Electron spraying device and ion implantation equipment

Abstract

The present invention relates to the field of semiconductor technology, and provides an electron spray device and ion implantation equipment. The electron spray device includes: an electron generator and a blocking unit; the electron generator is used to generate electrons, and the electron generator has an electron emission port, which is connected to a process chamber for electrons to enter the process chamber; the blocking unit is arranged on the inner wall of the process chamber, and the process chamber has a placement position for placing wafers; along the irradiation direction of the ion beam, the blocking unit is located between the electron emission port and the placement position; along a first direction, the blocking unit is located between the electron emission port and the ion beam, and the first direction is the direction from the electron emission port perpendicular to the ion beam. With such a configuration, the electron spray device of the present invention can neutralize the ion beam and ensure uniform charge distribution on the wafer surface.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to an electron spraying device and ion implantation equipment. Background Art

[0002] Ion implantation is a crucial doping technique in modern integrated circuit manufacturing. It uses ion implantation equipment to accelerate ions and inject dopant elements into semiconductor wafers, altering their conductive properties and ultimately forming the desired device structure. Ion implantation equipment typically consists of an ion source, ion extraction and mass analyzer, an accelerator tube, a scanning system, a process chamber, and a high-vacuum system. The high-vacuum system creates a negative pressure environment in the process chamber. The ion source generates an ion beam, which is separated by ion extraction and mass analyzer. The ion beam is then accelerated by the accelerator tube and enters the process chamber to bombard the wafer surface, achieving ion implantation.

[0003] During the ion implantation process, since a positively charged ion beam is used to implant the wafer, the doping ion beam will generate charge accumulation on the wafer surface. This charge accumulation can lead to hazards such as uneven doping and gate oxide breakdown. Therefore, the ion beam usually needs to be neutralized in the ion implanter. The existing method is to introduce electrons into the process chamber. The electrons will be attracted by the positive potential of the ion beam and merge into the ion beam for neutralization. However, since the neutralization position is close to the wafer, the electrons will be directly attracted to the wafer surface while neutralizing the ion beam, resulting in over-neutralization of the wafer and uneven charge distribution on the wafer surface. This phenomenon can easily change the charge balance in the ion beam, causing the beam spot to change and the dose distribution to be uneven. It can also damage the oxide layer on the wafer surface. For example, damage to the gate oxide layer can cause reliability issues in the device.

[0004] In order to improve the above-mentioned phenomenon of uneven charge distribution on the wafer surface caused by electrons, the present invention proposes an electron spray device and an ion implantation device. Summary of the Invention

[0005] The invention provides an electron spray device and ion implantation equipment. The electron spray device can neutralize ion beams and improve the phenomenon of uneven charge distribution on the wafer surface caused by electrons.

[0006] The electronic spray device includes: an electron generator and a blocking unit;

[0007] The electron generator is used to generate electrons, and the electron generator has an electron emission port, which is connected to the process chamber for electrons to enter the process chamber;

[0008] The blocking unit is arranged on the inner wall of the process chamber, and the process chamber has a placement position for placing the wafer;

[0009] Along the irradiation direction of the ion beam, the blocking unit is located between the electron emission port and the placement position;

[0010] The blocking unit is located between the electron emission port and the ion beam along a first direction, where the first direction is a direction perpendicularly pointing from the electron emission port to the ion beam.

[0011] Optionally, a positive voltage is applied to the blocking unit.

[0012] Optionally, the blocking unit includes a first blocking member and a second blocking member, the first blocking member is applied with a positive voltage, and a portion of the second blocking member is located between the ion beam and the first blocking member.

[0013] Optionally, the first blocking member is made of a conductive material, and is insulated from and connected to an inner wall of the process chamber.

[0014] Optionally, the second blocking member is made of insulating material.

[0015] Optionally, the second blocking member is C-shaped, and an opening side of the second blocking member faces the electron emission port along an irradiation direction of the ion beam.

[0016] Optionally, the first blocking member is disposed inside the second blocking member.

[0017] Optionally, the first blocking member is grounded.

[0018] Optionally, along a second direction, a size of the blocking unit is greater than or equal to a diameter of a wafer to be implanted, and the second direction is perpendicular to an irradiation direction of the ion beam and perpendicular to the first direction.

[0019] The present invention also provides an ion implantation device, comprising the above-mentioned electron spraying device.

[0020] To sum up, the electron spray device includes: an electron generator and a blocking unit; the electron generator is used to generate electrons, and the electron generator has an electron emission port, and the electron emission port is connected to the process chamber for supplying electrons to enter the process chamber; the blocking unit is arranged on the inner wall of the process chamber, and the process chamber has a placement position for placing the wafer; along the irradiation direction of the ion beam, the blocking unit is located between the electron emission port and the placement position; along the first direction, the blocking unit is located between the electron emission port and the ion beam, and the first direction is the direction from the electron emission port vertically pointing to the ion beam.

[0021] With such configuration, the electron spray device of the present invention, after the electron generator generates electrons, enters the process chamber through the electron emission port. The electrons are located above the ion beam, and move in the direction close to the ion beam, gradually merging into the ion beam to neutralize the ion beam. In addition, a blocking unit is provided between the electron emission port and the placement position to block the electrons from moving toward the placement position, thereby preventing the electrons from being directly attracted by the wafer surface, thereby preventing the wafer from being over-neutralized, ensuring uniform charge distribution on the wafer surface, and ensuring charge balance in the ion beam, so that the beam spot remains consistent and the dose distribution is uniform, so that the wafer is uniformly doped and the doping quality is improved; it can also prevent the oxide layer on the wafer surface from being damaged, thereby preventing the gate oxide layer from being damaged, and improving the reliability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic side view of the structure of an electronic spray device according to some embodiments of the present invention;

[0023] Figure 2 is a schematic top view of the structure of an electronic spray device according to some embodiments of the present invention;

[0024] Figure 3 is a schematic structural diagram of a blocking unit in some embodiments of the present invention;

[0025] Figure 4 Schematic diagrams of the structures of blocking units in other embodiments of the present invention;

[0026] Figure 5 Schematic diagrams of the structures of blocking units in other embodiments of the present invention;

[0027] Figure 6 Schematic diagrams of the structures of blocking units according to other embodiments of the present invention.

[0028] In the attached figure:

[0029] 100-process chamber; 200-wafer; 300-placement position;

[0030] 10-electron generator; 11-electron emission port;

[0031] 20-blocking unit; 21-first blocking member; 22-second blocking member;

[0032] 30-ion beam;

[0033] a-first direction; b-second direction; c-third direction, which is also the irradiation direction of the ion beam.

[0034] As used in the present invention, the singular forms "a," "an," and "the" include plural referents. The term "or" is generally used to include "and / or," the term "several" is generally used to include "at least one," and the term "at least two" is generally used to include "two or more." Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, features defined as "first," "second," and "third" may explicitly or implicitly include one or at least two of the features. Furthermore, as used in the present invention, the terms "mounted," "connected," and "connected," or "an element being "disposed" on another element, should be understood broadly and generally only indicate a connection, coupling, mating, or transmission relationship between the two elements, which can be direct or indirect through an intermediate element. They should not be understood to indicate or imply a spatial positional relationship between the two elements, i.e., one element can be located inside, outside, above, below, or to the side of another element, unless the context clearly indicates otherwise. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used with respect to the exemplary embodiments as they are shown in the figures, with the upward or upper direction being toward the top of the corresponding figure and the downward or lower direction being toward the bottom of the corresponding figure.

[0035] The present invention provides an ion implantation apparatus, comprising an ion source, an ion extraction and mass analyzer, an accelerator tube, a scanning system, a process chamber 100, and a high vacuum system. The process chamber 100 is provided with a placement position 300 for a wafer 200, on which the wafer 200 to be doped is placed. The high vacuum system is used to create a negative pressure environment in the process chamber 100. The ion source generates an ion beam 30, which is separated by ion extraction and a mass analyzer. The ion beam is then accelerated by the accelerator tube, allowing the ion beam to enter the process chamber 100 and bombard the surface of the wafer 200 to achieve ion implantation. All components of the above-described ion implantation apparatus can be consistent with existing equipment.

[0036] Please refer to Figure 1 As shown, the ion implantation apparatus further includes an electron spray device for neutralizing the positively charged ion beam 30 and preventing electrons from being attracted by the surface of the wafer 200 and causing over-neutralization, thereby improving the uneven charge distribution on the surface of the wafer 200 .

[0037] Please refer to Figure 1 and Figure 2As shown, the electron spray device includes: an electron generator 10 and a blocking unit 20;

[0038] The electron generator 10 is used to generate electrons. For example, the electron generator 10 can be a plasma flood gun (FPG). High-voltage pulse ionization generates electrons within the FPG. A magnetic field causes the electrons to move along a predetermined trajectory and enter the process chamber through an electron emission port 11. The electron generator 10 employs existing structures and will not be described in detail here.

[0039] Please continue to refer to Figure 1 As shown, the electron generator 10 is mounted on the outer wall of the process chamber 100 of the ion implantation equipment, and the side wall of the process chamber 100 is provided with an opening, which serves as an electron emission port 11 of the electron generator 10. Therefore, the electron emission port 11 is connected to the process chamber 100, allowing the electrons generated by the electron generator 10 to enter the process chamber 100.

[0040] Figure 1 is a schematic side view of the process chamber 100. Figure 1 Only a portion of the sidewalls of the process chamber 100 is shown, and only some components relevant to the present invention are shown within the process chamber 100. In this embodiment, the electron generator 10 is preferably mounted at the top of the process chamber 100. Accordingly, the electrons generated by the electron generator 10 enter the process chamber from top to bottom.

[0041] Please continue to refer to Figure 1 As shown, in this embodiment, the ion beam 30 enters the process chamber 100 after being accelerated by an accelerating tube. Figure 1 In the embodiment, the irradiation direction of the ion beam 30 is horizontal from left to right. A placement position 300 for placing the wafer 200 is provided near the right side of the process chamber 100. The placement position 300 is used to fix the wafer 200, so the ion beam 30 is irradiated from left to right onto the wafer 200, so that high-energy ions bombard the wafer surface to achieve the purpose of doping. In this embodiment, the concept of the placement position 300 is proposed in order to further clearly define the position of the blocking unit 20. The placement position 300 adopts an existing structure. For example, the placement position 300 is each position on the existing scanning disk for carrying wafers, which will not be described here one by one.

[0042] In order to further clearly define the blocking unit 20, the first direction a, the second direction b and the third direction c are introduced in this embodiment, wherein the first direction a is the direction from the electron emission port 11 vertically pointing to the ion beam 30 (corresponding to Figure 1 The second direction b is perpendicular to the irradiation direction of the ion beam 30 and perpendicular to the first direction a (corresponding to Figure 1The third direction c corresponds to the emission direction of the ion beam (corresponding to the direction perpendicular to the paper). Figure 1 left and right directions in the .

[0043] Please continue to refer to Figure 1 As shown, the blocking unit 20 is disposed on the inner wall of the top of the process chamber 100. Along the third direction c, the blocking unit 20 is located between the electron emission port 11 and the placement position 300.

[0044] Along the first direction a, the blocking unit 20 is located between the electron emission port 11 and the ion beam 30 .

[0045] It should be explained that the electron spray device in this embodiment does not include components such as the ion beam 30 , the wafer 200 , and the placement position 300 . The above concepts are introduced to more clearly discuss the structure of the electron spray device.

[0046] Please continue to refer to Figure 1 As shown, after the electron generator 10 generates electrons, they pass through the electron emission port 11 downward into the process chamber 100. The electrons are located above the ion beam 30, so due to their own weight and the attraction of the ion beam 30 on the electrons, the electrons naturally move downward and gradually merge into the ion beam to neutralize the ion beam.

[0047] To ensure a good neutralization effect, in this embodiment, the electron emission port 11 is preferably located relatively close to the placement position 300 along the third direction c. This distance is defined as a first distance, and is preferably 300 mm to 400 mm. Therefore, electrons entering through the electron emission port 11 are relatively close to the wafer 200. In the absence of the blocking unit 20, the electrons will be attracted to the wafer surface while neutralizing the ion beam, causing some electrons to be directly adsorbed on the wafer surface, resulting in over-neutralization and uneven charge distribution on the wafer surface.

[0048] In this embodiment, a blocking unit 20 is provided between the electron emission port 11 and the placement position 300 to block electrons from moving along the third direction c toward the placement position 300, thereby preventing electrons from being directly attracted by the wafer surface, thereby preventing over-neutralization of the wafer, ensuring uniform charge distribution on the wafer surface, and ensuring charge balance in the ion beam 30, so that the beam spot remains consistent and the dose distribution is uniform, thereby making the wafer doped uniform and improving the doping quality; and it can also prevent the oxide layer on the surface of the wafer 200 from being damaged, thereby preventing the gate oxide layer from being damaged, and improving the reliability of the device.

[0049] Furthermore, a positive voltage, for example, 0-20V, is applied to the blocking unit 20 to attract electrons, so that electrons moving in the third direction c toward the wafer 200 are blocked and adsorbed by the blocking unit 20 to prevent the electrons from being directly adsorbed on the wafer surface.

[0050] In this embodiment, the distance between the blocking unit 20 and the electron emission port 11 along the third direction c is a second distance, which is preferably less than half of the first distance, and preferably 50 mm to 150 mm. By setting the second distance reasonably, most of the electrons can be emitted along the first direction a ( Figure 1 The electrons move from top to bottom in the ion beam and then merge into the ion beam to achieve neutralization. The blocking unit 20 absorbs a small number of electrons to improve the electron neutralization efficiency. At the same time, the reasonable limitation of the first distance ensures that the blocking unit 20 is placed at a reasonable distance 300 along the third direction c. This ensures that after the electrons merge into the ion beam, there is still a reasonable irradiation distance between the ion beam and the wafer surface. During this irradiation distance, the electrons are evenly distributed in the ion beam, that is, after the ion beam bombards the wafer, the charge distribution on the wafer surface is uniform.

[0051] Please refer to Figure 1 and Figure 2 As shown, along the second direction b, the size of the blocking unit 20 is greater than or equal to the diameter of the wafer 200 to be implanted. For example, if the diameter of the wafer 200 is 300 mm, then the size of the blocking unit 20 along the second direction b is at least 300 mm to achieve effective shielding within the wafer range.

[0052] Furthermore, along the first direction a, the barrier unit 20 is smaller than half the size of the wafer 200. For example, if the wafer diameter is 300 mm, the barrier unit 20 is 50 mm in the first direction a. This distance ensures that the distance from the wafer center along the first direction a to the barrier unit 20 is greater than half the wafer radius. This ensures a good doping effect while allowing some electrons to pass through the gap between the barrier unit 20 and the ion beam. At this point, since the electrons are closer to the ion beam, most of them will be directly integrated into the ion beam, thereby improving electron neutralization efficiency.

[0053] Furthermore, the number of blocking units 20 and their dimensions along the second direction b can be adjusted based on the number of electron emission ports 11. For example, in a case where there are two electron emission ports 11, two groups of blocking units 20 can be provided; alternatively, a single group can be provided. In this case, the dimension of the blocking units 20 along the second direction b should be greater than the distance between the two emission ports along the second direction b.

[0054] Furthermore, the blocking unit 20 includes a first blocking member 21 and a second blocking member 22. The first blocking member 21 is applied with a positive voltage, and a portion of the second blocking member 22 is located between the ion beam 30 and the first blocking member 21. A portion of the second blocking member 22 blocks the space between the first blocking member 21 and the ion beam 30, thereby reducing interference with the ion beam 30 caused by the positive voltage applied by the first blocking member 21, thereby preventing the ion beam 30 from being affected by the first blocking member 21 and causing uneven charge distribution within the ion beam 30.

[0055] Please refer to Figure 1 and Figure 3 As shown, the second blocking member 22 is C-shaped, with its open side facing the electron emitting port 11 along the irradiation direction of the ion beam 30. This arrangement makes it easier to capture electrons moving in the third direction c toward the placement position 300. Furthermore, the first blocking member 21 is disposed within the second blocking member 22, being half-enclosed by the second blocking member 22, thereby minimizing the impact of the positive voltage applied by the first blocking member 21 on the ion beam 30.

[0056] like Figure 1 and Figure 3 As shown, in this embodiment, the first blocking member 21 and the second blocking member 22 are adapted to form a C-shaped structure. The overall size of the first blocking member 21 is smaller than that of the second blocking member 22, and the first blocking member 21 is connected to the inner wall of the second blocking member 22. The C-shaped structure of the first blocking member 21 is conducive to increasing its contact area, thereby improving its ability to capture electrons.

[0057] In this embodiment, the first barrier 21 is made of a conductive material, such as a metallic conductive material such as a copper alloy or aluminum alloy, or a non-metallic conductive material such as a conductive plastic, conductive rubber, or conductive fiber fabric. The material of the first barrier 21 can be selected based on the adaptability of the actual use requirements. The first barrier 21 is made of a conductive material to ensure that it can effectively capture electrons when a forward voltage is applied. Furthermore, the first barrier 21 is grounded, for example, one end of the first barrier 21 is grounded via a lead, to neutralize the collected electrons.

[0058] The second blocking member 22 is made of insulating material, such as rubber, plastic and its products, glass, ceramics and other insulating materials.

[0059] In this embodiment, the insulating material is a material that is non-conductive under an allowable voltage, but is not an absolutely non-conductive material. For example, the resistivity of the insulating material is generally in the range of 10 10 Ωm to 10 22 Ωm.

[0060] In this embodiment, the first blocking member 21 is insulated and connected to the inner wall of the process chamber 100. Figure 3As shown, the second barrier 22 is connected to the inner wall of the process chamber 100. Since the first barrier 21 is disposed inside the second barrier 22 and connected to the second barrier 22, the first barrier 21 is naturally insulated from the inner wall of the process chamber 100 by the second barrier 22. This prevents the electrons collected by the first barrier 21 and the positive pressure applied thereto from interfering with the process chamber 100.

[0061] Please refer to Figure 4 As shown, in other alternative embodiments, the first blocking member 21 and the second blocking member 22 are plate-type structures, wherein the first blocking member 21 is directly insulated and connected to the inner wall of the process chamber 100, for example, by bonding with an insulating adhesive, or by applying insulating paint at the connection position between the inner wall of the process chamber and the first blocking member 21 to achieve an insulating connection. The first blocking member 21 is tilted toward the electron emission port 11 to achieve a better effect of blocking and capturing electrons. The second blocking member 22 is located at the first blocking member 21 along the third direction c( Figure 5 On the side away from the electron emission port 11 (in the left and right directions), the second blocking member 22 is parallel to the first blocking member 21, and the second blocking member 22 is longer than the first blocking member 21, so that the lower part of the second blocking member 22 extends downward to the bottom of the first blocking member 21 and blocks between the first blocking member 21 and the ion beam 30.

[0062] Please refer to Figure 5 As shown, in other alternative embodiments, the first blocking member 21 is a plate structure, and the second blocking member 22 is an L-shaped structure, wherein the first blocking member 21 is directly insulated and connected to the inner wall of the process chamber 100. The first blocking member 21 is along the first direction a ( Figure 5 The second barrier 22 is connected to the inner wall of the process chamber 100. A right-angled side of the second barrier 22 is connected to the first barrier 21 and is parallel to the first barrier 21. Another right-angled side of the second barrier 22 extends horizontally below the first barrier 21 and blocks the ion beam 30 between the first barrier 21 and the ion beam 30.

[0063] Please refer to Figure 6 As shown, Figure 6 The structures of the first blocking member 21 and the second blocking member 22 are similar to those of Figure 3 The difference is that the first blocking member 21 applies an electromagnetic field to attract electrons, for example, a pair of magnetic attraction or other magnetic field devices are provided on the first blocking member 21 to form the required magnetic field.

[0064] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0065] The above description is only a description of the preferred embodiments of the invention and does not limit the scope of the invention. Any changes and modifications made by ordinary technicians in the field of the invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. An electronic spray device, characterized in that: include: electron generator and barrier unit; The electron generator is used to generate electrons, and the electron generator has an electron emission port, which is connected to the process chamber for electrons to enter the process chamber; The blocking unit is arranged on the inner wall of the process chamber, and the process chamber has a placement position for placing the wafer; Along the irradiation direction of the ion beam, the blocking unit is located between the electron emission port and the placement position; The blocking unit is located between the electron emission port and the ion beam along a first direction, where the first direction is a direction perpendicularly pointing from the electron emission port to the ion beam.

2. The electronic spraying device according to claim 1, wherein: A positive voltage is applied to the blocking unit.

3. The electronic spraying device according to claim 1 or 2, characterized in that: The blocking unit includes a first blocking member and a second blocking member, the first blocking member is applied with a positive voltage, and a portion of the second blocking member is located between the ion beam and the first blocking member.

4. The electronic spraying device according to claim 3, wherein: The first blocking member is made of a conductive material and is insulated from and connected to an inner wall of the process chamber.

5. The electronic spraying device according to claim 3, wherein: The second blocking member is made of insulating material.

6. The electronic spray device according to claim 3, wherein: The second blocking member is C-shaped, and an opening side of the second blocking member faces the electron emission port along an irradiation direction of the ion beam.

7. The electronic spray device according to claim 6, wherein: The first blocking member is disposed in the second blocking member.

8. The electronic spray device according to claim 3, wherein: The first blocking member is grounded.

9. The electronic spray device according to claim 1, wherein: Along a second direction, a size of the blocking unit is greater than or equal to a diameter of a wafer to be implanted. The second direction is perpendicular to an irradiation direction of the ion beam and perpendicular to the first direction.

10. An ion implantation device, characterized in that: It comprises the electronic spray device according to any one of claims 1 to 9.

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