Method and system for locating the center of a transported semiconductor component

Abstract

To provide a method and a system for determining the central position of a conveyed semiconductor component.SOLUTION: The present invention relates to a method and a system for determining the central position of a conveyed semiconductor component. The method includes the steps in which: at least one pair of component detection sensors are arranged in a conveyance route of a semiconductor component; the component detection sensors detect different parts of a component; the central position of the component is detected on the basis of the detection result; and the component is fixed to a predetermined position on the basis of the result of the calculation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and a system for locating the center of a transported semiconductor component, and more particularly to a method and a system for locating the center of a transported semiconductor component for determining the center position of a semiconductor component that must be transported and fixed at a predetermined position for processing. [Background technology]

[0002] Patterns for the formation of highly integrated and highly efficient structures in semiconductor devices are becoming increasingly finer, and performance is being improved through the application of a variety of materials. At the same time, patterns are becoming increasingly finer and structures are becoming more complex and deeper. This is rapidly increasing the number and difficulty of overall processes. Maintaining and improving wafer yield is essential to proceed with these highly difficult processes while taking productivity into account. Therefore, overall process uniformity, production volume per unit time, and process profile formation are emerging as competitive factors for process equipment. Various semiconductor equipment manufacturers are striving to improve performance by developing various conditions, such as improving temperature uniformity, adjusting plasma density, and adjusting the sheath region. Among these factors, factors that influence process performance, such as substrate temperature and the correlation between the temperature and physical location of the electrostatic chuck below the substrate and the surrounding parts of the substrate, have recently emerged as key factors, leading to the improvement and development of related technologies. The precise positional relationship between the wafer substrate's position on the electrostatic chuck and its surrounding parts is also a major factor that determines the yield of the substrate edge, in relation to the temperature and fluid flow due to the structure. Therefore, technologies for adjusting the substrate position have been developed.

[0003] For example, in relation to a technology for placing a wafer at a predetermined position on an electrostatic chuck, Korean Patent Publication No. 10-2007-0004230 discloses a semiconductor wafer transfer robot that transfers wafers within a semiconductor device manufacturing facility. Conventional methods for specifying the position of a robot arm for wafer transfer involve changing the state of the module in which the wafer transfer robot is located, including the target chamber, from vacuum to atmospheric pressure while opening the module, potentially generating particles. This can cause the entire system to shut down, requiring a long time for normalization after completion, significantly affecting productivity. Furthermore, adjusting the position of the robot arm to specify the wafer placement position requires the use of specialized tools or the naked eye, which is time-consuming and complex, and can lead to operator-specific errors and discrepancies between process chambers. Operators exposed to the fast robot movements must pay particular attention to safety, and individual training on the use of related tools is required, making the process quite difficult. While wafer transfer position adjustment is an essential process during initial equipment setup and requires no additional work thereafter, it is one of the most important and frequently performed tasks that must be checked first if a problem occurs with the wafer transfer system or if process uniformity is unstable. A conventional method for determining the wafer center position uses an optical sensor. A sensor is placed where the wafer transfer robot connects to the chamber of the transfer module to detect the difference in the wafer center position as the wafer enters and exits the process chamber. If a deviation occurs, an alarm sounds and an inspection is initiated. However, because the transfer module and process module are separate modules and their relative physical positions are not always consistent, the position of the transfer module sensor and the position of the electrostatic chuck in the chamber vary depending on the chamber. This creates a drawback in that it is difficult to use a single data set to determine the wafer position in different chambers.

[0004] The present invention is intended to solve the problems of the prior art and has the following objects. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent Publication No. 10-2007-0004230 (Samsung Electronics Co., Ltd., published January 9, 2007) Semiconductor wafer transport robot Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a method and system for locating the center of a transported semiconductor component, which can detect two different parts of the transported semiconductor component using at least two sensors to detect the center position, transport direction, height, or tilt of the component, thereby allowing the component to be placed in a predetermined position. [Means for solving the problem]

[0007] According to a suitable embodiment of the present invention, a method for locating the center of a transported semiconductor component includes the steps of: arranging at least one pair of component detection sensors in a transport path of the semiconductor component; detecting different portions of the component by each of the component detection sensors; calculating the center position of the component based on the detection results; and fixing the component at a predetermined position based on the calculation results.

[0008] According to another suitable embodiment of the present invention, at least one pair of component detection sensors is arranged in an area where the semiconductor component is fixed.

[0009] According to yet another suitable embodiment of the present invention, the semiconductor component is a wafer or an edge ring.

[0010] According to yet another suitable embodiment of the invention, the different portions are located on either side of the center of the part.

[0011] According to yet another preferred embodiment of the invention, the height from a reference surface is detected by each component detection sensor.

[0012] According to yet another suitable embodiment of the present invention, a system for positioning the center of a transported semiconductor component includes: a transport robot that transports the semiconductor component; a pair of component detection sensors disposed in a process chamber in which a process on the semiconductor component proceeds; and a component positioning module that determines the center position of the component from two pairs of component positions detected by each of the pair of component detection sensors.

[0013] According to yet another suitable embodiment of the present invention, the component positioning module determines three-dimensional coordinates (R, θ, Z) for calculating the distance in the component transport direction, the rotation angle relative to the transport direction, the height, and the tilt. [Effects of the Invention]

[0014] The method for positioning the center of a transferred semiconductor component according to the present invention is preferably designed so that the sensor and the electrostatic chuck of the chamber are mounted on an integrated chamber body, thereby fixing the relative positions of the two parts. The positioning system according to the present invention constantly measures the center position of the wafer or edge ring, and either aligns the center position of the electrostatic chuck with the center position of the wafer or edge ring, or intentionally creates a difference. The positioning method according to the present invention overcomes the problems of conventional position adjustment by an operator and can be used as a new process uniformity control knob. The positioning system according to the present invention provides potential for automatic substrate adjustment or substrate periphery transfer through a new algorithm for substrate position adjustment, and automatically detects deviations that may occur in a robot arm, enabling preventive management. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing an embodiment of a method for locating the center of a transported semiconductor component according to the present invention; [Figure 2] 1 is a diagram illustrating an embodiment of a system for centering a transported semiconductor component according to the present invention. [Figure 3] 10 is a diagram showing another embodiment of a system for positioning the center of a transported semiconductor component according to the present invention; [Figure 4] 4A and 4B are views illustrating an embodiment of a process in which semiconductor components are transferred from a transfer module to a process module and fixed at a predetermined position according to the present invention; [Figure 5] 1 is a diagram illustrating an embodiment of a method for managing an operation error of a transport robot according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings, but the embodiments are for a clear understanding of the present invention and the present invention is not limited thereto. In the following description, components having the same reference numerals in different drawings have similar functions, and therefore, unless necessary for understanding the invention, repeated description will not be provided. Known components will be briefly described or omitted, but will not be understood as being excluded from the embodiments of the present invention.

[0017] FIG. 1 illustrates an embodiment of a method for centering a transported semiconductor component according to the present invention.

[0018] Referring to FIG. 1, the method for determining the center of a transported semiconductor component includes a step (P11) of disposing at least one pair of component detection sensors on a transport path of the semiconductor component; a step (P12) of detecting different portions of the component by each of the component detection sensors; a step (P13) of calculating the center position of the component based on the detection results; and a step (P14) of fixing the component at a predetermined position based on the calculation results.

[0019] The semiconductor component may be a component, such as a wafer or an edge ring, that is transferred from the outside of a process chamber to the inside and fixed in a predetermined position. The semiconductor component is transferred from a transfer module to a process module, such as a vacuum chamber, by, for example, a vacuum transfer module robot (VTM Robot). A pair of component detection sensors is disposed on the component transfer path, preferably in the same area where the component is fixed. For example, a wafer corresponding to the component is transferred from the transfer module to a vacuum chamber corresponding to the vacuum module. Then, a pair of component detection sensors is disposed on the wafer transfer path in the vacuum module, and the wafer is fixed to a vacuum chuck. The pair of component detection sensors are disposed spaced apart from each other in a direction perpendicular to the component transfer path. The pair of component detection sensors thus disposed detect different portions of the component (P12). For example, a first component detection sensor detects a first portion of the component, and a second component detection sensor detects a second portion of the component. Once different parts of a component are detected by a pair of component detection sensors, the center position of the component is calculated from the detection information (P13). For example, if the component is a circular wafer, the pair of component detection sensors detect different parts during the wafer transport process. The time at which each component detection sensor detects the component is detected, and since the wafer transport speed is predetermined, the lengths of the two chords are detected. If the lengths of the two chords are the same, it is determined that the center of the wafer passes through the midpoint of the line connecting the pair of component detection sensors. In contrast, if the lengths of the two chords are different, it is determined that the center of the wafer is located at a position deviated from the midpoint. The degree of deviation is then calculated using the lengths of the chords. In this way, the center position of the component is calculated from the detection information obtained by the two component detection sensors. Optionally, the vertical distance to the component is detected by each component detection sensor. If a component, such as a wafer, is transported parallel to a reference plane, the vertical distance measured by a pair of component detection sensors should be the same.In contrast, if the component is transported in an inclined state relative to the reference plane, the vertical distances measured by the pair of component detection sensors may differ. Once the component center position is calculated in this manner, the component is fixed at a predetermined position based on this calculation (P14). For example, a wafer is fixed to an electrostatic chuck in a process chamber. If the center of the wafer deviates from the center of the electrostatic chuck, the deviation level is calculated based on detection information from the pair of component detection sensors, and the position is corrected based on the calculation result, and the wafer is fixed to the electrostatic chuck. As a result, the center of the wafer can be centered on the electrostatic chuck. An embodiment in which the center position of the wafer is detected by a pair of component detection sensors will be described below.

[0020] FIG. 2 illustrates an embodiment of a system for centering transported semiconductor components according to the present invention.

[0021] Referring to FIG. 2, the system includes a transfer robot 21 that transfers semiconductor components; a pair of component detection sensors 26a, 26b disposed in a process chamber 24 where processes on the semiconductor components proceed; and a component positioning module that determines the center position of the component from two pairs of component positions (P11, P12, P21, P22) detected by each of the pair of component detection sensors 26a, 26b.

[0022] Once a wafer (W) is loaded from a Load Port Module (LPM) 221 into an Equipment Front End Module (EFEM) 22, it can be moved to a Transfer Module (TM) 23 by a Vacuum Transfer Module (VTM) 21 robot. Then, a gate valve is opened, and the robot arm 211 of the VTM robot 21 transfers the wafer (W) from the TM 23 to a process chamber 24, such as a processing chamber. A finger 27 for transferring the wafer (W) is attached to the front of the robot arm 211, and the wafer (W) can be loaded onto the finger 27 and moved from the TM 23 to the process chamber 24. An electrostatic chuck (ESC) 28 is disposed inside the process chamber 24, and the wafer (W) is fixed on the electrostatic chuck 28. When the wafer (W) is fixed on the electrostatic chuck 28, the wafer center (CP1) and the fixing surface center (CP2) of the electrostatic chuck 28 must coincide with each other. The wafer (W) loaded on the fingers 27 is transported along the transport path and fixed to the upper fixing surface of the electrostatic chuck 28. The wafer (W) must move so that the wafer center (CP1) coincides with the fixing surface center (CP2) of the electrostatic chuck 28. According to one embodiment of the present invention, the wafer (W) transported along the transport path is detected by a pair of component detection sensors 26a, 26b, and the center position of the wafer (W) is calculated based on the detection information obtained by the pair of component detection sensors 26a, 26b. The pair of component detection sensors 26a, 26b are installed in the body of the process chamber, and the wafer (W) is installed on the transport path. A plurality of component detection sensors 26a, 26b are provided, and each of the component detection sensors 26a, 26b may be an optical sensor such as a laser sensor, an ultrasonic sensor, or any other similar sensor, but the present invention is not limited thereto. The finger 27 moves at a predetermined speed along a predetermined direction, and the component detection sensors 26a and 26b detect different portions of the wafer W. For example, the first component detection sensor 26a detects first and second points P1 and P2 on the wafer W.In addition, the first component detection sensor 26b detects the third and fourth points (P3, P4). The length of the wafer (W) passing through the first component detection sensor 26a is detected by detecting the first and second points (P1, P2). In addition, the length of the wafer (W) passing through the second component detection sensor 26b is detected by detecting the third and fourth points (P3, P4). The first and second component detection sensors 26a, 26b are disposed on both sides of a straight line connecting the center of the electrostatic chuck 27 and the center of the wafer (W) located on the transfer path. If the distance between points P1 and P2 and the distance between points P3 and P4 detected by the first and second component detection sensors 26a and 26b are the same, the wafer W moves along a line connecting the midpoint of the line connecting the first and second component detection sensors 26a and 26b to the center CP2 of the fixing surface of the electrostatic chuck 28. In contrast, if the lengths of the two lines are not the same, the center CP1 of the wafer W moves away from the connecting line. The deviation of the wafer center CP1 can be calculated from the difference in the lengths of the two lines, and position correction can be performed based on this calculated value when fixing the wafer W to the electrostatic chuck 28.

[0023] According to one preferred embodiment of the present invention, at least two component detection sensors 26a, 26b detect the height between the reference surface and the wafer (W), with each component detection sensor 26a, 26b detecting the height of a different portion of the wafer (W). The wafer (W) must be transported while held parallel to the reference surface. If the heights detected by each component detection sensor 26a, 26b are the same, it is determined that the wafer (W) is being transported horizontally. In contrast, if the heights detected by each component detection sensor 26a, 26b are different, it is determined that the wafer (W) is being transported tilted. Then, height adjustment or tilt correction of the wafer (W) can be performed based on the heights detected by each component detection sensor 26a, 26b. Various components fixed to the electrostatic chuck 28 are detected by the component detection sensors 26a, 26b.

[0024] FIG. 3 illustrates another embodiment of a system for centering transported semiconductor components according to the present invention.

[0025] Referring to FIG. 3, an edge ring, cover ring, or focus ring (R) is fixed to the peripheral surface of the electrostatic chuck 28. The edge ring (R) may have a circular or annular shape. First and second component detection sensors 26a and 26b are disposed in the process chamber 24, and the center (CP3) of the edge ring, which is transported on the finger 27, can pass between the first and second component detection sensors 26a and 26b. The first and second component detection sensors 26a and 26b detect first and second points (P1 and P2) and third and fourth points (P3 and P4), respectively, and calculate the distances between the first and second points (P1 and P2) and the third and fourth points (P3 and P4). Based on the calculated distances, it is determined whether the edge ring (R) is being transported along the predetermined transport path. The component detection sensors 26a and 26b detect the heights of four points (P1, P2, P3, and P4), thereby detecting the height or tilt of the edge ring (R) relative to the horizontal plane during the transfer process. The edge ring (R) has an inner diameter and an outer diameter, and the inner diameter is calculated based on the detection information acquired by the first and second component detection sensors 26a and 26b. The outer diameter of the edge ring (R) is calculated based on the detection information acquired by the first and second component detection sensors 26a and 26b. This allows the thickness of the edge ring (R) to be calculated. The center positions of the inner diameter and the outer diameter are also calculated. If the center positions of the inner diameter and the outer diameter do not coincide, it is determined that the thickness of the edge ring (R) is not uniform. The center position of the edge ring (R) acquired and calculated by the first and second component detection sensors 26a and 26b can be used, for example, as a function similar to a control knob. For example, in order to achieve uniformity in the temperature profile or plasma density profile, the center (CP3) of the edge ring (R) may be intentionally deviated from the center (CP2) of the fixing surface of the electrostatic chuck. In such a case, the calculated center coordinates of the edge ring (R) can be used to determine the position of the edge ring (R) on the electrostatic chuck 28.The center (CP1) of the edge ring (R) detected by the first and second component detection sensors 26a and 26b or the center position of the semiconductor component being transferred from the transfer module 23 to the fixing module 28 may be utilized in various ways, and the present invention is not limited thereby.

[0026] FIG. 4 illustrates an embodiment of a process in which a semiconductor component is transferred from a transfer module to a process module and fixed at a predetermined position according to the present invention.

[0027] Referring to FIG. 4, the process of transporting and fixing a semiconductor component such as a wafer or edge ring at a predetermined position includes the steps of: arranging at least two component detection sensors on a transport path of a process module (P41); transporting a semiconductor component such as a wafer or edge ring along the transport path (P42); detecting two points on the component by each component detection sensor (P43); calculating the distance and height based on the detection information (P44); calculating the center position, height, or tilt of the component from the calculated distance and height (P45); and correcting the position of the component based on the calculated value and fixing the component at a predetermined position (P46).

[0028] The component detection sensor is disposed in the same area where the component is fixed. For example, it may be disposed at the entrance of a process chamber where an electrostatic chuck is disposed, where a wafer or edge ring enters the process chamber, but is not limited thereto. The component detection sensor can be various types of sensors, including optical sensors, capable of detecting components. The component detection sensor is disposed on the transport path along which the component moves. For example, it may be disposed above or below the transport path to detect components moving along the transport path. As the component is transported along the transport path (P42), the component is detected by at least one component detection sensor disposed on the transport path (P43). Each component detection sensor detects a different portion of the component. Specifically, each component detection sensor detects two different points on the component (P43). The shape of the component and the component transport speed are predetermined, and the time at which the two points on the component are detected is detected. The distance between the two points is calculated. The component detection sensor may also be a distance detection sensor, and the component height relative to the reference plane may be detected by the component detection sensor. The midpoint of the line connecting the component detection sensors may be set as the reference point, and the line connecting the reference point and the center of the electrostatic chuck on which the component is fixed may be set as the reference line. If two component detection sensors calculate the distance between two points and detect heights at different points, the distance in the component transport direction, the rotation angle relative to the transport direction, and the height of four points relative to the reference point and the reference line are displayed as three-dimensional coordinates (R, θ, Z). The center position and the height or inclination of the component relative to the reference plane are then calculated from the three-dimensional coordinates (R, θ, Z) of the four points (P45). Once the center position, height, or inclination of the component is calculated in this manner, the component fixing position is corrected based on the calculated value, and the component is fixed (P46). The center position, height, or inclination of the component may be calculated in various ways, and the present invention is not limited thereto. Furthermore, the detection information of such a component detection sensor can be applied to preventive management of the transport arm or finger.

[0029] FIG. 5 illustrates an embodiment of a method for managing the operating errors of a transport robot by means of a method according to the invention.

[0030] Referring to FIG. 5, the method for managing operational errors of a transfer robot includes a step (P51) in which a plurality of parts are transferred by the transfer robot; a step (P52) in which average values ​​of the center position, height, and tilt of the parts are calculated; a step (P53) in which the center position, height, and tilt of the parts are calculated as the parts are transferred; a step (P54) in which the calculated center position, height, and tilt are compared with the reference values; and a step (P56) in which a change in the transfer function of the transfer robot is estimated based on the comparison result.

[0031] A number of components are transferred, and components with different specifications are transferred (P51). For example, a number of wafers with different diameters are transferred. The transferred components are detected by component detection sensors, and their respective center positions, heights, and tilts are calculated. The center positions and tilts of the detected components may be averaged. The calculated averages are set as reference values ​​(P53). These averages may also be used to determine the error ranges of the center position, height, and tilt that may occur during the transfer process of the transfer robot. These averages may also be set as reference values ​​(P53). Semiconductor components are transferred to a process chamber, and their center positions, heights, and tilts are calculated (P54). These calculated center positions, heights, and tilts are then compared with the center position range, height, and tilt ranges set as reference values ​​(P55). If the calculated center position, height, or tilt falls outside the range set as the reference value, and such errors persist, it is assumed that the transfer robot's transfer function has changed (p. 56). As a result, the transfer robot's transfer function must be reset or adjusted. The part detection sensor can be applied to preventive management of various devices, including transfer robots.

[0032] Although the present invention has been described in detail above with reference to the illustrated embodiments, those skilled in the art may make various modifications and alterations without departing from the technical spirit of the present invention by referring to the illustrated embodiments. The present invention is not limited by such modifications and alterations, but is limited only by the scope of the claims. [Explanation of symbols]

[0033] 21:Transport robot 22:EFEM 23:TM 24: Process chamber 27: Finger 26a, 26b: Part detection sensors

Claims

1. a step of disposing at least one pair of component detection sensors on a transport path of the semiconductor components; detecting different portions of the semiconductor component by respective component detection sensors; calculating a center position of the semiconductor component based on the detection result; a step of fixing the semiconductor component in a predetermined position based on the calculation result; Including, the semiconductor component is a wafer or an edge ring; The step of disposing at least one pair of component detection sensors includes disposing first and second component detection sensors 26a and 26b on both sides of a line connecting a center (CP2) of a fixing surface of an electrostatic chuck 28 and a center (CP1) of a semiconductor component inside a process chamber 24 in which an electrostatic chuck 28 is disposed, on which a semiconductor component is fixed; The step of detecting includes detecting different portions of the semiconductor component while it is being transported along the transport path inside the process chamber 24.

2. A method for locating the center of a transported semiconductor component.

2. Each component detection sensor includes a distance detection sensor that detects a vertical distance to the semiconductor component, and the height from a reference plane is detected based on the vertical distance to the semiconductor component.

2. The method for locating the center of a transported semiconductor component according to claim 1.

3. a transport robot 21 for transporting semiconductor components; a pair of component detection sensors 26a, 26b disposed in a process chamber 24 where a process for a semiconductor component is performed; a component positioning module for determining the center position of a semiconductor component from two pairs of component positions (P1, P2, P3, P4) detected by the pair of component detection sensors 26a, 26b, respectively; Including, the semiconductor component is a wafer or an edge ring; The pair of component detection sensors 26a and 26b are disposed on both sides of a straight line connecting the center CP2 of the fixing surface of the electrostatic chuck 28 disposed inside the process chamber 24 and the center CP1 of the semiconductor component. The two pairs of component positions (P1, P2, P3, P4) are positions of semiconductor components that are transported along the transport path inside the process chamber 24.

1. A system for centering a transported semiconductor component, comprising:

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