CN118641814A

CN118641814A - Protection structure and method of WAT test machine

Info

Publication number: CN118641814A
Application number: CN202410668474.7A
Authority: CN
Inventors: 邢阳阳; 陆尉
Original assignee: Shanghai Huali Integrated Circuit Manufacturing Co Ltd
Current assignee: Shanghai Huali Integrated Circuit Manufacturing Co Ltd
Priority date: 2024-05-27
Filing date: 2024-05-27
Publication date: 2024-09-13

Abstract

The present invention discloses a protection structure of a WAT test machine, including: a protection resistor. The protection resistor is connected in series with the Force end cable of the WAT test machine. The protection resistor is used to protect the machine hardware of the WAT test machine when a maximum fault signal appears in the test loop of the WAT test machine. The maximum fault signal is a current signal or a voltage signal. The protection resistor is set according to the tolerance of the machine hardware to be protected, so that when the maximum fault signal is generated, the maximum fault signal is reduced to below the tolerance. The present invention also discloses a protection method for the WAT test machine. The present invention can protect the machine hardware and probe card in the WAT test.

Description

Protection structure and method of WAT test machine

Technical Field

The present invention relates to the field of semiconductor integrated circuit fabrication, and more particularly, to a protection structure for a Wafer Acceptance Test (WAT) machine. The invention also relates to a protection method of the WAT test machine.

Background

In the daily WAT test, sometimes, a large current or voltage is generated in the test loop due to the influence of the tip particle (particle) contamination of the probe card or the failure of the machine, and when the current or voltage exceeds the tolerance of the machine hardware or the design of the probe card itself, the machine hardware or the probe card in direct contact with the wafer (wafer) is damaged.

As shown in fig. 1, the connection structure diagram of the WAT test machine in the prior WAT test is shown; the probe substrate 101 of the WAT tester is connected to the probe card 102, and a plurality of probes 103 are disposed on the probe card 102, and the probes 103 are connected to test pads (pads) of a device under test on the wafer 104.

When WAT testing is performed, electrical signals, such as current, voltage, etc., are applied, and the applied electrical signals are excitation signals, which are transmitted from the probe substrate 101 to the wafer 104 through the probe card 102 in a direction indicated by arrow 106.

The WAT test also measures the electrical signal, the direction of transmission being indicated by arrow 107.

As shown in fig. 2, the current test data curve is shown when the current WAT test fails (current); in fig. 2, the abscissa represents MIMVBD, which represents the applied voltage across the MIM capacitor; the ordinate is leakage current Ileak, and it can be seen that when MIMVBD increases to a certain value, a rapid rise in current occurs as indicated by the dashed circle 108, which indicates that a WAT test fault associated with the current signal occurs, and at this time, the larger current signal may cause damage to the hardware of the machine and the probe card in the WAT test.

Disclosure of Invention

The invention aims to provide a protection structure of a WAT test machine, which can protect machine hardware and a probe card in WAT test. Therefore, the invention also provides a protection method of the WAT test machine.

In order to solve the above technical problems, the protection structure of the WAT test machine provided by the present invention includes: and protecting the resistor.

And the protection resistor is connected with a Force end cable of the WAT test machine in series.

The protection resistor is used for protecting the hardware of the WAT test machine when the maximum fault signal occurs in the test loop of the WAT test machine.

The maximum fault signal is a current signal or a voltage signal.

And setting the protection resistor according to the tolerance of the hardware of the machine to be protected, so that the maximum fault signal is reduced below the tolerance when the maximum fault signal is generated.

A further improvement is that the maximum fault signal is generated when a particle defect occurs at a needle tip or when a machine fault occurs at the WAT test machine.

Further improvements are that the WAT test machine comprises a probe substrate (pin board) and a probe card (probe card).

And the Force end cable is arranged on the probe substrate.

The probe substrate is also provided with a plurality of groups of port line combinations consisting of Gnd port lines, force port lines and Sense port lines. Gnd denotes ground, force denotes an excitation signal, and Sense denotes a measurement signal.

And each Force port line is connected with the corresponding Force end cable line.

The Gnd port line is grounded.

And each Gnd port line, each Force port line and each Sense port line are connected with the probe card, and the Force port line and the Sense port line are short-circuited together on the probe card.

A further improvement is that a plurality of probes are arranged on the probe card.

The first end of each probe is fixed on the probe card and is shorted to the Force port line in one of the port line combinations.

The second end of each probe is used for being connected with a test pad on the tested wafer.

In a further improvement, the Force port wires of each port wire combination are all connected to the same Force end cable wire.

A further improvement is that the wafer under test is placed on a chuck (chuck).

The probe substrate is also provided with a second cable conductor and a second port line combination.

The second port line combination includes a first port line, a second port line, and a third port line.

The first port line and the second port line are shorted together and the second port line and the second cable line are connected.

The second port wire is also connected to the chuck by a first lead.

The third port line is grounded.

Further improvement is that the method further comprises: and a second protection resistor.

The second protection resistor is connected with the second cable in series.

The second protection resistor is used for protecting the hardware of the WAT test machine when the maximum fault signal occurs in the test loop.

And setting the second protection resistor according to the tolerance of the hardware of the machine to be protected, so that the maximum fault signal is reduced below the tolerance when the maximum fault signal is generated.

In a further improvement, the second protection resistor and the protection resistor have equal resistance.

The improvement is that the Force end cable and the second cable both adopt AUX coaxial cables.

Each Gnd port line is connected to a ground terminal of the Force terminal cable line.

The third port line is connected to a ground terminal of the second cable line.

A further improvement is that the resistance of the protection resistor is of the order of mΩ.

A further improvement is that the second protection resistor and the protection resistor are arranged in the same resistor box.

The resistor box comprises a first interface and a second interface.

The first interface is used for being connected with an interface of the Force end cable so as to realize the serial connection of the protection resistor and the Force end cable.

The second interface is used for being connected with an interface of the second cable so as to realize the serial connection of the second protection resistor and the second cable.

A further improvement is that the probe substrate is disposed on a test head (testhead).

A further improvement is that the chuck comprises an electrostatic chuck.

In order to solve the technical problems, the protection method of the WAT test machine provided by the invention comprises the following steps:

and connecting the protection resistor and the Force end cable in series.

And in the WAT test process, when the maximum fault signal appears in the test loop, the protection resistor reduces the maximum fault signal to be below the tolerance, so that the hardware of the WAT test machine is protected.

And connecting the interfaces of the first interface and the Force end cable and the interfaces of the second interface and the second cable of the resistor box to realize the serial connection of the protection resistor and the Force end cable and the serial connection of the second protection resistor and the second cable.

And in the WAT test process, when the maximum fault signal occurs to the test loop, the protection resistor reduces the maximum fault signal occurring to the Force end cable below the tolerance, and the second protection resistor reduces the maximum fault signal occurring to the second cable below the tolerance, so that the hardware of the WAT test machine is protected.

According to the invention, the protection resistor is arranged in series with the Force end cable, and the protection resistor is arranged according to the requirement that the maximum fault signal is reduced below the tolerance of the machine hardware when the maximum fault signal occurs, so that the machine hardware and the probe card can be protected in WAT test, thereby reducing the fault rate, the test problem and the equipment repairing time.

Drawings

The invention is described in further detail below with reference to the attached drawings and detailed description:

FIG. 1 is a connection structure diagram of a WAT test machine in the prior WAT test;

FIG. 2 is a graph of current test data for a WAT test fault in a prior art WAT test;

fig. 3 is a schematic diagram of a protection structure of a WAT test machine according to an embodiment of the present invention.

Detailed Description

FIG. 3 is a schematic diagram of a protection structure of a WAT test machine according to an embodiment of the present invention; the protection structure of the WAT test machine provided by the embodiment of the invention comprises: protection resistor 305a.

The protection resistor 305a is connected in series with the Force end cable 303 of the WAT test machine.

The protection resistor 305a is used for protecting the hardware of the WAT test machine when the maximum fault signal occurs in the test loop of the WAT test machine.

The maximum fault signal is a current signal or a voltage signal.

The protection resistor 305a is set according to the tolerance of the hardware to be protected, so that the maximum fault signal is reduced below the tolerance when the maximum fault signal is generated.

In some embodiments, the maximum fault signal is generated when a particle defect occurs at a tip or when a machine fault occurs at the WAT test machine.

The WAT test station includes a probe substrate 201 and a probe card 202.

The Force end cable 303 is disposed on the probe substrate 201.

In an embodiment of the present invention, the probe substrate 201 is disposed on a test head.

The probe substrate 201 is further provided with a plurality of sets of port line combinations 301 comprising Gnd port lines 301a, force port lines 301b and Sense port lines 301 c. In fig. 3, gnd port line 301a is also denoted by G, force port line 301b is also denoted by F, and Sense port line 301c is also denoted by S.

Each Force port line 301b is connected to the corresponding Force end cable line 303.

The Gnd port line 301a is grounded.

Each of the Gnd port line 301a, the Force port line 301b, and the Sense port line 301c is connected to the probe card 202, and the Force port line 301b and the Sense port line 301c are shorted together on the probe card 202.

The probe card 202 is provided with a plurality of probes 203.

A first end of each of the probes 203 is secured to the probe card 202 and shorted to the Force port line 301b in one of the port line combinations 301. As can be seen from fig. 3, one of the probes 203 corresponds to one of the port line combinations 301.

A second end of each of the probes 203 is configured to connect to a test pad on a wafer 204 under test.

In some embodiments, the Force port wires 301b of each of the port wire combinations 301 are all connected to the same Force side cable wire 303. That is, the plurality of port line combinations 301 share the same Force-side cable 303, so that only one protection resistor 305a is needed to be implemented.

The wafer 204 under test is placed on a chuck 205. In fig. 3, the Chuck 205 is also denoted by Chuck. The Wafer under test 204 is also denoted Wafer. The wafer under test 204 manufactures a plurality of semiconductor devices.

In some embodiments, the chuck 205 comprises an electrostatic chuck 205.

In the embodiment of the present invention, the probe substrate 201 is further provided with a second cable 304 and a second port line assembly 302.

The second port line combination 302 includes a first port line 302a, a second port line 302b, and a third port line 302c.

The first port line 302a and the second port line 302b are shorted together and the second port line 302b and the second cable line 304 are connected.

The second port wire 302b is also connected to the chuck 205 by a first lead 306.

The third port line 302c is grounded.

In the embodiment of the invention, the method further comprises the following steps: and a second protection resistor 305b.

The second protection resistor 305b is connected in series with the second cable 304.

The second protection resistor 305b is configured to protect the hardware of the WAT test machine when the maximum fault signal occurs in the test loop.

The second protection resistor 305b is set according to the tolerance of the hardware to be protected, so that the maximum fault signal is reduced below the tolerance when the maximum fault signal is generated.

In some embodiments, the resistances of the second protection resistor 305b and the protection resistor 305a are equal in magnitude. In other embodiments, it can also be: the resistances of the second protection resistor 305b and the protection resistor 305a are not equal, and only the requirements defined above need to be satisfied.

In some embodiments, the protection resistor 305a has a resistance of the order of mΩ, for example, all 1mΩ.

In the embodiment of the present invention, both the Force end cable 303 and the second cable 304 are AUX coaxial cables. The metal wire 303a wrapped around the Force-end cable 303 serves as a ground terminal, and each Gnd port wire 301a is connected to the ground terminal of the Force-end cable 303. The metal wire 304a wrapped around the second electric cable 304 serves as a ground terminal, and the third port wire 302c is connected to the ground terminal of the second electric cable 304.

In some embodiments, the second protection resistor 305b and the protection resistor 305a are disposed in the same resistor box.

The resistor box comprises a first interface and a second interface.

The first interface is configured to interface with the Force end cable 303, so as to realize the serial connection of the protection resistor 305a and the Force end cable 303.

The second interface is used for interfacing with the second cable 304 to realize the serial connection of the second protection resistor 305b and the second cable 304.

Through the arrangement of the resistor box, in the testing process, the first interface and the second interface of the resistor box are directly inserted into the interface of the Force end cable 303 and the interface of the second cable 304, and then the protection effect on the machine hardware and the probe card 202 can be realized when WAT is performed, so that the testing work is very convenient.

As shown in fig. 3, arrow lines 307 represent loops of electrical signals that would pass through probe card 202 during testing, and it can be seen that corresponding electrical signals are transmitted from the tips of probes 203 through probes 203, probe card 202, and Force port line 301b onto Force side cable line 303. It can be seen that by providing the protection resistor 305a, the maximum fault signal corresponding to the electrical signal corresponding to the arrow line 307 can be reduced and below the tolerance, so that the protection of the machine hardware and the probe card can be realized.

Arrow-headed line 308 represents a return path for electrical signals that do not pass through probe card 202 during testing, and it can be seen that corresponding electrical signals are transmitted from the chuck 205, first lead 306, and second port line 302b to the second electrical cable 304. It can be seen that, by providing the second protection resistor 305b, the maximum fault signal corresponding to the electrical signal corresponding to the arrow line 307 can be reduced and below the tolerance, so that the protection of the machine hardware and the probe card can be realized.

According to the embodiment of the invention, the protection resistor 305a is arranged in series with the Force end cable 303, and the protection resistor 305a is arranged according to the requirement that the maximum fault signal is reduced below the tolerance of the machine hardware when the maximum fault signal occurs, so that the machine hardware and the probe card 202 can be protected in WAT test, thereby reducing the fault rate and the test problem.

In some embodiments, the number of probes 203 included on the probe card 202 is 48, and the number of corresponding port line combinations 301 is also 48; the number of the second port line combinations 302 is 1. By setting 2 large resistors of 1MΩ, the machine hardware and the probe card in the test process can be effectively protected, the fault rate is reduced, for example, the daily (day) point detection fault rate is reduced from 0.2% to 0.1%, and the test problem and the equipment repair time are reduced, wherein the 1-equipment repair time is 2 hours.

Meanwhile, the protection structure of the embodiment of the invention does not influence the test result:

By comparing the test curves of classical (typical) device resistance, typical device capacitance, typical device current and typical device voltage with the existing structure without the protection structure of the embodiment of the invention, the test results of the two are consistent. Therefore, the protection structure of the embodiment of the invention does not influence the test result.

The protection method of the WAT test machine in the embodiment of the invention comprises the following steps:

the protection resistor 305a and the Force end cable 303 are connected in series.

And in the WAT test process, when the maximum fault signal occurs in the test loop, the protection resistor 305a reduces the maximum fault signal to be below the tolerance, so as to protect the hardware of the WAT test machine.

the interface connection between the first interface and the Force end cable 303 and the interface connection between the second interface and the second cable 304 of the resistor box are used for realizing the serial connection between the protection resistor 305a and the Force end cable 303 and the serial connection between the second protection resistor 305b and the second cable 304.

And in the WAT test process, when the maximum fault signal occurs in the test loop, the protection resistor 305a reduces the maximum fault signal occurring in the Force end cable 303 to be below the tolerance, and the second protection resistor 305b reduces the maximum fault signal occurring in the second cable 304 to be below the tolerance, so that the hardware of the WAT test machine is protected.

The present invention has been described in detail by way of specific examples, but these should not be construed as limiting the invention. Many variations and modifications may be made by one skilled in the art without departing from the principles of the invention, which is also considered to be within the scope of the invention.

Claims

1. The utility model provides a protection architecture of WAT test machine platform which characterized in that includes: a protection resistor;

The protection resistor is connected with a Force end cable of the WAT test machine in series;

The protection resistor is used for protecting the hardware of the WAT test machine when the maximum fault signal occurs in the test loop of the WAT test machine;

The maximum fault signal is a current signal or a voltage signal;

2. The WAT test station protection structure of claim 1, wherein: the maximum fault signal is generated when a particle defect occurs on a needle point or when a machine fault occurs on the WAT test machine.

3. The WAT test station protection structure of claim 1, wherein: the WAT test machine comprises a probe substrate and a probe card;

the Force end cable is arranged on the probe substrate;

The probe substrate is also provided with a plurality of groups of port line combinations consisting of Gnd port lines, force port lines and Sense port lines;

each Force port line is connected with the corresponding Force end cable line;

The Gnd port line is grounded;

4. The WAT test station protection structure of claim 3, wherein: the probe card is provided with a plurality of probes;

the first end of each probe is fixed on the probe card and is in short circuit with the Force port line in one port line combination;

5. The WAT test station protection structure of claim 4, wherein: and the Force port wires of each port wire combination are connected to the same Force end cable wire.

6. The WAT test station protection structure of claim 5, wherein: the wafer to be tested is placed on a chuck;

the probe substrate is also provided with a second cable conductor and a second port line combination;

the second port line combination comprises a first port line, a second port line and a third port line;

the first port line and the second port line are short-circuited together and the second port line is connected with the second cable;

the second port line is also connected with the chuck through a first lead;

The third port line is grounded.

7. The WAT test station protection structure of claim 6, further comprising: a second protection resistor;

the second protection resistor is connected with the second cable in series;

the second protection resistor is used for protecting the hardware of the WAT test machine when the maximum fault signal occurs in the test loop;

8. The WAT test station protection structure of claim 7, wherein: and the second protection resistor and the protection resistor have equal resistance.

9. The WAT test station protection structure of claim 7, wherein: the Force end cable and the second cable adopt AUX coaxial cables;

each Gnd port line is connected to the grounding end of the Force end cable line;

The third port line is connected to a ground terminal of the second cable line.

10. The WAT test station protection structure of claim 8, wherein: the resistance of the protection resistor is of the order of MΩ.

11. The WAT test station protection structure of claim 8, wherein: the second protection resistor and the protection resistor are arranged in the same resistor box;

The resistor box comprises a first interface and a second interface;

The first interface is used for being connected with an interface of the Force end cable so as to realize the serial connection of the protection resistor and the Force end cable;

12. The WAT test station protection structure of claim 3, wherein: the probe substrate is disposed on the test head.

13. The WAT test station protection structure of claim 6, wherein: the chuck comprises an electrostatic chuck.

14. A method of protecting a WAT test station using the protection architecture of claim 1, comprising the steps of:

the protection resistor is connected with the Force end cable in series;

15. A method of protecting a WAT test station using the protection architecture of claim 11, comprising the steps of:

Connecting the interfaces of the first interface and the Force end cable of the resistor box and the interfaces of the second interface and the second cable to realize the serial connection of the protection resistor and the Force end cable and the serial connection of the second protection resistor and the second cable;