Ion implanter

Abstract

This application provides an ion implanter, belonging to the semiconductor field, comprising an ion source for generating cations and electrons; an ion extraction module for extracting cations from the ion source and generating an ion beam; a first electron extraction module for extracting electrons from the ion source and generating an electron beam; a neutralization chamber for receiving the ion beam and electron beam and neutralizing the ion beam using the electron beam; and an implantation chamber connected to the neutralization chamber, where the ion beam is used for ion implantation. This application utilizes the first electron extraction module to extract electrons from the ion source, which on the one hand promotes the departure of cations from the ion source, facilitating the extraction of cations by the ion extraction module; on the other hand, it utilizes the electron beam formed by the extracted electrons to neutralize the ion beam, thereby eliminating the need for an electron gun, reducing costs, and preventing metal contamination, thus solving the problems of white spots and dark current in the product.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and more specifically to an ion implanter. Background Technology

[0002] In the large-scale integrated circuit manufacturing industry, ion implantation technology plays an important role in changing the local electrical properties of wafers, altering wafer surface characteristics, and assisting other processes. With its unique advantages such as high purity of doped ions, precise doping dosage, easy control of the distribution characteristics of doped ions inside the wafer, high process repeatability, low lateral diffusion, and low processing temperature, it plays an increasingly important role in the semiconductor integrated circuit manufacturing industry where feature sizes are constantly shrinking.

[0003] Ion implanters utilize a series of electric and magnetic fields to perform extraction, acceleration / deceleration, and screening operations. Therefore, their target is cations. As cations from the ion beam are continuously implanted onto the wafer, positive charges accumulate on the wafer surface, leading to a series of adverse effects. These include the repulsion of subsequent cation implantation by the positive charge on the wafer surface, positive charge discharge causing defects or even damage to the device, and severe ion beam edge divergence resulting in poor ion implantation uniformity. To prevent this continuous accumulation of positive charges on the wafer surface, ion implanters typically introduce a certain amount of electrons into the ion beam to neutralize the high potential generated by the cations. Therefore, ion implanters are equipped with an electron gun (Plasma Flood Gun, PFG). The principle is that electrons generated by the cathode filament in the electron gun are attracted to the positively charged cations in the ion beam, thus neutralizing the cations. The electron gun is usually located at the end of the ion implanter, after the ion beam has completed elemental and energy screening, and its parallelism and uniformity requirements are met, just before implantation onto the wafer, thereby reducing the impact on the ion beam.

[0004] To effectively neutralize the ion beam, the number of electrons emitted by the electron gun must be greater than the number of cations in the ion beam. Therefore, the voltage applied to the cathode filament of the electron gun must be increased, resulting in a shorter cathode filament lifespan. Different products have different ion beam currents, requiring frequent switching of the voltage applied to the cathode filament of the electron gun, further shortening the cathode filament lifespan. In addition, the cathode filament is usually made of tungsten, which may cause metal contamination, leading to an increase in white pixels (WP) and dark current in the product. Summary of the Invention

[0005] In view of this, the embodiments of this application aim to provide an ion implanter to solve the problems of short electron gun life and easy metal contamination in the prior art.

[0006] This application provides an ion implanter, comprising:

[0007] An ion source is used to generate cations and electrons;

[0008] An ion extraction module is used to extract the cations from the ion source and generate an ion beam;

[0009] The first electron extraction module is used to extract electrons from the ion source and generate an electron beam;

[0010] A neutralization chamber for receiving the ion beam and the electron beam, and for neutralizing the ion beam using the electron beam; and,

[0011] An injection chamber is connected to the neutralization chamber, and an ion implantation process is performed using the ion beam.

[0012] In some embodiments, the extraction electrode of the first electronic extraction module and the extraction electrode of the ion extraction module are respectively connected to the positive and negative terminals of the same power supply.

[0013] In some embodiments, the extraction electrode of the first electronic extraction module is connected to the positive terminal of the first power supply, and the extraction electrode of the ion extraction module is connected to the negative terminal of the second power supply.

[0014] In some embodiments, the voltage ratio of the first power supply to the voltage of the second power supply is 0.5 to 1.

[0015] In some embodiments, it also includes:

[0016] An electron transport pathway, connecting the first electron extraction module and the neutralization chamber, is used for electron beam transport; and...

[0017] An ion transport pathway connects the ion extraction module and the neutralization chamber for ion beam transport.

[0018] In some embodiments, it also includes:

[0019] A second electron extraction module is used to extract a portion of the electrons from the electron beam from the electron transport path; and...

[0020] An electron reflux path connects the second electron extraction module and the ion source, and is used to transfer the electrons extracted by the second electron extraction module to the ion source.

[0021] In some embodiments, the voltage applied to the extraction electrode of the second electronic extraction module is less than the voltage applied to the extraction electrode of the first electronic extraction module.

[0022] In some embodiments, it also includes:

[0023] A Faraday detection cup, located within the neutralization chamber, is used to detect the number of electrons remaining after the electron beam neutralizes the ion beam; and,

[0024] A control system is used to adjust the voltage applied to the extraction electrodes of the first electronic extraction module and / or the second electronic extraction module based on the detection result of the Faraday detection cup.

[0025] In some embodiments, the ion extraction module and the first electron extraction module are located on opposite sides of the ion source, and the ion implanter further includes:

[0026] The first deflection module is located on the ion transport path and is used to remove non-target ions from the ion beam and deflect the ion beam at a first predetermined angle so that it enters the neutralization chamber in a first direction.

[0027] A second deflection module, located on the electron transport path, is used to deflect the electron beam at a second predetermined angle so that it enters the neutralization chamber in a second direction, wherein the first direction is perpendicular to the second direction; and

[0028] The electron reflux path is located between the ion source and the electron transport path, and transports the electrons extracted by the second electron extraction module into the ion source in the first direction.

[0029] In some embodiments, the electron transport pathway has a main pathway and a first branch pathway and a second branch pathway. One end of the main pathway is connected to the first electron extraction module, and the other end of the main pathway is connected to one end of the first branch pathway and one end of the second branch pathway. The other end of the first branch pathway is connected to the ion source, and the other end of the second branch pathway is connected to the neutralization chamber; and...

[0030] The ion implanter also includes a third deflection module located on the first branch path, used to deflect electrons entering the first branch path by a third predetermined angle before they enter the ion source.

[0031] In some embodiments, the electron transport pathway has a first end and a second end, the first end being connected to the first electron extraction module, and the second end being connected to the neutralization chamber, the second end being funnel-shaped; and...

[0032] The ion implanter also includes an electron focusing and diverging device, which is located on the electron transport path and disposed near the second end to expand the divergence angle of the electron beam.

[0033] This application provides an ion implanter, including an ion source for generating cations and electrons; an ion extraction module for extracting the cations from the ion source and generating an ion beam; a first electron extraction module for extracting electrons from the ion source and generating an electron beam; a neutralization chamber for receiving the ion beam and the electron beam, and neutralizing the ion beam using the electron beam; and an implantation chamber connected to the neutralization chamber, where the ion beam is used for ion implantation. An unexpected benefit of this application is that by using the first electron extraction module to extract electrons from the ion source, it can promote the departure of cations from the ion source, facilitating the extraction of cations by the ion extraction module. Furthermore, it can utilize the electron beam formed by the extracted electrons to neutralize the ion beam, thereby eliminating the need for an electron gun, reducing costs, preventing metal contamination, and solving the problems of white spots and dark current in the product. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of an ion implanter provided in an embodiment of this application.

[0035] Figure 2 This is a schematic diagram showing the connection between the ion extraction module and the first electron extraction module and the ion source provided in an embodiment of this application.

[0036] Figure 3 This is another schematic diagram showing the connection between the ion extraction module and the first electron extraction module and the ion source provided in one embodiment of this application.

[0037] Figure 4 This is a schematic diagram showing the positions of the electronic deceleration cylinder and the electronic focusing and diverging device provided in an embodiment of this application.

[0038] Figure 5 This is a schematic diagram of another ion implanter provided in an embodiment of this application.

[0039] Figure 6 This is a schematic diagram of the structure of another ion implanter provided in an embodiment of this application.

[0040] The attached figures are labeled as follows:

[0041] 100 - Arc chamber; 101 - Inlet pipe; 201 - First electronic extraction module; 211 - First extraction electrode; 202 - Ion extraction module; 212 - Second extraction electrode; 203 - Second electronic extraction module; 213 - Third extraction electrode; 301 - Electron transport path; 302 - Ion transport path; 303 - Electron reflux path; 311 - Main path; 312 - First branch path; 313 - Second branch path; 501 - First deflection module; 502 - Second deflection module; 503 - Third deflection module; 600 - Electronic deceleration cylinder; 700 - Electron focusing and diverging device; 800 - Neutralization chamber; 801 - Faraday detection cup; 900 - Injection chamber; 901 - Wafer; E - Power supply; E1 - First power supply; E2 - Second power supply. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] Figure 1 This is a schematic diagram of the structure of an ion implanter provided in one embodiment of this application. Figure 1 As shown, the ion implanter includes an ion source, an ion extraction module 202, a first electron extraction module 201, a neutralization chamber 800, and an injection chamber 900.

[0044] Specifically, the ion source is used to generate cations and electrons. In some embodiments, the ion source includes structures such as an arc chamber 100 and an inlet pipe 101. The inlet pipe 101 can introduce process gas into the arc chamber 100. The arc chamber 100 has a filament. By heating the filament, the filament can release electrons. The electrons bombard the process gas in the arc chamber 100, and the process gas is ionized to obtain cations and electrons. Taking boron ion (B+) implantation as an example, the process gas can be boron trifluoride (BF3). When boron trifluoride gas collides with electrons, it will ionize, producing various cations such as B+, BF++, BF+, BF+++, B++, BF++, and F+. At the same time, it will also produce an equal number of electrons as the sum of these cations. There will be a large number of cations and electrons in the arc chamber 100, but B+ is the cation that actually needs to be implanted onto wafer 901 (target ion). B+ will be screened out before being implanted onto wafer 901, while other cations will be removed (and will not be implanted onto wafer 901). Including the electrons generated by the filament, the number of electrons in the arc chamber 100 is much greater than the number of target ions B+.

[0045] The ion extraction module 202 and the first electron extraction module 201 are located on opposite sides of the ion source. The ion extraction module 202 and the first electron extraction module 201 can respectively extract cations and electrons from the ion source to generate ion beams and electron beams. Figure 2 This is a schematic diagram showing the connection between the ion extraction module 202 and the first electron extraction module 201 and the ion source according to an embodiment of this application, as shown below. Figure 2 As shown, windows can be opened on opposite sides of the arc chamber 100 of the ion source. The ion extraction module 202 and the first electron extraction module 201 can be respectively installed in one of these windows. Both the ion extraction module 202 and the first electron extraction module 201 include extraction electrodes. For ease of description, the extraction electrode of the first electron extraction module 201 is referred to as the first extraction electrode 211, and the extraction electrode of the ion extraction module 202 is referred to as the second extraction electrode 212. The first extraction electrode 211 and the second extraction electrode 212 are connected to the positive and negative terminals of the power supply E, respectively. In this way, electrons in the ion source are drawn out from the window at the first extraction electrode 211, gaining corresponding energy and generating an electron beam. Similarly, cations in the ion source are drawn out from the window at the second extraction electrode 212, gaining corresponding energy and generating an ion beam. Since the ion source contains various cations, the ion beam will also contain various cations.

[0046] In some embodiments, the first electron extraction module 201 and the ion extraction module 202 can be staggered in the vertical direction. That is, the first electron extraction module 201 and the ion extraction module 202 are not symmetrically arranged on both sides of the two pairs of ion sources, so as to avoid mutual interference when the first electron extraction module 201 absorbs electrons and the ion extraction module 202 absorbs cations.

[0047] It should be noted that if the extraction electrode (first extraction electrode 211) of the first electron extraction module 201 and the extraction electrode (second extraction electrode 212) of the ion extraction module 202 are connected to the positive and negative terminals of the same power supply E respectively, the number of cations extracted by the ion extraction module 202 and the number of electrons extracted by the first electron extraction module 201 should theoretically be the same. Therefore, the number of electrons extracted by the first electron extraction module 201 will inevitably be more than the number of target ions in the ion beam, that is, the electron beam is sufficient to neutralize the ion beam.

[0048] In some embodiments, the extraction electrode of the first electronic extraction module 201 and the extraction electrode of the ion extraction module 202 may also be connected to the positive and negative terminals of different power sources, respectively. Figure 3 This is another schematic diagram showing the connection between the ion extraction module 202 and the first electron extraction module 201 and the ion source provided in one embodiment of this application, as shown below. Figure 3As shown, the extraction electrode (first extraction electrode 211) of the first electron extraction module 201 can be connected to the positive terminal of the first power supply E1, and the extraction electrode (second extraction electrode 212) of the ion extraction module 202 can be connected to the negative terminal of the second power supply E2. The voltages of the first power supply E1 and the second power supply E2 can be the same or different. In this way, the number of cations extracted by the ion extraction module 202 and the number of electrons extracted by the first electron extraction module 201 can theoretically be the same or different. However, since the extraction electrodes of the first electron extraction module 201 and the ion extraction module 202 are connected to different power supplies, the voltages of the first power supply E1 and the second power supply E2 can be adjusted independently, thereby controlling the number of cations extracted by the ion extraction module 202 and the number of electrons extracted by the first electron extraction module 201. Adjusting the voltages of the first power supply E1 and the second power supply E2 according to requirements ensures that the ion beam can better meet the ion implantation requirements, the electron beam can better meet the neutralization requirements, and the overall system energy utilization rate is also high.

[0049] In some embodiments, since only a portion of the cations extracted by the ion extraction module 202 are target ions, and not many electrons are needed for neutralization, the voltage of the first power supply E1 can be lower than the voltage of the second power supply E2, so that the number of electrons extracted by the first electron extraction module 201 is less than the number of cations extracted by the ion extraction module 202. Furthermore, to ensure the neutralization effect, the voltage difference between the first power supply E1 and the second power supply E2 should not be too large, thereby avoiding an insufficient number of extracted electrons that would fail to effectively neutralize the ion beam. For example, the ratio of the voltage of the first power supply E1 to the voltage of the second power supply E2 can be 0.5 to 1, but should not be limited to this.

[0050] Please continue reading. Figure 1 The ion implanter also includes an electron transport path 301 and an ion transport path 302. The electron transport path 301 connects the first electron extraction module 201 and the neutralization chamber 800 and is used for electron beam transport. The electron beam can travel from the first electron extraction module 201 to the neutralization chamber 800 through the electron transport path 301. The ion transport path 302 connects the ion extraction module 202 and the neutralization chamber 800 and is used for ion beam transport. The ion beam can travel from the ion extraction module 202 to the neutralization chamber 800 through the ion transport path 302.

[0051] Furthermore, since not all cations extracted from the ion extraction module 202 are target ions, the ion transport pathway 302 has a first deflection module 501. The first deflection module 501 can be located between the ion extraction module 202 and the neutralization chamber 800. The first deflection module 501 is typically a mass analyzer. On one hand, the first deflection module 501 can use the mass-to-charge ratio to screen out target ions in the ion beam and remove non-target ions. For example, the ion beam contains cations such as B+, BF++, BF+, BF+++, B++, BF++, and F+. Different cations have different mass-to-charge ratios, and therefore different deflection radii in the magnetic field. By adjusting the magnitude of the magnetic field, only B+ ions can pass through the magnetic field and continue along the ion transport pathway 302, while cations such as BF++, BF+, BF+++, B++, BF++, and F+ are absorbed by the structure in the first deflection module 501 and will not re-enter the ion transport pathway 302. On the other hand, the first deflection module 501 can also deflect the ion beam by a predetermined angle, thereby changing the path of the ion beam so that the ion beam enters the neutralization chamber 800 in the first direction. Figure 1 Since the neutralization chamber 800 is located to the lower right of the ion source (in order to facilitate the setting of structures such as vacuum structures and ion accelerators on the ion transmission path 302), the first deflection module 501 can be set above the neutralization chamber 800 and deflect the ion beam by 90° so that the ion beam can enter the neutralization chamber 800 vertically. At this time, the ion transmission path 302 is L-shaped.

[0052] It should be noted that the main function of the first deflection module 501 is to screen ions and change the path of the ion beam so that the target ions can reach the neutralization chamber 800. Therefore, the first deflection module 501 is not limited to deflecting the ion beam by 90°. The angle at which the first deflection module 501 deflects the ion beam can be designed according to the relative position between the ion source and the neutralization chamber 800.

[0053] Furthermore, the ion transport path 302 can also be equipped with structures such as an ion accelerator and a focusing collimator, thereby achieving the effects of accelerating, focusing, and collimating the ion beam, so that the ion beam meets the requirements of ion implantation, which will not be elaborated here.

[0054] Please continue reading. Figure 1 In some embodiments, the electron transmission path 301 has a second deflection module 502, which can also be a magnetic field controller, used to deflect the electron beam by a predetermined angle, thereby changing the path of the electron beam so that the electron beam enters the neutralization chamber 800 in a second direction. Figure 1Since the neutralization chamber 800 is located to the lower right of the ion source (to facilitate the installation of a vacuum structure on the ion transport path 302), the second deflection module 502 needs to deflect the electron beam by 180° so that the electron beam can enter the neutralization chamber 800 in parallel. At this time, the electron transport path 301 is C-shaped. The first direction can be perpendicular to the second direction, that is, the directions in which the electron beam and the ion beam reach the neutralization chamber 800 are exactly perpendicular. The electron beam and the ion beam converge in an orthogonal manner, which allows the electron beam to better neutralize the ion beam and improve the uniformity of ion implantation.

[0055] It should be noted that the main function of the second deflection module 502 is to change the path of the electron beam so that it can reach the neutralization chamber 800. Therefore, the second deflection module 502 is not limited to deflecting the electron beam by 180°. The angle at which the second deflection module 502 deflects the electron beam can be designed according to the relative position between the ion source and the neutralization chamber 800.

[0056] In some embodiments, the electron transport path 301 is further provided with an electron deceleration cylinder 600, which can add a deceleration electric field to the electron transport path 301 to decelerate the electrons in the electron beam, making it easier for the subsequent electron beam and ion beam to merge.

[0057] For further information, please refer to [link / reference]. Figure 1 The electron transport path 301 has a first end and a second end. The first end is connected to the first electron extraction module 201, and the second end is connected to the neutralization chamber 800. The second end can be funnel-shaped to widen the opening of the second end. The ion implanter may also include an electron focusing and diverging device 700, which can be located on the electron transport path 301 and disposed near the second end of the electron transport path 301. Figure 4 This is a schematic diagram showing the positions of the electronic deceleration cylinder 600 and the electronic focusing and diverging device 700 according to an embodiment of this application, as shown below. Figure 4 As shown, the electron focusing divergence device 700 can focus the electron beam and expand the divergence angle of the electron beam. Since the end of the electron transmission path 301 is horn-shaped, the electron beam can enter the neutralization chamber 800 with a larger divergence angle and merge with the ion beam in the neutralization chamber 800. At this time, the contact area between the electrons in the electron beam and the cations in the ion beam is larger, which is beneficial to the neutralization of the ion beam.

[0058] Please continue reading. Figure 1 The neutralization chamber 800 receives both ion beams and electron beams, and can neutralize the ion beams using the electron beams. Figure 1In this design, windows are opened at the top and side walls of the neutralization chamber 800. An ion beam enters the neutralization chamber 800 vertically through the window at the top, while an electron beam enters the neutralization chamber 800 parallel to it through the window at the side wall. The two beams converge, allowing electrons in the electron beam to combine with cations in the ion beam, thus neutralizing the ion beam. Therefore, this application utilizes the first electron extraction module 201 to extract electrons from the ion source. This promotes the departure of cations from the ion source, facilitating the extraction of cations by the ion extraction module 202. Furthermore, the electron beam formed by the extracted electrons neutralizes the ion beam, eliminating the need for an electron gun, reducing costs, preventing metal contamination, and solving the problems of white spots and dark current in the product.

[0059] Furthermore, the ion implanter may also include a Faraday detection cup 801 and a control system ( Figure 1 (Not shown in the image) The Faraday detection cup 801 is located in the neutralization chamber 800 and is used to detect the number of electrons remaining after the electron beam neutralizes the ion beam. The control system can adjust the voltage applied to the extraction electrode (first extraction electrode 211) of the first electron extraction module 201 according to the detection result of the Faraday detection cup 801, thereby adjusting the number of electrons extracted by the first electron extraction module 201 and avoiding the problem of excess electrons in the electron beam or insufficient electrons in the electron beam to neutralize the ion beam. Specifically, the Faraday detection cup 801 can be positioned on the opposite side of the electron beam. After the electrons in the electron beam neutralize the cations in the ion beam at high speed, if some electrons are not captured by the cations, they will continue to move forward until they reach the Faraday detection cup 801. The Faraday detection cup 801 can detect the magnitude of the remaining electron beam current, thereby determining the amount of electrons remaining. Based on the detection result of the Faraday detection cup 801, the control system can adaptively increase or decrease the voltage applied to the extraction electrode (first extraction electrode 211) of the first electron extraction module 201 (adjusting the voltage output of the first power supply E1), thereby adjusting the number of electrons extracted by the first electron extraction module 201.

[0060] Furthermore, the implantation chamber 900 is connected to the neutralization chamber 800. The implantation chamber 900 has a scanning disk, on which the wafer 901 is placed. After the ion beam is neutralized by the electron beam, it enters the implantation chamber 900. The ion beam can be used to perform ion implantation on the wafer 901.

[0061] Figure 5 This is a schematic diagram of another ion implanter provided in an embodiment of this application. Figure 5As shown, the ion implanter may further include a second electron extraction module 203 and an electron return path 303. The second electron extraction module 203 may be located between the second deflection module 502 and the electron deceleration cylinder 600. The electron return path 303 may connect the second electron extraction module 203 and the ion source. The second electron extraction module 203 can extract a portion of the electrons from the electron beam from the electron transport path 301. The electron return path 303 can transport the electrons extracted by the second electron extraction module 203 to the ion source. Specifically, corresponding windows may be opened on the electron transport path 301 between the second deflection module 502 and the electron deceleration cylinder 600 and on the arc chamber 100 of the ion source. The second electron extraction module 203 is positioned at the window on the electron transport path 301. The electron return path 303 connects the second electron extraction module 203 and the corresponding window on the arc chamber 100 of the ion source. The third extraction electrode 213 of the second electron extraction module 203 may be connected to a third power supply. Figure 5 (Not shown in the diagram) The positive electrode is used, so that electrons in the electron transport path 301 are drawn out through the window at the second electron extraction module 203 and return to the arc chamber 100 of the ion source along the electron return path 303. In this way, even if the first electron extraction module 201 extracts too many electrons, the excess electrons can be drawn out by the second electron extraction module 203, and the excess electrons can be reused in the arc chamber 100 of the ion source to continue bombarding the process gas, thereby improving energy utilization and avoiding excessive loss of electrons in the ion source, which would affect the ionization reaction.

[0062] In some embodiments, the electron reflux path 303 is located between the ion source and the electron transport path 301, and the electron reflux path 303 can transport the electrons extracted by the second electron extraction module 203 into the ion source in a first direction. That is, the electron reflux path 303 can be set perpendicular to the ion source and the electron transport path 301, in which case the electron reflux path 303 is in a straight line shape. In this way, the electrons can return to the ion source without changing the direction of electron movement in the electron reflux path 303, so there is no need to set a deflection module on the electron reflux path 303, thereby simplifying the structure of the ion implanter and saving costs.

[0063] In some embodiments, the voltage applied to the extraction electrode of the second electron extraction module 203 is typically lower than the voltage applied to the extraction electrode of the first electron extraction module 201. This prevents the second electron extraction module 203 from drawing out a large number of electrons from the electron transport path 301, thus affecting the neutralization effect of the ion beam. Furthermore, when the extraction electrodes of the first electron extraction module 201 and the ion extraction module 202 are connected to the positive and negative terminals of the same power supply, respectively, the number of electrons reaching the neutralization chamber 800 can be adjusted by adjusting the voltage applied to the extraction electrode of the second electron extraction module 203, thereby achieving system balance. For example, the control system can adjust the voltage applied to the extraction electrode (third extraction electrode 213) of the second electron extraction module 203 based on the detection results of the Faraday detection cup 801, thereby adjusting the number of electrons extracted by the second electron extraction module 203 and avoiding either an excess of electrons in the electron beam or an insufficient number of electrons in the electron beam to neutralize the ion beam. Specifically, the control system can adaptively increase or decrease the voltage applied to the extraction electrode (third extraction electrode 213) of the second electronic extraction module 203 (adjusting the voltage output of the third power supply) according to the detection result of the Faraday detection cup 801, thereby adjusting the number of electrons extracted by the second electronic extraction module 203.

[0064] Figure 6 This is a schematic diagram of another ion implanter provided in an embodiment of this application. Figure 6 As shown, in some embodiments, the electron transport path 301 may have a main path 311 and a first branch path 312 and a second branch path 313. One end of the main path 311 is connected to the first electron extraction module 201, and the other end of the main path 311 is connected to one end of the first branch path 312 and the second branch path 313. The other end of the first branch path 312 is connected to the ion source, and the other end of the second branch path 313 is connected to the neutralization chamber 800. The ion implanter also includes a third deflection module 503, which may be located on the first branch path 312 and is used to deflect the electrons entering the first branch path 312 by a third predetermined angle before they enter the ion source. Specifically, after the electron beam passes through the main path 311, part of it enters the first branch path 312 and the other part enters the second branch path 313. The third deflection module 503 deflects the electrons in the first branch path 312 at a certain angle and then transmits them into the ion source. This avoids the first electron extraction module 201 absorbing too many electrons from the ion source, which would affect the ionization reaction. Furthermore, the excess electrons can be reused in the arc chamber 100 of the ion source to continue bombarding the process gas, thereby improving energy utilization. Meanwhile, the electrons in the second branch path 313 can normally enter the neutralization chamber 800 to neutralize the ion beam.

[0065] It should be noted that the ion source, neutralization chamber 800, injection chamber 900, electron transport path 301, ion transport path 302, and electron return path 303 all require a vacuum environment. Therefore, the ion implanter also includes several vacuum modules for evacuating the ion source, neutralization chamber 800, injection chamber 900, electron transport path 301, ion transport path 302, and electron return path 303. The specific structure and location of the vacuum modules can be designed and adjusted according to actual conditions, and will not be illustrated here.

[0066] In summary, one embodiment of this application provides an ion implanter, including an ion source for generating cations and electrons; an ion extraction module 202 for extracting cations from the ion source and generating an ion beam; a first electron extraction module 201 for extracting electrons from the ion source and generating an electron beam; a neutralization chamber 800 for receiving the ion beam and electron beam and neutralizing the ion beam using the electron beam; and an implantation chamber 900 connected to the neutralization chamber 800, which performs the ion implantation process using the ion beam. This application utilizes the first electron extraction module 201 to extract electrons from the ion source, which on the one hand promotes the departure of cations from the ion source, facilitating the extraction of cations by the ion extraction module 202; on the other hand, it utilizes the electron beam formed by the extracted electrons to neutralize the ion beam, thereby eliminating the need for an electron gun, reducing costs, and preventing metal contamination, thus solving the problems of white spots and dark current in the product.

[0067] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0068] It should also be noted that although preferred embodiments have been disclosed above, these embodiments are not intended to limit this application. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this application, or modify them into equivalent embodiments, without departing from the scope of the technical solutions of this application. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this application, without departing from the content of the technical solutions of this application, shall still fall within the scope of protection of the technical solutions of this application.

[0069] It should also be understood that, unless otherwise specified or indicated, the terms “first,” “second,” “third,” etc., in the specification are used only to distinguish the various components, elements, and steps in the specification, and not to indicate the logical or sequential relationships between the various components, elements, and steps.

[0070] Furthermore, it should be recognized that the terminology described herein is used only to describe particular embodiments and is not intended to limit the scope of this application. It must be noted that the singular forms “a” and “an” as used herein include plural bases unless the context clearly indicates the opposite. For example, a reference to “a step” or “an apparatus” means a reference to one or more steps or apparatuses, and may include secondary steps and secondary apparatuses. All conjunctions used should be understood in the broadest sense. Also, the word “or” should be understood as having the definition of logical “or”, not logical “exclusive OR”, unless the context clearly indicates the opposite. Furthermore, implementations of the methods and / or devices in the embodiments of this application may include performing selected tasks manually, automatically, or in combination.

Claims

1. An ion implanter, comprising: include: An ion source is used to generate cations and electrons; An ion extraction module is used to extract the cations from the ion source and generate an ion beam; The first electron extraction module is used to extract electrons from the ion source and generate an electron beam; A neutralization chamber for receiving the ion beam and the electron beam, and for neutralizing the ion beam using the electron beam; as well as, An injection chamber is connected to the neutralization chamber, and an ion implantation process is performed using the ion beam; An electron transport path connects the first electron extraction module and the neutralization chamber for electron beam transport. The second electron extraction module is used to extract a portion of the electrons from the electron beam from the electron transport path; An electron reflux path connects the second electron extraction module and the ion source, and is used to transfer the electrons extracted by the second electron extraction module to the ion source.

2. The ion implanter of claim 1, wherein, The extraction electrode of the first electronic extraction module and the extraction electrode of the ion extraction module are respectively connected to the positive and negative terminals of the same power supply.

3. The ion implanter according to claim 1, characterized in that, The extraction electrode of the first electronic extraction module is connected to the positive terminal of the first power supply, and the extraction electrode of the ion extraction module is connected to the negative terminal of the second power supply.

4. The ion implanter according to claim 3, characterized in that, The voltage ratio of the first power supply to the voltage of the second power supply is 0.5 to 1.

5. The ion implanter according to claim 1, characterized in that, Also includes: An ion transport pathway connects the ion extraction module and the neutralization chamber for ion beam transport.

6. The ion implanter according to claim 1, characterized in that, The voltage applied to the extraction electrode of the second electronic extraction module is less than the voltage applied to the extraction electrode of the first electronic extraction module.

7. The ion implanter according to claim 1, characterized in that, Also includes: A Faraday detection cup, located within the neutralization chamber, is used to detect the number of electrons remaining after the electron beam neutralizes the ion beam; as well as, A control system is used to adjust the voltage applied to the extraction electrodes of the first electronic extraction module and / or the second electronic extraction module based on the detection result of the Faraday detection cup.

8. The ion implanter according to claim 5, characterized in that, The ion extraction module and the first electronic extraction module are located on opposite sides of the ion source, and the ion implanter further includes: The first deflection module is located on the ion transport path and is used to remove non-target ions from the ion beam and deflect the ion beam at a first predetermined angle so that it enters the neutralization chamber in a first direction. A second deflection module, located on the electron transport path, is used to deflect the electron beam at a second predetermined angle so that it enters the neutralization chamber in a second direction, wherein the first direction is perpendicular to the second direction; and The electron reflux path is located between the ion source and the electron transport path, and transports the electrons extracted by the second electron extraction module into the ion source in the first direction.

9. The ion implanter according to claim 1, characterized in that, The electron transport pathway has a main pathway and a first branch pathway and a second branch pathway. One end of the main pathway is connected to the first electron extraction module, and the other end of the main pathway is connected to one end of the first branch pathway and one end of the second branch pathway. The other end of the first branch pathway is connected to the ion source, and the other end of the second branch pathway is connected to the neutralization chamber. as well as, The ion implanter also includes a third deflection module located on the first branch path, used to deflect electrons entering the first branch path by a third predetermined angle before they enter the ion source.

10. The ion implanter according to claim 5 or 9, characterized in that, The electron transport pathway has a first end and a second end, the first end being connected to the first electron extraction module, and the second end being connected to the neutralization chamber; the second end is funnel-shaped. The ion implanter also includes an electron focusing and diverging device, which is located on the electron transport path and disposed near the second end to expand the divergence angle of the electron beam.

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