Inspection apparatus

Abstract

To accurately measure the surface temperature of a wafer having a plurality of objects to be inspected in a non-contact state using an infrared sensor by correcting factors causing errors.SOLUTION: According to the present invention, there is provided an inspection apparatus for inspecting an object to be inspected by bringing an electrical contactor 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 contactor, the inspection apparatus including: A temperature measurement control unit that controls temperature measurement of the measurement target based on an infrared radiation amount of the infrared rays received by the infrared ray receiving unit, the temperature measurement control unit including a temperature correction unit that corrects a measured temperature based on the infrared radiation amount of the wafer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inspection device, and can be applied to, for example, a semiconductor inspection device (hereinafter also referred to as an "inspection device") that inspects the electrical characteristics of a semiconductor integrated circuit (hereinafter also referred to as a "semiconductor device") formed on a semiconductor wafer (hereinafter also simply referred to as a "wafer"). [Background technology]

[0002] During the manufacturing process of semiconductor devices formed on a wafer, it is necessary to inspect whether the electrical characteristics of the semiconductor device meet predetermined values, and a semiconductor inspection device equipped with a probe card is used for this inspection.

[0003] For example, a probe card having multiple probes is connected to a test head, and the probes are brought into contact with the terminals of the semiconductor devices on the wafer. A tester then applies test signals to each semiconductor device on the wafer via the probes, and acquires the signals in response from each semiconductor device, thereby testing the electrical characteristics of the semiconductor devices.

[0004] In recent years, there has been a demand to inspect whether the electrical characteristics of semiconductor devices meet predetermined values ​​even under specified temperature environments, and it is therefore necessary to measure the surface temperature of the wafer (semiconductor device) during inspection accurately and with precision.

[0005] BACKGROUND ART Conventionally, a temperature measuring device for measuring the surface temperature of a wafer is disclosed in Patent Document 1, which uses an infrared sensor to measure the amount of infrared radiation emitted by the wafer (see Patent Document 1).

[0006] Here, the temperature measurement device must be calibrated using the emissivity of a blackbody. Conventional methods for calibrating a temperature measurement device involve, for example, removing the temperature measurement device from the prober and calibrating it using the radiation temperature of a blackbody furnace or the like as a reference. Alternatively, for example, a wafer-shaped blackbody is placed on the chuck of the prober, and changes in the measured value of the infrared radiation amount are monitored to confirm that the measured value is within a certain range. If the measured value is outside the certain range, the accuracy is checked again using the wafer-shaped blackbody, and recalibration is performed if necessary. In this way, the temperature of the wafer is measured non-contact using an infrared sensor. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-56253 Summary of the Invention [Problem to be solved by the invention]

[0008] However, when the surface temperature of a wafer (semiconductor device) under inspection is measured using a non-contact temperature sensor, the semiconductor device generates heat when an operating current is applied to the semiconductor device, and the heat is then transferred to the electrical signal probe that contacts the terminals of the semiconductor device, making the temperature of the semiconductor device change and difficult to stabilize.

[0009] This results in a large temperature difference between the temperature applied to the surface of the wafer (semiconductor device) by the conventional method and the actual temperature of the semiconductor device.

[0010] Furthermore, the temperature measurement method using an infrared sensor is an effective means because it can measure the wafer surface temperature non-contact, quickly, and with good response. However, in order to measure with higher accuracy, the following corrections are required, but these correction methods have not yet been established.

[0011] The measurement data of the infrared sensor is transmitted to the temperature measurement system via an optical path formed by optical fibers, a lens barrel, lenses, etc., but the transmittance deteriorates depending on the fitting condition and deterioration of the optical path components.

[0012] Furthermore, if the temperature of the optical path itself rises, infrared rays will be generated from the optical path itself, and there is a risk that the optical path will be affected by the infrared rays.

[0013] Furthermore, the amount of infrared radiation from the wafer changes depending on the color, roughness, and other conditions of the surface of the wafer being measured.

[0014] Furthermore, the amount of incident light changes due to a change in the incident angle caused by a change in the distance from the light incident surface (fiber tip, etc.) of the optical fiber to the workpiece.

[0015] In order to solve the above-mentioned problems, the present invention aims to provide an inspection device that can correct factors that may cause errors when measuring the surface temperature of a wafer having multiple test objects in a non-contact manner using an infrared sensor, and can perform measurements with high accuracy. [Means for solving the problem]

[0016] In order to solve such problems, the present invention provides an inspection device that inspects an object under test by bringing electrical contactors into contact with electrode terminals of the object under test formed on a wafer and electrically connecting a tester and the object under test via the electrical contactors, the inspection device comprising: a wafer support section that supports the wafer; an infrared receiving section that receives infrared rays emitted by at least the wafer as the measurement object; and a temperature measurement control section that controls temperature measurement of the object under test based on the infrared radiation amount of the infrared rays received by the infrared receiving section, wherein the temperature measurement control section has a temperature correction section that corrects the measured temperature based on the infrared radiation amount of the wafer. [Effects of the Invention]

[0017] According to the present invention, when measuring the surface temperature of a wafer having a plurality of test objects in a non-contact manner using an infrared sensor, factors that may cause errors can be corrected, and measurements can be made with high accuracy. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is an overall configuration diagram showing the overall configuration of an inspection device according to a first embodiment. [Figure 2] 1 is a plan view showing a configuration of a chuck according to a first embodiment in a plan view. [Figure 3] 5 is a flowchart (part 1) showing the operation of the calibration process of the temperature measuring device of the inspection apparatus according to the first embodiment. [Figure 4] FIG. 3 is an explanatory diagram illustrating the movement of the position of a black body in the first embodiment. [Figure 5] 10 is a flowchart (part 2) showing the operation of the calibration process of the temperature measuring device of the inspection apparatus according to the first embodiment. [Figure 6] FIG. 2 is an explanatory diagram illustrating distance measurement by a distance sensor according to the first embodiment. [Figure 7] FIG. 4 is a diagram showing the relationship between the distance between the wafer and the infrared receiving unit and the corrected temperature in the first embodiment. [Figure 8] FIG. 4 is a diagram showing the relationship between the environmental temperature and the correction temperature in the first embodiment. [Figure 9] FIG. 4 is an explanatory diagram illustrating a fiber temperature correction process according to the first embodiment. [Figure 10] FIG. 4 is a diagram showing the relationship between the temperature of the optical fiber according to the first embodiment and the correction temperature for the amount of infrared radiation increase of the optical fiber. [Figure 11] FIG. 4 is an explanatory diagram illustrating a ferrule temperature correction process according to the first embodiment. [Figure 12] FIG. 4 is a diagram showing the relationship between the temperature of the ferrule according to the first embodiment and the correction temperature for the infrared increase amount of the ferrule. [Figure 13] 3 is an explanatory diagram illustrating the arrangement of temperature sensors provided on the optical fiber and the ferrule in the first embodiment. FIG. [Figure 14] 5 is a diagram showing the surface temperatures of a wafer before and after correction by the temperature measuring device according to the first embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] (A) First embodiment A first embodiment of an inspection device according to the present invention will be described in detail below with reference to the drawings.

[0020] In the drawings relating to the embodiments, the same reference numerals are used to denote equivalent parts. However, it should be noted that the drawings are schematic, and the thickness ratios of the components may differ from those in reality. Furthermore, the drawings may include parts with different dimensional relationships and ratios. The embodiments are intended to exemplify devices and methods for embodying the technical ideas of the present invention, and are not intended to limit the materials, shapes, structures, arrangements, etc. of the components to those described in the embodiments.

[0021] (A-1) Configuration of the First Embodiment (A-1-1) Overall composition FIG. 1 is a diagram showing the overall configuration of an inspection device according to the first embodiment.

[0022] In FIG. 1, the inspection device 1 according to the first embodiment includes a temperature measuring device 10, a prober 50, and a test head 19.

[0023] Also, in Figure 1, the prober 50 has a chuck 40 on which the wafer 20 is placed and which has a temperature adjustment function that can adjust the temperature of the wafer 20 to a high or 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 movement drive mechanisms.

[0024] The inspection device 1 inspects the electrical characteristics of each semiconductor device (hereinafter also referred to as "device under test") formed on a wafer 20. In the inspection device 1, a probe card 14 is electrically connected to a second surface (e.g., the bottom surface) of a test head 19 via an electrical connection unit 18. During inspection, each probe 17 of the probe card 14 is brought into electrical contact with an electrode terminal of the semiconductor device. Then, the inspection device 1 applies an electrical signal from a tester to each semiconductor device on the wafer 20 via the probe, acquires a signal in response from each semiconductor device, and responds to the tester. In this way, the tester inspects the characteristics of the semiconductor device.

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

[0026] The electrical connection unit 18 is a mounting unit that mounts the probe card 14 on the test head 19 and electrically connects the test head 19 and the probe card 14 .

[0027] The probe card 14 brings probes 17 into contact with electrode terminals of semiconductor devices formed on the wafer 20, applies electrical signals to the semiconductor devices via the probes 17, and receives response signals from the semiconductor devices via the probes 17. The probe card 14 is an example of an electrical connection device that electrically connects the tester main body and the semiconductor devices on the wafer 20. The probe card 14 has a probe assembly 15 having a plurality of probes 17 provided on the second surface (e.g., the lower surface) side.

[0028] The probe assembly 15 is an assembly including a plurality of probes 17, and is provided on the second surface side of the probe card .

[0029] The probe 17 is an electrical contactor that electrically contacts an electrode terminal of a semiconductor device. The type of the probe 17 is not particularly limited, and it can be, for example, a cantilever type probe or a vertical type probe.

[0030] In this embodiment, the probe 17 is an electrical contactor that electrically contacts the electrode terminal of the semiconductor device. However, if the semiconductor device is an optical semiconductor, the probe 17 may include, in addition to the electrical contactor, an optical probe (e.g., an optical fiber) that transmits and receives optical signals between the probe 17 and the optical input / output section of the optical semiconductor.

[0031] The chuck 40 fixes the wafer 20 to the upper surface of the chuck 40 (also called the "chuck top" or "chuck stage") and moves in the X, Y, Z, and θ axes. The chuck 40 also has a temperature adjustment function, and adjusts the temperature of the wafer 20 fixed to the upper surface. Furthermore, the chuck 40 has one or more black bodies 30 provided on the upper surface of the chuck 40. The method of installing the black bodies 30 will be described later.

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

[0033] The temperature measuring device 10 is connected to an optical fiber 12 which is connected to an infrared receiving unit 13. The infrared receiving unit 13 receives infrared rays emitted by an object whose temperature is to be measured (hereinafter also simply referred to as the "object to be measured"), and the temperature measuring device 10 acquires the infrared rays emitted by the object to be measured through the optical fiber 12. The temperature measuring device 10 converts the amount of infrared radiation input from the infrared receiving unit 13 into temperature and measures the surface temperature of the object to be measured. This makes it possible to measure the surface temperature of the object to be measured without contact.

[0034] Furthermore, the temperature measuring device 10 measures the surface temperature of the black body 30 placed on the first surface (for example, the upper surface) of the chuck 40 periodically or as needed, and corrects the temperature measured by the temperature measuring device 10.

[0035] Furthermore, the temperature measuring device 10 is connected to a distance sensor 61 through an optical fiber 62. The temperature measuring device 10 acquires 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 the temperature measuring device 10 In FIG. 1, the temperature measuring device 10 roughly comprises an infrared sensor 16, a measurement temperature calibration 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, an input / output interface unit, etc. The temperature measuring device 10 may be configured to perform temperature measurement processing as hardware. Alternatively, the temperature measuring device 10 may have application software (e.g., a temperature measurement program) installed in the ROM, and the CPU may execute the software to realize the functions of the temperature measuring device 10. In either case, the functions of the temperature measuring device 10 can be expressed by the functional blocks exemplified in FIG. 1.

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

[0039] The radiation amount deriving section 102 collects infrared rays from the object to be measured that are received by the infrared receiving section 13 via the optical fiber 12, and derives the amount of infrared radiation emitted by the object to be measured.

[0040] The temperature derivation unit 105 derives the temperature based on the amount of infrared radiation of the object to be measured derived by the radiation amount derivation unit 102. Here, an existing method can be applied as the temperature derivation method, and the temperature is converted from the amount of infrared radiation based on the relationship between the amount of infrared radiation and temperature (for example, Planck's radiation law). In this way, the temperature can be found based on the amount of infrared radiation.

[0041] [Measuring temperature calibration section 100] The measurement temperature calibration unit 100 calibrates the temperature value of the wafer 20 (semiconductor device) measured by the temperature measurement device 10 periodically or during inspection. By calibrating the temperature value of the infrared sensor 16 periodically or during inspection, the temperature can be measured with high accuracy. Furthermore, as will be described later, the temperature value of the wafer 20 (semiconductor device) can be calibrated using a non-contact sensor such as the infrared sensor 16, so calibration can be performed non-contact, quickly, and with good responsiveness.

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

[0043] The storage unit 104 stores a reference table 104a that indicates the relationship between the temperature of the blackbody 30 (to be described later) and the amount of infrared radiation (hereinafter simply referred to as "amount of radiation"). The storage unit 104 also stores a processing program, data required for processing, and the like.

[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 creates a correction table based on the relationship between the radiation amount and temperature of the blackbody 30, and uses the correction table to correct the measurement values ​​due to changes over time in the infrared sensor 16, correct the temperature measuring device 10, detect abnormalities, etc.

[0046] [Temperature correction section 110] The temperature correction unit 110 performs temperature correction of factors (correction factors) that may cause errors when the surface temperature of the wafer 20 (semiconductor device) is measured using the infrared sensor 16.

[0047] The temperature correction unit 110 includes a Z-position temperature correction unit 111 , an environmental temperature correction unit 112 , a fiber temperature correction unit 113 , and a ferrule temperature correction unit 114 .

[0048] The temperature correction unit 110 may be a combination of any of the processing units among the Z position temperature correction unit 111, the environmental temperature correction unit 112, the fiber temperature correction unit 113, and the ferrule temperature correction unit 114, but here we will show an example in which it has all of these processing units.

[0049] The Z position temperature correction unit 111 corrects the temperature according to the distance (i.e., length in the Z axis direction; height) between the infrared receiving unit 13 located at the tip of the optical fiber 12 and the object to be measured (e.g., wafer 20).

[0050] For example, if the distance between the infrared receiving unit 13 and the wafer 20 is short, the amount of infrared light entering the infrared receiving unit 13 will be large, and conversely, if the distance is long, the amount of infrared light entering the infrared receiving unit 13 will be small. Therefore, using the relationship between the distance between the infrared receiving unit 13 and the wafer 20 and the temperature correction value, the temperature is corrected with a correction value according to the actual distance.

[0051] The environmental temperature correction unit 112 corrects the temperature in accordance with changes in the environmental temperature (for example, room temperature) where the infrared sensor 16 is placed.

[0052] For example, infrared sensor 16 uses a preamplifier (amplifier) ​​that amplifies the intensity of infrared light emitted by the object to be measured, but the measured temperature value can change depending on changes in the environmental temperature (room temperature) where the preamplifier of infrared sensor 16 is placed. Therefore, temperature correction is performed in response to changes in room temperature using the relationship between the temperature of the environment where the preamplifier of infrared sensor 16 is placed and the temperature correction value.

[0053] The fiber temperature correction unit 113 corrects the temperature in accordance with the temperature change of the optical fiber itself due to heat transferred from the chuck 40 having a temperature adjustment function.

[0054] For example, the temperature of the optical fiber connected to the infrared sensor 16 increases due to heat transfer from the chuck 40. Furthermore, the probe assembly 15 also receives heat from the chuck 40, and since the probe 17 also has heat, heat is transferred through the probe 17, causing the probe assembly 15 itself to have heat, and the temperature of the optical fiber itself changes. Therefore, the fiber temperature correction unit 113 corrects the surface temperature of the wafer 20 in accordance with the temperature change of the optical fiber itself.

[0055] In this case, to measure the temperature of the optical fiber itself, for example, a temperature sensor 191 such as a thermocouple is attached to the optical fiber of interest, and the temperature sensor 191 measures the temperature of the optical fiber itself and provides the temperature information to the temperature measuring device 10. The fiber temperature correction unit 113 corrects the value of the surface temperature of the wafer 20 using the temperature information sensed by the temperature sensor 191.

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

[0057] For example, when inserting the optical fiber 12 into a through-hole provided in the probe card 14, a ferrule, which is a tubular member with a flange, is inserted into the through-hole and the optical fiber 12 is inserted into the tube of the ferrule to make it easier to replace the optical fiber 12. During inspection, the temperature of the ferrule itself also changes, so the ferrule temperature correction unit 114 corrects the surface temperature of the wafer 20 in accordance with the temperature change of the ferrule itself.

[0058] Here, a case where all four correction methods are performed will be described, but any of the four correction methods may be combined.

[0059] [Temperature display section 120] The temperature display unit 120 displays the temperature derived by the infrared sensor 16, the temperature calibrated by the measurement temperature calibration 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 a liquid crystal display.

[0060] (A-1-3) Detailed configuration of chuck 40 FIG. 2 is a plan view showing the configuration of the chuck 40 according to the first embodiment.

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

[0062] A black body 30, which has a clear relationship between temperature and amount of infrared radiation, is disposed on the peripheral edge 42 of the wafer mounting surface of the chuck 40.

[0063] 2 shows a case where a total of five black bodies 30 are provided, including four black bodies 30 on the peripheral portion 42 of the wafer mounting surface of the chuck 40 and one black body 30 on a black body mounting portion 41 provided on the peripheral portion 42. The four black bodies 30 are arranged at equal intervals on the peripheral portion 42 of the chuck 40.

[0064] The number of black bodies 30 to be arranged is not limited to this, and one black body 30 may be arranged on the chuck 40, or two or more black bodies 30 may be arranged. The arrangement of the black bodies 30 is not particularly limited as long as the black bodies 30 can be moved to the position of the infrared receiving unit 13 when calibrating the temperature measuring device 10.

[0065] The black body 30 is a thermal radiator whose temperature and infrared radiation amount are known in advance. For example, various types of black body 30 can be used, such as a black body in the form of a sticker (black body sticker) or a black body coated with black body paint.

[0066] When the measurement accuracy of the temperature measuring device 10 is checked, an abnormality in the measurement accuracy occurs, or an abnormality in the measurement of the infrared sensor 16 occurs, the amount of infrared radiation emitted by the black body 30 is converted into temperature, and a correction table is created using the result.The correction table is then used to correct the temperature signal output value of the temperature measuring device 10.

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

[0068] Since the black body 30 is placed on the wafer placement surface of the chuck 40, the black body 30 can be moved to the position of the infrared receiving part 13 for measurement even during inspection, and the temperature signal output value of the temperature measuring device 10 can be calibrated without replacing the wafer 20.

[0069] It should be noted that the black body 30 does not need to be an ideal, completely black body, and anything that can be considered a black body can be applied. For example, instead of disposing the black body 30, a part of the upper surface (chuck top) of the chuck 40 or the entire upper surface of the chuck 40 may be black body color.

[0070] (A-2) Operation of the First Embodiment Next, the processing operation of measuring the temperature of the wafer 20 (semiconductor device) in the inspection device 1 of the first embodiment will be described with reference to the drawings.

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

[0072] (A-2-1-1) First calibration process FIG. 3 is a flowchart (part 1) showing the operation of the calibration process of the temperature measuring device 10 of the inspection device 1 according to the first embodiment.

[0073] Here, an example of periodic calibration of the temperature measuring device 10 as a non-contact thermometer of an optical fiber type will be described. Note that the order of the calibration process is not limited to that shown in FIG.

[0074] [Step S101] First, the θ-axis stage 51, Z-axis stage 52, Y-axis stage 53, and X-axis stage 54 serving as a movement drive mechanism are driven, and as illustrated in FIG. 4, the movement drive mechanism moves the peripheral area of ​​the wafer mounting surface of the chuck 40 and the black body 30 placed near the periphery to the position of the infrared receiving unit 13 (step S101).

[0075] [Step S102] Next, the temperature of the chuck 40 is set to a 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] When the temperature of the chuck 40 reaches the set temperature, the infrared light receiving unit 13 receives the infrared light emitted by the black body 30 and transmits the infrared light to the infrared sensor 16 via the optical fiber 12. In the temperature measuring device 10, the radiation amount derivation unit 102 derives the infrared radiation amount of the black body 30 based on the infrared light (signal) from the infrared light receiving unit 13 (step S103).

[0077] [Step S104] In the temperature measuring device 10, the temperature derivation unit 105 derives the temperature based on the amount of infrared radiation of a black body according to Planck's law of radiation (step S104).

[0078] [Step S105] Next, it is determined whether measurements have been completed at all temperatures required for the measurements (for example, -40°C, 25°C, and 125°C) (step S105).

[0079] If the measurement has been completed (step S105 / YES), the process proceeds to step S106, and if the measurement has not been completed (step S105 / NO), the process returns to step S102, where the set temperature of the chuck 40 is changed and the process continues.

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

[0081] For example, if a pre-existing relationship table is prepared 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 pre-existing 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 movement drive mechanism periodically moves the black body 30 on the chuck 40 to the position of the infrared receiving unit 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 receiving unit 13 receives the infrared rays emitted by the blackbody 30 and provides the infrared rays to the temperature measuring device 10 via the infrared sensor 16. In the temperature measuring device 10, the radiation amount deriving unit 102 derives the infrared radiation amount of the blackbody 30 based on the infrared rays from the infrared receiving unit 13 (step S109).

[0086] [Step S110] In the temperature measuring device 10, the temperature derivation unit 105 derives the temperature based on the amount of infrared radiation of a black body according to Planck's law of radiation (step S110).

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

[0088] For example, the comparison result is displayed on a display unit such as a liquid crystal display, etc. This allows the operator to determine whether or not there is an abnormality in the measurement value of the infrared sensor 16.

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

[0090] Here, an example will be described of calibrating a value obtained by converting the amount of infrared radiation corresponding to the surface temperature of a semiconductor device on a wafer during inspection using the infrared sensor 16. Note that the order of the calibration process is not limited to that shown in FIG.

[0091] The second calibration method is intended to perform calibration without removing the wafer 20 to be measured from the chuck 40.

[0092] For example, when the electrical characteristics of the semiconductor devices on a certain wafer 20 are being inspected, the calibration process is performed without replacing the wafer 20 and without removing the temperature measuring device 10 from the prober 50. Also, for example, after the inspection of a certain wafer 20 is completed and before the next wafer 20 is placed on the chuck 40, calibration using the amount of infrared radiation of the blackbody 30 may be performed.

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

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

[0095] [Step S203] The movement drive mechanism drives the θ-axis stage 51, Z-axis stage 52, Y-axis stage 53, and X-axis stage 54 to move the black body 30 on the chuck 40 to the position of the infrared receiving unit 13 (step S203).

[0096] [Step S204] The infrared receiving unit 13 receives the infrared rays emitted by the black body 30 and provides the infrared rays to the temperature measuring device 10. In the temperature measuring device 10, the radiation amount deriving unit 102 derives the amount of infrared radiation of the black body 30 based on the infrared rays from the infrared receiving unit 13 (step S204).

[0097] [Step S205] In the temperature measuring device 10, the temperature derivation unit 105 derives the temperature based on the amount of infrared radiation from the black body 30 according to Planck's law of radiation (step S205).

[0098] [Step S206] Next, a certain semiconductor device formed on the reference wafer is set as a reference device, and the reference device is moved to the position of the infrared receiving unit 13 (step S206). The reference device is set as an arbitrary device (semiconductor device) on the reference wafer.

[0099] [Step S207] The infrared receiving unit 13 receives the infrared rays emitted by the reference device and provides the infrared rays to the temperature measuring device 10. In the temperature measuring device 10, the radiation amount derivation unit 102 derives the amount of infrared radiation from the reference device based on the infrared rays from the infrared receiving unit 13 (step S207).

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

[0101] [Step S209] Next, it is determined whether measurements have been completed at all temperatures required for the measurements (for example, -40°C, 25°C, and 125°C) (step S209).

[0102] If the measurement has been completed (step S209 / YES), the process proceeds to step S210, and if the measurement has not been completed (step S209 / NO), the process returns to step S202, where 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 amount of infrared radiation and the derived temperature of the blackbody 30 with the relationship between the amount of infrared radiation and the derived temperature of the reference device to create a correction table (hereinafter also referred to as a "second correction table").

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

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

[0106] [Step S213] Periodically, as shown in FIG. 4, the movement drive mechanism moves the black body 30 on the chuck 40 to the position of the infrared receiving unit 13 (step S213).

[0107] For example, calibration is performed using the radiation amount of the blackbody 30 on the chuck 40 during exchange from one wafer 20 to the next, or during transition from testing one semiconductor device on one wafer 20 to testing the next.

[0108] [Step S214] The infrared receiving unit 13 receives the infrared rays emitted by the black body 30 and provides the infrared rays to the temperature measuring device 10. In the temperature measuring device 10, the radiation amount deriving unit 102 derives the amount of infrared radiation of the black body 30 based on the infrared rays from the infrared sensor 16 (step S214).

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

[0110] [Step S216] The calibration unit 103 detects and corrects changes over time in the infrared sensor and changes in the infrared radiation amount of the wafer using the correction table created in S210 and the infrared radiation amount and temperature of the blackbody 30 derived in S211 to S215 (step S216).

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

[0112] (A-2-2-1) Z position temperature correction processing FIG. 6 is an explanatory diagram illustrating distance measurement by the distance sensor 61 according to the first embodiment.

[0113] For example, in FIG. 6, during inspection, the infrared receiving unit 13 is positioned opposite the semiconductor device on the wafer 20, and the position of the light incident portion of the infrared receiving unit 13 serves as the reference for measuring the amount of infrared radiation.

[0114] It is assumed that the positions of the light entrance (end) of the infrared receiving unit 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 entrance of the infrared receiving unit 13 is "W2".

[0115] Furthermore, when the distance sensor 61 targets the upper surface of the wafer 20, the distance between the end of the distance sensor 61 and the upper surface of the wafer 20 (distance in the Z-axis direction; height) is defined as "W1."

[0116] The distance sensor 61 transmits light toward the upper surface of the wafer 20 as an object, receives the reflected light, and provides information about the distance to the upper surface of the wafer 20 to the Z position temperature correction unit 111 of the temperature measurement device 10.

[0117] The Z-position temperature correction unit 111 obtains the distance between the light entrance portion (edge) of the infrared receiving unit 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 entrance portion (edge) of the infrared receiving portion 13 and the upper surface of the wafer 20 by the Z position temperature correction portion 111 will be described.

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

[0120] The Z position temperature correction unit 111 refers to the relationship between the distance from the wafer 20 and the correction temperature that has been set in advance, and determines the correction temperature corresponding to the distance (W1-W2) between the light entrance part (end) of the infrared receiving unit 13 and the top surface of the wafer 20.

[0121] 7 is a diagram showing the relationship between the distance between the wafer 20 and the infrared receiving unit 13 and the corrected temperature in the first embodiment. In Fig. 7, the horizontal axis represents the distance between the wafer 20 and the infrared receiving unit 13, and the vertical axis represents the corrected temperature.

[0122] For example, as shown in FIG. 7, there is a relationship between the distance between the wafer 20 and the infrared receiving unit 13 and the corrected temperature. As the distance between the infrared light emitted by the wafer 20 and the infrared receiving unit 13 and the incident light increases, the angle of incidence to the infrared receiving unit 13 changes, the amount of infrared light incident decreases, and the temperature error increases. The relationship shown in FIG. 7 can be obtained, for example, by collecting in advance the distance between the wafer 20, which is an actual workpiece, and the incident unit, and correction data for the temperature error. The surface temperature value of the wafer 20 can be corrected using the relationship shown in FIG. 7 obtained in this manner.

[0123] 7, the Z-position temperature correction unit 111 obtains a correction temperature corresponding to the distance (W1-W2) between the light entrance portion (edge) of the infrared receiving unit 13 and the upper surface of the wafer 20. Then, the correction temperature is added to the actual measured surface temperature of the wafer 20, thereby correcting the corrected wafer surface temperature.

[0124] (A-2-2-2) Environmental temperature correction processing Fig. 8 is a diagram showing the relationship between the environmental temperature and the correction temperature according to the first embodiment. In Fig. 8, the horizontal axis represents the environmental temperature, such as room temperature, and the vertical axis represents the correction temperature.

[0125] For example, when inspecting the electrical characteristics of a wafer 20 (semiconductor device), the temperature sensor 191 measures the temperature at which the infrared receiving unit 13 is placed. For example, the temperature sensor 191 measures the environmental temperature during inspection and provides the temperature information to the temperature measuring device 10.

[0126] In the temperature measuring device 10, the environmental temperature correction unit 112 corrects the surface temperature of the wafer 20 according to the temperature information (e.g., room temperature) acquired from the temperature sensor 191, by referring to the relationship between the environmental temperature and the correction temperature illustrated in FIG. 8.

[0127] (A-2-2-3) Fiber temperature compensation processing FIG. 9 is an explanatory diagram illustrating the fiber temperature correction process according to the first embodiment.

[0128] 9, the temperature of the optical fiber 12 itself changes due to heat from the chuck 40 and radiant heat from the workpiece (such as the wafer 20). Since the optical fiber 12 itself also emits infrared rays, when the temperature of the optical fiber 12 itself changes, the amount of infrared radiation from the optical fiber 12 itself also changes, and an error also occurs in the value of the surface temperature of the wafer 20 measured by the temperature measuring device 10.

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

[0130] FIG. 10 is a diagram showing the relationship between the temperature of the optical fiber 12 according to the first embodiment and the correction temperature for the infrared gain of the optical fiber 12. In FIG.

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

[0132] Here, in order to measure the temperature of the optical fiber 12 itself, a temperature sensor 191 such as a thermocouple is provided at the tip of the optical fiber 12 (infrared receiving section 13, etc.).

[0133] In the temperature measuring device 10, the fiber temperature correction unit 113 corrects the surface temperature of the wafer 20 according to the temperature information acquired from the temperature sensor 191, by referring to the relationship between the temperature of the optical fiber 12 and the correction temperature illustrated in FIG. 10.

[0134] (A-2-2-4) Ferrule temperature correction processing FIG. 11 is an explanatory diagram illustrating the ferrule temperature correction process according to the first embodiment.

[0135] 11, the probe card 14 has a through-hole, and an optical fiber 12 is inserted into the through-hole, and an infrared receiver 13 captures infrared rays emitted from the wafer 20. At this time, for reasons such as making it easier to replace the optical fiber 12, a ferrule 171 is inserted into the through-hole as a tubular member with a flange, and then the optical fiber 12 is inserted into the tube of the ferrule 171.

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

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

[0138] FIG. 12 is a diagram showing the relationship between the temperature of the ferrule 171 according to the first embodiment and the correction temperature for the infrared increase amount of the ferrule 171. In FIG.

[0139] 12, for example, the temperature of the ferrule 171 is changed and the increase in the amount of infrared radiation emitted from the ferrule 171 is measured. Then, based on the increase in the amount of infrared radiation relative to the temperature change of the ferrule 171, a temperature correction amount relative to the temperature change is derived, and this is used as error data that affects the measured temperature of the actual workpiece.

[0140] Here, in order to measure the temperature of the ferrule 171 itself, a temperature sensor 191 such as a thermocouple is provided at the tip of the ferrule 171 .

[0141] In the temperature measuring device 10, the ferrule temperature correction unit 114 corrects the surface temperature of the wafer 20 according to the temperature information acquired from the temperature sensor 191, by referring to the relationship between the temperature of the ferrule 171 and the correction temperature illustrated in FIG.

[0142] (A-2-2-5) Arrangement of temperature sensor 191 The temperature sensor 191 provided on the optical fiber 12 inserted into the tube of the ferrule 171 will be described with reference to the drawings.

[0143] FIG. 13 is an explanatory diagram illustrating the arrangement of the temperature sensor 191 provided on the optical fiber 12 and the ferrule 171 in the first embodiment.

[0144] 13, when the above-described environment temperature correction process, fiber temperature correction process, and ferrule temperature correction process are performed, a temperature sensor 191a is arranged on the lower end (other end) 1711 side of the ferrule 171, and a temperature sensor 191b is arranged on the upper end (one end) 1712 side of the ferrule 171. For example, the diameter of the ferrule 171 is made larger than the diameter of the optical fiber 12, and the temperature sensor 191 is adhered to the inner wall of the ferrule 171 with an adhesive or the like. By arranging the temperature sensor 191 in such a position, it is possible to measure the temperature of a position where heat is easily transferred from the chuck 40 or the wafer 20.

[0145] 13, a temperature sensor 191c is disposed on the optical fiber 12 at a position away from the prober 50 in order to measure the environmental temperature.

[0146] (A-3) Example FIG. 14 is a diagram showing the surface temperature of the wafer 20 before and after correction by the temperature measuring device 10 according to the first embodiment.

[0147] The example of FIG. 14 shows a case where Z position temperature correction processing, environmental temperature correction processing, fiber temperature correction processing, and ferrule temperature correction processing are performed.

[0148] The measurement conditions were that the probes 17 were brought into electrical contact with the electrode terminals of the semiconductor device on the wafer 20, and the surface temperature of the wafer 20 (semiconductor device) was measured during an electrical characteristic test of the semiconductor device. The "contact" period shown in Figure 14 is the period during which the probes 17 are in contact with the electrode terminals, and the "uncontact" period is the period during which the probes 17 are released from contact with the electrode terminals.

[0149] The temperature of the chuck 40 was set to 126° C., the infrared receiving section 13 received infrared rays emitted from the wafer 20 (semiconductor device), and the temperature measuring device 10 measured the surface temperature based on the amount of infrared radiation.

[0150] Furthermore, the temperature measuring device 10 performed Z position temperature correction processing, environmental temperature correction processing, fiber temperature correction processing, and ferrule temperature correction processing.

[0151] Here, according to the correction method described above, the temperature correction value in the Z position temperature correction process was set to "+3°C," and the temperature correction value in the ferrule temperature correction process was set to "-6°C." In the environmental temperature correction process and fiber temperature correction process, the temperature 5 seconds after the start of measurement was set to 126°C, and the temperature correction values ​​obtained by the method described above were used.

[0152] As shown in FIG. 14, when the temperature measuring device 10 measures the surface temperature of the wafer 20 twice consecutively during the "contact" period, the corrected temperature is lower than the uncorrected temperature and is closer to the actual temperature, allowing the surface temperature of the wafer 20 to be measured more accurately.

[0153] (A-4) Effects of the First Embodiment As described above, according to the first embodiment, when measuring the surface temperature of a wafer having a plurality of test objects in a non-contact manner using the infrared receiving unit 13 at the tip of the optical fiber 12 and the infrared sensor 16, it is possible to correct factors that may cause errors, and as a result, it is possible to measure the surface temperature with high accuracy.

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

[0155] (B-1) In the first embodiment described above, an example was given in which all four correction methods were implemented, but even if any one of the four correction methods is implemented, the same effect as in the first embodiment can be obtained.

[0156] Alternatively, the same effect as in the first embodiment can be obtained by combining two or three of the four correction methods.

[0157] (B-2) Corrections can be made at any time based on the correction values ​​obtained from the calibration data obtained using a blackbody furnace during shipment of the inspection equipment and regular calibration. However, the transmittance may change due to the fitting condition or deterioration of the optical path (fiber, lens barrel, lens, etc.).

[0158] In contrast, according to this embodiment, inspection and secondary correction are required using a reference light-emitting body (i.e., a black body + constant temperature) in the actual usage environment, and a function can be provided to perform secondary calibration by providing a black body as part of the heat chuck or a thermo chuck with a separate black body, so that the difference in the amount of light emitted in each temperature range is kept below a certain level.

[0159] (B-3) When the temperature of the optical path itself rises, it is affected by infrared rays generated from the optical path itself, and when the temperature of the fiber tip changes due to radiant heat from the workpiece, the infrared light emitted from the fiber itself increases, and a temperature higher than the actual workpiece temperature is displayed. According to this embodiment, it is possible to have a function to make corrections as needed, based on the previously obtained data on the fiber temperature and the increase in infrared light, and the actual fiber temperature, so that the temperature obtained by subtracting the temperature effect of the fiber from the currently measured temperature is made positive.

[0160] (B-4) When the wafer with the most average finish among the devices to be measured or the wafer used for the initial correction is heated using a thermo chuck or the like, the error between the chuck temperature and the measured chuck surface temperature is measured, and a function can be provided to correct the measurement error, which differs depending on the design of the actual workpiece, etc.

[0161] (B-5) The system is equipped with a function to collect correction data for temperature errors due to the distance between the actual workpiece and the fiber in advance, monitor this distance information as needed, and adjust the amount of correction based on the obtained distance information. The distance information required for this correction can be obtained from the device that performs Z positioning, or by installing a height sensor around the temperature sensor. [Explanation of symbols]

[0162] 1 and 1A: inspection device, 10: temperature measurement control system, 11: connection wiring, 12: optical fiber, 13: infrared receiving unit, 19: test head, 14: probe card, 15: probe assembly, 16: infrared sensor, 17: probe, 171: ferrule (tubular member with flange), 1711: other end of ferrule, 1712: one end of ferrule, 18: electrical connection unit, 20: wafer, 30: black body, 40: cha rack, 41: blackbody mounting portion, 42: peripheral portion, 50: prober, 51: θ-axis stage, 52: Z-axis stage, 53: Y-axis stage, 54: X-axis stage, 61: distance sensor, 62: optical fiber, 100: measurement temperature calibration portion, 101: temperature acquisition portion, 102: radiation amount derivation portion, 103: calibration portion, 104: memory portion, 104a: reference table, 105: temperature derivation portion, 120: temperature display portion, 191 (191a to 191c): temperature sensor.

Claims

1. 1. An inspection apparatus for inspecting an object to be inspected by bringing electrical contacts into contact with electrode terminals of the object to be inspected formed on a wafer and electrically connecting a tester and the object to be inspected via the electrical contacts, a wafer support that supports the wafer; an infrared receiving unit that receives infrared rays emitted from at least the wafer as a measurement object; a temperature measurement control unit that controls temperature measurement of the measurement object based on the amount of infrared radiation of the infrared rays received by the infrared receiving unit; Equipped with The temperature measurement control unit has a temperature correction unit that corrects the measured temperature based on the amount of infrared radiation from the wafer. An inspection device characterized by:

2. 2. The inspection device according to claim 1, wherein the temperature correction unit corrects the measured temperature in accordance with a change in temperature of the infrared light path from the infrared receiving unit to the temperature measurement control unit.

3. an electrical connection means provided opposite to the wafer and having a plurality of the electrical contacts for electrically contacting the electrode terminals of the device under test on the wafer; The temperature correction unit corrects the measured temperature in accordance with temperature changes of the electrical connection means and the infrared receiving unit by the wafer support unit having a temperature adjustment unit.

3. The inspection device according to claim 2.

4. a tubular member is inserted into a through hole provided in the electrical connection means, and the infrared receiving unit is inserted into a tube of the tubular member inserted into the through hole to receive infrared rays emitted from the wafer, The temperature correction unit corrects the measured temperature in accordance with temperature changes of the electrical connection means and the infrared receiving unit by the wafer support unit having a temperature adjustment unit.

3. The inspection device according to claim 2.

5. a distance measuring unit that measures the distance between the wafer supported by the wafer support unit and the infrared receiving unit, The temperature correction unit corrects the measured temperature according to the distance between the wafer and the infrared receiving unit, by referring to a preset relationship between the distance of the infrared radiation amount and the correction temperature.

4. The inspection device according to claim 3.

6. The temperature correction unit corrects the measured temperature in accordance with the environmental temperature where the infrared sensor associated with the infrared receiving unit is placed.

4. The inspection device according to claim 3.

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