Method for Detecting Neutralization Ability of PFG and Detection System

Abstract

The present invention provides a method and system for detecting the neutralization ability of PFG, wherein the method includes: turning on the PFG and using the PFG's gas supply system to deliver an inert gas into the ionization chamber; providing cations and electrons generated by the ionization of the inert gas into the shielding cover of the ion detection module; using the cation detection cup of the ion detection module to detect the distribution of the cations in a direction parallel to the wafer surface; and obtaining the distribution of the electrons in a direction parallel to the wafer surface based on the distribution of the cations. The present application uses the cation detection cup to detect the distribution of cations emitted by the PFG to reversely characterize the distribution of electrons emitted by the PFG in the horizontal direction, thereby effectively detecting whether the overall distribution of free electrons drawn out of the PFG chamber can meet the requirements of positive ions (ion beam current), thereby realizing the detection of the neutralization ability of the PFG.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a method and a detection system for detecting the neutralization ability of PFG. Background Art

[0002] In the field of semiconductor manufacturing technology, ion implantation mainly changes electrical parameters by adjusting the number of carriers through doping. A large number of doped ions are injected into the wafer to accelerate the energy and form a specific distribution.

[0003] During the ion implantation process, carriers bombard the wafer surface in the form of a positive ion (cation) beam, so positive charges gradually accumulate on the wafer surface. PFG (plasma electron shower) is a device that generates electron beams. After the electrons reach the wafer surface with the ion beam, they neutralize the positive charges carried by the ion beam, making the wafer surface electrically neutral, thereby avoiding wafer damage defects caused by excessive charge.

[0004] In the existing ion beam emitting device, during the ion implantation process on the wafer, the ion beam enters a shield before reaching the wafer surface. The PFG is located on one of the electrode plates of the shield. In its own chamber, the PFG uses a filament to ionize the inert gas transported into the chamber, thereby generating free electrons. The free electrons are pulled to the ion beam in the shield through the extraction voltage to neutralize the cations in the ion beam.

[0005] Since the PFG chamber cover is a single-hole, the total number of free electrons in the inert gas can be measured through the current at the single hole leading from the arc chamber to the shield. However, it is impossible to detect the overall distribution of free electrons drawn out of the PFG chamber in the horizontal direction within the shield. Therefore, it is impossible to detect whether the overall distribution of free electrons drawn out of the PFG chamber can meet the requirements of positive ions (ion beam current). In other words, the neutralization ability of PFG cannot be detected at present. Summary of the Invention

[0006] The present application provides a method and a detection system for detecting the neutralization ability of PFG, which can solve the problem of being unable to detect the overall distribution of free electrons drawn out from the PFG chamber in the horizontal direction within the shielding cover.

[0007] In one aspect, an embodiment of the present application provides a method for detecting the neutralization ability of PFG, comprising:

[0008] Turning on the PFG and using the gas supply system of the PFG to supply an inert gas into the ionization chamber, wherein the inert gas is ionized in the ionization chamber to generate cations and electrons;

[0009] providing the cations and the electrons into a shielding cover of an ion detection module;

[0010] Using a cation detection cup of an ion detection module to detect the distribution of the cations in a direction parallel to the wafer surface;

[0011] According to the distribution of the cations, the distribution of the electrons in a direction parallel to the wafer surface is obtained.

[0012] Optionally, in the method for detecting the neutralization ability of PFG, the cation detection cup is arranged in the shielding cover and close to the ion outlet of the shielding cover, wherein, in the process of detecting the distribution of the cations in the direction parallel to the wafer surface, the ion detection cup moves in the direction perpendicular to the wafer surface.

[0013] Optionally, in the method for detecting the neutralization ability of PFG, the step of using a cation detection cup of an ion detection module to detect the distribution of the cations in a direction parallel to the wafer surface includes:

[0014] Utilizing the cation detection cup of the ion detection module to detect the current value when the cation passes through;

[0015] Obtaining the cross-sectional area of the surface of the cation detection cup facing the flow of cations;

[0016] The distribution of the cations in a direction parallel to the wafer surface is obtained according to the current value and the cross-sectional area.

[0017] Optionally, in the method for detecting the neutralization ability of PFG, the inert gas is xenon or argon.

[0018] Optionally, in the method for detecting the neutralization ability of PFG, the inert gas is argon, and the reaction formula for the ionization of argon is: Ar→Ar + +e - .

[0019] Optionally, in the method for detecting the neutralization ability of PFG, the inert gas is xenon, and the reaction formula for the ionization of xenon is: Xe→Xe + +e - .

[0020] Optionally, in the method for detecting the neutralization capability of PFG, before turning on the PFG, the method for detecting the neutralization capability of PFG further includes: confirming that the ion beam emitting device is in a shut-down state to ensure that the ion beam emitting device does not generate an ion beam flowing through the shielding cover.

[0021] On the other hand, the embodiment of the present application further provides a detection system, comprising: a PFG, an ion detection module and a data processing module, wherein the PFG comprises: an air supply system and an ionization chamber; the ion detection module comprises: a shielding cover and a cation detection cup; wherein,

[0022] The gas supply system is used to transport inert gas into the ionization chamber; the ionization chamber is used to ionize the inert gas to generate cations and electrons, and the ionization chamber is also used to provide the cations and electrons into the shielding cover; the cation detection cup and the data processing module are used to detect the distribution of the cations in a direction parallel to the wafer surface; the data processing module is also used to receive the distribution of the cations and, based on the distribution of the cations, obtain the distribution of the electrons in a direction parallel to the wafer surface.

[0023] Optionally, in the detection system, the cation detection cup is arranged in the shielding cover and close to the ion outlet of the shielding cover, wherein, in the process of detecting the distribution of the cations in a direction parallel to the wafer surface, the ion detection cup moves in a direction perpendicular to the wafer surface.

[0024] Optionally, in the detection system, the cation detection cup and the data processing module are used to detect the distribution of the cations in a direction parallel to the wafer surface, including:

[0025] The cation detection cup detects the current value when the cation passes through;

[0026] The data processing module obtains the distribution of the cations in a direction parallel to the wafer surface according to the current value and the cross-sectional area.

[0027] The technical solution of this application has at least the following advantages:

[0028] This application uses a cation detection cup to detect the distribution of cations emitted by the PFG in the horizontal direction parallel to the wafer surface to reversely characterize the distribution of electrons emitted by the PFG in the horizontal direction parallel to the wafer surface. That is, it can effectively monitor the distribution of electrons used to neutralize cations in the ion beam (electrons provided by the PFG), so as to effectively detect whether the overall distribution of free electrons introduced by the PFG chamber can meet the requirements of positive ions (ion beam), thereby realizing the detection of the neutralization ability of the PFG. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0030] Figure 1 is a flow chart of a method for detecting PFG neutralization capability according to an embodiment of the present invention;

[0031] Figure 2 2 is a schematic structural diagram of a detection system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in this application in conjunction with the accompanying drawings. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0033] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal connections between two components; they can refer to wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0035] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0036] The present invention provides a method for detecting the neutralization ability of PFG. Figure 1 , Figure 1 : is a flow chart of a method for detecting PFG neutralization capability according to an embodiment of the present invention, wherein the method for detecting PFG neutralization capability comprises:

[0037] Step S1: turning on the PFG and using the gas supply system of the PFG to deliver an inert gas into the ionization chamber, wherein the inert gas is ionized in the ionization chamber to generate cations and electrons;

[0038] Step S2: providing the cations and the electrons into the shielding cover of the ion detection module;

[0039] Step S3: using a cation detection cup of the ion detection module to detect the distribution of the cations in a direction parallel to the wafer surface;

[0040] Step S4: according to the distribution of the cations, obtaining the distribution of the electrons in a direction parallel to the wafer surface.

[0041] Based on the same inventive concept, the present application also provides a detection system. Specifically, refer to Figure 2 , Figure 2 : is a structural diagram of a detection system according to an embodiment of the present invention, wherein the detection system comprises: a PFG, an ion detection module and a data processing module, wherein the PFG comprises: an air supply system and an ionization chamber; the ion detection module comprises: a shielding cover and a cation detection cup; wherein,

[0042] The gas supply system is used to transport inert gas into the ionization chamber; the ionization chamber is used to ionize the inert gas to generate cations and electrons, and the ionization chamber is also used to provide the cations and electrons into the shielding cover; the cation detection cup and the data processing module are used to detect the distribution of the cations in a direction parallel to the wafer surface; the data processing module is also used to receive the distribution of the cations and, based on the distribution of the cations, obtain the distribution of the electrons in a direction parallel to the wafer surface.

[0043] Furthermore, the PFG may also include a shower gun and a power supply system, wherein the shower gun is disposed in the ionization chamber and is electrically connected to the power supply system. The ionization chamber communicates with the inner side of the shielding cover via a through hole in the chamber cover. The shielding cover generally includes a first electrode plate and a second electrode plate that are parallel to each other, and the ionization chamber is located on the side of the first electrode plate or the second electrode plate.

[0044] Preferably, the ion detection module may further include: a permanent magnet and a metering controller, wherein the permanent magnet is arranged on the periphery of the shielding cover to cover the shielding cover, one end of the dosage controller is electrically connected to the cation detection cup, and the other end of the dosage controller is grounded, and the dosage controller can also provide electrons for neutralizing the positive charge in the shielding cover.

[0045] In this embodiment, the cation detection cup is arranged in the shielding cover and close to the ion outlet of the shielding cover, the chip (wafer) and the target stage are located outside the ion outlet of the shielding cover and the center position of the chip is facing the ion outlet of the shielding cover, wherein, in the process of detecting the distribution of the cations in the direction parallel to the wafer surface, the ion detection cup moves in the direction perpendicular to the wafer surface.

[0046] Preferably, the cation detection cup and the data processing module are used to detect the distribution of the cations in a direction parallel to the wafer surface, including:

[0047] The cation detection cup detects the current value when the cation passes through;

[0048] The data processing module obtains the distribution of the cations in a direction parallel to the wafer surface according to the current value and the cross-sectional area.

[0049] Next, the method for detecting the neutralization ability of PFG provided by the application embodiment is described in detail.

[0050] In this embodiment, before turning on the PFG, the method for detecting the PFG neutralization capability may further include: step S0 , confirming that the ion beam emitting device is in a shutdown state to ensure that the ion beam emitting device does not generate an ion beam flowing through the shielding cover.

[0051] In this embodiment, the ion beam is shut down to prevent the positive ions in the ion beam from affecting the subsequent PFG test on the distribution of positive ions ionized by the inert gas.

[0052] Step S1: Turn on the PFG and use the PFG gas supply system to deliver an inert gas into the ionization chamber. The inert gas is ionized in the ionization chamber to generate cations and electrons. Specifically, the inert gas includes but is not limited to rare gases such as xenon and argon.

[0053] In this embodiment, the PFG is always in the on state.

[0054] Step S2: Providing the cations and the electrons into the shielding cover of the ion detection module. Specifically, a suction voltage is provided near the through hole on the cover of the ionization chamber, and the cations and the electrons are drawn into the shielding cover by the suction voltage.

[0055] In this embodiment, the inert gas is argon, and the reaction formula for the ionization of argon is: Ar→Ar + +e - Therefore, the cation detection cup is used to detect Ar + Ar in the horizontal direction parallel to the wafer surface + The distribution of electrons emitted by the PFG in the horizontal direction can be used to reversely characterize the distribution of electrons in the horizontal direction parallel to the wafer surface.

[0056] In this embodiment, by the extraction voltage, Ar + and free electrons are drawn into the shield.

[0057] In another embodiment, the inert gas may be xenon gas, and the reaction formula for the ionization of xenon gas is: Xe → Xe + +e - . With the detection of Ar + The principle of reverse characterization of the distribution of free electrons in the horizontal direction parallel to the wafer surface is the same. The cation detection cup is then used to detect Xe + Xe in the horizontal direction parallel to the wafer surface + The distribution of electrons emitted by the PFG in the horizontal direction can be used to reversely characterize the distribution of electrons in the horizontal direction parallel to the wafer surface.

[0058] Step S3: using the cation detection cup of the ion detection module to detect the distribution of the cations in a direction parallel to the wafer surface.

[0059] Specifically, the cation detection cup is arranged in the shielding cover and close to the ion outlet of the shielding cover, wherein, in the process of detecting the distribution of the cations in the direction parallel to the wafer surface, the ion detection cup moves in the direction perpendicular to the wafer surface.

[0060] In this embodiment, the step of using the cation detection cup of the ion detection module to detect the distribution of the cations in a direction parallel to the wafer surface may specifically include:

[0061] Step S3.1: using the cation detection cup of the ion detection module to detect the current value when the cation passes through;

[0062] Step S3.2: Obtaining the cross-sectional area of the surface of the cation detection cup facing the flow of cations;

[0063] Step S3.3: Obtain the distribution of the cations in a direction parallel to the wafer surface according to the current value and the cross-sectional area.

[0064] In the present application, the cation detection cup is used to detect the distribution of cations emitted by the PFG in the horizontal direction parallel to the wafer surface to reversely characterize the distribution of electrons emitted by the PFG in the horizontal direction parallel to the wafer surface. That is, the distribution of electrons used to neutralize cations in the ion beam (electrons provided by the PFG) can be effectively monitored, so as to effectively detect whether the overall distribution of free electrons introduced from the PFG chamber can meet the requirements of positive ions (ion beam), thereby realizing the detection of the neutralization ability of the PFG.

[0065] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of this application.

Claims

1. A method for detecting the neutralization ability of PFG, characterized in that: include: Turning on the PFG, and using the gas supply system of the PFG to supply an inert gas into the ionization chamber of the PFG, wherein the inert gas is ionized in the ionization chamber to generate cations and electrons; providing the cations and the electrons into a shielding cover of an ion detection module; Using a cation detection cup of an ion detection module to detect the distribution of the cations in a direction parallel to the wafer surface; According to the distribution of the cations, the distribution of the electrons in a direction parallel to the wafer surface is obtained.

2. The method for detecting the neutralization ability of PFG according to claim 1, characterized in that: The cation detection cup is arranged in the shielding cover and close to the ion outlet of the shielding cover, wherein, during the process of detecting the distribution of the cations in the direction parallel to the wafer surface, the ion detection cup moves in the direction perpendicular to the wafer surface.

3. The method for detecting the neutralization ability of PFG according to claim 2, characterized in that: The step of using the cation detection cup of the ion detection module to detect the distribution of the cations in a direction parallel to the wafer surface includes: Utilizing the cation detection cup of the ion detection module to detect the current value when the cation passes through; Obtaining the cross-sectional area of the surface of the cation detection cup facing the flow of cations; The distribution of the cations in a direction parallel to the wafer surface is obtained according to the current value and the cross-sectional area.

4. The method for detecting the neutralization ability of PFG according to claim 1, characterized in that: The inert gas is xenon or argon.

5. The method for detecting the neutralization ability of PFG according to claim 3, characterized in that: The inert gas is argon, and the reaction formula for the ionization of argon is: Ar→Ar + +e - .

6. The method for detecting the neutralization ability of PFG according to claim 3, characterized in that: The inert gas is xenon, and the reaction formula for the ionization of xenon is: Xe→Xe + +e - .

7. The method for detecting the neutralization ability of PFG according to claim 1, characterized in that: Before turning on the PFG, the method for detecting the neutralization capability of the PFG further includes: confirming that the ion beam emitting device is in a shut-down state to ensure that the ion beam emitting device does not generate an ion beam flowing through the shielding cover.

8. A detection system, characterized in that: include: PFG, ion detection module and data processing module, wherein the PFG includes: a gas supply system and an ionization chamber; the ion detection module includes: a shielding cover and a cation detection cup; wherein, The gas supply system is used to transport inert gas into the ionization chamber; the ionization chamber is used to ionize the inert gas to generate cations and electrons, and the ionization chamber is also used to provide the cations and electrons into the shielding cover; the cation detection cup and the data processing module are used to detect the distribution of the cations in a direction parallel to the wafer surface; the data processing module is also used to receive the distribution of the cations and, based on the distribution of the cations, obtain the distribution of the electrons in a direction parallel to the wafer surface.

9. The detection system according to claim 8, characterized in that: The cation detection cup is arranged in the shielding cover and close to the ion outlet of the shielding cover, wherein, during the process of detecting the distribution of the cations in the direction parallel to the wafer surface, the ion detection cup moves in the direction perpendicular to the wafer surface.

10. The detection system according to claim 9, characterized in that: The cation detection cup and the data processing module are used to detect the distribution of the cations in a direction parallel to the wafer surface, including: The cation detection cup detects the current value when the cation passes through; The data processing module obtains the distribution of the cations in a direction parallel to the wafer surface according to the current value and the cross-sectional area of the surface of the cation detection cup facing the flow of the cations.

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