conductive type.

[Discussion]
As shown in Table 1, in Comparative Examples 1 to 9 in which the silicon wafer was not cooled, the conductive type could be discriminated when the resistivity was 18,000 Ωcm, but the conductive type could not be discriminated when the resistivity was 20000 Ωcm or more. ..
On the other hand, in Examples 1 to 8 in which the silicon wafer was cooled, the conductive type could be discriminated even when the resistivity was 20000 Ωcm or more in addition to the case where the resistivity was 18000 Ωcm.
From these facts, by cooling the first contact and heating the second contact, even a silicon wafer having a resistivity of 20000 Ωcm or more and a low dopant concentration has a carrier density in the vicinity of both contacts. It was confirmed that the difference became large, and as a result, a thermoelectromotive force having a large absolute value could be generated, and the conductive type could be discriminated with high accuracy.

Further, FIG. 3 shows the relationship between the temperature difference between the silicon wafer and the second probe and the resistivity of the silicon wafer for Examples 1 to 8.
From FIG. 3, for a silicon wafer containing an n-type dopant and having a resistivity of 20000 Ωcm or more, the conductive type can be determined by setting the temperature difference between the silicon wafer and the second probe to 175 ° C. or more. It was confirmed that For a silicon wafer containing an n-type dopant and having a resistivity of 80,000 Ωcm or more and 180,000 Ωcm or more, the temperature difference between the silicon wafer and the second probe is set to 210 ° C. or more and 240 ° C. or more, respectively. , It was confirmed that the conductive type can be discriminated.
For silicon wafers containing a p-type dopant and having resistivityes of 50,000 Ωcm or more, 80,000 Ωcm or more, and 180,000 Ωcm or more, the temperature difference between the silicon wafer and the second probe is 160 ° C or more and 180 ° C or more, respectively. It was confirmed that the conductive type can be discriminated by setting the temperature to 220 ° C. or higher.

1 ... Conductive type discriminator, 2 ... 1st probe, 3 ... 2nd probe, 4 ... Cooling part, 5 ... Heating part, 8 ... Discriminating part, W ... Silicon wafer (semiconductor product, cooling target).

Claims (9)

The first probe and the second probe that come into contact with the semiconductor product,
A cooling unit that cools at least one of the first probe and the semiconductor product,
A heating unit that heats the second probe,
Determination to determine the conductive type of the semiconductor product based on the thermoelectromotive force generated by the temperature difference between the first contact with the first probe and the second contact with the second probe in the semiconductor product. A conductive type discriminator for semiconductor products, which is characterized by having a part. A cooling process that cools the first contact between the semiconductor product and the first probe,
A heating step of heating the second contact between the semiconductor product and the second probe,
A determination step for determining the conductive type of a semiconductor product based on a thermoelectromotive force generated by a temperature difference between the first contact and the second contact is performed. Method. In the method for determining the conductive type of a semiconductor product according to claim 2.
The semiconductor product contains an n-type dopant and has an electrical resistivity of 20000 Ωcm or more.
The cooling step and the heating step are characterized in that cooling and heating are performed so that the temperature difference between at least one of the first probe and the semiconductor product and the second probe is 175 ° C. or more. A method for determining the conductive type of a semiconductor product. In the method for determining the conductive type of a semiconductor product according to claim 3.
The semiconductor product has an electrical resistivity of 80,000 Ωcm or more.
The cooling step and the heating step are characterized in that cooling and heating are performed so that the temperature difference between at least one of the first probe and the semiconductor product and the second probe is 210 ° C. or more. A method for determining the conductive type of a semiconductor product. In the method for determining the conductive type of a semiconductor product according to claim 4.
The semiconductor product has an electrical resistivity of 180,000 Ωcm or more.
The cooling step and the heating step are characterized in that cooling and heating are performed so that the temperature difference between at least one of the first probe and the semiconductor product and the second probe is 240 ° C. or more. A method for determining the conductive type of a semiconductor product. In the method for determining the conductive type of a semiconductor product according to claim 2.
The semiconductor product contains a p-type dopant and has an electrical resistivity of 50,000 Ωcm or more.
The cooling step and the heating step are characterized in that cooling and heating are performed so that the temperature difference between at least one of the first probe and the semiconductor product and the second probe is 160 ° C. or more. A method for determining the conductive type of a semiconductor product. In the method for determining the conductive type of a semiconductor product according to claim 6,
The semiconductor product has an electrical resistivity of 80,000 Ωcm or more.
The cooling step and the heating step are characterized in that cooling and heating are performed so that the temperature difference between at least one of the first probe and the semiconductor product and the second probe is 180 ° C. or more. A method for determining the conductive type of a semiconductor product. In the method for determining the conductive type of a semiconductor product according to claim 7.
The semiconductor product has an electrical resistivity of 180,000 Ωcm or more.
The cooling step and the heating step are characterized in that cooling and heating are performed so that the temperature difference between at least one of the first probe and the semiconductor product and the second probe is 220 ° C. or more. A method for determining the conductive type of a semiconductor product. In the method for determining the conductive type of a semiconductor product according to any one of claims 2 to 8.
A method for determining the conductive type of a semiconductor product, wherein the semiconductor product is a silicon wafer or a silicon single crystal.

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