A system, process chamber, and detection method for detecting wafer bias.

Abstract

This invention relates to a system, process chamber, and detection method for detecting wafer bias, belonging to the field of semiconductor manufacturing technology. It solves the problem of low product yield caused by the lack of a device for detecting wafer bias in existing semiconductor manufacturing equipment. The wafer bias detection system includes a chuck, sensing components, a control system, and a data acquisition and processing system. Multiple sensing components are located on the back edge of the chuck. The detection method includes placing the wafer on the chuck; the sensing components sensing data; the data acquisition and processing system acquiring the data and comparing it with data before wafer placement; if wafer position adjustment is needed, a command is sent to the control system, which adjusts the wafer position; if wafer position adjustment is not needed, subsequent processing steps are performed. This invention achieves accurate, efficient, and convenient detection of wafer bias.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a system, process chamber, and detection method for detecting wafer bias. Background Technology

[0002] In semiconductor manufacturing equipment, during the etching process, wafers often slip when placed on the chuck, affecting subsequent processes, leading to product defects and reduced yield. For example, if wafer slippage or misalignment is not detected in time, it will result in uneven etched wafers with poor consistency.

[0003] Existing semiconductor manufacturing equipment lacks the technology to detect wafer bias, resulting in low product yield. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a system, process chamber, and detection method for detecting wafer bias, in order to solve the problem that existing semiconductor manufacturing equipment does not have a device for detecting whether the wafer is biased, resulting in low product yield.

[0005] The objective of this invention is mainly achieved through the following technical solutions:

[0006] On one hand, the present invention provides a system for detecting wafer bias, including a chuck, a sensing component, a control system, and a data acquisition and processing system. The sensing component is located on the back edge of the chuck, and there are multiple sensing components, each of which is connected to the data acquisition and processing system. The data acquisition and processing system is used to acquire and receive data from the sensing components. The control system is connected to the data acquisition and processing system, and the control system adjusts the wafer position by controlling a robotic arm.

[0007] Based on the above solution, the present invention has made the following improvements:

[0008] Based on further improvements to the above system, the sensing component includes a temperature sensor.

[0009] Based on further improvements to the above system, the number of sensing components is at least four, and multiple sensing components are evenly distributed along the circumferential direction on the edge of the chuck.

[0010] Based on further improvements to the above system, the number of sensing components is more than four, with four sensing components evenly distributed along the circumferential direction on the edge of the chuck, and the remaining sensing components located on the opposite side of the side of the wafer that is prone to bias.

[0011] Based on a further improvement to the above system, the chuck is a heated chuck.

[0012] Based on further improvements to the above system, the data acquisition and processing system compares the data received from the sensing component with the data before the wafer was placed to determine whether the wafer position needs to be adjusted.

[0013] Based on further improvements to the above system, the sensing component also includes a photosensitive sensor, which is embedded in the chuck, with the top of the photosensitive sensor lower than the upper surface of the chuck.

[0014] Based on further improvements to the above system, the number of photosensitive sensors is at least four, and multiple photosensitive sensors are evenly distributed along the circumferential direction on the edge of the chuck.

[0015] On the other hand, the present invention also provides a method for detecting wafer bias, including...

[0016] The robotic arm places the wafer onto the chuck;

[0017] The sensing component senses data after the wafer is placed.

[0018] The data acquisition and processing system collects the data sensed by the sensing components and compares it with the data before the wafer was placed to determine whether the wafer's position needs to be adjusted.

[0019] If the wafer's position needs to be adjusted, the data acquisition and processing system sends a command to the control system, which then controls the robotic arm to adjust the wafer's position.

[0020] If the wafer position does not need to be adjusted, then proceed with the subsequent processing steps.

[0021] Based on a further improvement of the above detection method, the sensing component is a temperature sensor. When the wafer is placed on the chuck, if the temperature sensed by all the temperature sensors drops instantly, it indicates that the wafer is not biased; if the temperature sensed by one or more temperature sensors remains unchanged, it indicates that the wafer is biased and the wafer position needs to be adjusted.

[0022] Based on the further improvement of the above detection method, the sensing component is a photosensitive sensor. When the wafer is placed on the chuck, if the intensity of the light sensed by all the photosensitive sensors drops instantaneously, it indicates that the wafer is not biased; if the intensity of the light sensed by one or more photosensitive sensors remains unchanged, it indicates that the wafer is biased and the wafer position needs to be adjusted.

[0023] In addition, the present invention also provides a process chamber including the above-described system for detecting wafer bias.

[0024] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0025] (1) This invention uses a temperature sensor on the back of the chuck to detect whether the wafer is biased on the chuck by measuring the temperature change of the chuck the instant the wafer is placed on it. The detection system of this invention has a simple structure and is easy to operate.

[0026] (2) By setting up multiple temperature sensors and optimizing the positions of the multiple temperature sensors (i.e., the four temperature sensors are evenly distributed along the circumference), the present invention can accurately reflect whether the wafer is biased.

[0027] (3) By setting up multiple photosensitive sensors and optimizing the positions of the multiple photosensitive sensors (i.e., the four photosensitive sensors are evenly distributed along the circumference), the present invention can accurately reflect whether the wafer is biased.

[0028] (4) By optimizing the setting position of the photosensitive sensor (i.e., the photosensitive sensor is embedded in the chuck and the top of the photosensitive sensor is lower than the upper surface of the chuck), the present invention can prevent the photosensitive sensor from protruding from the upper surface of the chuck and avoid scratching the wafer surface.

[0029] (5) The present invention uses multiple methods (i.e., by simultaneously setting temperature sensors and photosensitive sensors on the chuck) to detect whether the wafer is biased, which can improve the accuracy of detecting wafer bias, so as to adjust the position of the wafer in time, so that subsequent processes can proceed smoothly and improve product yield.

[0030] (6) The detection system of the present invention has a simple structure and is easy to operate and control.

[0031] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages will become apparent from the description or may be learned by practicing the invention. Attached Figure Description

[0032] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0033] Figure 1 This is a schematic diagram of the detection system according to an embodiment of the present invention;

[0034] Figure 2 This is a front view of the wafer without bias on the chuck.

[0035] Figure 3 Several scenarios where the wafer is offset along the line connecting the sensing element and the wafer center to set up four sensing elements;

[0036] Figure 4To set up 4 sensing components, the wafer is not biased along the line connecting the sensing components and the center of the wafer;

[0037] Figure 5 A schematic diagram showing the setup of 6 sensing components;

[0038] Figure 6 The wafer is slightly offset to accommodate six sensing components;

[0039] Figure 7 Temperature profiles of the chuck before and after wafer placement (wafer not biased);

[0040] Figure 8 Temperature profile of the chuck before and after wafer placement (wafer is biased).

[0041] Figure label:

[0042] 1-Heating chuck; 2-Temperature sensor; 3-Control system; 4-Data acquisition and processing system; 5-Wafer. Detailed Implementation

[0043] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0044] The accompanying drawings illustrate various structural schematics according to embodiments of the present disclosure. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0045] In the context of this disclosure, when a layer / element is referred to as being "above" another layer / element, the layer / element may be directly above the other layer / element, or there may be an intermediate layer / element between them. Additionally, if a layer / element is "above" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.

[0046] Example 1

[0047] A specific embodiment of the present invention discloses a system for detecting wafer bias, including a heated chuck 1, a sensing component, a control system 3, and a data acquisition and processing system 4, such as... Figure 1 As shown.

[0048] The functions of each part of the detection system and the connection relationships between the components are described below.

[0049] A sensing element is located at the edge of the heated chuck 1 to sense data at the moment the wafer is placed on the heated chuck. In one possible embodiment, the sensing element is a temperature sensor 2, and the temperature sensor 2 is located on the back of the heated chuck 1. Whether the wafer is biased is reflected by the change in the temperature of the heated chuck at the moment the wafer 5 is placed on it. Generally, there are multiple sensing elements. For example, there can be four.

[0050] When the robotic arm places the wafer onto the heated chuck, if all the temperature sensors detect a sudden drop in temperature, it indicates that the wafer is not biased. Figure 2 and Figure 7 As shown; if one or more temperature sensors detect a constant or minimal temperature change, it indicates wafer bias, requiring adjustment of the wafer's position, such as... Figure 8 As shown.

[0051] Considering that the wafer may be biased in any direction on the heated chuck, this embodiment distributes multiple temperature sensors evenly along the circumference of the edge of the heated chuck, such as... Figure 1 As shown.

[0052] Figure 3 Several scenarios are illustrated where the wafer is biased along the line connecting the sensing element and the wafer center. However, in actual production, the wafer may be biased in any direction; that is, the wafer is not necessarily biased along the line connecting the sensing element and the wafer center. Figure 4 As shown. If the wafer is not offset along the line connecting the sensing element and the wafer center, the sensing element may only detect the offset if it is very severe. Therefore, multiple temperature sensors, such as 6, 7, or 8, can be placed along the entire edge of the heated chuck to ensure that even slight offsets in either direction can be detected, allowing for timely adjustment of the wafer's position. The number of sensing elements can also be flexibly adjusted as needed.

[0053] In addition, such as Figure 5 and Figure 6 As shown, for cases where the wafer is frequently biased in one direction, to further improve the accuracy of wafer bias detection—that is, to detect even very slight bias—several temperature sensors can be placed on the opposite side of the wafer bias direction. With this design, even when the wafer is not aligned with the line connecting the sensing element and the wafer center, and is slightly biased, the detection probability of wafer bias can be further improved.

[0054] In another possible implementation, the sensing element is a photosensitive sensor (not shown in the figure), which is located on the front of the heated chuck. To prevent the photosensitive sensor from protruding from the upper surface of the heated chuck and scratching the wafer surface, the photosensitive sensor is embedded in the heated chuck, and the top of the photosensitive sensor is lower than the upper surface of the heated chuck.

[0055] Whether a wafer is biased is determined by the change in light intensity sensed by a photosensitive device the instant the wafer is placed on a heated chuck. Generally, there are multiple photosensitive devices; for example, up to four.

[0056] To enable the photosensitive device to detect changes in light intensity even in the absence of an external light source, this embodiment includes a laser emitter (not shown in the figure) mounted on the inner wall of the process chamber. The laser emitted by this emitter illuminates the front edge of the heated chuck, and the photosensitive device receives the laser emitted and senses its intensity. Exemplarily, the laser emitter can be located on the top or side wall of the process chamber.

[0057] When the robotic arm (not shown in the figure) places the wafer on the heated chuck, if the intensity of the light sensed by all the photosensitive sensors drops instantaneously, it indicates that the wafer is not biased; if the intensity of the light sensed by one or more photosensitive sensors remains unchanged, it indicates that the wafer is biased and the wafer position needs to be adjusted.

[0058] The control system is used to control the robotic arm to adjust the position of the wafer.

[0059] The data acquisition and processing system is connected to the control system, and each sensing component is also connected to the data acquisition and processing system. The data acquisition and processing system collects and receives data from the sensing components and compares the received data with data from before the wafer was placed to determine if wafer positioning needs adjustment. If wafer positioning adjustment is required, the data acquisition and processing system sends a command to the control system, which then controls the robotic arm to adjust the wafer's position.

[0060] In a preferred embodiment, both a temperature sensor and a photosensitive sensor are installed on the heating chuck to detect wafer misalignment through multiple methods. This improves the accuracy of wafer misalignment detection, allowing for timely adjustment of the wafer's position and ensuring smooth operation of subsequent processes, thereby increasing product yield.

[0061] To achieve wafer bias calibration, in one possible implementation, the system for detecting wafer bias further includes a wafer calibration module for compensating and correcting the biased wafer.

[0062] Example 2

[0063] Another embodiment of the present invention discloses a method for detecting wafer bias, including a robotic arm placing a wafer on a chuck;

[0064] Temperature sensors detect temperature data after the wafer is placed.

[0065] The data acquisition and processing system collects the temperature of the chuck after the wafer is placed and compares it with the data before wafer placement. If all temperature sensors detect a temperature drop the instant the wafer is placed on the chuck, and the temperature drop is greater than 50%, it indicates that the wafer is not biased. If one or more temperature sensors detect a constant temperature or a slight temperature drop, it indicates that the wafer is biased and its position needs to be adjusted. For example, a robotic arm picks the wafer from the chuck, places it on the wafer calibration module, compensates for the bias direction, and then places the wafer back on the chuck until the criterion of a temperature drop of more than 50% is met. If the wafer position needs to be adjusted, the data acquisition and processing system sends a command to the control system, which then controls the robotic arm to adjust the wafer position.

[0066] If the wafer position does not need to be adjusted, then proceed with the subsequent processing steps.

[0067] Example 3

[0068] Another embodiment of the present invention discloses a method for detecting wafer bias, including a robotic arm placing a wafer on a chuck;

[0069] The photosensitive sensor detects the intensity data of light after the wafer is placed.

[0070] The data acquisition and processing system collects light intensity data after the wafer is placed and compares it with the data before the wafer is placed. If the light intensity sensed by all photosensitive devices decreases the instant the wafer is placed on the chuck, it indicates that the wafer is not biased. If the light intensity sensed by one or more photosensitive devices remains unchanged, it indicates that the wafer is biased and the wafer position needs to be adjusted.

[0071] If the wafer's position needs to be adjusted, the data acquisition and processing system sends a command to the control system, which then controls the robotic arm to adjust the wafer's position.

[0072] If the wafer position does not need to be adjusted, then proceed with the subsequent processing steps.

[0073] Example 4

[0074] Another embodiment of the present invention discloses a process chamber, including the wafer bias detection system of Embodiment 1, and a gas distribution device disposed on the process chamber.

[0075] Specifically, the gas distribution device includes a central hole and an edge hole. The main central gas line is connected to the central hole of the gas distribution device to deliver gas to the center of the wafer, and the main edge gas line is connected to the edge hole of the gas distribution device to deliver gas to the edge of the wafer.

[0076] The process chamber is equipped with a plasma generator and a chuck. The plasma generator is used to convert etching gas into plasma, and the electrostatic chuck is used to place the wafer.

[0077] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0078] (1) The present invention uses a temperature sensor on the back of the chuck to reflect whether the wafer is biased on the chuck by measuring the temperature change of the chuck the instant the wafer is placed on it. The above setup is simple and convenient.

[0079] (2) By setting up multiple temperature sensors and optimizing the positions of the multiple temperature sensors (i.e., the four temperature sensors are evenly distributed along the circumference), the present invention can accurately reflect whether the wafer is biased.

[0080] (3) By setting up multiple photosensitive sensors and optimizing the positions of the multiple photosensitive sensors (i.e., the four photosensitive sensors are evenly distributed along the circumference), the present invention can accurately reflect whether the wafer is biased.

[0081] (4) By optimizing the setting position of the photosensitive sensor (i.e., the photosensitive sensor is embedded in the chuck and the top of the photosensitive sensor is lower than the upper surface of the chuck), the present invention can prevent the photosensitive sensor from protruding from the upper surface of the chuck and avoid scratching the wafer surface.

[0082] (5) The present invention uses multiple methods (i.e., by simultaneously setting temperature sensors and photosensitive sensors on the chuck) to detect whether the wafer is biased, which can improve the accuracy of detecting wafer bias, so as to adjust the position of the wafer in time, so that subsequent processes can proceed smoothly and improve product yield.

[0083] (6) The detection system of the present invention has a simple structure and is easy to operate and control.

[0084] The above description does not provide detailed explanations of the technical aspects of each layer's patterning, etching, etc. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

[0085] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method for detecting wafer bias in an etch process, comprising: include ​ The robotic arm places the wafer onto the chuck; The sensing component senses data after the wafer is placed. The data acquisition and processing system collects the data sensed by the sensing components and compares it with the data before the wafer was placed to determine whether the wafer's position needs to be adjusted. If the wafer's position needs to be adjusted, the data acquisition and processing system sends a command to the control system, which then controls the robotic arm to adjust the wafer's position. If the wafer position does not need to be adjusted, proceed with subsequent processing steps; The number of sensing components is more than 4, of which 4 sensing components are evenly distributed along the circumferential direction on the edge of the chuck, and the remaining sensing components are located on the opposite side of the side of the wafer that is prone to bias. The sensing components are a temperature sensor and a photosensor. The temperature sensor is located on the back edge of the chuck; when the wafer is placed on the chuck, if the temperature sensed by all the temperature sensors drops instantly, it indicates that the wafer is not biased. If one or more temperature sensors detect a constant temperature, it indicates that the wafer is biased and the wafer position needs to be adjusted. The photosensitive sensor is embedded in the chuck, and the top of the photosensitive sensor is lower than the upper surface of the chuck. If the intensity of light sensed by all photosensitive devices drops instantaneously when the wafer is placed on the chuck, it indicates that the wafer is not biased. If the intensity of light sensed by one or more photosensitive devices remains unchanged, it indicates that the wafer is biased and the wafer position needs to be adjusted.

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