Impedance measuring device of wafer bearing platform

Abstract

The utility model provides an impedance measuring device of a wafer bearing platform. The impedance measuring device comprises an impedance measuring instrument, an impedance measuring line, a machine platform where the wafer bearing platform to be subjected to impedance measurement is located, a first relay and a first sensor, a signal output interface of the first sensor is connected to a cathode interface of the first relay; an anode interface of the first relay is connected to the positive power supply; a measurement input interface of the impedance measurement instrument is connected to a resistance block at the bottom of the wafer bearing platform to be subjected to impedance measurement through an impedance measurement line; one end of a normally closed contact of the impedance measuring instrument is connected with a positive power supply, and the other end of the normally closed contact is connected with a negative power supply through an electromagnetic valve; the impedance measuring instrument is also connected with the power supply through a normally open contact of the first relay; wherein the electromagnetic valve is arranged in an air pipe, used for controlling ascending, of the machine table, and the first sensor is configured to detect the descending state of the wafer bearing platform. According to the utility model, the impedance of the wafer bearing platform can be measured without destroying the vacuum environment.

Description

Technical Field

[0001] The utility model belongs to the technical field of semiconductors, and in particular relates to an impedance measuring device for a wafer carrying platform. Background Art

[0002] In the field of semiconductor manufacturing equipment, the Bumping UBM sputtering process is a key technology, and its process quality directly affects the performance and reliability of the product. In this process, the impedance of the wafer carrier platform is a key parameter, which directly affects the subsequent process quality and the quality of the product. However, due to factors such as the material properties of the wafer carrier platform itself and the thermal stress during the process, the impedance of the wafer carrier platform will change to a certain extent during the process, which may affect the subsequent process and the quality of the product. In addition, the wafer carrier platform has a relatively high vacuum requirement, which needs to reach 10 -8 Vacuum degree.

[0003] In existing technologies, the impedance of the wafer carrier platform is usually measured using a multimeter after manually opening the cavity, or by directly contacting the wafer carrier platform with the multimeter probes to perform impedance measurement. Both methods are inefficient and require a lot of time and manpower. Using the multimeter probes to directly contact the wafer carrier platform may also scratch the surface of the wafer carrier platform, affecting the accuracy of the measurement results. Both methods also have certain safety risks. For example, the manual cavity opening operation may cause the vacuum environment to be damaged. Currently, there is a lack of efficient wafer carrier platform impedance measurement devices that do not require the destruction of the vacuum environment. Summary of the Invention

[0004] The purpose of the utility model is to provide an impedance measurement device for a wafer carrying platform, which is used to solve the problems of low efficiency of impedance measurement of the wafer carrying platform and destruction of the vacuum environment.

[0005] In order to solve the above technical problems, the present application provides an impedance measurement device for a wafer carrying platform, which is characterized by comprising:

[0006] An impedance measuring instrument, an impedance measuring line, a machine on which a wafer carrying platform to be measured is located, a first relay, and a first sensor; the signal output interface of the first sensor is connected to the negative electrode interface of the first relay, and the positive electrode interface of the first relay is connected to a positive power supply;

[0007] The measurement input interface of the impedance measuring instrument is connected to the resistance block at the bottom of the wafer supporting platform to be measured through the impedance measurement line;

[0008] One end of the normally closed contact of the impedance measuring instrument is connected to the positive power supply, and the other end of the normally closed contact is connected to the negative power supply through the solenoid valve;

[0009] The impedance measuring instrument is also connected to a power source via the normally open contact of the first relay;

[0010] The solenoid valve is arranged in the air pipe of the machine for controlling the ascent, and the first sensor is configured to detect the descending state of the wafer carrying platform.

[0011] In one embodiment of the present invention, the impedance measuring instrument is connected to the power supply via the normally open contact of the first relay in the following manner:

[0012] The positive electrode interface of the impedance measuring instrument is connected to the positive power supply through the normally open contact of the first relay, and the negative electrode interface of the impedance measuring instrument is connected to the negative power supply.

[0013] In one embodiment of the present invention, the impedance measuring instrument is connected to the power supply via the normally open contact of the first relay in the following manner:

[0014] The negative electrode interface of the impedance measuring instrument is connected to the negative power supply through the normally open contact of the first relay, and the positive electrode interface of the impedance measuring instrument is connected to the positive power supply.

[0015] In one embodiment of the present invention, a second relay and a second sensor are further included;

[0016] The normally open contact of the second relay is arranged between the impedance measuring instrument and the power supply, and the normally open contact of the second relay is connected in series with the normally open contact of the first relay;

[0017] The signal output interface of the second sensor is connected to the negative electrode interface of the second relay, and the positive electrode interface of the second relay is connected to the positive power supply.

[0018] In an embodiment of the present invention, the impedance measurement wire is made of copper wire.

[0019] In an embodiment of the present invention, the length of the impedance measurement line is greater than 1.5 meters.

[0020] In one embodiment of the present invention, the impedance measuring instrument is a smart resistance meter.

[0021] In one embodiment of the present invention, the smart resistance meter includes a digital display screen.

[0022] In one embodiment of the present invention, the model of the smart resistance meter is E4980A.

[0023] Compared with the prior art, the impedance measurement device for the wafer carrying platform proposed in this utility model has the following beneficial effects:

[0024] (1) The impedance measuring instrument in the present invention is connected to the resistance block at the bottom of the wafer supporting platform to be measured through the impedance measuring line, thereby realizing measurement of the wafer supporting platform without opening the cavity of the wafer supporting platform.

[0025] (2) The present invention also ensures, through the first relay and the first sensor, that the impedance measurement device performs impedance measurement only when the wafer carrying platform is in a descending state, thereby ensuring the accuracy of the impedance measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention.

[0027] Figure 1 A structural schematic diagram of the impedance measuring device of the wafer carrying platform according to an embodiment of the present utility model is shown.

[0028] Figure 2 A schematic diagram of a resistor block C is shown.

[0029] Figure 3 A schematic diagram showing the position of the resistor block described in an embodiment of the present invention in the wafer supporting platform is shown.

[0030] Component number description:

[0031] S1 is the first sensor, S2 is the second sensor, K1 is the first relay, K2 is the second relay, Z is the impedance meter, C is the resistance block, GND is the ground wire, D is the solenoid valve, K1a is the normally open contact of the first relay K1, and K2a is the normally open contact of the second relay K2. DETAILED DESCRIPTION

[0032] The following describes the implementation of the present invention in detail with reference to the accompanying drawings and examples, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as no conflict arises, the various embodiments of the present invention and the various features in each embodiment can be combined with each other, and the resulting technical solutions are all within the scope of protection of the present invention.

[0033] The principle and implementation of the impedance measurement device for the wafer supporting platform of this embodiment will be described in detail below so that those skilled in the art can understand the impedance measurement device for the wafer supporting platform of this embodiment without creative work.

[0034] In order to solve the above-mentioned technical problems existing in the prior art, an embodiment of the present utility model provides an impedance measurement device for a wafer carrying platform.

[0035] Figure 1 The structure diagram of the impedance measurement device of the wafer carrying platform of the utility model is shown. Figure 1 As shown, the impedance measurement device for a wafer support platform according to an embodiment of the present invention includes an impedance meter Z, an impedance measurement line L, a machine platform on which a wafer support platform to be measured is located, the wafer support platform to be measured being the wafer support platform whose impedance is to be measured, a first relay K1, and a first sensor S1. The signal output interface of the first sensor S1 is connected to the negative terminal of the first relay K1, and the positive terminal of the first relay K1 is connected to a positive power supply. The measurement input interface IN of the impedance meter Z is connected to a resistor block C at the bottom of the wafer support platform to be measured via the impedance measurement line L. One end of the normally closed contact OUT of the impedance meter Z is connected to the positive power supply, and the other end of the normally closed contact OUT is connected to the negative power supply via a solenoid valve. The impedance meter Z is also connected to the power supply via the normally open contact K1a of the first relay K1. The ground interface G of the impedance meter Z is connected to the ground line GND. The solenoid valve D is installed in the air pipe of the machine platform for controlling descent. The first sensor K1 is configured to detect the descent state of the wafer support platform. Figure 1 The positive power supply and negative power supply in the figure represent the two power lines of the DC power supply, such as 24v and 0v. The 24v power line is the positive power supply of the DC power supply, and the 0v power line is the negative power supply of the DC power supply.

[0036] Specifically, the principle of the impedance measurement device of the wafer supporting platform of the embodiment of the present invention is as follows: there is a resistor block C at the bottom of the wafer supporting platform to be measured, and the resistor block C is in series with the wafer supporting platform on which it is located in the circuit. Figure 2 A schematic diagram of the resistor block C is shown, referring to Figure 2 As shown, the materials used to make the resistor block C include metal, ceramic and semiconductor. Figure 3 The schematic diagram of the position of the resistor block in the wafer carrying platform according to the embodiment of the present invention is shown. Figure 3 As shown, there is a resistor block C at the bottom of the wafer supporting platform. When the machine is in normal working condition, the charge generated by the machine operation is grounded and discharged. Therefore, the impedance of the wafer supporting platform is the same as the impedance of the resistor block C. Therefore, by measuring the impedance of the resistor block C, the impedance of the wafer supporting platform can be obtained. The present application draws an impedance measurement line L from the impedance measuring instrument Z and connects it to the resistor block C. The measured impedance of the resistor block C can represent the impedance of the wafer supporting platform. The impedance measurement result of the wafer supporting platform can be displayed in the impedance measuring instrument, so that the impedance of the wafer supporting platform can be measured without artificial cavity opening. The measurement is fast and does not require cavity opening operation, avoiding destroying the vacuum environment of the wafer supporting platform.

[0037] The signal output interface of the first sensor S1 is connected to the negative terminal of the first relay K1. The positive terminal of the first sensor S1 is connected to a positive power supply. The negative terminal of the first sensor S1 is connected to a negative power supply, while the positive terminal of the first relay S1 is connected to a positive power supply. The first sensor S1 detects the platform's descent state to determine whether the platform has descended to a preset position. Based on this result, it determines whether to allow the first relay K1 to conduct current. When the first sensor S1 detects that the wafer carrier platform has descended to the preset position, it sends a signal to the first relay K1, triggering the normally open contact K1a of the first relay K1 to close, allowing current to pass, thereby activating the operation of the impedance measuring instrument Z. Since the platform undergoes plasma dissociation after it rises, it will interfere with the measurement results. This embodiment only initiates the impedance measurement of the wafer carrier platform when the platform descends to the preset position, ensuring the accuracy of the measurement results.

[0038] One end of the normally closed contact of the impedance meter Z is connected to the positive power supply, and the other end is connected to the negative power supply through the solenoid valve D. When the normally closed contact is in the default state, the circuit remains connected. The solenoid valve D is set in the air pipe used to control the ascent of the machine. When the wafer carrier platform rises beyond the detection range of the first sensor, the first sensor stops sending an output signal to the first relay. At this time, the normally open contact of the first relay opens, and the normally closed contact of the impedance meter Z is de-energized. In addition, the solenoid valve D is also de-energized, and the air flow in the ascending air pipe cannot pass through, so the wafer carrier platform stops rising. The solenoid valve D acts as a safety control mechanism, and the first sensor is equivalent to controlling the switch of the solenoid valve. When the wafer carrier platform continues to rise beyond a certain position, the wafer carrier platform is locked in the descending position, further ensuring the accuracy of the measured impedance results.

[0039] In a specific embodiment, there are two ways to connect the impedance measuring instrument Z to the power supply via the normally open contact K1a of the first relay K1. In the first way, the impedance measuring instrument Z is connected to the power supply via the normally open contact K1a of the first relay K1 in the following manner: the positive terminal of the impedance measuring instrument Z is connected to the positive power supply via the normally open contact K1a of the first relay K1, and the negative terminal of the impedance measuring instrument Z is connected to the negative power supply. In the second way, the impedance measuring instrument Z is connected to the power supply via the normally open contact K1a of the first relay K1 in the following manner: the negative terminal of the impedance measuring instrument Z is connected to the negative power supply via the normally open contact K1a of the first relay K1, and the positive terminal of the impedance measuring instrument Z is connected to the positive power supply.

[0040] Optionally, the impedance measuring device of the wafer carrying platform of the embodiment of the present utility model further includes a second relay K2 and a second sensor S2. The normally open contact K2a of the second relay K2 is arranged between the impedance measuring instrument Z and the power supply, and the normally open contact K2a of the second relay K2 is connected in series with the normally open contact K1a of the first relay K1; the signal output interface of the second sensor S2 is connected to the negative electrode interface of the second relay K2, the positive electrode interface of the second relay K2 is connected to the positive power supply, the positive electrode interface of the second sensor S2 is connected to the positive power supply, the negative electrode interface of the second sensor S2 is connected to the negative power supply, and the second sensor S2 is configured to detect the descent state of the wafer carrying platform. It should be noted that the second sensor S2 and the first sensor S1 are arranged at different positions on the wafer carrying platform. The first sensor S1 detects the descent state of a certain position on the wafer carrier platform and triggers the first relay K1. The second sensor S2 detects the descent state of another position and triggers the second relay K2. Only when the two sensors meet the conditions at the same time (that is, the results of both sensors show that the wafer carrier platform has descended to the preset position), the normally open contact K1a of the first relay K1 and the normally open contact K2a of the second relay K2 will close simultaneously, connecting the impedance meter Z to the power supply and starting the impedance measurement. By adding the second relay K2 and the second sensor S2, the second sensor S2 and the first sensor S1 respectively detect the descent state of different positions. This application also designs the normally open contacts of the two relays in series, which can ensure that the system can only start the measurement under the premise that both conditions are met, thereby improving the accuracy and stability of the measurement. It is suitable for high-precision impedance measurement application scenarios that require strict control of the measurement environment and conditions.

[0041] Optionally, the impedance measurement line L is made of copper wire. Copper wire has very low resistivity, which can minimize the influence of the impedance measurement line's own resistance during impedance measurement, thereby ensuring measurement accuracy. Therefore, using a copper wire impedance measurement line in the impedance measurement device of the wafer support platform can effectively reduce the additional impedance error caused by the wire itself and improve measurement accuracy.

[0042] Optionally, the impedance measurement line L is longer than 1.5 meters. Because the wafer platform moves downward during the impedance measurement process, the impedance measurement line L must be long enough to ensure unrestricted platform movement. A length of impedance measurement line L greater than 1.5 meters ensures ample room for movement of the wafer platform, preventing the measurement line from being pulled or dislodged. This also increases the flexibility and adaptability of the device and ensures continuity during the impedance measurement process.

[0043] Optionally, the impedance measuring instrument Z is a smart resistance meter. Because even small impedance changes on the wafer platform may affect the production process and product quality, a smart resistance meter has very high measurement accuracy and can accurately measure impedance down to the milliohm or even microohm level, thus ensuring the accuracy of the wafer platform impedance measurement.

[0044] Optionally, the smart resistance meter includes a digital display. Using a smart resistance meter equipped with a digital display can intuitively display the impedance measurement results on the screen, allowing the user to visually observe the impedance value of the wafer support platform in real time, facilitating timely monitoring and adjustment.

[0045] Optionally, the smart resistance meter is model E4980A, which is capable of performing precise impedance measurement with a measurement range of 0.1mΩ to 1MΩ and a measurement accuracy of ±0.05% FS.

[0046] In summary, the impedance measuring instrument of the present invention connects an impedance measurement line to a resistor block at the bottom of the wafer platform to be measured, enabling measurement of the wafer platform without requiring any cavity opening. Furthermore, the first relay and first sensor ensure that the impedance measurement device performs impedance measurement only when the wafer platform is in the lowered state, thus ensuring the accuracy of the impedance measurement.

[0047] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical concepts disclosed in this application shall be covered by the claims of this application.

Claims

1. An impedance measurement device for a wafer carrying platform, characterized in that: include: An impedance measuring instrument, an impedance measuring line, a machine on which a wafer carrying platform to be measured is located, a first relay, and a first sensor; the signal output interface of the first sensor is connected to the negative electrode interface of the first relay, and the positive electrode interface of the first relay is connected to a positive power supply; The measurement input interface of the impedance measuring instrument is connected to the resistance block at the bottom of the wafer supporting platform to be measured through the impedance measurement line; One end of the normally closed contact of the impedance measuring instrument is connected to the positive power supply, and the other end of the normally closed contact is connected to the negative power supply through the solenoid valve; The impedance measuring instrument is also connected to a power source via the normally open contact of the first relay; The solenoid valve is arranged in the air pipe of the machine for controlling the ascent, and the first sensor is configured to detect the descending state of the wafer carrying platform.

2. The impedance measuring device according to claim 1, wherein The impedance measuring instrument is connected to the power supply via the normally open contact of the first relay in the following manner: The positive electrode interface of the impedance measuring instrument is connected to the positive power supply through the normally open contact of the first relay, and the negative electrode interface of the impedance measuring instrument is connected to the negative power supply.

3. The impedance measuring device according to claim 1, wherein: The impedance measuring instrument is connected to the power supply via the normally open contact of the first relay in the following manner: The negative electrode interface of the impedance measuring instrument is connected to the negative power supply through the normally open contact of the first relay, and the positive electrode interface of the impedance measuring instrument is connected to the positive power supply.

4. The impedance measuring device according to claim 1, wherein: Also included is a second relay and a second sensor; The normally open contact of the second relay is arranged between the impedance measuring instrument and the power supply, and the normally open contact of the second relay is connected in series with the normally open contact of the first relay; The signal output interface of the second sensor is connected to the negative electrode interface of the second relay, and the positive electrode interface of the second relay is connected to the positive power supply.

5. The impedance measuring device according to claim 1, wherein: The impedance measurement wire is made of copper wire.

6. The impedance measuring device according to claim 1, wherein: The length of the impedance measurement line is greater than 1.5 meters.

7. The impedance measuring device according to claim 1, wherein: The impedance measuring instrument is an intelligent resistance meter.

8. The impedance measuring device according to claim 7, wherein: The intelligent resistance meter includes a digital display screen.

9. The impedance measuring device according to claim 8, characterized in that: The model of the smart resistance meter is E4980A.

Images