Target disc grounding monitoring device of ion implanter

Abstract

The utility model relates to a target disc grounding monitoring device of an ion implanter, which is characterized by comprising a target disc for bearing a wafer to perform ion implantation operation, the target disc is opposite to an electronic shower system above the target disc, a grounding pole is arranged in the target disc, the target disc is provided with an abdicating hole for the grounding pole to extend out, and the abdicating hole is communicated with the target disc. The top of the grounding pole is in contact with the wafer, the bottom of the grounding pole is connected with a grounding wire extending towards the outside of the target disc, a sensor is arranged below the target disc, the sensor is used for detecting grounding current, and the sensor is electrically connected with a dose control system of the ion implanter. The target disc grounding device has the following advantages and effects: the performance of the target disc grounding device can be detected in real time so as to realize abnormal risk prevention of the target disc grounding device.

Description

TECHNICAL FIELD

[0001] The utility model relates to ion implanter technical field, concretely relates to a target disc ground monitoring device of ion implanter. BACKGROUND

[0002] Ion implanter is the key equipment in semiconductor manufacturing, and is used for implanting ions into silicon wafer to change its electrical properties. When implanting ions, the high-energy ion beam strikes the wafer surface to strip the electrons in the material, resulting in a positive charge on the wafer. Charge accumulation can cause electrostatic discharge (ESD), wafer warping or uneven implantation, affecting device performance and yield. Therefore, an electron shower system is provided in the ion implanter to emit low-energy electrons to neutralize the positive charge on the wafer surface, avoiding the above problems and ensuring the stability and accuracy of the implantation process.

[0003] However, in actual use, the electron shower system cannot neutralize 100% of the positive charge on the wafer surface, and the remaining positive charge needs to be neutralized by the target disc grounding device.

[0004] However, in actual use, the target disc grounding device may fail due to the following reasons:

[0005] a) The spring force of the spring at the bottom of the ground pin is insufficient, causing the ground pin to protrude from the target disc to a height that is not sufficient to contact the back of the wafer;

[0006] b) The ground wire inside the Roplat (target disc base) is loose or broken;

[0007] c) The coating (accumulated during the process) on the ground pin is too heavy, causing the ground pin to have a high resistance value (greater than 10 ohms) to ground, affecting the grounding effect.

[0008] Therefore, it is necessary to detect the performance of the target disc grounding device to prevent abnormal risks of the target disc grounding device. However, the existing target disc grounding device lacks effective monitoring function, and therefore needs to be improved. SUMMARY

[0009] In view of the deficiencies in the prior art, the utility model aims to provide a target disc grounding monitoring device for ion implanter, which can detect the performance of the target disc grounding device to prevent abnormal risks of the target disc grounding device.

[0010] In order to achieve the above object, the utility model provides a target disc ground monitoring device of ion implanter, including the target disc that carries wafer and carries out ion implantation operation, the target disc is opposite to the upper electronic shower system, be equipped with the grounding column in the target disc, be equipped with the hole that gives way to the grounding column to protrude on the target disc, the top of grounding column is contacted with wafer, the bottom of grounding column is connected with the grounding wire that extends to the target disc outside, the lower side of target disc is equipped with sensor, the sensor is used to detect ground current, the sensor is electrically connected with the dose control system of ion implanter.

[0011] The utility model further sets up: sensor is hall sensor.

[0012] The utility model further sets up: hall sensor includes hall sensor body, hall sensor body is connected with base, base is used for realizing detachable connection with target disc, be equipped with terminal row for being used for connecting on base.

[0013] The utility model further sets up: be equipped with the installation groove that is concave downward on base, be equipped with the magnetic attraction piece that is adapted with installation groove in installation groove, be equipped with the detachable cover plate on installation groove, the cover plate is used for opening or closing the slot mouth of installation groove.

[0014] The utility model further sets up: the bottom of cover plate is equipped with the extension groove that is concave upward, extension groove is adapted with magnetic attraction piece.

[0015] The utility model further sets up: be equipped with the first threaded hole on base, the first threaded hole is multiple and evenly distributes in the four around installation groove, be equipped with the second threaded hole opposite with first threaded hole on cover plate, be connected through locking piece between first threaded hole and second threaded hole, the periphery of second threaded hole is equipped with the counterbore that is communicated with second threaded hole.

[0016] Compared with the prior art, the utility model has the beneficial effects that:

[0017] Because the sensor is installed below the target disc, the sensor is preferably a Hall sensor, the Hall sensor converts the magnetic field strength change around the grounding wire into a current signal (ground current) output to the dose control system of the ion implanter, so that the dose control system compares the ground current with the difference between the received ion beam current and the electron shower gun plasma beam current to determine whether the grounding effect meets the expectation, and judges whether the grounding device of the target disc is abnormal based on this, therefore, effectively solves the technical problem of lack of effective monitoring function of the target disc grounding device in the prior art, and further realizes real-time monitoring of the target disc grounding device and timely detection of abnormalities in the target disc grounding device. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the structural principle schematic view of the utility model;

[0019] Figure 2 It is the local integral structure schematic view of the Hall sensor in the utility model;

[0020] Figure 3 It is the integral structure schematic view of the Hall sensor in the utility model;

[0021] Figure 4 It is the local sectional structure schematic view (1) of the Hall sensor in the utility model;

[0022] Figure 5 It is the local sectional structure schematic view (2) of the Hall sensor in the utility model. DETAILED DESCRIPTION

[0023] The technical solutions of the present application will be described clearly and completely below with reference to the drawings, obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0024] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "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, therefore it cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0025] As Figures 1 to 5 The utility model discloses a target disc ground monitoring device of ion implanter, including the target disc 1 of bearing wafer and carrying out ion implantation operation, and the target disc 1 is the metal material that can be magnetically attracted, and is equipped with high temperature resistant insulating coating on the surface. The target disc 1 top is opposite with electronic shower system 100, and electronic shower system 100 is used to emit low energy electron stream (electronic shower gun plasma beam flow b) to neutralize the positive charge on wafer surface, and this electronic shower system 100 can adopt prior art,

[0026] The target plate 1 is provided with a grounding column 200 embedded in the inside of the target plate 1, and the top of the grounding column 200 directly contacts the back of the wafer through the accommodation hole of the target plate 1. The grounding column 200 is made of conductive material, and the bottom of the grounding column 200 is connected to the grounding wire 2, which extends to the outside of the target plate 1 and is connected to the ground or the equipment grounding terminal. The above-mentioned target plate 1 and grounding column 200 can be realized by using the prior art;

[0027] A sensor 3 is arranged below the target plate 1, and the sensor 3 is used to detect the grounding current. The sensor 3 is preferably a Hall sensor 3. The principle of the Hall sensor 3 is that when a primary current I p flows through a long wire, a magnetic field will be generated around the wire, and the size of the magnetic field is proportional to the current flowing through the wire. The generated magnetic field is concentrated in the magnetic ring, and the output voltage V s accurately reflects the primary current I p , so that the Hall sensor 3 can convert the change of the magnetic field strength around the grounding wire 2 into a current signal output;

[0028] In addition, the sensor 3 is electrically connected to the dose control system 300 of the ion implanter, so that the current signal (grounding current) converted by the Hall sensor 3 can be output to the dose control system 300 of the ion implanter. At present, the dose control system 300 of the ion implanter already has the function of receiving the ion beam current a and the electron shower gun ion beam current b signals through wired or wireless mode. Therefore, by comparing the difference between the grounding current and the received ion beam current a and the electron shower gun ion beam current b through the dose control system 300, it can be determined whether the grounding effect reaches the expected value, and whether the grounding device of the target plate 1 is abnormal. The above-mentioned dose control system 300 can be understood as a controller in the electrical control field which can receive and process the signals sent by each sensor 3, so it will not be described in detail here. The calculation logic of the positive charge grounding neutralization ratio of the target plate 1 is as follows:

[0029]

[0030] Wherein, I (ground current) is the ground current, I (ion beam current) is the ion beam current a, I (pfg emission current) is the electron shower gun plasma beam current b, and the ion beam current a is approximately equal to the sum of the ground current and the electron shower gun plasma beam current b, and when the Ratio is lower than 80%, it indicates that the grounding effect of the target plate 1 is not as expected. The machine sets SPEC for the above parameters and sets the interlock function, and once the lower limit value is reached, the machine immediately alarms and stops product operation, and the equipment maintenance personnel stops the machine to open the process cavity to check the target plate 1 related hardware, so as to avoid a larger range of products being affected, so that real-time monitoring of the grounding device of the target plate 1 can be realized, and if an abnormality occurs, the product operation can be stopped in time, reducing the risk of product scrap.

[0031] In the embodiment, the specific structure of the Hall sensor 3 includes a Hall sensor body 31 and a base 32 integrally connected with the Hall sensor body 31, and the base 32 is provided with a terminal row 33 for connection, so that the specific circuit connection of the Hall sensor 3 is as follows:

[0032] The positive port of the terminal row 33 is connected to the positive of the power supply, and the negative port is connected to the negative of the power supply;

[0033] The ground port of the terminal row 33 is connected with the ground wire 2;

[0034] The output port of the terminal row 33 is connected with the input end of the dose control system 300.

[0035] In addition, the Hall sensor body 31 is detachably connected with the target plate 1 through the base 32, and specifically, the base 32 is provided with a downward recessed mounting groove 321, and the mounting groove 321 is provided with a magnetic suction block 34 matched with the mounting groove 321, the magnetic suction block 34 is a permanent magnet (such as neodymium iron boron), used for adsorbing and fixing the Hall sensor body 31, ensuring the constant distance between the Hall sensor body 31 and the ground wire 2, improving the detection accuracy, and in order to further improve the measurement accuracy, the Hall sensor body 31 adopts a multi-turn through core mode, which makes it close to the rated current of the Hall sensor 3, and in the embodiment, the winding is performed according to the primary through core turn number being equal to 5.

[0036] In addition, the detachable cover plate 35 is arranged on the installation groove 321, the cover plate 35 can cover the slot of the installation groove 321, and is fixed with the base 32 through the locking piece 400, so that the installation groove 321 can be closed after the magnetic block 34 is embedded into the installation groove 321, so as to reduce the invasion of external dust, and the bottom of the cover plate 35 is provided with an upwardly recessed extension groove 351, the extension groove 351 is matched with the magnetic block 34, so that one end of the magnetic block 34 can be embedded into the extension groove 351 after the cover plate 35 covers the slot of the installation groove 321, so that the distance between the magnetic block 34 and the target plate 1 can be shortened, and the stability of the Hall sensor body 31 adsorbed and fixed on the target plate 1 is ensured.

[0037] The structure that the cover plate 35 is fixed on the base 32 through the locking piece 400 is that the first threaded hole 322 is arranged on the base 32, the first threaded hole 322 is multiple and uniformly distributed around the installation groove 321, the second threaded hole is arranged on the cover plate 35 and matched with the first threaded hole 322, so that the locking piece 400 matched with the first threaded hole 322 and the second threaded hole is screwed in or out, the detachable connection between the cover plate 35 and the base 32 can be realized, in addition, the counterbore 352 communicated with the second threaded hole is arranged on the outer periphery of the second threaded hole, the counterbore 352 is used for accommodating the bolt head, so as to avoid the interference of the protruding structure on the installation of the sensor 3.

[0038] The specific embodiment is only an explanation of the utility model, and is not a limitation of the utility model, and the person skilled in the art can make a modification without creative contribution according to the need after reading the specification, but as long as it is within the scope of the claims of the utility model, it is protected by the patent law.

Claims

1. A target disk grounding monitoring device for an ion implanter, characterized in that, The target disc includes a target disc for carrying a wafer for ion implantation, the target disc is opposite to an electron shower system, the target disc is provided with a grounding column, the target disc is provided with a hole for the grounding column to extend, the top of the grounding column is in contact with the wafer, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a grounding wire extending out of the target disc, the bottom of the grounding column is connected with a 2. The target plate ground monitoring apparatus of an ion implanter according to claim 1, wherein ​ 3. The target plate ground monitoring apparatus of an ion implanter according to claim 2, wherein ​ 4. The target plate ground monitoring apparatus of claim 3, wherein the target plate ground monitoring apparatus further comprises a target plate ground monitoring apparatus controller for controlling the target plate ground monitoring apparatus. ​ 5. The target plate ground monitoring apparatus of an ion implanter according to claim 4, wherein ​ 6. A target plate earth monitoring apparatus for an ion implanter as claimed in claim 4 or 5, wherein, ​

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