Method and system for determining central position of conveyed 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 a process. [Background technology]

[0002] Patterns for forming high integration and efficient structures of semiconductor devices are becoming finer and finer, and performance is being improved by applying various materials. At the same time, patterns are becoming finer and structures are becoming more complex and deeper. As a result, the number and difficulty of the entire process are rapidly increasing. In order to proceed with the process while considering the productivity of the highly difficult process, it is essential to maintain and improve the wafer yield, and therefore the uniformity of the entire process, the production volume per unit time, and the formation of the process profile are emerging as competitiveness of the process equipment. In order to improve the main performance, various semiconductor equipment manufacturers are making efforts to improve performance by developing various conditions such as improving the uniformity of temperature, adjusting the density of plasma, or adjusting the sheath region. Among these matters, the influence of process performance such as the temperature of the substrate, the correlation between the temperature of the electrostatic chuck under the substrate and the peripheral parts of the substrate, and the physical position has recently emerged as a major factor, and the improvement and development of related technologies is being promoted. The position of the wafer substrate on the electrostatic chuck and the minute positional relationship with the surrounding parts are also major factors that determine the yield of the substrate edge in relation to the above-mentioned temperature and fluid flow due to the structure, and therefore technologies for adjusting the substrate position have been developed.

[0003] For example, in relation to a technique for placing a wafer at a predetermined position on an electrostatic chuck, Patent Document 1: Korean Patent Publication No. 10-2007-0004230 discloses a semiconductor wafer transport robot that transports a wafer in a semiconductor device manufacturing facility. In the known method of designating the position of a robot arm for wafer transfer, the state of a module in which the wafer transport robot is located, including the target chamber, is changed from vacuum to atmospheric pressure while being opened, which may cause particle generation, and thus the entire system may go down and require a long time to return to normal after completion, which has a significant impact on productivity. In addition, since a dedicated tool is manufactured and used to adjust the position of the robot arm for designating the wafer placement position, or the process is performed with the naked eye, the work takes a long time and the procedure is complicated, and there is a possibility that deviations due to operators may occur, resulting in differences between process chambers. Operators exposed to the fast movements of the robot must pay particular attention to safety, and individual training is further required in the use of related tools, and the work is quite difficult. The wafer transfer position adjustment is one of the essential processes in the initial equipment setup and no additional work is required after that. However, if a problem occurs in the wafer transfer system or the process uniformity is not constant, it is one of the tasks that must be checked first, and it is one of the most important and frequent tasks. In a known technology, a method of determining the center position of a wafer using an optical sensor has been applied. A wafer transfer robot has been applied to detect the center position of a wafer by placing a sensor at a part where the wafer transfer robot is connected to the chamber of the transfer module, checking the difference in the position of the wafer center during the process of entering and leaving the process chamber, and sounding an alarm to proceed with inspection if a deviation occurs. However, since the transfer module and the process module are separate modules and the relative positions are not always constant physically, there is a disadvantage that the position of the sensor of the transfer module and the position of the electrostatic chuck in the chamber differ depending on the chamber, and therefore it is difficult to apply one data to check the position of the wafer 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] Republic of Korea Patent Publication No. 10-2007-0004230 (Samsung Electronics Co., Ltd., published on 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 is capable of detecting 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 specified 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 a 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 a center position of the component based on the detection results; and fixing the component at a predetermined position based on the calculation result.

[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 is sensed from a reference surface by each component sensing 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 a 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 a 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 with respect to the transport direction, the height and the inclination. Effect of the Invention

[0014] The method for positioning the center of a transferred semiconductor component according to the present invention is preferably designed to mount a sensor and an electrostatic chuck of a chamber on an integrated chamber body to fix the relative positions of the two parts. The positioning system according to the present invention constantly measures the center position of a wafer or edge ring, and either makes the center position of the electrostatic chuck coincide with the center position of a wafer or edge ring, or intentionally creates a difference between them. The positioning method according to the present invention improves the problem of position adjustment by an operator in the related art and can be used as a new process uniformity control knob. The positioning system according to the present invention provides the possibility of use in an automatic substrate adjustment method or substrate peripheral transportation through a new algorithm of a substrate position adjustment method, and automatically detects deviations that may occur in a robot arm, enabling preventive management. [Brief description of the drawings]

[0015] [Figure 1] 1 is a diagram showing an embodiment of a method for positioning the center of a transported semiconductor component according to the present invention; [Diagram 2] 1 is a diagram illustrating an embodiment of a system for centering a transported semiconductor component according to the present invention. [Diagram 3] 13 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] 4 is a diagram illustrating 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; [Diagram 5] 1 is a diagram showing an embodiment of a method for managing an operation error of a transport robot according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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, so that they will not be described repeatedly unless necessary for understanding the invention, and known components will be described briefly or omitted, but will not be understood to be 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 position of a transported semiconductor component includes a step (P11) of disposing at least a 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 at a predetermined position. The semiconductor component is transferred from a transfer module to a process module, such as a vacuum chamber, by 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 as the 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 apart from each other in a direction perpendicular to the component transfer path. Then, different parts of the component are detected by the pair of component detection sensors disposed in this way (P12). For example, a first part of the component is detected by a first component detection sensor, and a second part of the component is detected by a second component detection sensor. When different parts of the component are detected by the pair of component detection sensors in this way, the center position of the component is calculated from the detection information (P13). For example, if the component is a wafer that is circular as a whole, different parts are detected by the pair of component detection sensors during the wafer transfer process. The time when the component is detected by each component detection sensor is detected, and since the wafer transfer speed is predetermined, the length of two chords is 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 calculated using the length of the chord. In this way, the center position of the component is calculated from the detection information obtained by the two component detection sensors. Alternatively, 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 identical.In contrast, if the component is transported in an inclined state with respect to the reference plane, the vertical distances measured by the pair of component detection sensors may differ from each other. Once the center position of the component is calculated in this manner, the component is fixed at a predetermined position based on the calculated center position (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 wafer is fixed to the electrostatic chuck with the position corrected based on the calculation result. As a result, the center of the wafer may 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 a transported semiconductor component 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 in which a process on the semiconductor components proceeds; and a component positioning module that determines the center position of the components from two pairs of component positions (P11, P12, P21, P22) detected by each of the pair of component detection sensors 26a, 26b.

[0022] When the wafer (W) is loaded from the LPM (Load Port Module) 221 to the EFEM (Equipment Front End Module) 22, it can be moved to the TM (Transfer Module) 23 by the VTM robot (Vacuum Transfer Module) 21. Then, the gate valve is opened and the wafer (W) is transferred from the TM 23 to a process chamber 24 such as a process chamber by the robot arm 211 of the VTM robot 21. The robot arm 211 is coupled to a finger 27 for transferring the wafer (W) at the front, and the wafer (W) can be moved from the TM 23 to the process chamber 24 while being loaded on the finger 27. An electrostatic chuck (ESC) 28 is disposed inside the process chamber 24, and the wafer (W) is fixed on the upper side of the electrostatic chuck 28. When the wafer (W) is fixed on the upper side of the electrostatic chuck 28, the center (CP1) of the wafer and the center (CP2) of the fixing surface 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 the wafer (W) is fixed to the upper fixing surface of the electrostatic chuck 28, and the wafer (W) must be moved 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 acquired 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 number 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 a similar type of sensor, and the present invention is not limited thereto. The finger 27 moves at a predetermined speed along a predetermined conveying direction, and the component detection sensors 26a, 26b detect different portions of the wafer W. For example, the first component detection sensor 26a detects first and second points P1, P2 on the wafer W.In addition, the third and fourth points (P3, P4) are detected by the first component detection sensor 26b, and 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 the first and second points (P1, P2) and the distance between the third and fourth points (P3, P4) detected by the first and second component detection sensors 26a, 26b are the same, the wafer (W) moves along a straight line connecting the midpoint of the line connecting the first and second component detection sensors 26a, 26b and the center (CP2) of the fixing surface of the electrostatic chuck 28. In contrast, if the lengths of the two straight lines are not the same, the center (CP1) of the wafer (W) moves away from the connecting straight line. The degree to which the wafer center (CP1) is off is calculated from the difference between the lengths of the two straight lines, and the position can be corrected based on the calculated value in the step of fixing the wafer (W) to the electrostatic chuck 28.

[0023] According to one suitable embodiment of the present invention, at least two component detection sensors 26a, 26b detect the height between the reference plane and the wafer (W), and each of the component detection sensors 26a, 26b detects the height of different parts of the wafer (W). The wafer (W) needs to be transferred while being held parallel to the reference plane. If the heights detected by each of the component detection sensors 26a, 26b are the same, it is determined that the wafer (W) is being transferred in a horizontal state. In contrast, if the heights detected by each of the component detection sensors 26a, 26b are different from each other, it is determined that the wafer (W) is being transferred in an inclined state. Then, the height of the wafer (W) can be adjusted or the inclination can be corrected based on the heights obtained by each of the component detection sensors 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 center positioning system for a transported semiconductor component according to the present invention.

[0025] 3, an edge ring, cover ring or focus ring R is fixed to the peripheral surface of the electrostatic chuck 28, and the edge ring R may have a circular ring or an annular shape. First and second component detection sensors 26a and 26b are disposed in the process chamber 24, and the edge ring center CP3, which is loaded on the finger 27 and transported, may pass between the first and second component detection sensors 26a and 26b. The first and second component detection sensors 26a and 26b detect the first and second points P1 and P2 and the third and fourth points P3 and P4, respectively, and calculate the distance between the first and second points P1 and P2 and the distance between the third and fourth points P3 and P4. Then, based on the calculated distances, it is determined whether the edge ring R is transported along the determined transport path. Also, the heights of the four points (P1, P2, P3, P4) are detected by the component detection sensors 26a and 26b, and thus the height or inclination of the edge ring (R) relative to the horizontal plane during the transfer process is detected. 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. Also, 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. Thus, the thickness of the edge ring (R) is calculated. Also, the center position of the inner diameter and the center position of the outer diameter are calculated. If the center position of the inner diameter and the center position of the outer diameter do not match, it is understood 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 applied to a function similar to, for example, 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) is intentionally made to deviate from the center (CP2) of the fixing surface of the electrostatic chuck. In such a case, the position of the edge ring (R) on the electrostatic chuck 28 can be determined using the calculated center coordinates of the edge ring (R).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 a variety of ways, and the present invention is not limited thereto.

[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, a process of transporting a semiconductor component such as a wafer or an edge ring and fixing it at a predetermined position includes a step of arranging at least two component detection sensors on a transport path of a process module (P41); a step of transporting a semiconductor component such as a wafer or an edge ring along the transport path (P42); a step of detecting two points of the component by each of the component detection sensors (P43); a step of calculating distance and height based on the detection information (P44); a step of calculating a center position, height or tilt of the component from the calculated distance and height (P45); and a step of 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 as the area where the component is fixed, for example, at an entrance portion where a wafer or edge ring is introduced into a process chamber where an electrostatic chuck is disposed, but is not limited thereto. The component detection sensor can be various types of sensors including an optical sensor capable of detecting the component. The component detection sensor is disposed on a transport path along which the component moves, for example, it is disposed above or below the transport path and can detect the component moving along the transport path. When 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). Different parts of the component are detected by each component detection sensor, specifically, two points of different parts of the component are detected by each component detection sensor (P43). The shape of the component and the transport speed of the component are predetermined, and the time when the two points of the component are detected are detected is calculated. The component detection sensor may also be a distance detection sensor, and the height of the component relative to the reference plane is 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 to which the component is fixed may be set as the reference line. If the distance between two points is calculated by two component detection sensors, and the heights are detected at different points, the distance in the component transport direction, the rotation angle based on 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). Then, the center position and the height or inclination of the component relative to the reference plane are calculated from the three-dimensional coordinates (R, θ, Z) of the four points (P45). If the center position, height, or inclination of the component is calculated in this manner, the fixing position of the component 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. In addition, the detection information of such a part detection sensor can be applied to preventive management of the transport arm or fingers.

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

[0030] Referring to FIG. 5, the method for managing the operational error of a transport robot includes a step (P51) of transporting a number of parts by a transport robot; a step (P52) of calculating average values ​​of the center position, height and inclination of the parts; a step (P53) of setting a reference value based on the average value; a step (P54) of calculating the center position, height and inclination of the parts as the parts are transported; a step (P55) of comparing the calculated center position, height and inclination with the reference value; and a step (P56) of estimating a change in the transport function of the transport robot based on the comparison result.

[0031] A number of components are transported, and components having different specifications are transported (P51). For example, a number of wafers having different diameters are transported. The number of components transported are detected by a component detection sensor, and the center position, height, and tilt of each are calculated, and the center positions and tilts of the detected number of components may be averaged. The average calculated in this way is set as a reference value (P53), and the average calculated in this way may be the error range of the center position, the error range of the height, and the tilt that appears during the transport process of the transport robot. The average calculated in this way may be set as the reference value (P53). Semiconductor components are transported to a process chamber, and the center positions, heights, and tilts of the components transported are calculated (P54). Then, the calculated center positions, heights, and tilts are compared with the center position range, the height, and tilt range that are set as the reference value (P55). If the calculated center position, height, or inclination falls outside the range set as the reference value, and such an error persists, it is assumed that the transport robot's transport function has changed (p. 56). As a result, the transport robot's transport function must be reset or adjusted. The part detection sensor can be applied to preventive management of various devices, including transport robots.

[0032] Although the present invention has been described in detail with reference to the embodiments presented above, 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 embodiments presented above. 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 sensor

Claims

1. providing at least one pair of component detection sensors on a semiconductor component transport path; detecting different portions of the part by respective part detection sensors; calculating a center position of the part based on the detection result; Fixing the part in a defined position based on the calculation result; Includes 2. A method for determining the center of a transported semiconductor component, comprising:

2. At least one pair of component detection sensors is disposed in an area where the semiconductor component is fixed.

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

3. The semiconductor component can be a wafer or an edge ring.

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

4. The different parts are located on either side of the center of the part.

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

5. Each part's height is detected from the reference plane by a component detection sensor.

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

6. A transport robot 21 for transporting semiconductor components; a pair of component detection sensors 26a, 26b disposed in a process chamber 24 in which a process for a semiconductor component is performed; a component positioning module for determining a center position of a component from two pairs of component positions (P11, P12, P21, P22) detected by each of the pair of component detection sensors 26a, 26b; Includes 13. A system for centering a transported semiconductor component, comprising:

7. The part positioning module determines three-dimensional coordinates (R, θ, Z) for calculating the distance in the part's transport direction, the rotation angle based on the transport direction, the height, and the inclination.

7. The system for centering a transported semiconductor component according to claim 6.

8. The semiconductor component may be a wafer or an edge ring, and the semiconductor component is transferred from the transfer module 23 to a process chamber 24.

7. The system for centering a transported semiconductor component according to claim 6.

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