Inspection method and inspection equipment

[0001] [Technical field to which the invention belongs] The present invention relates to an inspection method and an inspection apparatus for inspecting an inspected object in which conduction between inspection electrodes is established with a probe pin by utilizing a fretting phenomenon, and more specifically, a fretting power supply can be omitted. Regarding inspection methods and inspection equipment. [0002] [Conventional technology] The semiconductor processing step includes various steps such as a step of inspecting the wafer state as it is and a step of inspecting the inspected object in the package state. When the inspection is carried out, a contactor (for example, a probe pin) is brought into contact with the electrode pad for inspection of the wafer, and a signal is applied to the electrode pad via the probe pin. However, since an electrically insulating oxide film is formed on the electrode pad for inspection, a predetermined stylus pressure is applied from the probe pin to the electrode pad, and the electrode pad is pressed with the probe pin. The inspection is carried out after scraping and conducting the probe pin and the electrode pad. [0003] However, since the electrode pad and the wiring structure are thinned due to the densification of the device formed on the wafer, the electrode pad and the electrode pad are removed by scraping the oxide film of the electrode pad P with the probe pin when inspecting the wafer. There is a risk of damaging the underlying layer of the wafer. Therefore, in order to prevent such damage, a method of removing the oxide film of the electrode pad by utilizing the fretting phenomenon has been proposed (Patent Document 1). [0004] The technique described in Patent Document 1 will be outlined based on, for example, FIG. As shown in FIG. 2, the probe card 1 has a pair of probe pins 2 in contact with a plurality of electrode pads P of the wafer, and a relay 3 connected to each probe pin 2, via the relay 3. The pair of probe pins 2 are switched and connected between the tester 4 and the fretting power supply 5. Then, when inspecting the wafer, first, the pair of probe pins 2 are brought into contact with each electrode pad P, and then the pair of probe pins 2 and the fretting power supply 5 are connected via the relay 3. When a voltage is applied to one probe pin 2 from the fretting power supply 5 to the pair of probe pins 2 and the voltage is gradually increased, the oxide film between the pair of probe pins 2 is broken by the fretting phenomenon and the pair of probe pins. A current flows between the two and electrically conducts between the probe pin 2 and the electrode pad P. Next, the pair of probe pins 2 are switched from the fretting power supply 5 to the tester 4 side via the relay 3 and connected to the tester 4 side. Subsequently, an inspection signal is applied from the tester 4 to the electrode pad P via one of the probe pins 2, and a predetermined inspection of the wafer is performed. When using the fretting phenomenon in this way, the stylus pressure between the probe pin 2 and the electrode pad P can be set extremely low, there is no risk of damaging the electrode pad, etc., and a highly reliable inspection can be performed. Can be done. The fretting phenomenon is that the potential gradient applied to the oxide film formed on the surface of the metal (electrode pad in the present invention) is 10.⁵~10⁶When it reaches about V / cm, a phenomenon in which an electric current flows due to the non-uniformity of the thickness of the oxide film and the composition of the metal and the oxide film is destroyed. [0005] [Patent Document 1] JP-A-2002-139542 (Claims 1 and paragraph [0046]) [0006] [Problems to be Solved by the Invention] However, in the case of the inspection method and the inspection apparatus described in Patent Document 1, since the probe pin 2 is fritting for each signal line for inspection of the tester 4 at the time of inspection, the probe inspection is performed. There is a problem that a lot of time is spent on fretting and the throughput of inspection is reduced. Further, in the case of this inspection device, a power supply 5 for flitting and a relay 3 must be provided, and the relay 3 must be mounted on the probe card 1, so that the semiconductor device is highly integrated. As the number of probe pins 2 increases, the number of relays 3 also increases, and the number of relays 3 mounted on the probe card 1 is naturally limited. [0007] The present invention has been made to solve the above problems, and an object of the present invention is to provide an inspection method and an inspection apparatus capable of remarkably improving the inspection throughput and omitting a relay. [0008] [Means for solving problems] The inspection method according to claim 1 of the present invention<u style="single">This is an inspection method for inspecting the electrical characteristics of the object to be inspected, and is described above.</u>Corresponds to each of multiple inspection electrodes of the object to be inspected<u style="single">Multiple pairs</u>of<u style="single">1st and 2nd probe pins</u>To<u style="single">For each of the above inspection electrodes</u>Contact each<u style="single">With the first process</u>、<u style="single">From the driver provided on the tester corresponding to the above 1st probe pin</u>the above<u style="single">1st</u>Probe pin<u style="single">To</u>Apply voltage<u style="single">By doing so, the tip of the first and second probe pins that come into contact with the inspection electrode</u>Fretting phenomenon between<u style="single">And a third step in which the comparator provided in the tester corresponding to the second probe pin detects the fretting phenomenon based on the current from the second probe pin. The driver applies an inspection signal to the inspection electrode via the first probe pin.</u>Inspect the electrical characteristics of the object to be inspected<u style="single">A fourth step is provided, and between the second step and the fourth step, the driver and the comparator come into contact with each of the inspection electrodes via a signal line connected to the fourth step. Connected to the 1st and 2nd probe pins</u>It is characterized by that. [0009] Further, the inspection method according to claim 2 of the present invention is claimed.<u style="single">To 1</u>In the described invention, the above<u style="single">The driver is the above comparator</u>When the limit voltage is detected<u style="single">Fretting voltage</u>It is characterized in that the application is stopped. [0010] Further, the inspection method according to claim 3 of the present invention is claimed in claim 1.<u style="single">Or claim 2</u>The invention described in the above is characterized in that a fretting voltage is applied from each of the above drivers at the same time. [0011] Further, the inspection device according to claim 4 of the present invention<u style="single">An inspection device that inspects the electrical characteristics of the object to be inspected.</u>Corresponds to each of multiple inspection electrodes of the object to be inspected<u style="single">Multiple pairs</u>of<u style="single">With the 1st and 2nd probe pins</u>、<u style="single">The tester is provided corresponding to the first probe pin, and the first probe pin is provided.</u>Above via probe pin<u style="single">Inspection</u>Apply voltage to inspection electrode<u style="single">By doing so, the tips of the above 1st and 2nd probe pins</u>Fritting phenomenon between<u style="single">With the driver that causes</u>、<u style="single">The tester is provided corresponding to the second probe pin.</u>the above<u style="single">1st, 2nd</u>Probe pin<u style="single">Occurs between the tips of</u>Fretting phenomenon<u style="single">Is provided with a comparator that detects based on the current from the second probe pin, and the driver applies an inspection signal from the first probe pin to the inspection electrode.</u>Inspect the electrical characteristics of the object to be inspected<u style="single">Has a function</u>、<u style="single">When the first and second probe pins are in electrical contact with the inspection electrode, the driver and the comparator are in contact with the inspection electrode via a signal line connected to each of the first and second probe pins. Connected to the 2nd probe pin</u>It is characterized by that. [0013] BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described based on the embodiment shown in FIG. In the inspection device 10 of the present embodiment, for example, as shown in FIG. 1, a pair of first and second probe pins 11A and 11B that come into contact with a plurality of electrode pads P of the wafer, and a pair of first and second probe pins 11A and 11B, respectively. 2 The probe card 12 to which the probe pins 11A and 11B are attached, the signal line 13 formed on the probe card 12 and connected to the first and second probe pins 11A and 11B, respectively, and the terminal 14 of these signal lines 13 It is provided with a relay terminal 15 made of a pogo pin or the like that comes into contact with each other electrically and detachably, and is configured to be connectable to the tester 20 via these relay terminals 15. Further, the probe card 12 is fixed to, for example, the head plate (not shown) in the prober chamber of the inspection device 10, and the test head (not shown) on the tester 20 side is fixed via an insert ring (not shown) in which the relay terminal 15 is built. (Not shown) makes electrical contact. [0014] Further, although not shown, the inspection device 10 of the present embodiment has a mounting table on which the wafer is mounted and moves in the X, Y, Z and θ directions, and the wafer in cooperation with the mounting table. It is equipped with an alignment mechanism that aligns the probe pins 11A and 11B. [0015] On the other hand, as shown in FIG. 1, the tester 20 includes a driver 21 and a comparator 22 corresponding to the first and second probe pins 11A and 11B, and the driver 21 can be separated to one of the first probe pins 11A. Along with being connected, the comparator 22 is detachably connected to the other second probe pin 11B side. In addition, signal lines 23 and 24 are connected to the driver 21 and the comparator 22, and are electrically connected to the relay terminals 15 corresponding to the first and second probe pins 11A and 11B via the terminals 25 and 26, respectively. It can be separated. Further, the driver 21 can apply a voltage of a magnitude required for causing the fretting phenomenon to the first probe pin 11A side. [0016] Therefore, with the first and second probe pins 11A and 11B in contact with the electrode pad P with a slight stylus pressure (for example, 1 mN or less), the driver 21 on the tester 20 side passes through the signal line 23 to the inspection device 10 side. When a voltage for fritting is applied to the electrode pad P via the relay terminal 15, the signal line 13 and the first probe pin 11A of the above, and the voltage is gradually increased, the electrode is initially formed between the first and second probe pins 11A and 11B. After a minute current flows through the oxide film P of the pad, it breaks through the oxide film and the current rapidly increases and flows. This current flows from the second probe pin 11B on the inspection device 10 side to the comparator 22 from the signal line 24 on the tester 20 side via the signal line 13 and the relay terminal 15, and when the comparator 22 detects the limit voltage value, the driver Do not apply voltage from 21. After fretting, the first and second probe pins 11A and 11B are used as probe pins for inspection while still in contact with the electrode pads. [0017] Next, an embodiment of the inspection method of the present invention using the inspection device 10 will be described. The wafer is placed on the mounting table in the inspection device 10, the mounting table is moved in the X, Y, and θ directions, and the mounting table and the alignment mechanism cooperate with the electrode pad P of the wafer on the mounting table and the first unit. After aligning with the 2nd probe pins 11A and 11B, the mounting table rises and the electrode pads P of the wafer and the 1st and 2nd probe pins 11A and 11B corresponding to these electrode pads P become For example, contact is performed with a low stylus pressure of 1 mN or less. [0018] After that, all the drivers 21 corresponding to each electrode pad P of the tester 20 pass through the signal line 23, the relay terminal 15 on the inspection device 10 side, the signal line 13 of the probe card 12, and the fritting voltage 11A. Is applied to each electrode P at the same time, a minute current initially flows between the first and second probe pins 11A and 11B on each electrode pad P, and when the voltage is gradually increased for fritting, the first due to the fritting phenomenon. , The current between the 2nd probe pins 11A and 11B suddenly increases and the oxide film of each electrode pad P breaks at the same time, and the 1st and 2nd probe pins 11A and 11B and the electrode pad P become electrically conductive. At the same time, the voltage application from all the drivers 21 is stopped at the same time via the comparator 22. Therefore, it is possible to obtain electrical conduction between all the probe pins 11A and 11B and the corresponding electrode pads P by applying the fretting voltage once, and this is the case where it is performed for each signal line as in the conventional case. Compared with, the time required for fretting can be significantly reduced. [0019] After that, the inspection signal is transmitted from these drivers 21 via the respective signal lines 23, and the inspection signal is applied to the electrode pad P from the first probe pin 11A corresponding to these drivers 21. Similarly, the electrical characteristics of the wafer can be inspected. Moreover, since the inspection can be performed with an extremely low stylus pressure, there is no risk of damaging the first and second probe pins 11A and 11B, the electrode pad P, and the like, and a highly reliable inspection can be performed. [0020] As described above, according to the present embodiment, the first and second probe pins 11A and 11B corresponding to the plurality of electrode pads P of the wafer are brought into contact with each other, and for each electrode via the first probe pin 11A. After applying a voltage for fretting to the pad P and establishing electrical conduction with the second probe pin 11B corresponding to these first probe pins 11A due to the fretting phenomenon, the driver 21 of the tester 20 When inspecting the electrical characteristics of the wafer based on the inspection signal of, the first and second probe pins 11A and 11B connected to each of the plurality of drivers 21 of the tester 20 are connected to the first probe pin 11A. Since the voltage for fretting is applied, it is possible to perform fretting without performing fretting by switching from the fretting dedicated power supply to the tester side power supply for each signal line as in the conventional case. Further, when the fretting voltage is applied, it is applied to all the electrode pads P at the same time, so that the time required for fretting can be remarkably shortened, and the inspection throughput can be remarkably improved. it can. [0021] [0021] Further, according to the present embodiment, since the tester 20 is used as the fretting power source, it is not necessary to provide the fretting dedicated power source and the relay, and the manufacturing cost can be reduced. Further, since the relay on the probe card 12 can be omitted, the mounting area can be expanded by the area for mounting the relay, and it is possible to cope with the high integration of the semiconductor device. Further, since the second probe pin 11B is connected to the comparator 22 of the tester 20, the limiting voltage at the time of fretting can be detected via the comparator 22. [0022] The present invention is not limited to the above embodiment, and each component can be appropriately modified as needed. [0023] [Effect of the invention] Main departure<u style="single">Ming</u>Therefore, it is possible to provide an inspection method and an inspection apparatus capable of remarkably improving the inspection throughput, omitting a relay, and performing a highly reliable inspection.<u style="single"></u>[Simple explanation of drawings] FIG. 1 is a block diagram showing a main part of an embodiment of the inspection device of the present invention. FIG. 2 is a block diagram showing an example of a conventional inspection device. [Explanation of symbols] 10 Inspection equipment 11A, 11B probe pin 20 tester 21 driver 22 Comparator P electrode pad (inspection electrode)