Inspection method, inspection device, and program

Abstract

To provide a technique that allows a probe to accurately contact an electrode formed on an object to be inspected.SOLUTION: An inspection method performed by an inspection device including a mounting table on which an object to be inspected is placed, and a probe card provided with a probe used for inspecting the object to be inspected includes steps of: bringing the probe into contact with an electrode on the basis of a first offset value; setting a second offset value on the basis of a needle mark area formed by bringing the probe into contact with the electrode on the basis of the first offset value; and bringing the probe into contact with the electrode on the basis of the second offset value.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to an inspection method, an inspection apparatus, and a program.

Background Art

[0002] In a semiconductor manufacturing process, an inspection apparatus (prober) is used to bring a probe into contact with an electrode (pad) included in a wiring pattern formed on a semiconductor wafer and inspect the electrical characteristics of the wiring pattern by a tester. During probing, correction is made to the position where the probe contacts on the pad.

[0003] For example, the prober disclosed in Patent Document 1 compares a post-contact image including the pad after the probe has contacted with a pre-contact image including the pad before the probe contacts, obtains the position of the latest pin mark region among a plurality of pin mark regions in the post-contact image due to the contact of the probe with the electrode, and obtains the amount of deviation of the contact position of the probe with respect to the pad based on the position of the latest pin mark region.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides a technique capable of accurately bringing a probe into contact with an electrode formed on a test object.

Means for Solving the Problems

[0006] According to one aspect of the present disclosure, an inspection method is provided for an inspection apparatus comprising a mounting table on which an object to be inspected is placed, and a probe card on which a probe used for inspecting the object to be inspected is provided, the method comprising the steps of: bringing the probe into contact with an electrode based on a first offset value; setting a second offset value based on a needle mark region formed by the probe contacting the electrode based on the first offset value; and bringing the probe into contact with an electrode based on the second offset value. [Effects of the Invention]

[0007] From one perspective, the probe can be brought into precise contact with the electrodes formed on the object being inspected. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view showing an example of an inspection apparatus according to one embodiment. [Figure 2] This figure shows an example of a semiconductor wafer according to one embodiment. [Figure 3] A block diagram showing an example of the hardware configuration of a control device according to one embodiment. [Figure 4] This is a block diagram showing an example of the functional configuration of a control device according to one embodiment. [Figure 5] This is a block diagram showing an example of the functional configuration of the offset calculation unit according to one embodiment. [Figure 6] This figure shows an example of the relationship between needle mark data and offset values ​​related to conventional technology. [Figure 7] This figure shows an example of the relationship between needle mark data and offset values ​​according to one embodiment. [Figure 8] This figure shows the first example of calculating an offset value using multiple needle mark data. [Figure 9] This figure shows a second example of calculating an offset value using multiple needle mark data. [Figure 10] This figure shows a third example of calculating an offset value using multiple needle mark data. [Figure 11] This figure shows an example of needle mark data according to one embodiment. [Figure 12] This figure shows an example of an amendment rule according to one embodiment. [Figure 13] This figure shows an example of an offset value when a correction rule is applied to needle mark data. [Figure 14] This is a conceptual diagram showing an example of offset information according to one embodiment. [Figure 15] This flowchart shows an example of an inspection method according to one embodiment. [Figure 16] This flowchart shows an example of the offset calculation process according to one embodiment. [Modes for carrying out the invention]

[0009] The following describes embodiments for implementing this disclosure with reference to the drawings. In each drawing, the same reference numerals are used for identical components, and redundant explanations may be omitted.

[0010] [Embodiment] <Overview> In inspection equipment, as the size of electrodes (pads) formed on the electronic devices being inspected decreases, higher contact accuracy is required. However, deviations in the probe's contact position on the pad are caused by a combination of factors, including the mechanical precision and variations of the inspection equipment, the precision and variations of the probe card, temperature changes in the mounting stage, and heat generation of the semiconductor wafer. Therefore, improving contact accuracy is difficult. Maintaining stable contact accuracy is crucial regardless of the combination of inspection equipment, probe card, and semiconductor wafer temperature.

[0011] Conventional inspection devices required periodically checking the position of the needle mark area formed by the probe contacting the pad and adjusting the offset value to correct the contact position. However, with conventional inspection devices, adjusting the offset value required manual work by the user, which reduced the operating rate and productivity.

[0012] One embodiment of the present disclosure is an inspection apparatus that automatically adjusts an offset value based on a contact position where a probe contacts a pad. The inspection apparatus according to this embodiment implements software that includes an algorithm and a dataset for adjusting the contact position of the probe with respect to the pad based on pin mark data representing the actual contact position, a rule for adjusting the offset value, a predefined set value, and an offset value used in the past.

[0013] <Configuration of the inspection apparatus> FIG. 1 is a cross-sectional schematic view showing an example of the inspection apparatus according to this embodiment. As shown in FIG. 1, the inspection apparatus 1 includes a mounting table 10, a mounting table drive unit 20, an inspection unit 30, an imaging unit 40, a temperature control device 50, and a control device 60.

[0014] The mounting table 10 sucks and fixes a semiconductor wafer W, which is an example of the object to be inspected, by means of a vacuum chuck, an electrostatic chuck, or the like. The mounting table drive unit 20 relatively moves the mounting table 10 with respect to the inspection unit 30 or the imaging unit 40. The imaging unit 40 images the semiconductor wafer W to obtain a multi-tone image of the semiconductor wafer W. The temperature control device 50 controls the temperature of the semiconductor wafer W placed on the mounting table 10. The control device 60 controls the other components of the inspection apparatus 1.

[0015] The mounting table drive unit 20 includes an X-direction movement mechanism 21, a Y-direction movement mechanism 22, a Z-direction movement mechanism 23, and a rotation mechanism 24. The X-direction movement mechanism 21 moves the mounting table 10 in the X direction shown in FIG. 1. The Y-direction movement mechanism 22 moves the mounting table 10 in the Y direction shown in FIG. 1. The Z-direction movement mechanism 23 moves the mounting table 10 in the Z direction shown in FIG. 1. The rotation mechanism 24 rotates the mounting table 10 about a rotation axis perpendicular to the XY plane.

[0016] The inspection unit 30 includes a probe card 31, probes 32, a test head 33, and an infrared sensor 34. The probe card 31 is positioned above the mounting base 10, facing the mounting base 10. Multiple probes 32, which are contacts, are arranged in two dimensions on the probe card 31. The probe card 31 is connected to the test head 33. An external tester 35 is connected to the test head 33.

[0017] When each probe 32 contacts a pad of an electronic device formed on the semiconductor wafer W, each probe 32 supplies the electrical signal output from the tester 35 to the electronic device via the test head 33. Conversely, each probe 32 transmits the electrical signal output from the electronic device to the tester 35 via the test head 33. Therefore, the probes 32 and the test head 33 function as power supply members that provide power to the electronic device.

[0018] The probe card 31 has a base substrate and a multilayer ceramic substrate, with multiple probes 32 protruding from the multilayer ceramic substrate. An infrared sensor 34 is mounted on the multilayer ceramic substrate to measure the temperature of the electronic device during inspection.

[0019] The infrared sensor 34 is a non-contact temperature sensor that detects the temperature of an object to be measured from the amount of infrared radiation emitted according to the object's temperature. Various conventionally used elements can be applied to the infrared sensor 34, such as a thermal diode. The infrared sensor 34 may also be used in the form of an infrared camera or a radiation thermometer.

[0020] The semiconductor wafer mounting surface of the mounting table 10 has adsorption holes for adsorbing the semiconductor wafer W. Furthermore, multiple temperature sensors 11 are embedded in the semiconductor wafer mounting surface at positions spaced apart from each other in a plan view. Thermocouples can be used as such temperature sensors 11.

[0021] The imaging unit 40 includes an illumination unit 41, an optical system 42, and an imaging device 43. The illumination unit 41 emits illumination light. The illumination unit 41 is implemented, for example, by a halogen lamp. The optical system 42 guides illumination light to the semiconductor wafer W and receives reflected light from the semiconductor wafer W. The imaging device 43 converts the image of the semiconductor wafer W formed by the optical system 42 into an electrical signal and outputs image data of the semiconductor wafer W. The imaging device 43 is implemented, for example, by arranging CCD (Charge Coupled Device) elements.

[0022] Figure 2 shows an example of a semiconductor wafer W. As shown in Figure 2, the semiconductor wafer W, which is the substrate to be inspected, has a plurality of electronic devices D formed on its surface at predetermined intervals from each other by etching and wiring processes on a substantially disc-shaped silicon substrate. Pads E are formed on the surface of the electronic devices D, and the pads E are electrically connected to the circuit elements inside the electronic devices D. By applying a voltage to the pads E, current can be passed to the circuit elements inside each electronic device D.

[0023] The temperature control device 50 includes a heating mechanism 51, a cooling mechanism 52, and a temperature controller 53. The temperature control device 50 controls the temperature of the electronic device D formed on the semiconductor wafer W on the mounting table 10 to a constant target temperature by heating with the heating mechanism 51, cooling with the cooling mechanism 52, and controlling heating and cooling with the temperature controller 53.

[0024] The heating mechanism 51 is configured as a light irradiation mechanism. The heating mechanism 51 heats the semiconductor wafer W and the electronic device D formed on the semiconductor wafer W by irradiating light onto the semiconductor wafer mounting surface of the mounting table 10 and heating the mounting table 10.

[0025] The heating mechanism 51 has, for example, a plurality of LEDs that irradiate light toward the semiconductor wafer W as a heating source. Each LED emits, for example, near-infrared light. The light emitted from the LEDs passes through the mounting stage 10, which is made of a light-transmitting member, and is incident on the semiconductor wafer mounting surface. When the light from the LEDs is near-infrared light, polycarbonate, quartz, polyvinyl chloride, acrylic resin, or glass can be used as the light-transmitting member.

[0026] The cooling mechanism 52 includes a chiller unit for storing refrigerant and refrigerant piping for circulating the refrigerant. For example, water, a liquid through which light irradiated from the heating mechanism 51 can pass, is used as the refrigerant. The refrigerant piping is connected to the supply and discharge ports of a refrigerant flow path provided inside the mounting base 10, and is also connected to the chiller unit. The refrigerant in the chiller unit is circulated and supplied to the refrigerant flow path via the refrigerant piping by a pump provided in the refrigerant piping.

[0027] The temperature controller 53 receives a temperature measurement signal of the electronic device D measured by the infrared sensor 34 during inspection of the electronic device D. Based on the measurement signal, the temperature controller 53 controls the heating mechanism 51 and the cooling mechanism 52, providing feedback control of the temperature of the electronic device D. This enables the temperature controller 53 to perform highly accurate temperature control. When not in use during inspection, the temperature controller 53 switches the temperature measurement signal to the temperature sensor 11 located on the semiconductor wafer mounting surface of the mounting table 10 for temperature control.

[0028] <Control device hardware configuration> Figure 3 is a block diagram showing an example of the hardware configuration of the control device 60 according to this embodiment. As shown in Figure 3, the control device 60 includes a CPU (Central Processing Unit) 500, RAM (Random Access Memory) 501, ROM (Read Only Memory) 502, auxiliary storage device 503, communication interface (I / F) 504, input / output interface (I / F) 505, and media interface (I / F) 506.

[0029] The CPU 500 operates based on programs stored in the ROM 502 or auxiliary storage device 503, and controls each part. The ROM 502 stores boot programs executed by the CPU 500 when the control device 60 starts up, as well as programs that depend on the hardware of the control device 60.

[0030] The auxiliary storage device 503 is, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The auxiliary storage device 503 stores the program executed by the CPU 500 and the data used by the program. The CPU 500 reads the program from the auxiliary storage device 503, loads it onto the RAM 501, and executes the loaded program.

[0031] The communication interface 504 communicates with other components of the inspection device 1 via a communication line such as a LAN (Local Area Network). The communication interface 504 receives data from other components of the inspection device 1 via the communication line and sends it to the CPU 500, and the CPU 500 transmits the generated data to other components of the inspection device 1 via the communication line.

[0032] The CPU 500 controls input devices such as keyboards and output devices such as displays via the I / F 505. The CPU 500 receives signals from input devices via the I / F 505 and sends them to the CPU 500. The CPU 500 also outputs the generated data to the output devices via the I / F 505.

[0033] The media interface 506 reads the program or data stored in the recording medium 507 and stores it in the auxiliary storage device 503. The recording medium 507 is, for example, an optical recording medium such as a DVD (Digital Versatile Disc) or PD (Phase change rewritable Disk), a magneto-optical recording medium such as an MO (Magneto-Optical disk), tape media, magnetic recording medium, or semiconductor memory.

[0034] The CPU 500 of the control device 60 reads the program loaded onto the RAM 501 from the recording medium 507 and stores it in the auxiliary storage device 503. Alternatively, the program may be obtained from another device via a communication line and stored in the auxiliary storage device 503.

[0035] <Functional Configuration> The functional configuration of the control device according to this embodiment will be described with reference to Figure 4. Figure 4 is a block diagram showing an example of the functional configuration of the control device 60 according to this embodiment.

[0036] As shown in Figure 4, the control device 60 according to this embodiment includes an imaging control unit 601, a needle mark position acquisition unit 602, a warning output unit 603, an offset acquisition unit 604, an offset calculation unit 605, an offset setting unit 606, an inspection execution unit 607, a setting information storage unit 610, a needle mark data storage unit 611, and an offset storage unit 612.

[0037] The imaging control unit 601, needle mark position acquisition unit 602, warning output unit 603, offset acquisition unit 604, offset calculation unit 605, offset setting unit 606, and inspection execution unit 607 are implemented, for example, by the CPU 500 shown in Figure 3 executing a program loaded onto the RAM 501. The setting information storage unit 610, needle mark data storage unit 611, and offset storage unit 612 are implemented, for example, by the RAM 501 or auxiliary storage device 503 shown in Figure 3.

[0038] The setting information storage unit 610 stores setting information used for calculating the offset value. This setting information includes predefined rules and predefined setting values. The predefined rules include calculation rules for controlling the timing of offset value calculation and correction rules for correcting the calculated offset value. The setting information can be edited at any time based on user operations. Details of the setting information will be described later.

[0039] The needle mark data storage unit 611 stores needle mark data acquired by the needle mark position acquisition unit 602. The needle mark data represents the position of the needle mark area (i.e., the contact position) formed when the probe 32 contacts the pad E.

[0040] The offset storage unit 612 stores offset information related to the offset value set by the offset setting unit 606. The offset information includes the set offset value and environmental information representing the environment in which the offset value was calculated. Details of the offset information will be described later.

[0041] The imaging control unit 601 controls the imaging unit 40 to image the semiconductor wafer W, including the pad E, after the probe 32 has made contact. The imaging unit 40 images the semiconductor wafer W placed on the mounting table 10 according to the control from the imaging control unit 601. The imaging control unit 601 acquires the multi-tone image (hereinafter also referred to as the "post-contact image") captured by the imaging unit 40.

[0042] The needle mark position acquisition unit 602 acquires the position of the latest needle mark region from the post-contact image acquired by the imaging control unit 601. The needle mark position acquisition unit 602 stores the needle mark data representing the position of the latest acquired needle mark region in the needle mark data storage unit 611.

[0043] The warning output unit 603 determines whether or not to bring the probe 32 into contact with the pad E (in other words, whether or not to continue the inspection) based on the position of the latest needle mark area acquired by the needle mark position acquisition unit 602. The warning output unit 603 determines whether or not to bring the probe 32 into contact with the pad E based on the correction rules included in the setting information. When the warning output unit 603 determines that the probe 32 should not be brought into contact with the pad E, it outputs a warning to the user and stops the inspection.

[0044] For example, the warning output unit 603 may determine that the probe 32 should not be brought into contact with the pad E when the cumulative amount of the deviation between the position of the needle mark area and the center position of the pad E exceeds a predetermined first threshold, and output a warning. The warning output unit 603 may also determine that the probe 32 should not be brought into contact with the pad E when the amount of the deviation between the position of the latest needle mark area and the center position of the pad E exceeds a predetermined second threshold, and output a warning. The first threshold or the second threshold used by the warning output unit 603 for determination may be defined in the setting information.

[0045] The offset acquisition unit 604 acquires offset information, including environmental information that matches the current environment, from the offset information stored in the offset storage unit 612. When the offset acquisition unit 604 acquires offset information that matches the current environment, it sends the offset information to the offset setting unit 606.

[0046] The offset calculation unit 605 calculates a new offset value based on the needle mark data stored in the needle mark data storage unit 611. The offset calculation unit 605 also calculates a new offset value according to the setting information stored in the setting information storage unit 610.

[0047] The offset setting unit 606 sets the offset value calculated by the offset calculation unit 605 as the current offset value. When the offset setting unit 606 receives offset information from the offset acquisition unit 604, it sets the offset value included in the offset information as the current offset value.

[0048] The inspection execution unit 607 performs electrical testing on the semiconductor wafer W placed on the mounting table 10 by controlling the mounting table drive unit 20 and the tester 35. The inspection execution unit 607 controls the mounting table drive unit 20 based on the current offset value set by the offset setting unit 606 to bring the probe 32 into contact with the pads E formed on the semiconductor wafer W placed on the mounting table 10. The tester 35 tests the electrical characteristics of the electronic device D by supplying power to the probe 32 via the test head 33.

[0049] ≪Offset Calculation Section≫ Figure 5 is a block diagram showing an example of the functional configuration of the offset calculation unit 605 according to this embodiment. As shown in Figure 5, the offset calculation unit 605 according to this embodiment includes a needle mark data determination unit 701, a displacement amount calculation unit 702, an offset estimation unit 703, and an offset correction unit 704.

[0050] The needle mark data determination unit 701 determines the needle mark data to be used for calculating the offset value from the needle mark data stored in the needle mark data storage unit 611. The needle mark data determination unit 701 determines the needle mark data based on the calculation rules and set values ​​included in the setting information.

[0051] The displacement calculation unit 702 calculates the displacement between the position of the needle mark region and the center position of the pad E for each needle mark data determined by the needle mark data determination unit 701. The displacement is a vector indicating the distance between the position of the needle mark region and the center position of the pad E, and the direction from the center position of the pad E to the position of the needle mark region.

[0052] The offset calculation unit 703 calculates the offset value based on the amount of displacement calculated by the displacement calculation unit 702. The offset calculation unit 703 calculates the offset value according to the offset calculation method included in the setting information.

[0053] The offset correction unit 704 corrects the offset value calculated by the offset calculation unit 703. The offset correction unit 704 corrects the offset value based on the correction rules included in the setting information.

[0054] ≪Setting Information≫ The configuration information according to this embodiment will be explained with reference to Figures 6 to 13.

[0055] (calculation rules) Figures 6 to 10 illustrate an example of the calculation rule according to this embodiment. The calculation rule is a rule for controlling the timing of calculating the offset value.

[0056] Figure 6 shows an example of the relationship between needle mark data and offset values ​​in the conventional technology. In the conventional technology, as shown in Figure 6(A), an offset value is initially calculated based on the needle mark data, and once this offset value is set, the same offset value is continuously used in subsequent inspections. Alternatively, as shown in Figure 6(B), an offset value is calculated based on the needle mark data, and once this offset value is set, this offset value is used multiple times consecutively, and the offset value is adjusted at any arbitrary timing.

[0057] Figure 7 shows an example of the relationship between needle mark data and offset value according to this embodiment. As shown in Figure 7, in this embodiment, first an offset value is calculated based on the needle mark data, and once this offset value is set, an inspection is performed based on this offset value to acquire needle mark data. Next, a new offset value is calculated based on the acquired needle mark data, and this offset value is corrected according to a predetermined correction rule. Subsequently, an inspection is performed based on the corrected offset value, and needle mark data is acquired again.

[0058] The inspection device 1 according to this embodiment automatically adjusts the offset value by repeatedly performing the acquisition of needle mark data, calculation of the offset value, and correction of the offset value. As a result, the inspection device 1 according to this embodiment improves the operating rate and settlement rate.

[0059] In Figure 7, an example is shown where the offset value is calculated and corrected each time a needle mark data is acquired. However, the offset value may also be calculated and corrected when a predetermined number of needle mark data has been acquired. The timing of calculating and correcting the offset value may be defined in the settings information.

[0060] When calculating an offset value using multiple needle mark data, a method for determining the needle mark data to be used to calculate the offset value may be defined. Figure 8 shows a first example of calculating an offset value using multiple needle mark data. In the example shown in Figure 8, first, semiconductor wafers W1 to W5 from the 1st to the 5th wafers are inspected, and a new offset value is calculated based on semiconductor wafers W1 to W5 after inspection. Next, semiconductor wafers W6 to W10 from the 6th to the 10th wafers are inspected based on the new offset value, and a new offset value is calculated again based on semiconductor wafers W6 to W10 after inspection. In this way, it is possible to set the system to calculate the offset value based on the five semiconductor wafers W that were inspected most recently.

[0061] Figure 9 shows a second example of calculating offset values ​​using multiple needle mark data. In the example shown in Figure 9, first, new offset values ​​are calculated based on semiconductor wafers W1 to W5 after inspection. Then, a sixth semiconductor wafer W6 is inspected based on these new offset values, and new offset values ​​are calculated again based on semiconductor wafers W2 to W6 after inspection. Thus, it is also possible to set the system to calculate offset values ​​based on the most recently inspected semiconductor wafer W and the four semiconductor wafers W inspected before it.

[0062] Figure 10 shows a third example of calculating offset values ​​using multiple needle mark data. In the example shown in Figure 10, first, new offset values ​​are calculated based on semiconductor wafers W1 to W5 after inspection. Then, the sixth and seventh semiconductor wafers W6 to W7 are inspected based on the new offset values, and new offset values ​​are calculated again based on semiconductor wafers W43 to W87 after inspection. Thus, it is also possible to set the system to calculate offset values ​​based on the two semiconductor wafers W that were inspected most recently and the three semiconductor wafers W that were inspected before that.

[0063] The number of needle mark data points used to calculate the offset value, and the number of most recently acquired needle mark data points among them, may be defined in the settings information. For example, in the first example shown in Figure 8, the number of needle mark data points can be set to 5, and the number of most recently acquired needle mark data points can be set to 5. Similarly, in the second example shown in Figure 9, the number of needle mark data points can be set to 5, and the number of most recently acquired needle mark data points can be set to 1. In the third example shown in Figure 10, the number of needle mark data points can be set to 5, and the number of most recently acquired needle mark data points can be set to 32.

[0064] (Amendment rules) Figures 11 to 13 illustrate an example of a correction rule according to this embodiment. The correction rule is a rule for correcting the offset value calculated based on needle mark data.

[0065] Figure 11 shows an example of needle mark data according to this embodiment. As shown in Figure 11, the position of the needle mark region can be represented on an XY plane with the center position of the pad E as the origin. In the example shown in Figure 11, the positions of the needle mark regions used to calculate the current offset value (hereinafter also referred to as "original positions") 91-1 to 91-3 are represented by black circles. In addition, the positions of the needle mark regions formed by bringing the probe 32 into contact with the pad E based on the current offset value (hereinafter also referred to as "new positions") 92-1 to 92-3 are represented by white circles.

[0066] In this embodiment, multiple needle mark data are used to calculate the offset value. Therefore, in Figure 11, the original position and new position for each needle mark data are shown on the same XY plane.

[0067] Figure 12 shows an example of a correction rule according to this embodiment. As shown in Figure 12, the correction rule according to this embodiment allows for the definition of a rule for calculating a new offset value for each combination of the range in which the original positions 91-1 to 91-3 exist and the range in which the new positions 92-1 to 92-3 exist.

[0068] In the example shown in Figure 11, the original positions 91-1 to 91-3 and the new positions 92-1 to 92-3 all exist in the same quadrant (i.e., the contact positions tend to shift in a certain direction). Therefore, in the correction rule shown in Figure 12, the original and new positions are defined using absolute values. If the original and new positions exist in different quadrants (i.e., the contact positions shift randomly), the correction rule can be defined using a combination of ranges including the sign.

[0069] For example, if the original position is within ±3 μm of the origin (i.e., the center position of pad E) and the new position is within ±3 μm of the origin, the calculated offset value is used as the new offset value without correction. The calculated offset value is an offset value with the center position of pad E as the target position. Here, the target position is the position on pad E that is the target for aligning the contact position.

[0070] Furthermore, for example, if the original position is within ±3 μm of the origin and the new position is within ±5 μm of the origin (3 μm or more), the calculated offset value is corrected to an offset value that aligns the contact position to the ±3 μm position. The ±3 μm position refers to any of the coordinates (+3, +3), (+3, -3), (-3, +3), or (-3, -3) in the XY plane with the center position of pad E as the origin.

[0071] The coordinate system to which the contact point is aligned depends on which quadrant the original and new positions are located in. For example, in the example shown in Figure 11, since the original and new positions are in the first quadrant, the offset value is corrected to align the contact point to the coordinates (+3, +3). If the original and new positions were in the third quadrant, the offset value would be corrected to align the contact point to the coordinates (-3, -3).

[0072] Figure 13 shows an example of an offset value when the correction rule shown in Figure 12 is applied to the needle mark data shown in Figure 11. As shown in Figure 13, the offset value calculated based on the new position 92-1 is used as the offset value to align the contact position with the center position of the pad E. This is because the new position 92-1 is in a range of less than ±3 μm, and the original position 91-1 corresponding to the new position 92-1 is in a range of less than ±3 μm.

[0073] Furthermore, the offset value calculated based on the new position 92-2 is corrected to an offset value that aligns the contact position to the coordinates (+3, +3). This is because the new position 92-2 lies in the range of ±3 μm or more and less than ±5 μm, and the original position 91-2 corresponding to the new position 92-2 lies in the range of ±3 μm or more and less than ±5 μm.

[0074] For the new position 92-3, the offset value is not corrected, and an alarm is output. This is because the new position 92-3 is located within a range of ±7 μm or more. In this case, the inspection device 1 stops the inspection and does not contact the pad E with the probe 32 based on the offset value calculated based on the new position 92-3.

[0075] The correction rule may define a rule that outputs an alarm based on the cumulative value of the deviation. In the example of the correction rule shown in Figure 12, it is defined that an alarm is output when the cumulative value of the deviation becomes 10 μm or more. In this case as well, the inspection device 1 stops the inspection and does not contact the pad E with the probe 32 based on the newly calculated offset value.

[0076] Note that the cumulative value of the deviation is calculated including the sign. For example, if the first deviation is +5 and the second deviation is -2, the cumulative value of the deviation is |3|. Here, |·| is a symbol representing the absolute value of the value ·.

[0077] If the contact position misalignment is large, it may indicate an event different from contact position variations caused by the temperature of the probe card 31 or semiconductor wafer W (for example, a malfunction of the inspection equipment). Furthermore, if the contact position misaligns beyond the area of ​​pad E, the probe 32 may contact an area outside of pad E. Therefore, if the contact position misalignment is large, the inspection will be stopped and an alarm will be issued. The user will inspect the inspection equipment 1 in response to the issued alarm and take necessary actions such as repair or replacement. This will help prevent malfunctions.

[0078] (Setting value) The configuration information in this embodiment includes setting values ​​that define the reference values ​​used when executing various rules. The setting values ​​in this embodiment include outliers, whether or not outliers are used, whether or not initial values ​​are used, data period, and offset calculation method.

[0079] Outliers are defined by a set value that sets a threshold for determining whether needle mark data is an outlier or not. An outlier is a value that differs significantly from other needle mark data.

[0080] The "Outlier Use" setting defines whether or not needle mark data indicating outliers is used in calculating the offset value. Using outliers in offset value calculation may result in an inaccurate offset value. Therefore, it is possible to set whether or not to use needle mark data indicating outliers in offset value calculation.

[0081] The "Use Initial Value" setting defines whether or not the initial needle mark data is used to calculate the offset value. The initial needle mark data refers to the needle mark data obtained when the first semiconductor wafer W of each lot is inspected, or when the first semiconductor wafer W is inspected after the probe card 31 has been replaced. The contact accuracy of the initial needle mark data may not be stable, and using the initial needle mark data to calculate the offset value may result in an inaccurate offset value. Therefore, it is possible to set whether or not to use the initial needle mark data to calculate the offset value.

[0082] The data period is a setting that defines the period of needle mark data used to calculate the offset value. The needle mark data period is the number of semiconductor wafers inspected from the first needle mark data to the last needle mark data used to calculate the offset value. For example, if 5 needle mark data are used to calculate the offset value, and the data period is set to 20, then the offset value will be calculated if, out of 20 semiconductor wafers inspected, there are 5 or more semiconductor wafers for which usable needle mark data could be obtained.

[0083] For example, when inspecting a semiconductor wafer W, there may be cases where no needle mark data is generated, such as when the needle mark region cannot be recognized from the post-contact image. If the period between the first needle mark data and the last needle mark data is long, it may not be possible to calculate an appropriate offset value. Therefore, the period of needle mark data used to calculate the offset value can be defined.

[0084] The offset calculation method is a set of values ​​that defines the number of needle mark data points used to calculate the offset value, and the type of statistical value calculated based on the needle mark data. The number of needle mark data points per semiconductor wafer used to calculate the offset value is, for example, 4 points or 5 points. The configurable statistical values ​​are, for example, the arithmetic mean, median, centroid, moving average, etc.

[0085] Offset Information The offset information according to this embodiment will be explained with reference to Figure 14. Figure 14 is a conceptual diagram showing an example of the offset information according to this embodiment.

[0086] As shown in Figure 14, the offset information according to this embodiment is information associated with the offset value, cell number, variety, probe card number, temperature, and update date and time. Of these, the cell number, variety, probe card number, and temperature are environmental information representing the environment at the time the offset value was calculated.

[0087] The cell number is identification information that identifies the position of the semiconductor wafer W in an inspection system having multiple inspection devices. The product type is information that represents the type of electronic device D. The probe card number is identification information that identifies the type of probe card 31. The temperature is the temperature of the semiconductor wafer W or the semiconductor wafer mounting surface of the mounting table 10. The update date and time is information that represents the date and time when the offset value was set.

[0088] <Processing Procedure> The inspection method according to this embodiment will be described with reference to Figure 15. Figure 15 is a flowchart showing an example of the inspection method according to this embodiment. The inspection method according to this embodiment is performed by the inspection device 1.

[0089] In step S1, first, the imaging control unit 601 controls the imaging unit 40 to image the pads E of the semiconductor wafer W placed on the mounting table 10. Next, the inspection execution unit 607 controls the mounting table drive unit 20 based on the current offset value stored in a storage unit such as the auxiliary storage device 503, and moves the mounting table 10 below the inspection unit 30. As a result, the multiple pads E formed on the semiconductor wafer W placed on the mounting table 10 and the multiple probes 32 face each other.

[0090] Next, the inspection execution unit 607 controls the mounting table drive unit 20 to raise the mounting table 10 by a certain amount of overdrive. As a result, multiple probes 32 come into contact with multiple opposing pads E. At this time, the tips of the probes 32 pressed against the pads E slightly scrape the surface of the pads E, thereby ensuring electrical contact between the probes 32 and the pads E.

[0091] Next, the inspection execution unit 607 instructs the tester 35 to start the inspection. The tester 35 outputs a predetermined electrical signal to the test head 33. The electrical signal output from the tester 35 is supplied to the pads E of the semiconductor wafer W via the test head 33 and probe 32. The electrical signal output from the pads E of the semiconductor wafer W is output to the tester 35 via probe 32 and test head 33. Based on the electrical signal output to the test head 33 and the electrical signal output from the test head 33, the tester 35 evaluates the electrical characteristics of the semiconductor wafer W and outputs the evaluation result to the control device 60.

[0092] Once the inspection is complete, the inspection execution unit 607 controls the mounting table drive unit 20 to lower the mounting table 10. This causes the probe 32 to move away from the pad E, leaving a contact mark (i.e., the most recent needle mark area) on the pad E.

[0093] In step S2, the imaging control unit 601 controls the mounting table drive unit 20 to move the mounting table 10 below the imaging unit 40. This brings the semiconductor wafer W placed on the mounting table 10 and the imaging device 43 to face each other.

[0094] Next, the imaging control unit 601 controls the imaging unit 40 to image the semiconductor wafer W placed on the mounting table 10. This acquires a multi-gradation post-contact image including the pads E on the semiconductor wafer W.

[0095] Next, the imaging control unit 601 acquires the post-contact image output from the imaging unit 40. The imaging control unit 601 then sends the acquired post-contact image to the needle mark position acquisition unit 602.

[0096] In step S3, the needle mark position acquisition unit 602 receives the post-contact image from the imaging control unit 601. Next, the needle mark position acquisition unit 602 acquires the position of the latest needle mark region and the center position of the pad E from the post-contact image. A method for acquiring the position of the latest needle mark region from the post-contact image is disclosed, for example, in Patent Document 1.

[0097] Next, the needle mark position acquisition unit 602 generates needle mark data representing the position of the acquired needle mark region. Then, the needle mark position acquisition unit 602 stores the generated needle mark data in the needle mark data storage unit 611.

[0098] In step S4, the warning output unit 603 obtains the latest needle mark data from the needle mark data storage unit 611. Next, the warning output unit 603 reads the setting information from the setting information storage unit 610. Subsequently, the warning output unit 603 determines whether or not to bring the probe 32 into contact with the pad E (i.e., whether or not to continue the inspection) based on the correction rules included in the setting information.

[0099] Specifically, the warning output unit 603 calculates the amount of deviation between the position of the latest needle mark area and the center position of the pad E based on the latest needle mark data acquired. Next, the warning output unit 603 adds the calculated amount of deviation to the cumulative value of deviations stored in the memory unit. If the cumulative value of deviations is greater than or equal to the threshold value of cumulative values ​​included in the correction rule, the warning output unit 603 determines not to bring the probe 32 into contact with the pad E (i.e., not to continue the inspection). On the other hand, if the cumulative value of deviations is less than the threshold value of cumulative values ​​included in the correction rule, the warning output unit 603 determines to bring the probe 32 into contact with the pad E (i.e., to continue the inspection).

[0100] The warning output unit 603 may determine that the probe 32 should not be brought into contact with the pad E if the amount of deviation based on the latest needle mark data is greater than or equal to the threshold amount of deviation included in the correction rule. In this case, the warning output unit 603 should determine that the probe 32 should be brought into contact with the pad E if the amount of deviation based on the latest needle mark data is less than the threshold amount of deviation included in the correction rule.

[0101] If the warning output unit 603 determines that the probe 32 will not be brought into contact with the pad E (i.e., the inspection will not be continued) (NO), the process proceeds to step S5. On the other hand, if the warning output unit 603 determines that the probe 32 will be brought into contact with the pad E (i.e., the inspection will be continued) (YES), the process proceeds to step S6.

[0102] In step S5, the warning output unit 603 outputs a warning to the user. The warning is output to an output device such as a display via the input / output interface 505 provided by the control device 60. After that, the warning output unit 603 terminates the processing of the inspection method.

[0103] In step S6, the offset acquisition unit 604 acquires the current environment. The current environment consists of the type of electronic device D, the identification information of the probe card 31, and the temperature of the semiconductor wafer W or the semiconductor wafer mounting surface of the mounting table 10. The type of electronic device D and the identification information of the probe card 31 are assumed to have been input to the control device 60 by the user and stored in the storage unit.

[0104] The temperature of the semiconductor wafer W is obtained from the infrared sensor 34. The temperature of the semiconductor wafer mounting surface of the mounting table 10 is obtained from the temperature sensor 11. When a semiconductor wafer W is placed on the mounting table 10, the temperature of the semiconductor wafer W can be obtained from the infrared sensor 34. On the other hand, when no semiconductor wafer W is placed on the mounting table 10, the temperature of the semiconductor wafer mounting surface of the mounting table 10 can be obtained from the temperature sensor 11.

[0105] Next, the offset acquisition unit 604 acquires offset information, including environmental information that matches the current environment, from the offset information stored in the offset storage unit 612. The offset acquisition unit 604 does not acquire offset information if the current temperature matches the temperature at which the current offset value was calculated. If the current temperature does not match the temperature at which the current offset value was calculated, the offset acquisition unit 604 acquires offset information that matches the type of electronic device D and the identification number of the probe card 31.

[0106] Whether the temperatures match can be determined by whether or not they fall within a certain temperature range. For example, if the current temperature is within ±10°C of the temperature at which the current offset value was calculated, the temperatures can be determined to match.

[0107] In step S7, the offset acquisition unit 604 determines whether or not it has acquired offset information that matches the current environment. If it has not acquired offset information that matches the current environment (NO), the offset acquisition unit 604 proceeds to step S8. Even if it has acquired offset information that matches the current environment, the offset acquisition unit 604 may still proceed to step S8.

[0108] If offset information matching the current environment is obtained (YES), the offset acquisition unit 604 sends the acquired offset information to the offset setting unit 606. At this time, the offset acquisition unit 604 deletes the needle mark data stored in the needle mark data storage unit 611. After that, the offset acquisition unit 604 skips step S8 and proceeds to step S9.

[0109] In step S8, the offset calculation unit 605 calculates a new offset value based on the needle mark data stored in the needle mark data storage unit 611 and the setting information stored in the setting information storage unit 610. The offset calculation unit 605 sends the calculated new offset value to the offset setting unit 606.

[0110] ≪Offset Calculation Process≫ The details of the offset calculation process according to this embodiment (step S8 in Figure 15) will be explained with reference to Figure 16. Figure 16 is a flowchart showing an example of the offset calculation process according to this embodiment.

[0111] In step S8-1, the needle mark data determination unit 701 reads the setting information stored in the setting information storage unit 610. Next, the needle mark data determination unit 701 reads the needle mark data stored in the needle mark data storage unit 611.

[0112] In step S8-2, the needle mark data determination unit 701 determines the needle mark data to be used for calculating the offset value from the needle mark data read in step S8-1, based on the calculation rules and setting values ​​included in the setting information.

[0113] First, the needle mark data determination unit 701 extracts needle mark data included in a predefined data period. Next, the needle mark data determination unit 701 determines whether or not to use needle mark data indicating outliers, according to a predefined outlier usage status. If the needle mark data indicating outliers is not to be used, the needle mark data determination unit 701 excludes needle mark data from the extracted data whose deviation is larger than the predefined outlier value.

[0114] Next, the needle mark data determination unit 701 determines whether or not to use the initial needle mark data according to a predefined initial value usage status. If the initial needle mark data is not to be used, the needle mark data determination unit 701 excludes the initial needle mark data from the extracted needle mark data.

[0115] In step S8-3, the needle mark data determination unit 701 determines whether or not it was able to obtain the needle mark data necessary for calculating the offset value in step S8-1. The needle mark data determination unit 701 determines whether or not it was able to obtain the needle mark data necessary for calculating the offset value by determining whether or not it satisfies the number of needle mark data required by a predefined offset calculation method.

[0116] If the needle mark data necessary for calculating the offset value can be obtained (YES), the needle mark data determination unit 701 sends the determined needle mark data to the displacement amount calculation unit 702 and proceeds to step S8-4. On the other hand, if the needle mark data necessary for calculating the offset value cannot be obtained (NO), the needle mark data determination unit 701 terminates the offset calculation process.

[0117] In step S8-4, the displacement calculation unit 702 receives needle mark data from the needle mark data determination unit 701. Next, the displacement calculation unit 702 calculates the displacement between the position of the needle mark region and the center position of the pad E for each of the received needle mark data. Subsequently, the displacement calculation unit 702 sends each calculated displacement to the offset estimation unit 703.

[0118] In step S8-5, the offset calculation unit 703 receives each displacement amount from the displacement amount calculation unit 702. Next, the offset calculation unit 703 calculates an offset value based on each displacement amount according to the offset calculation method included in the setting information. Subsequently, the offset calculation unit 703 sends the calculated offset value to the offset correction unit 704.

[0119] In step S8-6, the offset correction unit 704 receives the offset value from the offset calculation unit 703. Next, the offset correction unit 704 corrects the offset value by applying the correction rules included in the setting information. Subsequently, the offset correction unit 704 outputs the corrected offset value as the new offset value.

[0120] The offset correction unit 704 first identifies the ranges on the XY plane where the original position and the new position exist. Next, the offset correction unit 704 obtains a predefined correction rule based on the combination of the ranges where the original position exists and the ranges where the new position exists. Subsequently, the offset correction unit 704 corrects the estimated offset value according to the obtained correction rule. Depending on the obtained correction rule, the estimated offset value may be used as is, or the estimated offset value may be discarded and an alarm may be output.

[0121] Let's return to Figure 15 for explanation. In step S9, the offset setting unit 606 receives a new offset value from the offset calculation unit 605 or the offset acquisition unit 604. The offset setting unit 606 sets the received new offset value as the current offset value. Specifically, the offset setting unit 606 updates the current offset value stored in the memory unit to the new offset value. Therefore, in subsequent processing, the new offset value received from the offset calculation unit 605 or the offset acquisition unit 604 is used as the current offset value.

[0122] In step S10, the inspection execution unit 607 controls the mounting table drive unit 20 and the tester 35 based on the current offset value stored in the memory unit (i.e., the new offset value set in step S9) to perform an electrical inspection of the semiconductor wafer W placed on the mounting table 10. The inspection procedure is the same as in step S1, so it will not be explained here.

[0123] <Effects of the Embodiment> In this embodiment, the inspection device 1 sets a new offset value based on the needle mark area formed by contacting the pad E with the probe 32, based on the current offset value, and then contacts the pad E with the probe 32 based on the new offset value. In other words, the inspection device 1 in this embodiment automatically adjusts the offset value based on the needle mark area formed by contacting the pad E with the probe 32. Therefore, according to the inspection device 1 in this embodiment, the probe 32 can be brought into contact with the pad E formed on the electronic device D with high precision.

[0124] In this embodiment, the inspection device 1 stores a set offset value in association with the environmental information at the time the offset value was calculated, and if an offset value calculated in the same environment exists, it uses that offset value. Therefore, in order to reuse proven offset values, the inspection device 1 in this embodiment can accurately contact the pad E formed on the electronic device D with the probe 32.

[0125] In this embodiment, the inspection device 1 calculates an offset value according to different rules depending on the amount of deviation between the position of the needle mark area and the center position of the pad E. The rules for calculating the offset value are stored as setting information and can be edited as appropriate. Therefore, according to the inspection device 1 in this embodiment, an appropriate rule can be set according to the trend of the contact position deviation, and the probe 32 can be made to contact the pad E formed on the electronic device D with high precision.

[0126] In this embodiment, the inspection device 1 determines whether or not to bring the probe 32 into contact with the pad E based on the amount of deviation between the position of the needle mark area and the center position of the pad E. If the amount of deviation is greater than a predetermined threshold, the inspection device 1 does not bring the probe 32 into contact with the pad E and outputs an alarm. Therefore, according to the inspection device 1 of this embodiment, malfunctions can be avoided.

[0127] [supplement] In the embodiments described above, the current offset value is an example of a first offset value. The new offset value is an example of a second offset value. The inspection apparatus and inspection method according to the embodiments disclosed herein are illustrative in all respects and are not restrictive. The embodiments can be modified and improved in various ways without departing from the scope and spirit of the appended claims. The matters described in the above embodiments can be otherwise configured and combined in a non-consistent manner. [Explanation of symbols]

[0128] W Semiconductor wafer D Electronic devices E Pad 1. Inspection device 10 Mounting platform 11. Temperature sensor 20 Mounting platform drive unit 21 X direction movement mechanism 22 Y direction movement mechanism 23 Z direction movement mechanism 24 Rotating Mechanisms 30 Inspection Units 31 Probe Card 32 probes 33 Test Heads 34 Infrared Sensor 35 Tester 40 Imaging Units 41 Lighting Section 42 Optical system 43 Imaging devices 50 Temperature control device 51 Heating mechanism 52 Cooling mechanism 53 Temperature controller 60 Control device 601 Imaging Control Unit 602 Needle mark position acquisition unit 603 Warning output section 604 Offset acquisition section 605 Offset Calculation Unit 606 Offset setting section 607 Inspection Execution Department 610 Configuration Information Storage Unit 611 Needle Mark Data Storage Unit 612 Offset storage unit 701 Needle Mark Data Determination Unit 702 Calculation unit for displacement 703 Offset Calculation Department 704 Offset Correction Section

Claims

1. A platform on which the object to be inspected is placed, A probe card equipped with a probe used for inspecting the object to be inspected, An inspection method performed by an inspection device equipped with, A step of bringing the probe into contact with an electrode formed on the object to be inspected based on a first offset value, A step of determining whether or not to bring the probe into contact with the electrode based on the amount of displacement between the position of the needle mark region formed when the probe contacts the electrode based on the first offset value and the center position of the electrode, A step of setting a second offset value based on the needle mark region formed when the probe contacts the electrode based on the first offset value, A step of bringing the probe into contact with the electrode based on the second offset value, Execute, The determination step involves comparing the cumulative value of the displacement between the position of the needle mark region and the center position of the electrode with a predetermined threshold value to determine whether or not to bring the probe into contact with the electrode. Testing method.

2. The inspection method according to claim 1, The process of storing the second offset value in association with at least one of the type of object to be inspected, the type of probe card, and the temperature of the object to be inspected or the temperature of the stand described above is further performed. Testing method.

3. The inspection method according to claim 2, The step of obtaining the second offset value based on the type of object to be inspected, the type of probe card, the temperature of the object to be inspected, or the temperature of the stand described above is further performed. Testing method.

4. The inspection method described in claim 3, The second offset value is calculated according to different rules depending on the amount of displacement between the position of the needle mark region and the center position of the electrode. Testing method.

5. The inspection method according to claim 4, The aforementioned rules include rules that specify different target positions for contacting the probe with the electrode. Testing method.

6. The inspection method according to claim 5, The target position is determined based on the positional relationship between the position of the needle mark region used to calculate the first offset value and the position of the needle mark region formed when the probe contacts the electrode based on the first offset value. Testing method.

7. A testing method according to any one of claims 1 to 6, If it is determined that the probe does not come into contact with the electrode, the process of outputting a warning is further executed. Testing method.

8. A platform on which the object to be inspected is placed, A probe card equipped with a probe used for inspecting the object to be inspected, Control device and An inspection device equipped with, The control device is A step of bringing the probe into contact with an electrode formed on the object to be inspected based on a first offset value, A step of determining whether or not to bring the probe into contact with the electrode based on the amount of displacement between the position of the needle mark region formed when the probe contacts the electrode based on the first offset value and the center position of the electrode, A step of setting a second offset value based on the needle mark region formed when the probe contacts the electrode based on the first offset value, A step of bringing the probe into contact with the electrode based on the second offset value, Execute, The determination step involves comparing the cumulative value of the displacement between the position of the needle mark region and the center position of the electrode with a predetermined threshold value to determine whether or not to bring the probe into contact with the electrode. Inspection device.

9. A platform on which the object to be inspected is placed, A probe card equipped with a probe used for inspecting the object to be inspected, A control device that controls an inspection device equipped with the following: A procedure for bringing the probe into contact with an electrode formed on the object to be inspected based on a first offset value, A procedure for determining whether or not to bring the probe into contact with the electrode, based on the amount of displacement between the position of the needle mark region formed when the probe contacts the electrode based on the first offset value and the center position of the electrode, A procedure for setting a second offset value based on the needle mark region formed when the probe contacts the electrode based on the first offset value, A procedure for bringing the probe into contact with the electrode based on the second offset value, Make it run, The procedure for making the determination involves comparing the cumulative value of the displacement between the position of the needle mark region and the center position of the electrode with a predetermined threshold value to determine whether or not to bring the probe into contact with the electrode. program.

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