JP2012191083A - Semiconductor element test method and semiconductor element test device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor element test method and a test device capable of preventing air discharge during application of a high voltage without using a method of increasing the distance between the electrodes of a semiconductor element or a method of using an expensive prober, when wafer test is performed with the specification maximum voltage.SOLUTION: The semiconductor element test method of testing the electrical characteristics of a semiconductor element for a wafer where multiple semiconductor elements are fabricated includes a step (S11) for connecting the electrode of an inspected semiconductor element out of the multiple semiconductor elements electrically with an external terminal, a step (S12) for supplying a liquid or a gas of low ionization from a supply section to the surface of the inspected semiconductor element while connecting the electrode and the external terminal electrically, and a step (S13) for applying a test voltage from a voltage application section via the external terminal to the inspected semiconductor element while covering the surface with the liquid or gas.

Description

  The present invention relates to a semiconductor element test method and a semiconductor element test apparatus for inspecting electrical characteristics of a semiconductor element on a wafer on which a plurality of semiconductor elements are formed.

  Semiconductor products used at a high voltage such as a power device having a horizontal structure are subjected to a test for inspecting characteristics at a specified maximum voltage in the manufacturing process in order to ensure shipping quality. However, when a high voltage is applied in the wafer test, the surface of the semiconductor element (semiconductor chip) is in direct contact with the air, so that it is not covered with a protective film between the electrodes of the semiconductor element (electrode pads, scribe lines, etc.) An air discharge occurs at a portion directly exposed in the air), which may damage the semiconductor element or possibly break down.

  Therefore, in general, in the wafer test, air discharge is suppressed by reducing the test voltage to a voltage at which air discharge does not occur. In the latter half of the process after packaging, since the surface of the semiconductor element is covered with the mold resin, air discharge does not occur. Therefore, the test of the maximum specification voltage is performed in the final shipping test after packaging. In this way, the test voltage is set low in the wafer test, and the product quality is guaranteed by performing the test of the maximum specification voltage in the final shipping test after packaging.

  However, when a test with the maximum specification voltage is performed in the final shipping test, a semiconductor element that becomes defective only when a high voltage is applied is detected in the final shipping test without being detected in the wafer test. When a defect is detected after packaging, the material cost and assembly process cost of the package are lost, and the cost is increased compared to the case where a defect is detected by a wafer test.

  Here, the voltage at which air discharge occurs is proportional to the distance between the electrodes of the semiconductor element. Therefore, in order to perform a test with the maximum specified voltage in the wafer test, a method has been proposed in which the distance between the electrodes of the semiconductor element is increased to a distance at which no air discharge occurs as a countermeasure against discharge during the wafer test with high voltage applied. .

  In addition, a vacuum prober in which the atmosphere in the wafer transfer apparatus is evacuated as a method capable of performing a wafer test with high voltage application while preventing air discharge without using a method of increasing the distance between the electrodes of the semiconductor element. There are a method of performing a test in a vacuum using the method and a method of performing a test in a state where a wafer is immersed in a fluorine-based or silicon-based insulating liquid. Next, as an example of a conventional method for performing a test in an insulating liquid, an electronic component inspection apparatus described in Patent Document 1 will be briefly described with reference to FIG.

  FIG. 7 is a diagram showing a schematic configuration of the electronic component inspection apparatus 200 described in Patent Document 1. As shown in FIG. The electronic component inspection apparatus 200 fills the insulating liquid cup 202 installed in the wafer prober 201 with the insulating liquid 203 having a high insulating property, and tests the semiconductor wafer 208 under test in the insulating liquid 203. This prevents air discharge when a high voltage is applied.

  A prober stage 204 is provided in the insulating liquid cup 202 that can be filled with the insulating liquid 203 by overflowing. The prober stage 204 is used to transport the semiconductor wafer 208 to be tested and to immerse and hold the semiconductor wafer 208 in the insulating liquid 203. It has been. A probe card 205 having a probe 206 protruding toward the prober stage 204 is provided outside the insulating liquid cup 202 and above the prober stage 204. A characteristic is inspected by applying a test voltage from the probe 206 to the semiconductor wafer 208 to be tested while the semiconductor wafer 208 to be tested is immersed in the insulating liquid 203. In the insulating liquid cup 202, the liquid amount is adjusted by the liquid amount adjusting valve 207 so that the insulating liquid 203 is always filled.

JP 2003-130889 A (published May 8, 2003)

  However, the conventional method capable of performing a wafer test with high voltage application while preventing air discharge has the following problems.

  First, the method of increasing the distance between the electrodes of the semiconductor element has a problem that the distance between the electrodes must be increased to a distance at which air discharge does not occur even at the specified maximum voltage, that is, a relatively large distance. . This increases the surface area and increases the cost of the semiconductor element.

  Second, the wafer test method in a vacuum or in an insulating liquid is an expensive prober (for example, approximately 5,000 vacuum probers) in which the atmosphere in the wafer transfer apparatus is evacuated or an insulating liquid that immerses the wafer is provided. Million yen) is necessary. For this reason, equipment costs increase, resulting in an increase in manufacturing costs. In fact, such probers are so expensive that they are used for research and development, but not for mass production.

  The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a method for increasing the distance between electrodes of a semiconductor element and an expensive prober when performing a test of a maximum specification voltage in a wafer test. An object of the present invention is to provide a semiconductor element test method and a semiconductor element test apparatus that can prevent air discharge when a high voltage is applied without using a method to be used.

  In order to solve the above problems, a semiconductor element test method of the present invention is a semiconductor element test method for inspecting electrical characteristics of a semiconductor element on a wafer on which a plurality of semiconductor elements are formed. The step of electrically connecting the electrode of the semiconductor element to be inspected among the semiconductor elements to the external terminal and the surface of the semiconductor element to be inspected in a state where the electrode and the external terminal are electrically connected A step of supplying a liquid or gas having low ionization from the supply unit, and a test is performed on the semiconductor element to be inspected from the voltage application unit via the external terminal in a state where the surface is covered with the liquid or gas. And a step of applying a voltage.

  According to the above configuration, before applying the test voltage, a liquid or gas having a low ionization property is supplied to the surface of the semiconductor element to be inspected, and the surface to be inspected is covered with the liquid or gas. A test voltage is applied to the semiconductor element. Therefore, it is possible to prevent air discharge between the electrodes of the semiconductor element that occurs when a high voltage is applied.

  Accordingly, since the maximum specified voltage of the semiconductor element can be inspected by the wafer test, the defect rate in the final shipping test after packaging the semiconductor element can be greatly reduced. Further, it is not necessary to use a method of increasing the distance between the electrodes of the semiconductor element or a method of using an expensive prober such as a vacuum prober, which has been conventionally performed to prevent the air discharge. As a result, the cost can be significantly reduced.

  Therefore, it is possible to prevent air discharge at the time of applying a high voltage without using a conventionally performed method when performing a test with a specified maximum voltage in a wafer test.

  In the semiconductor element test method of the present invention, the low ionizing liquid or gas may be composed of an inert substance or a substance having an activation energy exceeding 15 eV.

  In order to solve the above problems, a semiconductor element test apparatus of the present invention is a semiconductor element test apparatus for inspecting electrical characteristics of a semiconductor element on a wafer on which a plurality of semiconductor elements are formed. A supply unit that supplies a liquid or gas with low ionization to the surface of the semiconductor element to be inspected among the semiconductor elements, and a test voltage applied to the semiconductor element to be inspected after the supply unit supplies the liquid or gas. And a voltage applying unit to be applied.

  According to said structure, before applying a test voltage, it becomes possible to supply the liquid or gas with low ionization property to the surface of the semiconductor element to be examined. Therefore, it is possible to apply a test voltage to the semiconductor element to be inspected in a state where the surface of the semiconductor element to be inspected is covered with the liquid or gas, and the air between the electrodes of the semiconductor element generated when a high voltage is applied. It becomes possible to prevent discharge.

  Accordingly, since the maximum specified voltage of the semiconductor element can be inspected by the wafer test, the defect rate in the final shipping test after packaging the semiconductor element can be greatly reduced. Further, it is not necessary to use a method of increasing the distance between the electrodes of the semiconductor element or a method of using an expensive prober such as a vacuum prober, which has been conventionally performed to prevent the air discharge. As a result, the cost can be significantly reduced.

  Therefore, it is possible to prevent air discharge when a high voltage is applied, without using a conventionally performed method when performing a test with a maximum specified voltage in a wafer test.

  In the semiconductor element test apparatus of the present invention, the low ionizing liquid or gas may be composed of an inert substance or a substance whose activation energy exceeds 15 eV.

  In the semiconductor element test apparatus of the present invention, it is preferable that the supply unit includes a nozzle that ejects the liquid or gas. As a result, the supply unit can be realized easily and inexpensively (300,000 yen or less) without having an expensive (more than 10 million yen) and complicated mechanism such as a sealing mechanism for configuring the vacuum state of the vacuum prober. be able to.

  In the semiconductor device testing apparatus of the present invention, it is preferable that the supply unit includes a supply pipe for flowing out the liquid or gas. Thus, the entire wafer is not targeted like a vacuum prober, but only the semiconductor element to be inspected is not discharged, so that the amount of liquid or gas used can be suppressed. Further, the supply unit can be realized simply and inexpensively without having an expensive and complicated mechanism as described above.

  In the semiconductor device test apparatus of the present invention, the voltage application unit is electrically connected to the supply unit, and the instruction to supply the liquid or gas is given before a predetermined period of time when the test voltage is applied. It is preferable to give to a supply part. This makes it possible to reliably apply a test voltage to the semiconductor element to be inspected in a state where the surface of the semiconductor element to be inspected is covered with the liquid or gas. Moreover, the timing which supplies the said liquid or gas can be arbitrarily set before the application of a test voltage.

  In the semiconductor element test apparatus of the present invention, it is preferable that the voltage application unit is electrically connected to the supply unit and controls the supply amount of the liquid or gas. Thereby, the supply amount of the liquid or gas can be arbitrarily set. In addition, useless supply can be reduced, leading to cost reduction.

  The semiconductor element test method of the present invention is a semiconductor element test method for inspecting electrical characteristics of a semiconductor element on a wafer on which a plurality of semiconductor elements are formed, and the inspection of each semiconductor element includes It is characterized in that the surface of the semiconductor element to be inspected is covered with a liquid or gas having low ionization properties.

  According to the above configuration, since the inspection of each semiconductor element is performed in a state where the surface of the semiconductor element to be inspected is covered with a liquid or gas having low ionization properties, between the electrodes of the semiconductor element generated when a high voltage is applied. Air discharge can be prevented.

  Accordingly, since the maximum specified voltage of the semiconductor element can be inspected by the wafer test, the defect rate in the final shipping test after packaging the semiconductor element can be greatly reduced. Further, it is not necessary to use a method of increasing the distance between the electrodes of the semiconductor element or a method of using an expensive prober such as a vacuum prober, which has been conventionally performed to prevent the air discharge. As a result, the cost can be significantly reduced.

  Therefore, it is possible to prevent air discharge at the time of applying a high voltage without using a conventionally performed method when performing a test with a specified maximum voltage in a wafer test.

  As described above, the semiconductor element testing method of the present invention includes a step of electrically connecting an electrode of a semiconductor element to be inspected with an external terminal, and a state in which the electrode and the external terminal are electrically connected. A step of supplying a liquid or gas having a low ionization property from a supply unit to the surface of the semiconductor element to be inspected, and a voltage applied to the semiconductor element to be inspected in a state where the surface is covered with the liquid or gas. Applying a test voltage from the application unit via the external terminal.

  The semiconductor element testing apparatus according to the present invention includes a supply unit that supplies a liquid or gas having low ionization to the surface of a semiconductor element to be inspected, and the semiconductor to be inspected after the supply unit supplies the liquid or gas. And a voltage application unit that applies a test voltage to the element.

  The semiconductor element testing method of the present invention is a method for inspecting each semiconductor element in a state where the surface of the semiconductor element to be inspected is covered with a liquid or gas having low ionization properties.

  Therefore, there is an effect that air discharge at the time of applying a high voltage can be prevented without using a conventionally performed method when performing a test of the maximum specification voltage in the wafer test.

It is a schematic block diagram which shows one Embodiment of the semiconductor element test apparatus in this invention. It is a flowchart which shows the flow of a process of the said semiconductor element test apparatus in the semiconductor element test of one wafer to be tested. (A)-(d) is a figure which shows the mode on the to-be-tested wafer in the said semiconductor element test. It is a schematic block diagram which shows other embodiment of the semiconductor element test apparatus in this invention. It is a flowchart which shows the flow of a process of the said semiconductor element test apparatus in the semiconductor element test of one wafer to be tested. (A)-(c) is a figure which shows the mode on the to-be-tested wafer in the said semiconductor element test. It is a schematic block diagram which shows the conventional electronic component inspection apparatus.

  The present invention relates to a test apparatus used in a wafer test for measuring electrical characteristics of a semiconductor element formed on a wafer and selecting non-defective and defective products. In general, in wafer testing, a probe is a jig used for electrical connection between a tester and a wafer after the wafer is transferred into a wafer prober and placed on a prober stage mounted on the wafer prober. An electrical test is performed on a semiconductor element formed on a wafer via a card. In a wafer test, a test voltage is applied from a tester to a semiconductor element via a probe card, and an output corresponding to the test voltage is supplied to the tester via a probe card to measure whether or not the semiconductor element is defective. Are inspected.

  In the semiconductor element in a wafer state to be inspected, elements constituting an electric circuit such as active elements, electrode pads, and wirings are formed, but since they are not separated into pieces, they are not sealed with resin. Those that have been selected as non-defective products proceed to the second half of the process where they are diced and packaged.

  The semiconductor device test apparatus according to the embodiment of the present invention to be described below includes, in addition to the notable configuration as a feature, an apparatus generally equipped in the conventional test apparatus used in the wafer test as described above as appropriate. It is to be realized. Therefore, in the following description, a noteworthy configuration that characterizes the semiconductor element test apparatus will be mainly described. Description and illustration of the conventional general configuration provided in the semiconductor element testing apparatus will be omitted as appropriate.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to the drawings.

(1-1) Configuration FIG. 1 is a diagram illustrating a configuration example of a semiconductor element test apparatus 10 according to the present embodiment. The semiconductor element test apparatus 10 (hereinafter abbreviated as “test apparatus 10”) is an apparatus used for a wafer test of a wafer under test 1 and inspects the electrical characteristics of the semiconductor elements formed on the wafer under test 1. A plurality of semiconductor elements, for example, hundreds to thousands of semiconductor elements are formed on one wafer 1 to be tested.

  As shown in FIG. 1, the test apparatus 10 includes a wafer prober 11, a nozzle column 12, a nozzle 13, a supply controller 15, and a tester 19 (voltage application unit).

  The wafer prober 11 is a portion where a test voltage is applied to the semiconductor element of the wafer under test 1. The wafer prober 11 is electrically connected to the tester 19 by a control bus 21. A plurality of control buses 21 can be provided depending on the function. The wafer prober 11 is provided with a probe card 16 and a prober stage 18.

  The probe card 16 is a jig for electrically connecting the tester 19 and the semiconductor element of the wafer 1 to be tested. The probe card 16 has a structure in which a probe 17 (external terminal) is mounted on a printed board. The probe 17 is a metal needle directly connected to the electrode of the semiconductor element. The number of probes 17 corresponds to the number of inputs and outputs necessary for the test. Each probe 17 is electrically connected to the tester 19 via an internal wiring formed on the printed circuit board and an external wiring (control bus 21) that connects the internal wiring and the tester 19. .

  The probe card 16 is fixed inside the wafer prober 11 so that the probe 17 protrudes toward the prober stage 18. At this time, the tip of the probe 17 is arranged according to the arrangement of the electrodes formed on the semiconductor element. An opening is formed in the center portion of the probe card 16. Here, let the direction which the probe 17 protrudes be a downward direction.

  The prober stage 18 is a table for holding and transporting the wafer under test 1 during the test of the wafer under test 1. The prober stage 18 is mounted on the inside of the wafer prober 11 and below the probe card 16 so as to be able to move 360 degrees with the surface holding the wafer 1 to be tested facing upward. The prober stage 18 is electrically connected to the tester 19 via the control bus 21. In response to an instruction from the tester 19, the prober stage 18 carries the wafer 1 to be tested so that the semiconductor element to be inspected is electrically connected to the probe 17.

  The nozzle support 12 is for fixing the nozzle 13. The nozzle column 12 is fixed to the wafer prober 11 above the probe card 16. The nozzle 13 ejects the supplied liquid in the form of a mist. As the liquid, Fluorinert (registered trademark), which is an electrically inactive liquid, is used.

  The nozzle 13 is fixed to the nozzle column 12 such that the injection port faces downward, that is, toward the prober stage 18. In addition, the nozzle 13 is arranged such that its injection port is located above the opening of the probe card 16 and directly above the semiconductor element to be inspected. Thereby, it is possible to spray Fluorinert from the nozzle 13 to the semiconductor element to be inspected. The nozzle 13 is connected to a supply controller 15 by a pipe 14.

  The supply controller 15 is a device that adjusts the amount of florinate sprayed from the nozzle 13. The supply controller 15 stores florinate. The supply controller 15 is electrically connected to the tester 19 via the control bus 20. A plurality of control buses 20 can be provided depending on the function. The supply controller 15 supplies florinate to the nozzle 13 through the pipe 14 in accordance with an instruction from the tester 19.

  The tester 19 is a device for inspecting whether or not there is a defect in the semiconductor element by supplying a preset test voltage and measuring an output in response thereto. For example, the tester 19 automatically operates according to a test program in which a test order is defined. The measurement conditions such as the test voltage can be input by the user or appropriately changed by the input device of the tester 19 or the like. The tester 19 controls the supply timing and supply amount from the supply controller 15 to the nozzle 13 by instructing the supply controller 15. As a result, the tester 19 can arbitrarily set the ejection timing of the nozzle 13 and the amount of fluorinate liquid ejected from the nozzle 13.

(1-2) Test Method Next, a test method for a semiconductor element test using the test apparatus 10 will be described.

  FIG. 2 is a flowchart showing a processing flow of the test apparatus 10 in the semiconductor element test of one wafer 1 to be tested. FIGS. 3A to 3D are views showing a state on the wafer under test 1 in the semiconductor element test. In addition, illustration of the probe 17 is abbreviate | omitted in FIG.

  In the semiconductor element test, first, the wafer to be tested 1 is transferred into the wafer prober 11 and held on the prober stage 18. The prober stage 18 stands by at a position away from the probe 17 so that the wafer under test 1 does not contact the probe 17. At this time, measurement conditions such as a test voltage may be set in the tester 19 or may be set in the tester 19 in advance. The wafer prober 11 (or tester 19) stores (registers) information (number of semiconductor elements, arrangement, etc.) of the wafer 1 under test.

<Step S11>
When the measurement environment is ready, the wafer prober 11 (or tester 19) electrically connects the semiconductor element to be inspected (measurement object) to the probe 17 (step S11). Specifically, the wafer prober 11 (or tester 19) outputs a position setting signal for setting the position of the semiconductor element to be inspected to the prober stage 18. The position setting signal includes position information of the semiconductor element to be inspected.

  The prober stage 18 automatically moves in the left-right direction based on the received position setting signal. As a result, the semiconductor element to be inspected is located directly below the probe 17. If the semiconductor element to be inspected is located directly below the probe 17, the prober stage 18 may be moved not only in the left-right direction but also in an upward direction or an oblique direction.

  After the semiconductor element to be inspected is located directly below the probe 17, the prober stage 18 is then lifted as it is. Thereby, the electrode of the semiconductor element to be inspected is pressed against the probe 17. At this time, since the electrical connection between the probe 17 and the electrode of the semiconductor element is not sufficient simply by bringing them into contact with each other, they are pressed against each other while applying a certain amount of pressure. That is, since the probe card 16 is fixed to the wafer prober 11, the probe card 16 is further pressed and pressed from the position where the electrode of the semiconductor element first touches the probe 17.

  Thus, the electrode of the semiconductor element to be inspected is electrically connected to the probe 17. When the connection is completed, the prober stage 18 outputs a preparation completion signal indicating that preparation for voltage application is completed to the tester 19.

<Step S12>
Subsequently, the tester 19 starts measuring the semiconductor element to be inspected. In the measurement, the nozzle 13 sprays Fluorinert on the surface of the semiconductor element to be inspected (step S12).

  Specifically, after receiving the preparation completion signal, the tester 19 outputs an injection instruction signal for blowing florinart to the supply controller 15. The supply controller 15 supplies florinate to the nozzle 13 based on the injection instruction signal. The injection port of the nozzle 13 is located above the opening of the probe card 16 and directly above the semiconductor element to be inspected. Thereby, in a state where the electrode of the semiconductor element and the probe 17 are electrically connected, the mist-like fluorinate is sprayed on the semiconductor element to be inspected. Fluorinate is uniformly attached to the surface of the semiconductor element to be inspected by being sprayed in a mist form. The fluorinate diffuses, and after several tens of milliseconds, completely covers the surface of the semiconductor element to be inspected.

  The manner in which florinate is supplied in this way is shown in FIGS. When the electrical connection between the semiconductor element to be inspected and the probe 17 is completed (FIG. 3A), a mist-like fluorinate 25 is sprayed from the nozzle 13 onto the semiconductor element to be inspected (FIG. 3B). The florinate 26 adhering and diffusing to the surface of the target semiconductor element completely covers the surface of the semiconductor element to be inspected (FIG. 3C).

  Here, as shown in FIG. 3B, the fluorinate 25 ejected from the nozzle 13 is scattered and adhered to other than the semiconductor element to be inspected. For this reason, as shown in FIG. 3C, the surface of the semiconductor element that is not the inspection target is also covered with the fluorinate 26. In addition, components existing in the vicinity of the semiconductor element to be inspected, such as the probe 17, are also covered with fluorinate. However, since fluorinate is highly volatile and easily vaporized, there is no problem even if it adheres to parts other than the semiconductor element to be inspected.

<Step S13>
Subsequently, a test voltage is applied to the semiconductor element to be inspected in a state where the surface of the semiconductor element to be inspected is covered with fluorinate (Step S13).

  Specifically, the tester 19 outputs a test voltage to the probe card 16 after a predetermined time has elapsed from the output of the injection instruction signal. The predetermined time is set according to the time required for the fluorinate to completely cover the surface of the semiconductor element to be inspected. As a result, a test voltage is applied to the semiconductor element to be inspected via the probe 17 of the probe card 16 when the florinate completely covers the surface (the state shown in FIG. 3C).

  A semiconductor element to be inspected generates an output in response to application of a test voltage. This output is transmitted to the tester 19 via the probe 17 of the probe card 16. The tester 19 inspects whether or not the semiconductor element is defective by measuring the output.

  Here, when the test voltage is applied, the surface of the semiconductor element to be inspected is completely covered with Fluorinert. Therefore, it is possible to prevent air discharge when a high voltage is applied. Therefore, even when a high test voltage is applied, the inspection can be performed without generating an air discharge.

  Further, the tester 19 controls the timing of florinate injection. Therefore, the injection timing can be arbitrarily set and can be synchronized with the test program. Therefore, the tester 19 operates the tester 19 so as to give the supply controller 15 an instruction to inject florinate (injection instruction signal) before a predetermined period of time when the test voltage is applied. A test voltage can be applied to the semiconductor element to be inspected in a state where the surface of the target semiconductor element is covered with fluorinate.

<Step S14>
When the inspection is completed, the tester 19 determines whether or not the inspected semiconductor element is the last semiconductor element (step S14).

  If it is not the last semiconductor element (NO in step S14), the tester 19 once lowers the prober stage 18, and then electrically connects the next semiconductor element to be inspected to the probe 17 (step S11). ). Then, the tester 19 inspects the semiconductor element by spraying florinate onto the semiconductor element to be inspected and then applying a test voltage to the semiconductor element (steps S12 to S13). After the inspection, it is determined whether or not it is the last semiconductor element (step S14), and if it is not the last semiconductor element, the next semiconductor element to be inspected is similarly inspected. Thus, by repeating the operations of steps S11 to S14, the tester 19 sequentially inspects all the semiconductor elements formed on the wafer 1 to be tested.

  When the inspection of the last semiconductor element is completed (YES in step S14), the tester 19 determines that the inspection of all the semiconductor elements has been completed, and ends the semiconductor element test of the wafer 1 to be tested.

  After the test is completed, the florinate remaining on the wafer under test 1 is naturally dried. Since Fluorinert is highly volatile, it completely volatilizes within a few minutes after the end of the test (when sprayed) (FIG. 3 (d)). Volatilizes at any time during the test. Therefore, it is not necessary to perform a residual liquid treatment of florinate sprayed on the surface of the semiconductor element after the test is completed. As a result, efficient production becomes possible, and the production efficiency of the wafer under test 1 is good.

(1-3) Summary As described above, the test apparatus 10 inspects the electrical characteristics of a semiconductor device to be tested 1 on which a plurality of semiconductor devices are formed. Nozzle 13 for blowing florinate onto the surface of the element, supply controller 15 for adjusting the amount of florinate injected from nozzle 13, probe card 16 for electrically connecting the semiconductor element to be inspected and tester 19, and nozzle 13 includes a tester 19 for applying a test voltage to a semiconductor element to be inspected after jetting florinate.

  The semiconductor element testing method using the test apparatus 10 includes a step of electrically connecting an electrode of a semiconductor element to be inspected with a probe 17 provided on the probe card 16, and the electrode and the probe 17 are electrically connected. The step of spraying Fluorinert from the nozzle 13 onto the surface of the semiconductor element to be inspected in a state of being connected to the semiconductor element, and the tester 19 through the probe 17 to the semiconductor element to be inspected in a state where the surface is covered with Fluorinert. And applying a test voltage.

  According to the above configuration and method, before applying the test voltage, fluorinate is supplied to the surface of the semiconductor element to be inspected, and the test voltage is applied to the semiconductor element to be inspected in a state where the surface is covered with the fluorinate. ing. Therefore, it is possible to prevent air discharge between the electrodes of the semiconductor element that occurs when a high voltage is applied.

  Accordingly, since the maximum specified voltage of the semiconductor element can be inspected by the wafer test, the defect rate in the final shipping test after packaging the semiconductor element can be greatly reduced. Further, it is not necessary to use a method of increasing the distance between the electrodes of the semiconductor element or a method of using an expensive prober such as a vacuum prober, which has been conventionally performed to prevent the air discharge. As a result, the cost can be significantly reduced.

  Therefore, when testing the maximum specified voltage in the wafer test, when applying a high voltage without using the conventional methods (a method of increasing the distance between the electrodes of the semiconductor element or a method using an expensive prober). It is possible to prevent air discharge.

  The semiconductor element test is particularly effective for a semiconductor product (IC chip) having a high specification maximum voltage such as a power device having a horizontal structure. The maximum specification voltage of such a semiconductor product is a high voltage exceeding 100 V (for example, about 100 V to 7000 V). The semiconductor element test can be applied to products having a maximum specification voltage of 30V to 100V.

  Further, the supply of florinate to the semiconductor element to be inspected is performed by the nozzle 13. Therefore, the supply unit can be realized easily and inexpensively (300,000 yen or less) without having an expensive (more than 10 million yen) and complicated mechanism such as a sealing mechanism for configuring the vacuum state of the vacuum prober. Can do.

  Note that the nozzle 13 may be configured so that the injection angle can be adjusted in order to inject florinate to an optimal place. Moreover, although the nozzle 13 was being fixed to the nozzle support | pillar 12, you may comprise so that it may move. Furthermore, the amount of liquid ejected from the nozzle 13 can be optimized by the tester 19. As a result, it is possible to prevent an unnecessary amount of injection by reducing the extra supply, which leads to a reduction in cost.

  Further, although the nozzle 13 is connected to the supply controller 15 by the pipe 14, the nozzle 13 and the supply controller 15 may be integrated. Depending on the space where the test apparatus 10 can be installed, the test apparatus 10 may be separated or integrated. In other words, the test apparatus 10 is not limited to the form of the nozzle 13 and the supply controller 15, but may be provided with a supply unit that supplies florinate to the surface of the semiconductor element to be inspected.

  By providing the supply unit, the inspection of each semiconductor element formed on the wafer 1 to be tested is performed by a method in which the surface of the semiconductor element to be inspected is covered with Fluorinert. Can be carried out while preventing air discharge between the electrodes of the semiconductor element that occurs when a high voltage is applied.

  In the above-described semiconductor element test, the semiconductor element to be inspected is covered with Fluorinert, but is not limited to Fluorinert. Instead of Fluorinert, a liquid with low ionization may be used, or a gas with low ionization may be used. By covering the surface of the semiconductor element to be inspected with a liquid or gas having a low ionization property, it is possible to prevent air discharge between the electrodes of the semiconductor element that occurs when a high voltage is applied.

  The liquid or gas having low ionization property is an inert substance or a substance having an activation energy exceeding 15 eV. Examples of the liquid with low ionization include a fluorine-based inert liquid. Further, an ether-based solution having a high chemical stability can also be used as the liquid having low ionization properties. Examples of the gas having low ionization include a gas made of sulfur hexafluoride and a gas classified as an inert gas (made of a rare gas such as helium or neon, or nitrogen).

  Low ionization means that ionization is difficult, that is, the activation energy (ionization energy) of the substance is high ("low ionization" = "difficult to ionize" = "the substance Has high activation energy "). In general, helium, neon, nitrogen, and the like are known as gases that are difficult to ionize (room temperature). These activation energies are as follows.

Helium: about 25 eV
Neon: Approximately 21 eV
Nitrogen: about 15 eV
Therefore, a substance made of a substance having an activation energy exceeding 15 eV can be used as a liquid or gas having low ionization properties.

  Further, even when a liquid with low ionization other than florinate is used, by selecting a highly volatile liquid, post-processing can be eliminated. On the other hand, when a gas with low ionization properties is used, there is no post-processing. Furthermore, any of the above-mentioned low ionizing liquids and gases are not affected even if they adhere to other than the semiconductor element to be inspected.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to the drawings. Configurations other than those described in the present embodiment are the same as those in the first embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of the first embodiment are given the same reference numerals, and explanation thereof is omitted.

(2-1) Configuration FIG. 4 is a diagram illustrating a configuration example of the semiconductor element test apparatus 30 according to the present embodiment. The semiconductor element test apparatus 30 (hereinafter abbreviated as “test apparatus 30”) has a function equivalent to that of the test apparatus 10. The test apparatus 30 has the same configuration as that of the test apparatus 10 except that the supply means of florinate is different.

  As shown in FIG. 4, the test apparatus 30 includes a wafer prober 11 provided with a probe card 16 and a prober stage 18, a supply pipe support 31, a supply pipe 32, a supply controller 15, and a tester 19.

  The supply pipe column 31 is for fixing the supply pipe 32. The supply pipe column 31 is fixed to the wafer prober 11 above the probe card 16. The supply pipe 32 discharges the supplied liquid. As the liquid, fluorinate which is an electrically inactive liquid is used. It should be noted that not only fluorinate but also a liquid or gas with low ionization properties may be used.

  The supply pipe 32 is fixed to the supply pipe column 31 so that the outlet is directed downward (or obliquely downward), that is, toward the prober stage 18. Further, the supply pipe 32 is arranged so that its outlet is located above the opening of the probe card 16 and directly above the semiconductor element to be inspected. Thereby, it is possible to pour florinate from the supply pipe 32 into the semiconductor element to be inspected. The supply pipe 32 is connected to the supply controller 15 by the pipe 14.

  In the present embodiment, the supply controller 15 adjusts the amount of fluorinate that flows out from the supply pipe 32. The supply controller 15 supplies florinate to the supply pipe 32 through the pipe 14 in accordance with an instruction from the tester 19.

  Further, the tester 19 instructs the supply controller 15 to control the supply timing and the supply amount from the supply controller 15 to the supply pipe 32. Thereby, the tester 19 can control the outflow timing of the supply pipe 32 and the liquid amount of the florinate discharged from the supply pipe 32.

(2-2) Test Method Next, a test method for a semiconductor element test using the test apparatus 30 will be described.

  The test method using the test apparatus 30 is different from the test method using the test apparatus 10 in that the supply means of florinate is changed from the nozzle 13 to the supply pipe 32. That is, in the test method using the test apparatus 30, only the configuration for performing the process of step S12 among the processes of steps S11 to S14 in FIG. 2 is changed, and the other processes are the same.

  FIG. 5 is a flowchart showing a processing flow of the test apparatus 30 in the semiconductor element test of one wafer 1 to be tested. FIGS. 6A to 6C are views showing the state on the wafer under test 1 in the semiconductor element test. In addition, illustration of the probe 17 is abbreviate | omitted in FIG.

<Step S21>
When the measurement environment is ready, the wafer prober 11 (or tester 19) electrically connects the semiconductor element to be inspected (measurement target) to the probe 17 (step S21). Specifically, the wafer prober 11 (or tester 19) outputs a position setting signal for setting the position of the semiconductor element to be inspected to the prober stage 18. The prober stage 18 moves based on the received position setting signal to electrically connect the electrode of the semiconductor element to be inspected with the probe 17. When the connection is completed, the prober stage 18 outputs a preparation completion signal indicating that preparation for voltage application is completed to the tester 19.

<Step S22>
Subsequently, the tester 19 starts measuring the semiconductor element to be inspected. In the measurement, the supply pipe 32 flows florinate into the semiconductor element to be inspected (step S22).

  Specifically, after receiving the preparation completion signal, the tester 19 outputs an outflow instruction signal for pouring florinate to the supply controller 15. The supply controller 15 supplies florinate to the supply pipe 32 based on the outflow instruction signal. The outlet of the supply pipe 32 is located above the opening of the probe card 16 and directly above the semiconductor element to be inspected. Thereby, in a state where the electrode of the semiconductor element and the probe 17 are electrically connected, the liquid fluorinate is poured into the semiconductor element to be inspected. The poured florinate diffuses, and after several tens of milliseconds, completely covers the surface of the semiconductor element to be inspected.

  The manner in which florinate is supplied in this way is shown in FIGS. When the electrical connection between the semiconductor element to be inspected and the probe 17 is completed (FIG. 6A), the liquid fluorinate 33 is poured into the semiconductor element to be inspected from the supply pipe 32 and diffuses, so that The surface of the semiconductor element is completely covered (FIG. 6B).

  Here, as shown in FIG. 6B, since the florinate 33 flowing out from the supply pipe 32 diffuses in addition to the semiconductor element to be inspected, the surface of the semiconductor element not to be inspected is also covered with the fluorinate 33. End up. In addition, components existing in the vicinity of the semiconductor element to be inspected, such as the probe 17, are also covered with fluorinate. However, as described above, fluorinate is highly volatile and easily vaporized, so there is no problem at all.

<Step S23>
Subsequently, a test voltage is applied to the semiconductor element to be inspected in a state where the surface of the semiconductor element to be inspected is covered with fluorinate (Step S23).

  Specifically, the tester 19 outputs a test voltage to the probe card 16 after a predetermined time has elapsed since the output of the outflow instruction signal. The predetermined time is set according to the time required for the fluorinate to completely cover the surface of the semiconductor element to be inspected. As a result, a test voltage is applied to the semiconductor element to be inspected via the probe 17 of the probe card 16 when the florinate completely covers the surface (the state of FIG. 6B).

  A semiconductor element to be inspected generates an output in response to application of a test voltage. This output is transmitted to the tester 19 via the probe 17 of the probe card 16. The tester 19 inspects whether or not the semiconductor element is defective by measuring the output.

  Here, when the test voltage is applied, the surface of the semiconductor element to be inspected is completely covered with Fluorinert. Therefore, it is possible to prevent air discharge when a high voltage is applied. Therefore, even when a high test voltage is applied, the inspection can be performed without generating an air discharge.

  In addition, the tester 19 controls the timing of the outflow of florinate. Therefore, the timing of outflow can be arbitrarily set and can be synchronized with the test program. Therefore, before the test voltage is applied for a predetermined period, the tester 19 operates the tester 19 so as to give the supply controller 15 an instruction to flow out the florinate (outflow instruction signal). A test voltage can be applied to the semiconductor element to be inspected in a state where the surface of the target semiconductor element is covered with fluorinate.

<Step S24>
When the inspection is completed, the tester 19 determines whether or not the inspected semiconductor element is the last semiconductor element (step S24).

  If it is not the last semiconductor element (NO in step S24), the tester 19 sequentially inspects all the semiconductor elements formed on the wafer under test 1 by repeating the operations in steps S21 to S24.

  When the inspection of the last semiconductor element is completed (YES in step S24), the tester 19 determines that the inspection of all the semiconductor elements has been completed, and ends the semiconductor element test of the wafer 1 to be tested.

  After the test is completed, the florinate remaining on the wafer under test 1 is naturally dried. Since fluorinate is highly volatile, it completely volatilizes within a few minutes after the end of the test (when it was poured) (FIG. 6 (c)). Volatilizes at any time during the test. Therefore, after the test is completed, it is not necessary to perform a residual liquid treatment of florinate sprayed on the surface of the semiconductor element, and efficient production is possible.

(2-3) Summary As described above, the test apparatus 30 inspects the electrical characteristics of a semiconductor device to be tested 1 on which a plurality of semiconductor devices are formed, and is a semiconductor to be inspected. A supply pipe 32 for flowing florinate into the surface of the element, a supply controller 15 for adjusting the amount of florinate discharged from the supply pipe 32, a probe card 16 for electrically connecting the semiconductor element to be inspected and the tester 19; And a tester 19 for applying a test voltage to the semiconductor element to be inspected after the supply pipe 32 flows out of the fluorinate.

  Then, in the semiconductor element testing method using the test apparatus 30, the step of electrically connecting the electrode of the semiconductor element to be inspected with the probe 17 provided on the probe card 16, and the electrode and the probe 17 are electrically connected. In a state where the surface of the semiconductor element to be inspected is supplied to the surface of the semiconductor element to be inspected, and the probe 17 from the tester 19 is applied to the semiconductor element to be inspected in a state where the surface is covered with the florinart. And applying a test voltage via the method.

  According to the above configuration and method, before applying the test voltage, fluorinate is supplied to the surface of the semiconductor element to be inspected, and the test voltage is applied to the semiconductor element to be inspected with the surface covered with the fluorinate. is doing. Therefore, it is possible to prevent air discharge between the electrodes of the semiconductor element that occurs when a high voltage is applied.

  Therefore, similarly to the test apparatus 10 and the semiconductor element test method using the same, when performing the test of the maximum specified voltage in the wafer test, the air discharge at the time of applying the high voltage is performed without using the method conventionally performed. It becomes possible to prevent.

  The supply of florinate to the semiconductor element to be inspected is performed by the supply pipe 32. Therefore, the entire wafer is not targeted like a vacuum prober, but only the semiconductor element to be inspected is not discharged, so that the amount of fluorinate used can be suppressed. Further, the supply unit can be realized simply and inexpensively without having an expensive and complicated mechanism.

  Note that the supply pipe 32 may be configured to be movable such that the installation angle can be adjusted in order to flow the florinate into an optimal place. Furthermore, the amount of liquid flowing out from the supply pipe 32 can be optimized by the tester 19. As a result, it is possible to prevent a wasteful amount of outflow by reducing the excess supply, which leads to a cost reduction.

  Further, although the supply pipe 32 is connected to the supply controller 15 by the pipe 14, the supply pipe 32 and the supply controller 15 may be integrated. Depending on the space where the test apparatus 10 can be installed, the test apparatus 10 may be separated or integrated. The test apparatus 10 is not limited to the form of the supply pipe 32 and the supply controller 15, but may be provided with a supply unit that supplies florinate to the surface of the semiconductor element to be inspected as described above.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be suitably used in the field related to a test apparatus and a test method used in a wafer test of a semiconductor element. In particular, the present invention is most suitable for a wafer test of a semiconductor product used at a high voltage such as a power device having a lateral structure.

1 Test wafer (wafer)
DESCRIPTION OF SYMBOLS 10 Semiconductor device test apparatus 11 Wafer prober 13 Nozzle (supply part)
15 Supply controller (supply unit)
16 Probe card 17 Probe (external terminal)
18 Prober stage 19 Tester (voltage application part)
25, 26 Fluorinert 30 Semiconductor device test equipment 32 Supply pipe (supply section)
33 Florinato

Claims (9)

A semiconductor element test method for inspecting electrical characteristics of a semiconductor element on a wafer on which a plurality of semiconductor elements are formed,
Electrically connecting an electrode of a semiconductor element to be inspected among the plurality of semiconductor elements to an external terminal;
Supplying a liquid or gas having a low ionization property from a supply unit to the surface of the semiconductor element to be inspected in a state where the electrode and the external terminal are electrically connected;
Applying a test voltage from a voltage application unit to the semiconductor element to be inspected via the external terminal in a state where the surface is covered with the liquid or gas. .   2. The semiconductor element testing method according to claim 1, wherein the low ionizing liquid or gas is made of an inactive substance or a substance having an activation energy exceeding 15 eV. A semiconductor element testing apparatus for inspecting electrical characteristics of a semiconductor element on a wafer on which a plurality of semiconductor elements are formed,
A supply unit for supplying a liquid or gas having a low ionization property to the surface of the semiconductor element to be inspected among the plurality of semiconductor elements;
A semiconductor device testing apparatus, comprising: a voltage application unit that applies a test voltage to the semiconductor element to be inspected after the supply unit supplies the liquid or gas.   4. The semiconductor element testing apparatus according to claim 3, wherein the low ionizing liquid or gas is made of an inactive substance or a substance having an activation energy exceeding 15 eV.   The semiconductor device testing apparatus according to claim 3, wherein the supply unit includes a nozzle that ejects the liquid or gas.   The semiconductor element testing apparatus according to claim 3, wherein the supply unit includes a supply pipe for flowing out the liquid or gas.   The said voltage application part is electrically connected with the said supply part, The instruction | indication which supplies the said liquid or gas is given to the said supply part before the predetermined period of the time of applying the said test voltage, The said supply part is characterized by the above-mentioned. 3. The semiconductor element test apparatus according to 3.   The semiconductor device testing apparatus according to claim 3, wherein the voltage application unit is electrically connected to the supply unit and controls a supply amount of the liquid or gas. A semiconductor element test method for inspecting electrical characteristics of a semiconductor element on a wafer on which a plurality of semiconductor elements are formed,
The semiconductor element testing method is characterized in that the inspection of each semiconductor element is performed in a state where the surface of the semiconductor element to be inspected is covered with a liquid or gas having low ionization properties.

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