Wafer stage and load lock device

Abstract

The utility model provides a wafer stage and a loading locking device, which comprise a platform body, at least one pair of probes and a detection mechanism, the platform body is provided with a plurality of through holes, the probes and the through holes are arranged in a one-to-one correspondence manner, the probes are arranged in the corresponding through holes and can be vertically moved and adjusted, and the probes are used for bearing wafers. The detection mechanism is respectively connected with the at least one pair of probes, and the detection mechanism is used for conveying current to the probes and detecting the potential difference between each pair of probes so as to judge the particle condition on the surface of the wafer. According to the utility model, the particle condition of the wafer surface area corresponding to the probe can be judged according to the potential difference detected by the detection mechanism, so that whether dust particles capable of generating electric sparks during CDSEM measurement exist on the surface of the wafer can be detected in time, and the wafer is prevented from being scrapped due to short-circuit sparking.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of semiconductor manufacturing, especially to a wafer loading platform and loading locking device. BACKGROUND

[0002] In the field of semiconductor manufacturing, measurement is a very important link. Among them, the role of the Applied Materials Critical Dimension Scanning Electron Microscope (AMAT CDSEM) in the entire process is: defect inspection, detecting whether the pattern size meets the standard. The AMAT CDSEM measurement is in a high-vacuum lens barrel. The electron beam generated by the electron gun forms an electron beam after electron convergence. The electron beam scans point by point on the wafer surface to generate a series of electronic signals. The various electronic signals are received by the corresponding detector and amplified by the electronic amplifier, and then input to the kinescope. When the focused electron beam scans the wafer surface, due to the differences in physical, chemical properties, surface potential, and concave-convex topography of different parts of the wafer surface, the electronic signals generated by the electron beam at different parts of the wafer surface are different, resulting in a constant change in the electron beam intensity of the kinescope. Ultimately, the corresponding electron microscope image of the wafer surface measurement point is displayed on the fluorescent screen.

[0003] Currently, the measurement method of the critical dimension scanning electron microscope is mainly through the electron beam hitting the wafer surface to receive the secondary electron signal strength for measurement. The electron beam emitter is very close to the wafer surface. There are dust particles on the wafer surface. If the dust particles are within the allowable size range, they will not affect the yield of the machine and the wafer, which is acceptable. However, when the dust particles reach a certain size range, due to the very close distance between the microscope lens and the wafer surface, when the electron beam excites the wafer surface, an instantaneous short-circuit arcing phenomenon occurs, greatly increasing the risk of wafer scrap.

[0004] Therefore, it is necessary to provide a wafer loading platform and loading locking device to solve the above problems. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a wafer loading platform and loading locking device to improve the problem of electric spark caused by dust particles on the wafer surface during CDSEM measurement.

[0006] The utility model provides a wafer loading platform, which comprises:

[0007] The platform body is provided with a plurality of perforations;

[0008] At least one pair of probes, which are arranged in one-to-one correspondence with the through holes, are arranged in the corresponding through holes and can be vertically adjusted, and the probes are used to support the wafer;

[0009] Detection mechanism, respectively connected with the at least one pair of probes, for transmitting current to the probes and detecting the potential difference between each pair of probes to determine the particle condition of the wafer surface.

[0010] In a possible embodiment, the platform body is provided with through holes arranged staggered with the through holes.

[0011] In a possible embodiment, the detection mechanism includes at least one branch wire and a potential difference detection piece arranged in one-to-one correspondence with the branch wire, each pair of probes is connected through a branch wire, and the potential difference detection piece is arranged on the corresponding branch wire and used to detect the potential difference between a pair of probes of the corresponding branch wire.

[0012] In a possible embodiment, the detection mechanism includes a main wire connected with each branch wire respectively, and a power supply and a current detection piece arranged on the main wire.

[0013] In a possible embodiment, the wafer stage further includes a controller connected with the detection mechanism, which is used to compare the potential difference between each pair of probes with a set threshold value, and if the potential difference is greater than or equal to the set threshold value, it is determined that the probe corresponding wafer surface area is abnormal.

[0014] In a possible embodiment, the wafer stage further includes an alarm connected with the controller, and when it is determined that the potential difference is greater than or equal to the set threshold value, the controller controls the alarm to issue an alarm.

[0015] In a possible embodiment, the wafer stage further includes a protective pad with flexibility and insulation, which is arranged on the platform body and used as a protective pad in contact with the wafer.

[0016] In a possible embodiment, the wafer stage further includes a driving mechanism connected with the probes, which is arranged in one-to-one correspondence with the probes or one driving mechanism corresponding to each pair of probes, and the driving mechanism is used to drive the corresponding probes to move vertically.

[0017] In a possible embodiment, the probe includes a first connecting segment and a second connecting segment connected with each other, the first connecting segment is connected with the detection mechanism and has conductivity, and the first connecting segment is used to contact with the wafer, and the second connecting segment has insulation and is connected with the driving mechanism.

[0018] In one possible embodiment, the first connecting section is a top end of the probe, and the second connecting section is a part of the probe other than the top end; or

[0019] The first connecting section is an upper part of the probe, and the second connecting section is a lower part of the probe; or

[0020] The second connecting section is a bottom end of the probe, and the first connecting section is a part of the probe other than the bottom end.

[0021] The utility model also provides a loading locking device, comprising:

[0022] Loading locking chamber, with critical dimension scanning electron microscope chamber connection;

[0023] The wafer carrier in any one of the above embodiments is arranged in the loading locking chamber.

[0024] The wafer carrier provided by the utility model has the beneficial effects that when detecting, a pair of the probes contact the wafer, the detection mechanism supplies current to the pair of the probes and detects the potential difference between the pair of the probes, the particle condition of the wafer surface region corresponding to the probes can be judged according to the potential difference, so that whether the wafer surface has dust particles capable of generating electric sparks during CDSEM measurement can be detected in time, and the wafer is prevented from being scrapped due to short-circuit sparking. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a schematic view of the wafer carrier of the utility model.

[0026] Figure 2 It is a schematic view of the platform body in the wafer carrier of the utility model.

[0027] Figure 3 It is a logic block diagram of the wafer carrier of the utility model.

[0028] Figure 4 It is a state diagram of the probe supporting the wafer in the wafer carrier of the utility model.

[0029] Figure 5 It is a state diagram of a pair of probes detecting the wafer in the wafer carrier of the utility model.

[0030] Figure 6 It is a state diagram of another pair of probes not detecting the wafer in the wafer carrier of the utility model.

[0031] Figure 7 It is a schematic view of the probe, the driving mechanism and the branch wire in the wafer carrier of the utility model.

[0032] Explanation of reference signs: 110, platform body; 111, perforation; 112, through hole; 120, probe; 121, first connecting section; 122, second connecting section; 130, detection mechanism; 131, branch lead wire; 132, main lead wire; 133, potential difference detection piece; 134, current detection piece; 135, power supply; 140, controller; 150, alarm; 160, protection pad; 170, driving mechanism; 200, wafer. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0034] In view of the problems in the prior art, the embodiments of the present application provide a wafer carrier, referring to Figure 1 and Figure 2 The wafer carrier comprises a platform body 110, at least one pair of probes 120 and a detection mechanism 130. The platform body 110 is provided with a plurality of perforations 111. The probes 120 are arranged in one-to-one correspondence with the perforations 111. The probes 120 are arranged in the corresponding perforations 111 and can be vertically moved and adjusted. The probes 120 are used for supporting the wafer 200. The detection mechanism 130 is connected with the at least one pair of probes 120 respectively. The detection mechanism 130 is used for delivering current to the probes 120 and detecting the potential difference between each pair of probes 120, so as to judge the particle condition on the surface of the wafer 200.

[0035] In the embodiment, the wafer carrier of the load lock chamber is improved, the probes 120 and the detection mechanism 130 are arranged on the wafer carrier, during the process of placing the wafer 200 on the platform body 110, the probes 120 are first lifted, then the wafer 200 is placed on the probes 120, the wafer 200 is supported by the probes 120, and then the probes 120 are lowered to place the wafer 200 on the platform body 110. When detecting the particles on the wafer 200, the detection mechanism 130 supplies current to the probes 120 and detects the potential difference between each pair of probes 120. It should be noted that the detection of each pair of probes 120 can be performed one by one, and of course, multiple pairs of probes 120 can be detected simultaneously. The specific detection method is not limited here and can be flexibly selected according to process requirements. Each potential difference is analyzed, when the particles on the surface of the wafer 200 exceed a certain size range, the resistance of the wafer 200 will increase, and the current will generate a potential difference after passing through the wafer 200. Therefore, the change of the potential difference can reflect whether there are dust particles on the surface of the wafer 200 that may cause short-circuit sparking. The detection method in the embodiment can timely find the problem that the dust particles on the surface of the wafer 200 exceed the size range before the critical dimension scanning electron microscope (CDSEM) measurement, so as to avoid the problem that the wafer 200 is scrapped due to excessive dust particles during the CDSEM measurement.

[0036] It should be noted that the number and specific distribution of the probes 120 are not limited here and can be flexibly set according to actual process, for example, the distribution density of the probes 120 can be set to be dense, and the distribution range can cover the entire wafer 200 range, so as to ensure comprehensive detection of the dust particles on the surface of the wafer 200. Of course, according to actual process experience, the distribution density of the probes 120 can be set to be relatively dense in the area where the dust particles are prone to be generated on the surface of the wafer 200, and the distribution density of the probes 120 can be set to be relatively sparse in the area where the dust particles are not prone to be generated on the surface of the wafer 200, so as to reduce the setting density of the probes 120, simplify the structure of the wafer carrier, and reduce the manufacturing cost.

[0037] In one embodiment, referring to Figure 2 The platform body 110 is provided with a through hole 112 which is arranged in a staggered manner with the through hole 111. In the embodiment, since the wafer 200 needs to be vacuumized in the load lock chamber after entering the load lock chamber, the through hole 112 arranged on the platform body 110 can avoid the problem that the wafer 200 is broken due to the vacuum formed between the wafer 200 and the platform body 110.

[0038] In a specific embodiment, referring to Figure 2The through hole 112 is located in the center of the platform body 110.

[0039] In an embodiment, referring to Figure 1 The detection mechanism 130 includes at least one branch wire 131 and a potential difference detection element 133 corresponding to each branch wire 131. Each pair of probes 120 is connected by a branch wire 131, and the potential difference detection element 133 is arranged on the corresponding branch wire 131 and used to detect the potential difference between the pair of probes 120 of the corresponding branch wire 131.

[0040] In this embodiment, each pair of probes 120 is connected by an independent branch wire 131, and the potential difference detection element 133 is arranged on each branch wire 131 to detect the potential difference between the pair of probes 120 of the branch wire 131. According to the potential difference, the particle condition of the wafer 200 surface area corresponding to the probes 120 can be determined.

[0041] In a specific embodiment, referring to Figure 1 The detection mechanism 130 includes a main wire 132 connected to each branch wire 131, and a power supply 135 and a current detection element 134 arranged on the main wire 132.

[0042] In an embodiment, referring to Figure 3 The wafer stage further includes a controller 140 connected to the detection mechanism 130. The controller 140 is used to compare the potential difference between each pair of probes 120 with a set threshold value. If the potential difference is greater than or equal to the set threshold value, it is determined that the wafer 200 surface area corresponding to the probes 120 has abnormal particles.

[0043] In this embodiment, the controller 140 can automatically compare the potential difference between each pair of probes 120 with the set threshold value, thereby realizing automatic detection and judgment of the wafer 200 surface particle condition, improving the detection efficiency and accuracy.

[0044] In a specific embodiment, referring to Figure 3 The wafer stage further includes an alarm 150 connected to the controller 140. When it is determined that the potential difference is greater than or equal to the set threshold value, the controller 140 controls the alarm 150 to issue an alarm.

[0045] In this embodiment, before the wafer 200 enters the critical dimension scanning electron microscope chamber, the wafer 200 is placed on the wafer carrier for particle detection. The detection mechanism 130 transmits the detected potential difference data to the controller 140 in real time. The controller 140 compares the detected potential difference with the set threshold value. Once it is determined that the potential difference is greater than or equal to the set threshold value, i.e., the particle size range on the wafer 200 is abnormal, the controller 140 immediately controls the wafer 200 with abnormal particles to exit the CDSEM machine. At the same time, the controller 140 also controls the alarm 150 to issue an alarm to remind the staff to handle the wafer 200 with abnormal particles in a timely manner, so as to effectively prevent the wafer 200 with abnormal particles from entering the critical dimension scanning electron microscope chamber, thereby avoiding the problem of electric sparks caused by excessive dust particles during the CDSEM measurement of the wafer 200, and improving the yield of the wafer 200. If it is determined that the potential difference is less than the set threshold value, i.e., the particle size range of the wafer 200 meets the requirements, the wafer 200 can enter the critical dimension scanning electron microscope chamber for measurement.

[0046] In one embodiment, referring to Figure 2 , the wafer carrier further comprises a protective pad 160 having flexibility and insulation, and the protective pad 160 is arranged on the platform body 110 and used for contacting the wafer 200.

[0047] In this embodiment, on the one hand, compared with the direct contact between the wafer 200 and the platform body 110, the wafer 200 and the platform body 110 are isolated by the protective pad 160, and the protective pad 160 provides flexible support for the wafer 200, thereby reducing the abrasion of the wafer 200 surface. On the other hand, the flexible design of the protective pad 160 can provide a buffering effect for the wafer 200, thereby reducing the physical impact and vibration of the wafer 200 during placement. The flexibility and buffering effect of the protective pad 160 help to prevent physical damage such as scratches and cracks on the wafer 200 surface, thereby improving the yield of the wafer 200.

[0048] In one specific embodiment, referring to Figure 2 , the protective pad 160 is one and annular, and the protective pad 160 is arranged along the edge of the platform body 110.

[0049] In another specific embodiment, the protective pad 160 is a plurality of protective pads 160, and the plurality of protective pads 160 are distributed along the edge of the platform body 110 at intervals.

[0050] In one specific embodiment, the material of the protective pad 160 is rubber or the like, and the thickness of the protective pad 160 is relatively thin.

[0051] In some embodiments, referring to Figure 3 and Figure 4The wafer carrier further comprises a driving mechanism 170 connected with the probes 120, the driving mechanism 170 is arranged in one-to-one correspondence with the probes 120 or one driving mechanism 170 corresponds to each pair of probes 120, and the driving mechanism 170 is used for driving the corresponding probe 120 to move vertically.

[0052] It should be noted that the specific type and specific arrangement mode of the driving mechanism 170 are not limited here, the driving mechanism 170 adopts a micro device, which can be a cylinder, a hydraulic cylinder, an electric telescopic rod or a linear module.

[0053] In a preferred embodiment, referring to Figure 1 and Figure 4 The probe 120 comprises a first connecting section 121 and a second connecting section 122 connected with each other, the first connecting section 121 is connected with the branch lead 131 of the detection mechanism 130, the first connecting section 121 has conductivity and is used for contacting the wafer 200, and the second connecting section 122 has insulation and is connected with the driving mechanism 170.

[0054] In a first specific embodiment, referring to Figure 4 The first connecting section 121 is the top end of the probe 120, and the second connecting section 122 is the part of the probe 120 except the top end.

[0055] In a second specific embodiment, the first connecting section 121 is the upper part of the probe 120, and the second connecting section 122 is the lower part of the probe 120.

[0056] In a third specific embodiment, the second connecting section 122 is the bottom end of the probe 120, and the first connecting section 121 is the part of the probe 120 except the bottom end.

[0057] The utility model further provides a kind of load locking device, comprising: load locking chamber and wafer carrier in any embodiment as above, load locking chamber is connected with critical dimension scanning electron microscope chamber, wafer carrier is located in load locking chamber.

[0058] The detection process of the wafer carrier of the utility model will be explained in detail in combination with a specific embodiment.

[0059] Referring to Figure 5The probe 120 is driven upward by the driving mechanism 170 to a certain height, and the probe 120 is extended out of the platform body 110 from the perforation 111. The mechanical arm places the wafer 200 on the probe 120. The probe 120 supports the wafer 200. The probe 120 is driven downward by the driving mechanism 170 to place the wafer 200 on the platform body 110. The detection is performed by each pair of probes 120. The position of the probe 120 is adjusted by the driving mechanism 170. In each detection, only one pair of probes 120 is in contact with the surface of the wafer 200, as shown in Figure 6 , and the other pairs of probes 120 are not in contact with the surface of the wafer 200, as shown in Figure 7 . The power supply 135 supplies current to the pair of probes 120 in contact with the surface of the wafer 200. The potential difference detection member 133 detects the potential difference between the pair of probes 120. The controller 140 compares the detected potential difference with a set threshold value. Once it is determined that the potential difference is greater than or equal to the set threshold value, the controller 140 controls the wafer 200 with the particle anomaly to exit the CDSEM machine. At the same time, the controller 140 controls the alarm 150 to issue an alarm.

[0060] In the description of the present application, it should be understood that the terms "comprising" and "having" and any variations thereof used in this text are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units does not have to be limited to the clearly listed steps or units, but can include other steps or units that are not clearly listed or inherent to the process, method, product or device.

[0061] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0062] In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" can explicitly or implicitly include one or more features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0063] Although the embodiments of the present application have been described in detail above, it is obvious to those skilled in the art that various modifications and changes can be made to the embodiments without departing from the spirit and scope of the present application as defined in the following claims. Moreover, the present application described herein can have other embodiments and be practiced or implemented in various ways. Unless otherwise defined, technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

Claims

1. A wafer carrier, characterized in that, The platform body is provided with a plurality of through holes. At least one pair of probes is provided in one-to-one correspondence with the through holes, the probes are arranged in the corresponding through holes and can be vertically moved and adjusted, and the probes are used to support the wafer. A detection mechanism is connected with the at least one pair of probes, the detection mechanism is used to deliver current to the probes and detect the potential difference between each pair of probes to determine the particle condition of the wafer surface. The platform body is provided with a through hole arranged staggered with the through hole.

2. The wafer stage of claim 1, wherein, The detection mechanism includes at least one branch wire and a potential difference detection piece arranged in one-to-one correspondence with the branch wire, each pair of probes is connected through a branch wire, and the potential difference detection piece is arranged on the corresponding branch wire and used to detect the potential difference between a pair of probes of the corresponding branch wire.

3. The wafer stage of claim 1, wherein, The detection mechanism includes a main wire connected with each branch wire and a power supply and a current detection piece arranged on the main wire.

4. The wafer stage of claim 3, wherein, Further comprising a controller connected with the detection mechanism, the controller is used to compare the potential difference between each pair of probes with a set threshold value, if the potential difference is greater than or equal to the set threshold value, it is judged that the particle of the wafer surface area corresponding to the probe is abnormal.

5. The wafer stage of claim 1, wherein, Further comprising an alarm connected with the controller, when it is judged that the potential difference is greater than or equal to the set threshold value, the controller controls the alarm to issue an alarm.

6. The wafer stage of claim 5, wherein, Further comprising a protective pad with flexibility and insulation, the protective pad is arranged on the platform body and used to contact the wafer.

7. The wafer stage according to any one of claims 1-6, wherein, Further comprising a driving mechanism connected with the probe, the driving mechanism is arranged in one-to-one correspondence with the probe or one driving mechanism corresponds to each pair of probes, and the driving mechanism is used to drive the corresponding probe to move vertically.

8. The wafer stage of any of claims 1-6, wherein, The probe includes a first connecting segment and a second connecting segment connected with each other, the first connecting segment is connected with the detection mechanism and has conductivity, the first connecting segment is used to contact the wafer, and the second connecting segment has insulation and is connected with the driving mechanism.

9. The wafer stage of claim 8, wherein, The platform body is provided with a plurality of through holes.

10. A load lock apparatus, characterized by, At least one pair of probes is provided in one-to-one correspondence with the through holes, the probes are arranged in the corresponding through holes and can be vertically moved and adjusted, and the probes are used to support the wafer. A detection mechanism is connected with the at least one pair of probes, the detection mechanism is used to deliver current to the probes and detect the potential difference between each pair of probes to determine the particle condition of the wafer surface. The platform body is provided with a through hole arranged staggered with the through hole. The detection mechanism includes at least one branch wire and a potential difference detection piece arranged in one-to-one correspondence with the branch wire, each pair of probes is connected through a branch wire, and the potential difference detection piece is arranged on the corresponding branch wire and used to detect the potential difference between a pair of probes of the corresponding branch wire. The detection mechanism includes a main wire connected with each branch wire and a power supply and a current detection piece arranged on the main wire. Further comprising a controller connected with the detection mechanism, the controller is used to compare the potential difference between each pair of probes with a set threshold value, if the potential difference is greater than or equal to the set threshold value, it is judged that the particle of the wafer surface area corresponding to the probe is abnormal. Further comprising an alarm connected with the controller, when it is judged that the potential difference is greater than or equal to the set threshold value, the controller controls the alarm to issue an alarm. Further comprising a protective pad with flexibility and insulation, the protective pad is arranged on the platform body and used to contact the wafer. Further comprising a driving mechanism connected with the probe, the driving mechanism is arranged in one-to-one correspondence with the probe or one driving mechanism corresponds to each pair of probes, and the driving mechanism is used to drive the corresponding probe to move vertically. The probe includes a first connecting segment and a second connecting segment connected with each other, the first connecting segment is connected with the detection mechanism and has conductivity, the first connecting segment is used to contact the wafer, and the second connecting segment has insulation and is connected with the driving mechanism. The platform body is provided with a plurality of through holes. At least one pair of probes is provided in one-to-one correspondence with the through holes, the probes are arranged in the corresponding through holes and can be vertically moved and adjusted, and the probes are used to support the wafer.

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