Method and system for detecting wafer scratches by robotic arm and semiconductor processing equipment

Abstract

The present application relates to a method, system and semiconductor processing equipment for detecting scratches on wafers by a robot in the field of semiconductor technology, wherein the robot comprises a base, a wafer clamping part, a plurality of joints and a plurality of rotating shafts, and each rotating shaft is provided with a driving motor; the method for detecting scratches on wafers by the robot comprises: the wafer clamping part grasps the wafer; each driving motor drives the corresponding rotating shaft to rotate, driving the wafer clamping part to move from inside the wafer box to outside the wafer box or from outside the wafer box to inside the wafer box; real-time measurement of the current signal of the circuit of at least one of the driving motors; judging the degree of scratches caused by the robot to the wafer located below the wafer clamping part in the wafer box according to the magnitude of the current signal. The detection method of the present application can prevent and reduce mechanical scratches on wafers.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a method and system for detecting wafer scratches by a robotic arm, and semiconductor processing equipment. Background Art

[0002] Wafers are the most important raw materials in semiconductor production. They have now developed to 12 inches. During the wafer processing, the wafers need to be taken out of the wafer box and transferred to the reaction chamber several times, and then transferred back to the wafer box after the reaction. This process is performed by the robotic arm in the transmission module of the semiconductor processing equipment. In the process of using the robotic arm to grasp and transfer the wafer, since the distance between the wafers in the wafer box is very small, and the robotic arm will have a slight position deviation during tens of thousands of uses, it is very easy for the robotic arm to scratch the surface of the wafer below, affecting the wafer yield. Summary of the invention

[0003] In view of the problems existing in the background technology, the present application provides a method and system for detecting scratches on wafers by a robotic arm, and semiconductor processing equipment, which can prevent and reduce mechanical scratches on wafers.

[0004] According to a first aspect of the present invention, there is provided a method for detecting scratches on a wafer by a robot arm, wherein the robot arm comprises a base, a wafer clamping portion, a plurality of joints and a plurality of rotating shafts, wherein the plurality of joints are arranged in sequence from the base to the wafer clamping portion, and the plurality of rotating shafts are respectively connected between a joint close to the base and the base and between every two adjacent joints, and a driving motor is correspondingly arranged for each rotating shaft; the method for detecting scratches on a wafer by the robot arm comprises the following steps: the wafer clamping portion grasps the wafer; each driving motor drives the corresponding rotating shaft to rotate, and drives the wafer clamping portion to move from inside a wafer box to outside a wafer box or from outside a wafer box to inside a wafer box; a current signal of a circuit of at least one of the driving motors is measured in real time; and the degree of scratches caused by the robot arm to the wafer located below the wafer clamping portion in the wafer box is judged according to the magnitude of the current signal.

[0005] In some embodiments of the present invention, the current signal is measured by a microcurrent measuring device.

[0006] In some embodiments of the present invention, the microcurrent measuring device is a current amplifier.

[0007] In some embodiments of the present invention, an oscilloscope is connected to the circuit of the microcurrent measuring device.

[0008] In some embodiments of the present invention, an alarm value is set for the current signal, and when the current signal measured in real time is greater than or equal to the alarm value, an alarm is issued and / or the operation of the robotic arm is stopped.

[0009] In some embodiments of the present invention, the alarm value is less than or equal to the current signal of the driving motor when the robot arm is able to scratch the wafer.

[0010] According to a second aspect of the present invention, there is provided a system for detecting scratches on wafers by a robot arm, comprising a microcurrent measuring device and an oscilloscope, wherein the microcurrent measuring device is connected to the circuit of a driving motor of the robot arm; the oscilloscope is connected to the microcurrent measuring device.

[0011] In some embodiments of the present invention, the system for detecting wafer scratches by a robotic arm further includes a controller, which is connected to the microcurrent measuring device and / or the oscilloscope and to the robotic arm, and which controls the robotic arm to stop working when the current signal measured by the microcurrent measuring device and / or the oscilloscope is greater than or equal to a preset alarm value.

[0012] In some embodiments of the present invention, the detection system for wafer scratches by a robotic arm also includes an alarm, which is connected to the controller. When the current signal measured by the microcurrent measuring device and / or the oscilloscope is greater than or equal to a preset alarm value, the controller controls the alarm to issue a warning.

[0013] According to a third aspect of the present invention, there is provided a semiconductor processing device, comprising the above-mentioned detection system for wafer scratches by the robot arm.

[0014] Compared with the prior art, the present invention achieves the following technical effects:

[0015] The present application utilizes the change in the current signal of the driving motor caused by the friction between the robotic arm and the wafer. By measuring the microcurrent of the driving motor of the robotic arm in real time, and comparing the real-time measured current signal with the current signal when the robotic arm is working normally, it is determined whether scratches have occurred between the wafer and the robotic arm, and whether scratches have occurred on the wafer if scratches have occurred. The robotic arm can then be paused in time for maintenance, thereby reducing the impact on subsequent wafers and preventing and reducing mechanical scratches on the wafers. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0017] Figure 1 It is a schematic diagram of the structure of the robotic arm;

[0018] Figure 2 It is a structural diagram reflecting the detection system;

[0019] Figure 3 It is a schematic diagram showing the conversion of current signals into waveform graphs. A1 is the waveform of the normal current signal driving the motor when the robot arm is working normally, A2 is the waveform of the current signal when contact friction occurs, and A3 is the set alarm line.

[0020] The reference numerals in the accompanying drawings represent the following: 10, robotic arm; 101, base; 102, wafer clamping part; 103, joint; 104, rotating shaft; 105, driving motor; 20, detection system; 201, microcurrent measuring device; 202, oscilloscope; 203, controller; 204, alarm. DETAILED DESCRIPTION

[0021] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0022] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0023] In the description of the present application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0024] An embodiment of the present application discloses a method for detecting scratches on a wafer by a robotic arm.

[0025] like Figure 1 and Figure 2As shown, the robot arm 10 includes a base 101, a wafer clamping part 102, N joints 103 and N rotating shafts 104. The N joints 103 are arranged in sequence from the base 101 to the wafer clamping part 102. The N rotating shafts 104 are respectively connected between the joints 103 close to the base 101 and the base 101 and between every two adjacent joints 103, so that the joints 103 and the base 101 and between the joints 103 can rotate. A driving motor 105 is correspondingly arranged for each rotating shaft 104. The circuits of the M driving motors 105 are connected to a microcurrent measuring device 201. The wafer clamping part 102 is fixed at the end of the joint 103 away from the base 101.

[0026] Wherein, N is a positive integer, and M is a positive integer selected from 1 to N.

[0027] It should be noted that the number of joints 103 and rotating shafts 104 in this embodiment is not limited to Figure 1 In other embodiments of the present invention, the robot arm 10 can select more joints 103 and rotating shafts 104 as needed.

[0028] A microcurrent measuring device 201 can be installed on the circuit of the driving motor 105 of each rotating shaft 104, that is, M is equal to N; it can also be installed on the circuit of one or more of the driving motors 105, that is, M is less than N; further, when multiple driving motors 105 form a parallel circuit, a microcurrent measuring device 201 can be connected to the parallel circuit of the multiple driving motors 105; it is sufficient to ensure that when the wafer clamping part 102 moves from inside the wafer box to outside the wafer box or from outside the wafer box to inside the wafer box, the driving motor 105 corresponding to the microcurrent measuring device 201 is in an operating state, and this embodiment is not limited here.

[0029] The method for detecting wafer scratches by a robotic arm includes the following steps:

[0030] The wafer clamping part 102 holds the wafer;

[0031] Each driving motor 105 drives the corresponding rotating shaft 104 to rotate, driving the wafer clamping part 102 to move from inside the wafer box to outside the wafer box or from outside the wafer box to inside the wafer box;

[0032] Each micro-current measuring device 201 measures the current signal of the circuit of the corresponding driving motor 105 in real time;

[0033] It is determined according to the magnitude of each current signal whether the wafer clamping part 102 or the joint 103 causes scratches to the wafer located below the wafer clamping part 102 in the wafer box.

[0034] It is understandable that when the wafer scrapes against the wafer clamping portion 102 or the joint 103 , the friction between the robot arm 10 and the wafer will change, and the current of the driving motor 105 connected to the robot arm 10 will change accordingly.

[0035] Therefore, when each microcurrent measuring device 201 measures that the current signal of the circuit of the corresponding driving motor 105 exceeds the corresponding normal current signal, it can be determined that a scratch has occurred between the wafer clamping part 102 or the joint 103 and the wafer located below the wafer clamping part 102 in the wafer box.

[0036] It should be noted that the normal current signal is the current signal when there is no contact friction between the wafer clamping part 102 or the joint 103 and the wafer in the wafer box. The normal current signal can be measured by the microcurrent measuring device 201 when the robot arm 10 is working normally when transferring similar wafers when it leaves the factory or after calibration.

[0037] Taking into account the different hardness of wafers of different materials and the different materials of different robotic arms 10, the actual friction force required to form scratches on different types of wafers is different; therefore, the upper limit of the current signal of each microcurrent measuring device 201 can be set according to the actual friction force required to form scratches on the wafer.

[0038] Specifically, when the current signal of the microcurrent measuring device 201 is equal to the normal current signal, it is judged that the wafer clamping part 102 or the joint 103 has no contact friction with the wafer in the wafer box; when the current signal of the microcurrent measuring device 201 is greater than the normal current signal but less than the set upper limit of the current signal, it is judged that the wafer clamping part 102 or the joint 103 has a certain contact with the wafer in the wafer box but no scratches are formed; when the current signal of the microcurrent measuring device 201 is greater than or equal to the set upper limit of the current signal, it is judged that the wafer clamping part 102 or the joint 103 has contact friction with the wafer in the wafer box and can form scratches.

[0039] In some embodiments of the present invention, the microcurrent measuring device 201 may use a current amplifier; since the current captured by the driving motor 105 is very small, the current amplifier can quickly respond to instantaneous current changes and continuously output a corresponding, amplified current signal.

[0040] Furthermore, if Figure 2 As shown, an oscilloscope 202 is also connected to the circuit of the current amplifier; the current signal amplified and processed by the current amplifier is transmitted to the oscilloscope 202, and the oscilloscope 202 converts the current signal into a visual waveform graph, and the staff can analyze the circuit according to the waveform graph.

[0041] Furthermore, if Figure 3As shown, in the waveform graph of the oscilloscope 202, an alarm line is set according to the scratch formation condition (friction force). When the current signal exceeds the alarm value corresponding to the alarm line, it can be more intuitively determined that the wafer and the robot arm 10 have scratched and can cause scratches to the wafer. At this time, the robot arm 10 stops working to reduce the impact on subsequent wafers. It should be noted that the alarm value can also be directly set for the current signal of the current amplifier according to the scratch formation condition.

[0042] It should be noted that the setting of the alarm line of the waveform graph of the oscilloscope 202 can be based on the actual friction force required to form scratches on the wafer, thereby achieving detection closer to the critical point of scratches and reducing the maintenance frequency of the robot. In addition, the alarm line can also be set according to actual production needs. For example, the alarm line can use a current signal in a certain contact state where scratches cannot be formed. The robot arm 10 stops in time before the alarm line, which can ensure that the wafer currently in contact is not damaged, thereby improving the protection effect on the wafer.

[0043] The present application also proposes a system for detecting scratches on wafers by a robotic arm, such as Figure 2 As shown, the detection system 20 includes a micro-current measuring device 201, an oscilloscope 202 and a controller 203; wherein the micro-current measuring device 201 is connected to the circuit of the driving motor 105 of the robotic arm 10, and the current measuring device measures the current signal of the circuit of the driving motor 105 in real time; the oscilloscope 202 is connected to the micro-current measuring device 201, and the current signal measured by the micro-current measuring device 201 is transmitted to the oscilloscope 202, and the oscilloscope 202 converts the current signal into a visual waveform graph; the controller 203 is connected to the oscilloscope 202 and the robotic arm 10, and the controller 203 controls the robotic arm 10 to stop working when the oscilloscope 202 shows that the current signal reaches the alarm line.

[0044] Furthermore, if Figure 2 As shown, the detection system 20 also includes an alarm 204, which is connected to the controller 203. When the current signal displayed by the oscilloscope 202 reaches the alarm line, the controller 203 controls the alarm 204 to issue an early warning. Specifically, the alarm 204 can be a sound alarm or an acousto-optic alarm.

[0045] The embodiment of the present application further proposes a semiconductor processing device, which includes a robotic arm 10 and a detection system 20 for detecting scratches on wafers by the robotic arm.

[0046] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for detecting wafer scratches by a robotic arm, characterized in that: The robot arm includes a base, a wafer clamping part, a plurality of joints and a plurality of rotating shafts, wherein the plurality of joints are arranged in sequence from the base to the wafer clamping part, and the plurality of rotating shafts are respectively connected between the joints close to the base and the base and between each two adjacent joints, and each rotating shaft is correspondingly provided with a driving motor; The method for detecting wafer scratches by the robotic arm comprises the following steps: The wafer clamping portion grasps the wafer; Each of the driving motors drives the corresponding rotating shaft to rotate, driving the wafer clamping part to move from inside the wafer box to outside the wafer box or from outside the wafer box to inside the wafer box; Measuring in real time a current signal of a circuit of at least one of the drive motors; Determining the extent of scratches caused by the robot arm to the wafer located below the wafer clamping portion in the wafer box according to the magnitude of the current signal; An alarm value is set for the current signal, and when the current signal measured in real time is greater than or equal to the alarm value, an alarm is issued and / or the operation of the robot arm is stopped; The alarm value is less than or equal to the current signal of the driving motor when the robot arm can scratch the wafer.

2. The method for detecting wafer scratches by a robotic arm according to claim 1, characterized in that: The current signal is measured by a microcurrent measuring device.

3. The method for detecting wafer scratches by a robotic arm according to claim 2, characterized in that: The micro-current measuring device is a current amplifier.

4. The method for detecting wafer scratches by a robotic arm according to claim 2, characterized in that: An oscilloscope is connected to the circuit of the micro-current measuring device.

5. A wafer scratch detection system using a robotic arm, characterized in that: It comprises a micro-current measuring device and an oscilloscope. The micro-current measuring device is connected to the circuit of the driving motor of the mechanical arm; the oscilloscope is connected to the micro-current measuring device.

6. The wafer scratch detection system of the robot arm according to claim 5, characterized in that: It also includes a controller, which is connected to the microcurrent measuring device and / or the oscilloscope and to the robotic arm. When the current signal measured by the microcurrent measuring device and / or the oscilloscope is greater than or equal to a preset alarm value, the controller controls the robotic arm to stop working.

7. The wafer scratch detection system of the robot arm according to claim 6, characterized in that: It also includes an alarm, which is connected to the controller. When the current signal measured by the microcurrent measuring device and / or the oscilloscope is greater than or equal to a preset alarm value, the controller controls the alarm to issue a warning.

8. A semiconductor processing equipment, characterized in that: A wafer scratch detection system comprising a robotic arm as described in any one of claims 5 to 7.

Images