Inspection device

Abstract

When an infrared sensor is used to measure the surface temperature of a wafer having a plurality of objects to be inspected in a non-contact manner, the main cause of error generation can be corrected, and the measurement can be performed with good precision. The present invention provides an inspection apparatus for inspecting an object to be inspected by bringing an electrical contact into contact with an electrode terminal of the object to be inspected on a wafer and electrically connecting a tester and the object to be inspected via the electrical contact, the inspection apparatus comprising: a wafer support unit for supporting the wafer; an infrared light receiving unit that receives infrared rays radiated from the wafer at least with the wafer as a measurement target; and a temperature measurement control unit that controls the measurement of the temperature of the measurement target on the basis of the infrared radiation amount of the infrared rays received by the infrared light receiving unit, the temperature measurement control unit having a temperature correction unit that corrects the measurement temperature based on the infrared radiation amount of the wafer.

Description

TECHNICAL FIELD

[0001] The present application relates to an inspection apparatus, for example, which can be applied to a semiconductor inspection apparatus (hereinafter also referred to as "inspection apparatus") for inspecting electrical characteristics of semiconductor integrated circuits (hereinafter also referred to as "semiconductor devices") formed on a semiconductor wafer (hereinafter also referred to as "wafer"). BACKGROUND

[0002] In a manufacturing process of semiconductor devices formed on a wafer, it is necessary to check whether or not electrical characteristics of the semiconductor devices satisfy a prescribed value, and a semiconductor inspection apparatus equipped with a probe card is used in this checking.

[0003] For example, a probe card having a plurality of probes is connected to a test head, and terminals of semiconductor devices on a wafer are brought into contact with the probes. Then, a tester supplies inspection signals to each semiconductor device on the wafer via the probes, and the tester acquires signals in response from each semiconductor device, thereby performing electrical characteristic inspection of the semiconductor devices.

[0004] In recent years, it is required to check whether or not electrical characteristics of semiconductor devices satisfy a prescribed value even in a prescribed temperature environment, and it is necessary to accurately and highly precisely measure a surface temperature of a wafer (semiconductor devices) in the checking.

[0005] Conventionally, as a temperature measuring apparatus for measuring a surface temperature of a wafer, there is an apparatus described in Patent Document 1, which measures an infrared radiation amount radiated from a wafer using an infrared sensor (see Patent Document 1).

[0006] Here, the temperature measuring apparatus needs to be corrected using an emissivity of a black body. A correction method of the conventional temperature measuring apparatus is, for example, to take the temperature measuring apparatus off from a probe, and to correct it based on a radiation temperature of a black body furnace or the like. Alternatively, for example, a wafer-shaped black body is placed on a chuck of the probe, a change in a measured value of the infrared radiation amount is monitored, and it is confirmed that the measured value is within a certain range. When the measured value deviates from the certain range, the accuracy is confirmed again using the wafer-shaped black body, and if necessary, correction is performed again. In this way, the temperature of the wafer is measured in a non-contact manner using the infrared sensor. PRIOR ART DOCUMENT PATENT DOCUMENT

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-56253 SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, in the case of measuring the surface temperature of a wafer (semiconductor device) under inspection using a non-contact temperature sensor, when an operating current is applied to the semiconductor device, the semiconductor device generates heat, and the heat is further transferred to an electrical signal probe in contact with a terminal of the semiconductor device, so that the temperature of the semiconductor device changes, making it difficult to stabilize.

[0009] Therefore, a large temperature difference is generated between the applied temperature of the surface of the wafer (semiconductor device) and the actual temperature of the semiconductor device using the conventional method.

[0010] In addition, the temperature measurement method using an infrared sensor is an effective means because it can non-contact and high-speed measure the wafer surface temperature with good responsiveness, but in order to measure with higher accuracy, the following corrections need to be made, but these correction methods cannot be established.

[0011] The measurement data of the infrared sensor is transmitted to the temperature measurement system via an optical path formed by an optical fiber, a lens barrel, a lens, or the like, but the transmittance deteriorates due to the fitting state or deterioration of the optical path member.

[0012] In addition, if the temperature of the optical path itself rises, infrared rays are generated from the optical path itself, so it is possible to be affected by the infrared rays.

[0013] Further, depending on the state such as the color or roughness of the surface of the wafer as a measurement target, the amount of infrared radiation of the wafer changes.

[0014] In addition, the amount of light entering changes due to the change in the angle of incidence that changes depending on the distance from the light entrance surface (optical fiber tip or the like) of the optical fiber to the workpiece.

[0015] To solve the above problems, the present application provides an inspection device that can correct the main cause of error that can occur when measuring the surface temperature of a wafer having a plurality of inspection targets non-contact using an infrared sensor, and can measure with high accuracy. Technical means to solve the problem

[0016] To solve the above problems, the present application provides an inspection device that makes an electrical contact come into contact with an electrode terminal of an inspection target formed on a wafer, electrically connects a tester and the inspection target via the electrical contact, and thereby inspects the inspection target, the inspection device characterized by comprising: a wafer support portion that supports the wafer; an infrared light receiving portion that receives infrared rays radiated from the wafer as a measurement target at least with the wafer; and a temperature measurement control portion that controls temperature measurement of the measurement target based on the amount of infrared radiation of the infrared rays received by the infrared light receiving portion, the temperature measurement control portion having a temperature correction portion that corrects the measured temperature based on the amount of infrared radiation of the wafer. Effects of the Invention

[0017] According to the present invention, when measuring the surface temperature of a wafer having multiple inspected objects non-contactly using an infrared sensor, the main causes of possible errors can be corrected, enabling high-precision measurement. Attached Figure Description

[0018] Figure 1 This is an overall configuration diagram showing the overall structure of the inspection device according to the first embodiment. Figure 2 This is a top view showing the configuration of the chuck in the first embodiment. Figure 3 This is a flowchart (one of the flowcharts) showing the operation of the calibration process of the temperature measuring device of the inspection device in the first embodiment. Figure 4 This is an explanatory diagram illustrating the positional movement of the black body in the first embodiment. Figure 5 This is a flowchart (second part) showing the operation of the calibration process of the temperature measuring device of the inspection device in the first embodiment. Figure 6 This is an explanatory diagram illustrating the distance measurement performed by the distance sensor of the first embodiment. Figure 7 This is a graph showing the relationship between the distance between the wafer and the infrared light-receiving part and the correction temperature in the first embodiment. Figure 8 This is a graph showing the relationship between ambient temperature and correction temperature in the first embodiment. Figure 9 This is an explanatory diagram illustrating the fiber optic temperature correction process of the first embodiment. Figure 10 This is a graph showing the relationship between the temperature of the optical fiber in the first embodiment and the corrected temperature relative to the increase in infrared radiation of the optical fiber. Figure 11 This is an explanatory diagram illustrating the ring temperature correction process of the first embodiment. Figure 12 This is a graph showing the relationship between the temperature of the collar in the first embodiment and the correction temperature relative to the increase in infrared radiation of the collar. Figure 13 This is an explanatory diagram illustrating the configuration of the temperature sensor provided on the optical fiber and the ferrule in the first embodiment. Figure 14 This is a graph showing the surface temperature of the wafer before and after calibration using the temperature measuring device of the first embodiment. Detailed Implementation

[0019] (A) First Embodiment Hereinafter, the first embodiment of the inspection device of the present invention will be described in detail with reference to the accompanying drawings.

[0020] In the accompanying drawings of the embodiments, the same symbols are used to label the same parts. However, it should be noted that the drawings are schematic, and the thickness ratios of the constituent elements, etc., differ from reality. Furthermore, the drawings also include parts with different dimensional relationships and ratios. In this embodiment, apparatus and methods for embodying the technical concept of the present invention are illustrated, rather than specifying the materials, shapes, structures, arrangements, etc., of the constituent parts as described in the embodiments.

[0021] (A-1) Configuration of the first embodiment (A-1-1) Overall Composition Figure 1 This is an overall configuration diagram showing the overall structure of the inspection device according to the first embodiment.

[0022] exist Figure 1 In the first embodiment, the inspection device 1 includes a temperature measuring device 10, a detector 50, and a test head 19.

[0023] In addition, Figure 1 In the detector 50, there are: a chuck 40 on which a wafer 20 is placed and has a temperature adjustment function that can adjust the temperature of the wafer 20 to a high temperature or a low temperature; and a θ-axis stage 51, a Z-axis stage 52, a Y-axis stage 53 and an X-axis stage 54 as a motion drive mechanism.

[0024] Inspection apparatus 1 inspects the electrical characteristics of each semiconductor device (hereinafter also referred to as "the device under inspection") formed on wafer 20. Inspection apparatus 1 has a probe card 14 electrically connected to the second side (e.g., the lower surface) of test head 19 via an electrical connection unit 18. During inspection, each probe 17 of probe card 14 is brought into electrical contact with the electrode terminals of the semiconductor device. Then, inspection apparatus 1 provides an electrical signal from the tester to each semiconductor device on wafer 20 via the probes, acquiring a response signal from each semiconductor device to the tester. Thus, the tester performs a characteristic inspection of the semiconductor device.

[0025] The test head 19 is connected to the probe card 14 via an electrical connection unit 18 on a second surface (e.g., the lower surface). The test head 19 is connected to a tester body (not shown) and transmits electrical signals between the tester body and the probe card 14. This allows for the inspection of the electrical characteristics of the semiconductor devices on the wafer 20.

[0026] The electrical connection unit 18 is a mounting unit for mounting the probe card 14 on the test head 19, and electrically connecting the test head 19 and the probe card 14.

[0027] The probe card 14 contacts the probes 17 with the electrode terminals of the semiconductor device formed on the wafer 20, provides an electrical signal to the semiconductor device via the probes 17, and receives a response signal from the semiconductor device via the probes 17. The probe card 14 is an example of an electrical connection device that electrically connects the tester body and the semiconductor device on the wafer 20. The probe card 14 has a probe assembly 15 with a plurality of probes 17 on its second surface (e.g., the lower surface).

[0028] The probe assembly 15 is an assembly having multiple probes 17 and is disposed on the second side of the probe card 14.

[0029] Probe 17 is an electrical contact that makes electrical contact with the electrode terminals of a semiconductor device. There is no particular limitation on the type of probe 17; for example, a cantilever probe or a vertical probe can be used.

[0030] In addition, in this embodiment, the probe 17 is exemplified as an electrical contact that makes electrical contact with the electrode terminal of the semiconductor device. However, when the semiconductor device is an optical semiconductor, in addition to the probe 17 being an electrical contact, the probe 17 may also include an optical probe (e.g., an optical fiber) that receives and transmits light signals between the optical input / output section of the optical semiconductor.

[0031] The chuck 40 holds the wafer 20 on its upper surface (also called the "chuck top" or "chuck stage"), allowing it to move along the XYZθ axes. Additionally, the chuck 40 has a temperature adjustment function to regulate the temperature of the wafer 20 held on its upper surface. Furthermore, one or more blackbodies 30 are disposed on the upper surface of the chuck 40. The method for setting the blackbodies 30 will be described later.

[0032] The θ-axis stage 51, Z-axis stage 52, Y-axis stage 53, and X-axis stage 54 are the moving drive mechanisms that move the chuck 40.

[0033] The temperature measuring device 10 is connected to the optical fiber 12, which in turn is connected to the infrared light-receiving unit 13. The infrared light-receiving unit 13 receives infrared radiation emitted by the object being measured (hereinafter also referred to as the "object being measured"). The temperature measuring device 10 acquires the infrared radiation emitted by the object being measured via the optical fiber 12. The temperature measuring device 10 converts the amount of infrared radiation input from the infrared light-receiving unit 13 into temperature and measures the surface temperature of the object being measured. Therefore, the surface temperature of the object being measured can be measured non-contactly.

[0034] In addition, the temperature measuring device 10 periodically or as needed measures the surface temperature of the blackbody 30 placed on the first side (e.g., the upper surface) of the chuck 40 to correct the measured temperature of the temperature measuring device 10.

[0035] Additionally, the temperature measuring device 10 is connected to the distance sensor 61 via an optical fiber 62. The temperature measuring device 10 obtains distance information from the distance sensor 61 and derives the distance between the infrared sensor 16 and the wafer 20.

[0036] (A-1-2) Detailed configuration of temperature measuring device 10 exist Figure 1 In this device, the temperature measuring device 10 generally includes an infrared sensor 16, a temperature measurement and correction unit 100, a temperature correction unit 110, a storage unit 104, and a temperature display unit 120.

[0037] Here, the temperature measuring device 10 is a device equipped with a CPU, ROM, RAM, EEPROM, input / output interface, etc. The temperature measuring device 10 can also perform temperature measurement processing as hardware. Alternatively, the temperature measuring device 10 can also function as a temperature measuring device by installing application software (such as a temperature measuring program) in the ROM and having the CPU execute the software. In short, the functions of the temperature measuring device 10 can be implemented in various ways. Figure 1 The example uses functional blocks to represent this.

[0038] [Infrared Sensor 16] The infrared sensor 16 converts the infrared radiation input from the infrared light-receiving unit 13 into temperature to measure the surface temperature of the object being measured. The infrared sensor 16 is a non-contact temperature conversion unit (non-contact thermometer) that converts infrared radiation into temperature. The infrared sensor 16 has a radiation output unit 102 and a temperature output unit 105 as its functions.

[0039] The radiation output unit 102 focuses the infrared radiation received by the infrared light receiving unit 13 from the object to be measured via the optical fiber 12, and outputs the infrared radiation emitted by the object to be measured.

[0040] The temperature derivation unit 105 derives the temperature based on the infrared radiation quantity of the object being measured, which is derived by the radiation quantity derivation unit 102. Here, the temperature derivation method can employ existing methods, calculating the temperature from the infrared radiation quantity based on the relationship between infrared radiation quantity and temperature (e.g., Planck's law of radiation). Therefore, the temperature can be determined from the infrared radiation quantity.

[0041] [Temperature Measurement and Correction Unit 100] The temperature calibration unit 100 periodically or during inspections calibrates the temperature value of the wafer 20 (semiconductor device) measured by the temperature measuring device 10. By periodically or during inspections calibrating the temperature value of the infrared sensor 16, high-precision temperature measurement is possible. Furthermore, as described later, by using a non-contact sensor such as the infrared sensor 16, the temperature value of the wafer 20 (semiconductor device) can be calibrated, thus enabling non-contact and high-speed calibration with good responsiveness.

[0042] The temperature measurement and correction unit 100 includes a temperature acquisition unit 101 and a correction unit 103.

[0043] Storage unit 104 stores reference table 104a, which shows the relationship between the temperature of the blackbody 30 and the amount of infrared radiation (hereinafter also referred to as "radiation"). In addition, storage unit 104 stores processing programs, data required for processing, etc.

[0044] The temperature acquisition unit 101 acquires the temperature of the object to be measured from the temperature sensor 191.

[0045] The calibration unit 103 generates a correction table based on the relationship between the radiation amount and temperature of the blackbody 30. Using the correction table, it corrects the measured values ​​caused by the time-dependent changes of the infrared sensor 16, corrects the temperature measuring device 10, and detects anomalies.

[0046] [Temperature Correction Unit 110] When the temperature correction unit 110 uses the infrared sensor 16 to measure the surface temperature of the wafer 20 (semiconductor device), it performs temperature correction based on the main causes (correction factors) that may cause errors.

[0047] The temperature correction unit 110 includes a Z position temperature correction unit 111, an ambient temperature correction unit 112, an optical fiber temperature correction unit 113, and a collar temperature correction unit 114.

[0048] Alternatively, the temperature correction unit 110 may be a processing unit that combines any one of the Z position temperature correction unit 111, the ambient temperature correction unit 112, the fiber optic temperature correction unit 113, and the ferrule temperature correction unit 114, but here we illustrate the case with all of the processing units.

[0049] Z-position temperature correction unit 111 corrects the temperature based on the distance (i.e., length or height in the Z-axis direction) between the infrared light receiving unit 13 located at the top of the optical fiber 12 and the object being measured (e.g., wafer 20).

[0050] For example, considering that if the distance between the infrared light-receiving section 13 and the wafer 20 is short, the amount of infrared light incident on the infrared light-receiving section 13 will be greater, and conversely, if the distance is long, the amount of infrared light incident will be less. Therefore, by utilizing the relationship between the distance between the infrared light-receiving section 13 and the wafer 20 and the temperature correction value, the temperature is corrected using a correction value corresponding to the actual distance.

[0051] The ambient temperature correction unit 112 corrects the temperature based on the change in the ambient temperature (e.g., room temperature) of the infrared sensor 16.

[0052] For example, the infrared sensor 16 uses a preamplifier (amplifier) ​​to amplify the intensity of the infrared radiation emitted by the object being measured. However, the measured temperature value may change depending on the ambient temperature (room temperature) where the preamplifier of the infrared sensor 16 is located. Therefore, temperature correction is performed to correspond to changes in room temperature by utilizing the relationship between the ambient temperature of the environment in which the preamplifier of the infrared sensor 16 is configured and the temperature correction value.

[0053] The fiber temperature correction unit 113 uses the heat transferred from the chuck 40 with temperature adjustment function to correct the temperature according to the temperature change of the fiber itself.

[0054] For example, the temperature of the optical fiber connected to the infrared sensor 16 increases because it transfers heat from the chuck 40. Additionally, since the probe assembly 15 also receives heat from the chuck 40, and the probe 17 also generates heat, the probe assembly 15 itself generates heat due to heat transfer via the probe 17, causing a temperature change in the optical fiber itself. Therefore, the optical fiber temperature correction unit 113 corrects the surface temperature of the wafer 20 based on the temperature change of the optical fiber itself.

[0055] At this time, in order to determine the temperature of the optical fiber itself, a temperature sensor 191, such as a thermocouple, is installed on the optical fiber. The temperature sensor 191 measures the temperature of the optical fiber itself and provides the temperature information to the temperature measuring device 10. The optical fiber temperature correction unit 113 uses the temperature information sensed by the temperature sensor 191 to correct the value of the surface temperature of the wafer 20.

[0056] The ferrule temperature correction unit 114 corrects the temperature based on the temperature change of the ferrule used when inserting the optical fiber 12 into the through hole provided on the probe card 14.

[0057] For example, when inserting the optical fiber 12 into the through hole provided on the probe card 14, in order to facilitate the replacement of the optical fiber 12, a flanged tubular member is inserted into the through hole, and the optical fiber 12 is inserted into the tube of the flange. During inspection, since the temperature of the flange itself also changes, the flange temperature correction unit 114 corrects the surface temperature of the wafer 20 according to the temperature change of the flange itself.

[0058] This section describes the case where all four correction methods are used, but it is also possible to combine any of the four correction methods.

[0059] [Temperature display unit 120] The temperature display unit 120 displays the temperature derived by the infrared sensor 16, the temperature corrected by the temperature measurement correction unit 100, and the temperature corrected by the temperature correction unit 110. For example, the temperature display unit 120 can be a display unit such as an LCD.

[0060] (A-1-3) Detailed Composition of Chuck 40 Figure 2 This is a top view showing the configuration of the chuck 40 in the first embodiment.

[0061] like Figure 2 As shown, the shape of the wafer mounting surface of the chuck 40 (i.e., the shape of the top of the chuck) is approximately circular, and the size of the chuck 40 is slightly larger than the size of the wafer 20.

[0062] A blackbody 30 with a clear relationship between temperature and infrared radiation is pre-positioned on the periphery 42 of the wafer mounting surface of the chuck 40.

[0063] Here, in Figure 2 In the example, it represents a case where four black bodies 30 are provided on the peripheral portion 42 of the wafer mounting surface of the chuck 40, and one black body 30 is provided on the black body mounting portion 41 on the peripheral portion 42, for a total of five black bodies 30. The four black bodies 30 are arranged at equal intervals on the peripheral portion 42 of the chuck 40.

[0064] Furthermore, the number of blackbody 30s is not limited to this; one blackbody 30 or more blackbody 30s may be configured on the chuck 40. The blackbody 30 is used as a reference for the amount of infrared radiation. In addition, when calibrating the temperature measuring device 10, there are no particular limitations as long as the blackbody 30 can be moved to the position of the infrared light-receiving part 13.

[0065] A blackbody 30 is a thermal radiator whose relationship with temperature and infrared radiation is known in advance. For example, a blackbody 30 can be made of various types of materials, such as a sticker-type blackbody (blackbody sticker), a blackbody coated with blackbody paint, etc.

[0066] When issues arise, such as verification of the measurement accuracy of the temperature measuring device 10, abnormal measurement accuracy, or measurement abnormality of the infrared sensor 16, the blackbody 30 converts the amount of infrared radiation radiated by it into temperature and uses the result to create a correction table. Then, referring to the correction table, the temperature signal output value of the temperature measuring device 10 is corrected.

[0067] In other words, the infrared radiation of the blackbody 30 is measured during inspection or periodically, and the temperature is derived from the infrared radiation. By comparing this temperature with a correction table, the temperature signal output value of the temperature measuring device 10 can be corrected.

[0068] Since a blackbody 30 is disposed on the wafer mounting surface of the chuck 40, the blackbody 30 can be moved to the position of the infrared light receiving part 13 for measurement even during inspection. Therefore, the temperature signal output value of the temperature measuring device 10 can be calibrated without replacing the wafer 20.

[0069] Furthermore, the blackbody 30 does not have to be an ideal, perfect blackbody; something that is considered a blackbody can be used. For example, a portion of the upper surface (top of the chuck) of the chuck 40 or the entire upper surface of the chuck 40 can also be a blackbody color instead of configuring the blackbody 30.

[0070] (A-2) Operation of the first embodiment Next, the temperature measurement process of the wafer 20 (semiconductor device) in the inspection apparatus 1 of the first embodiment will be described with reference to the accompanying drawings.

[0071] (A-2-1) Correction Process First, an example of a calibration method for calibrating the measured values ​​of the temperature measuring device 10 during inspection or periodically will be described.

[0072] (A-2-1-1) First Correction Process Figure 3 This is a flowchart (one of the flowcharts) showing the operation of the calibration process of the temperature measuring device 10 of the inspection device 1 in the first embodiment.

[0073] Here, an example of periodic calibration of the temperature measuring device 10, for instance, as a fiber optic non-contact thermometer, is described. Furthermore, the order of the calibration process is not limited to... Figure 3 .

[0074] [Step S101] First, the θ-axis stage 51, Z-axis stage 52, Y-axis stage 53, and X-axis stage 54, which serve as the motion drive mechanisms, are driven as follows: Figure 4 As shown, the moving drive mechanism moves the blackbody 30, which is located in the peripheral area of ​​the wafer mounting surface of the chuck 40 and near the periphery, to the position of the infrared light receiving part 13 (step S101).

[0075] [Step S102] Next, the temperature of the chuck 40 is set to the temperature required for measurement (step S102). For example, in this embodiment, the temperature is set to "-40°C", "25°C", or "125°C".

[0076] [Step S103] The temperature of the chuck 40 becomes the set temperature. The infrared light receiving unit 13 receives infrared radiation from the blackbody 30 and provides infrared radiation to the infrared sensor 16 via the optical fiber 12. In the temperature measuring device 10, the radiation output unit 102 outputs the infrared radiation amount of the blackbody 30 based on the infrared radiation (signal) from the infrared light receiving unit 13 (step S103).

[0077] [Step S104] In the temperature measuring device 10, the temperature output unit 105 outputs the temperature based on the amount of infrared radiation emitted by the blackbody according to Planck's radiation law (step S104).

[0078] [Step S105] Next, determine whether the measurements at all required temperatures (e.g., -40°C, 25°C, 125°C) are complete (step S105).

[0079] Then, if the measurement is completed (step S105 / Yes), the process proceeds to step S106; if it is not completed (step S105 / No), the process returns to step S102, the set temperature of the chuck 40 is changed, and the process continues.

[0080] [Step S106] The correction unit 103 generates a correction table (hereinafter also referred to as "the first correction table") based on the infrared radiation of the blackbody 30 and the derived temperature (step S106).

[0081] For example, if a prior relationship table exists based on the relationship between the temperature of the blackbody 30 and the amount of infrared radiation, a correction table is created by comparing the prior relationship table with the measurement results obtained in S102 to S106.

[0082] [Step S107] Steps S107 to S113 are processes for periodically calibrating the infrared sensor 16 using the correction table created in step S106.

[0083] First, the moving drive mechanism periodically moves the blackbody 30 on the chuck 40 to the position of the infrared light-receiving part 13 (step S107).

[0084] [Step S108] Next, the temperature sensor 191 provides the set temperature of the chuck 40 to the temperature measuring device 10 (step S108).

[0085] [Step S109] The infrared light receiving section 13 receives infrared radiation from the blackbody 30 and provides it to the temperature measuring device 10 via the infrared sensor 16. In the temperature measuring device 10, the radiation output section 102 outputs the amount of infrared radiation from the blackbody 30 based on the infrared radiation from the infrared light receiving section 13 (step S109).

[0086] [Step S110] In the temperature measuring device 10, the temperature output unit 105 outputs the temperature based on the amount of infrared radiation emitted by the blackbody according to Planck's radiation law (step S110).

[0087] [Step S111] The calibration unit 103 compares the correction table with the measurement results measured in S107 to S110, and based on the comparison results, detects and corrects the time-related changes of the infrared sensor and the changes in the infrared radiation of the wafer (step S111).

[0088] For example, the comparison results are displayed on a display such as an LCD screen. This allows the operator to determine if the measurement value of the infrared sensor 16 is abnormal.

[0089] (A-2-1-2) Second Correction Process Figure 5 This is a flowchart (second part) showing the operation of the calibration process of the temperature measuring device 10 of the inspection device 1 in the first embodiment.

[0090] Here, we illustrate an example of correcting the value of infrared radiation corresponding to the surface temperature of a semiconductor device on a wafer using an infrared sensor 16 after temperature conversion, for instance, during inspection. Furthermore, the order of the correction process is not limited to... Figure 5 .

[0091] In addition, the second calibration process is intended to perform calibration without removing the wafer 20, which is the object of measurement, from the chuck 40.

[0092] For example, when checking the electrical characteristics of a semiconductor device on a wafer 20, the wafer 20 can be checked without replacing it and without detaching the temperature measuring device 10 from the detector 50, and the calibration process can be performed. Alternatively, for example, calibration using the infrared radiation amount from the blackbody 30 can be performed during the period between the completion of the inspection of a wafer 20 and the placement of the next wafer 20 on the chuck 40.

[0093] [Steps S201, S202] First, the reference wafer is placed on the chuck 40 (step S201), and the temperature of the chuck 40 is set to the temperature required for the measurement (step S202).

[0094] For example, in this embodiment, the temperature is set to "-40°C", "25°C", and "125°C", but the temperature value is not limited to these, and the number of temperature settings is not limited to 3.

[0095] [Step S203] The θ-axis stage 51, Z-axis stage 52, Y-axis stage 53 and X-axis stage 54, which serve as the moving drive mechanism, are driven to move the blackbody 30 on the chuck 40 to the position of the infrared light-receiving part 13 (step S203).

[0096] [Step S204] The infrared light receiving section 13 receives infrared radiation from the blackbody 30 and provides it to the temperature measuring device 10. In the temperature measuring device 10, the radiation output section 102 outputs the infrared radiation amount of the blackbody 30 based on the infrared radiation from the infrared light receiving section 13 (step S204).

[0097] [Step S205] In the temperature measuring device 10, the temperature output unit 105 outputs the temperature based on the amount of infrared radiation of the blackbody 30 according to Planck's radiation law (step S205).

[0098] [Step S206] Next, a semiconductor device formed on the reference wafer is used as a reference device, and the reference device is moved to the position of the infrared light-receiving part 13 (step S206). The reference device is any device (semiconductor device) on the reference wafer.

[0099] [Step S207] The infrared light receiving section 13 receives infrared radiation from the reference device and provides it to the temperature measuring device 10. In the temperature measuring device 10, the radiation amount deriving section 102 derives the infrared radiation amount of the reference device based on the infrared radiation from the infrared light receiving section 13 (step S207).

[0100] [Step S208] In the temperature measuring device 10, the temperature output unit 105 outputs the temperature based on the amount of infrared radiation from the reference device according to Planck's radiation law (step S208).

[0101] [Step S209] Next, determine whether the measurements at all required temperatures (e.g., -40°C, 25°C, 125°C) are complete (step S209).

[0102] Then, if the measurement is completed (step S209 / Yes), the process proceeds to step S210; if it is not completed (step S209 / No), the process returns to step S202, the set temperature of the chuck 40 is changed, and the process continues.

[0103] [Step S210] The calibration unit 103 compares the relationship between the infrared radiation amount and the output temperature of the blackbody 30 and the relationship between the infrared radiation amount and the output temperature of the reference device, and creates a correction table (hereinafter also referred to as "the second correction table").

[0104] [Steps S211, S212] Steps S211 to S216 are processes for calibrating the temperature measuring device 10 by using the correction table created in step S210 to inspect the semiconductor devices on the wafer 20 or periodically measure the radiation of the blackbody 30.

[0105] First, the wafer 20 to be measured is placed on the chuck 40 (step S211), and the electrical characteristics of the semiconductor device on the wafer 20 are checked (step S212).

[0106] [Step S213] like Figure 4 As shown, the moving drive mechanism periodically moves the blackbody 30 on the chuck 40 to the position of the infrared light-receiving part 13 (step S213).

[0107] For example, during the process of changing from one wafer 20 to the next, or during the inspection of transferring a semiconductor device on one wafer 20 to the next semiconductor device, the amount of radiation from the blackbody 30 on the chuck 40 is corrected.

[0108] [Step S214] The infrared light receiving section 13 receives infrared radiation from the blackbody 30 and provides it to the temperature measuring device 10. In the temperature measuring device 10, the radiation quantity deriving section 102 derives the infrared radiation quantity of the blackbody 30 based on the infrared radiation from the infrared sensor 16 (step S214).

[0109] [Step S215] In the temperature measuring device 10, the temperature deriving unit 105 derives the temperature based on the amount of infrared radiation emitted by the blackbody 30 according to Planck's radiation law (step S215).

[0110] [Step S216] The calibration unit 103 uses the correction table created in S210, the infrared radiation amount of the blackbody 30 derived in S211 to S215, and the temperature to detect and correct the time-related changes of the infrared sensor and the changes in the infrared radiation amount of the wafer (step S216).

[0111] (A-2-2) Temperature Correction Process Next, with reference to the accompanying drawings, a method for correcting the measured value of the surface temperature of the wafer 20 using the temperature measuring device 10 will be described in detail.

[0112] (A-2-2-1) Temperature Correction Process at Z Position Figure 6 This is an explanatory diagram illustrating the distance measurement performed by the distance sensor 61 of the first embodiment.

[0113] For example, in Figure 6 During inspection, the infrared light-receiving part 13 is positioned opposite to the semiconductor device on the wafer 20. In the measurement of infrared radiation, the position of the light-receiving part 13 becomes the reference.

[0114] The positions of the light-receiving part (end) of the infrared light-receiving part 13 and the end of the distance sensor 61 are known in advance, and the distance (distance in the Z-axis direction; height) between the end of the distance sensor 61 and the light-receiving part of the infrared light-receiving part 13 is set to "W2".

[0115] In addition, when the distance sensor 61 is aimed at the upper surface of the wafer 20, the distance (distance in the Z-axis direction; height) between the end of the distance sensor 61 and the upper surface of the wafer 20 is set to "W1".

[0116] The distance sensor 61 sends light to the upper surface of the wafer 20, which is the object, receives the reflected light, and provides the distance information between itself and the upper surface of the wafer 20 to the Z position temperature correction unit 111 of the temperature measuring device 10.

[0117] The Z-position temperature correction unit 111 calculates the distance between the light-receiving part (end) of the infrared light-receiving part 13 and the upper surface of the wafer 20 based on the distance information from the distance sensor 61.

[0118] Here, an example of a method for deriving the distance between the light-receiving portion (end) of the infrared light-receiving portion 13 and the upper surface of the wafer 20 derived from the Z-position temperature correction unit 111 is described.

[0119] For example, the distance (distance in the Z-axis direction; height) W2 between the end of the distance sensor 61 and the light-receiving part of the infrared light-receiving part 13 is preset. Therefore, by subtracting W2 from the distance W1 measured from the distance sensor 61 to the wafer 20, the Z position temperature correction unit 111 can derive the distance "W1-W2" between the light-receiving part (end) of the infrared sensor 16 and the upper surface of the wafer 20.

[0120] The Z-position temperature correction unit 111 calculates the correction temperature corresponding to the distance (W1-W2) between the light-receiving part (end) of the infrared light-receiving part 13 and the upper surface of the wafer 20 by referring to the pre-set relationship between the distance and the correction temperature.

[0121] Figure 7 This is a graph showing the relationship between the distance between the wafer 20 and the infrared light-receiving part 13 and the correction temperature in the first embodiment. Figure 7 In the diagram, the horizontal axis represents the length of the distance between the wafer 20 and the infrared light-receiving part 13, and the vertical axis represents the correction temperature.

[0122] For example, such as Figure 7 As shown, there is a relationship between the distance between the wafer 20 and the infrared light-receiving part 13 and the correction temperature. If the distance to the infrared light-receiving part 13 receiving the infrared light emitted by the wafer 20 increases, the incident angle to the infrared light-receiving part 13 changes, the amount of infrared light entering the part decreases, and the temperature error increases. Figure 7 The illustrated relationship can be obtained, for example, by collecting prior correction data on the distance and temperature error between the wafer 20 (the actual workpiece) and the incident light section. Using data obtained in this way... Figure 7 The illustrated relationship can correct the value of the surface temperature of wafer 20.

[0123] For example, the Z-position temperature correction unit 111 refers to Figure 7 Using the formula, the correction temperature corresponding to the distance (W1-W2) between the light-receiving part (end) of the infrared light-receiving part 13 and the upper surface of the wafer 20 is determined. Then, the corrected wafer surface temperature is corrected by adding the correction temperature to the actual measured surface temperature of the wafer 20.

[0124] (A-2-2-2) Ambient temperature correction treatment Figure 8 This is a graph showing the relationship between the ambient temperature and the correction temperature in the first embodiment. Figure 8 In the diagram, the horizontal axis represents ambient temperature, such as room temperature, and the vertical axis represents the corrected temperature.

[0125] For example, when inspecting the electrical characteristics of wafer 20 (semiconductor device), temperature sensor 191 measures the temperature of infrared light-receiving section 13. For example, temperature sensor 191, which measures the ambient temperature during inspection, provides temperature information to temperature measuring device 10.

[0126] In the temperature measuring device 10, the ambient temperature correction unit 112 refers to... Figure 8 The illustrated relationship between ambient temperature and correction temperature is used to correct the surface temperature of wafer 20 based on temperature information (e.g., room temperature) obtained from temperature sensor 191.

[0127] (A-2-2-3) Fiber optic temperature correction processing Figure 9 This is an explanatory diagram illustrating the fiber optic temperature correction process of the first embodiment.

[0128] like Figure 9 As shown, the temperature of the optical fiber 12 itself changes due to heat from the chuck 40 and radiant heat from the workpiece (wafer 20, etc.). Since the optical fiber 12 also emits infrared radiation, if the temperature of the optical fiber 12 changes, the amount of infrared radiation emitted from the optical fiber 12 itself changes, so the value of the surface temperature of the wafer 20 measured by the temperature measuring device 10 also produces an error.

[0129] Therefore, the fiber temperature correction unit 113 corrects the surface temperature value of the wafer 20 by referring to the relationship between the temperature of the fiber 12 and the correction temperature relative to the increase in infrared radiation emitted by the fiber 12.

[0130] Figure 10 This is a graph showing the relationship between the temperature of the optical fiber 12 in the first embodiment and the corrected temperature relative to the increase in infrared radiation of the optical fiber 12.

[0131] For example, Figure 10 The relationship shown is that the temperature of optical fiber 12 is changed, and the increase in the amount of infrared radiation emitted from optical fiber 12 is measured. Then, based on the increase in the amount of infrared radiation emitted relative to the temperature change of optical fiber 12, a temperature correction amount relative to the temperature change is derived, which is used as error data affecting the measured temperature of the actual workpiece.

[0132] In order to measure the temperature of the optical fiber 12 itself, a temperature sensor 191, such as a thermocouple, is installed at the top of the optical fiber 12 (such as the infrared light-receiving part 13).

[0133] In the temperature measuring device 10, the fiber optic temperature correction unit 113 refers to... Figure 10 The illustrated relationship between the temperature of the optical fiber 12 and the correction temperature is used to correct the surface temperature of the wafer 20 based on the temperature information obtained from the temperature sensor 191.

[0134] (A-2-2-4) Ring Temperature Correction Treatment Figure 11 This is an explanatory diagram illustrating the ring temperature correction process of the first embodiment.

[0135] like Figure 11 As shown, the probe card 14 has a through hole, through which an optical fiber 12 is inserted. The infrared light-receiving part 13 captures the infrared light emitted by the wafer 20. At this time, for the sake of easy replacement of the optical fiber 12, a flanged tubular member 171 is inserted into the through hole, and then the optical fiber 12 is inserted into the tube of the flange 171.

[0136] The temperature of the collar 171 inserted into the through hole of the probe card 14 also varies due to heat from the chuck 40 or radiant heat from the workpiece (wafer 20, etc.). When the temperature of the collar 171 itself changes, the temperature of the optical fiber 12 passing through it also changes, thus causing an error in the value of the surface temperature of the wafer 20 measured by the temperature measuring device 10.

[0137] Therefore, the ring temperature correction unit 114 corrects the surface temperature value of the wafer 20 by referring to the relationship between the temperature of the ring 171 and the correction temperature relative to the increase in infrared radiation emitted by the optical fiber 12.

[0138] Figure 12 This is a graph showing the relationship between the temperature of the collar 171 in the first embodiment and the corrected temperature relative to the increase in infrared radiation of the collar 171.

[0139] For example, Figure 12 The relationship shown is determined by measuring the increase in the amount of infrared radiation emitted from the collar 171 by changing the temperature of the collar 171. Then, based on the increase in the amount of infrared radiation emitted relative to the temperature change of the collar 171, a temperature correction amount relative to the temperature change is derived, which is used as error data affecting the measured temperature of the actual workpiece.

[0140] In order to measure the temperature of the collar 171 itself, a temperature sensor 191 such as a thermocouple is installed on the top of the collar 171.

[0141] In the temperature measuring device 10, the ring temperature correction unit 114 refers to... Figure 12 The illustrated relationship between the temperature of the collar 171 and the correction temperature is used to correct the surface temperature of the wafer 20 based on the temperature information obtained from the temperature sensor 191.

[0142] (A-2-2-5) Configuration of Temperature Sensor 191 The accompanying drawings illustrate a temperature sensor 191 mounted on an optical fiber 12 inserted into a tube connected to a collar 171.

[0143] Figure 13This is an explanatory diagram illustrating the configuration of the temperature sensor 191 provided on the optical fiber 12 and the collar 171 in the first embodiment.

[0144] When implementing the above-mentioned environmental temperature correction processing, optical fiber temperature correction processing, and ferrule temperature correction processing, such as Figure 13 As shown, a temperature sensor 191a is disposed on the lower end (one end) 1711 side of the collar 171, and a temperature sensor 191b is disposed on the upper end (one end) 1712 side of the collar 171. For example, the diameter of the collar 171 is made larger than the diameter of the optical fiber 12, and the temperature sensor 191 is bonded to the inner wall of the collar 171 with an adhesive material or the like. By disposing the temperature sensor 191 in such a position, the temperature at a location where heat can easily be transferred from the chuck 40 or the wafer 20 can be measured.

[0145] In addition, such as Figure 13 As shown, in order to measure the ambient temperature, a temperature sensor 191c is placed in the optical fiber 12 at a position away from the detector 50.

[0146] (A-3) Example Figure 14 This is a graph showing the surface temperature of the wafer 20 before and after correction using the temperature measuring device 10 of the first embodiment.

[0147] exist Figure 14 The example shows the implementation of Z-position temperature correction processing, ambient temperature correction processing, fiber optic temperature correction processing, and ferrule temperature correction processing.

[0148] The measurement conditions are to make the probe 17 electrically contact the electrode terminals of the semiconductor device on the wafer 20, and measure the surface temperature of the wafer 20 (semiconductor device) during the electrical characteristic inspection of the semiconductor device. Figure 14 The “contact” period shown is the period during which probe 17 is in contact with the electrode terminal, and the “non-contact” period is the period during which the contact between probe 17 and the electrode terminal is released.

[0149] The temperature of the chuck 40 is set to 126°C. The infrared light receiving part 13 receives infrared radiation from the wafer 20 (semiconductor device). The temperature measuring device 10 measures the surface temperature based on the amount of infrared radiation.

[0150] Furthermore, the temperature measuring device 10 performs Z-position temperature correction processing, ambient temperature correction processing, optical fiber temperature correction processing, and ring temperature correction processing.

[0151] Here, according to the above correction method, the temperature correction value for the Z-position temperature correction is "+3℃", and the temperature correction value for the ring temperature correction is "-6℃". In the ambient temperature correction and fiber optic temperature correction, the temperature 5 seconds after the start of the measurement is set to 126℃, and the temperature correction value obtained by the above method is used.

[0152] like Figure 14 As shown, during the "contact" period, when the temperature measuring device 10 measures the surface temperature of the wafer 20 twice in succession, the corrected temperature takes a lower value than the temperature before correction, which is closer to the actual temperature, and the surface temperature of the wafer 20 can be measured with higher accuracy.

[0153] (A-4) Effects of the first embodiment As described above, according to the first embodiment, when the surface temperature of a wafer having multiple inspected objects is measured non-contactly using the infrared light-receiving part 13 at the top of the optical fiber 12 and the infrared sensor 16, the main causes of possible errors can be corrected, and as a result, the surface temperature can be measured with high accuracy.

[0154] (B) Other implementation methods Various modifications have been mentioned in the first embodiment described above, but the present invention can also be applied to the following modified embodiments.

[0155] (B-1) In the first embodiment described above, the case of implementing all four correction methods was illustrated. However, even if any one of the four correction methods is implemented, the same effect as in the first embodiment can be obtained.

[0156] Alternatively, combining two or three of the four modification methods can achieve the same effect as the first embodiment.

[0157] (B-2) It can be corrected at any time based on correction values ​​using a blackbody furnace that is calibrated during the factory and periodic calibration of the inspection device. However, transmittance changes may occur due to factors such as the fit or degradation of the optical path (fiber, lens barrel, lens, etc.).

[0158] In contrast, according to this embodiment, the reference light source (i.e., blackbody + a certain temperature) needs to be checked and corrected twice in the actual use environment. A hot chuck with a blackbody set on a part of the hot chuck or a hot chuck with a blackbody set on another part can be prepared to perform a two-fold correction so that the difference in the amount of light emitted in each temperature zone is below a certain value.

[0159] (B-3) When the temperature of the optical path itself rises, it is affected by the infrared radiation generated by the optical path itself. Due to the radiant heat from the workpiece, the temperature at the tip of the optical fiber changes, and the emission of infrared radiation from the optical fiber itself increases, displaying a temperature higher than the actual workpiece temperature. According to this embodiment, it can have the following function: it can continuously correct based on the pre-obtained data of the increase in optical fiber temperature and infrared radiation, and the actual temperature of the optical fiber, so that the temperature after subtracting the influence of the optical fiber temperature from the current measured temperature is positive.

[0160] (B-4) In the device to be measured, it has the following function: by measuring the error of the chuck temperature when the temperature is applied to the most average finished wafer or the wafer used for correction for the first time using a heated chuck or the like, and the measured chuck surface temperature, it corrects the measurement error that varies due to the design of the actual workpiece, etc.

[0161] (B-5) It has the function of pre-collecting correction data for temperature errors caused by the distance between the actual workpiece and the optical fiber, monitoring this distance information at any time, and adjusting the correction amount based on the obtained distance information. Alternatively, the distance information required for the correction can be obtained from the device performing Z-positioning, or a height sensor can be placed around the temperature sensor. Symbol Explanation

[0162] 1 and 1A: Inspection device; 10: Temperature measurement and control system; 11: Connection wiring; 12: Optical fiber; 13: Infrared light receiving part; 19: Test head; 14: Probe card; 15: Probe assembly; 16: Infrared sensor; 17: Probe; 171: Chord (a tubular component with a flange); 1711: The other end of the chord; 1712: One end of the chord; 18: Electrical connection unit; 20: Wafer; 30: Blackbody; 40: Chuck; 41: Blackbody carrier. 42: Peripheral section; 50: Detector; 51: θ-axis stage; 52: Z-axis stage; 53: Y-axis stage; 54: X-axis stage; 61: Distance sensor; 62: Fiber optic cable; 100: Temperature measurement and correction section; 101: Temperature acquisition section; 102: Radiation quantity deriving section; 103: Calibration section; 104: Storage section; 104a: Reference table; 105: Temperature deriving section; 120: Temperature display section; 191 (191a~191c): Temperature sensor.

Claims

1. An inspection apparatus which makes an electrical contact with an electrode terminal of an object to be inspected formed on a wafer, makes an electrical connection between a tester and the object to be inspected via the electrical contact, and thereby inspects the object to be inspected, the inspection apparatus characterized by comprising: a wafer support section which supports the wafer; an infrared light receiving section which receives infrared light radiated from the wafer as a measurement target; and a temperature measurement control section which controls temperature measurement of the measurement target based on an amount of infrared light radiation of the infrared light received by the infrared light receiving section, wherein the temperature measurement control section has a temperature correction section which corrects a measured temperature based on the amount of infrared light radiation of the wafer.

2. The inspection apparatus according to claim 1, wherein the temperature correction section corrects a measured temperature based on a temperature change in an infrared light path from the infrared light receiving section to the temperature measurement control section.

3. The inspection apparatus according to claim 2, wherein an electrical connection unit is provided opposite the wafer and has a plurality of the electrical contacts which make an electrical contact with the electrode terminal of the object to be inspected on the wafer, and the temperature correction section corrects a measured temperature based on a temperature change in the electrical connection unit and the infrared light receiving section by the wafer support section having a temperature adjustment section.

4. The inspection apparatus according to claim 2, wherein a tubular member is inserted into a through hole provided in the electrical connection unit, and the infrared light receiving section receives infrared light radiated from the wafer by being inserted into a tube of the tubular member inserted into the through hole, and the temperature correction section corrects a measured temperature based on a temperature change in the electrical connection unit and the infrared light receiving section by the wafer support section having a temperature adjustment section.

5. The inspection apparatus according to claim 3, wherein a distance measurement section measures a distance between the wafer supported by the wafer support section and the infrared light receiving section, and the temperature correction section corrects a measured temperature based on the distance between the wafer and the infrared light receiving section with reference to a relationship between a distance and a correction temperature of an amount of infrared light radiation set in advance.

6. The inspection apparatus according to claim 3, wherein the temperature correction section corrects a measured temperature based on an ambient temperature in which an infrared sensor associated with the infrared light receiving section is placed. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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