A method for eliminating the charge accumulation of an electrode

Abstract

The present invention discloses a method for eliminating the charge accumulation on electrodes. The charges continuously provided by a constant-current power supply are used to neutralize the opposite charges accumulated on the electrodes, ensuring the stability of the electrode potential. This method relates to an ion implanter and belongs to the field of semiconductor device manufacturing. The high-voltage power supply A (1) outputs a DC positive voltage and provides a positive potential to the electrode A (2) for accelerating the ion beam and enabling it to obtain energy. The high-voltage resistor A (4) forms a circuit. The electrons (7) provided by the constant-current power supply A (5) are used to neutralize the positive charges (6) accumulated on the electrode A, ensuring the stability of the potential on the electrode A. The high-voltage power supply B (8) outputs a DC negative voltage and provides a negative potential to the electrode B (9) for suppressing the divergence of electrons in the ion beam. The high-voltage resistor B (9) forms a circuit. The positive charges (13) provided by the constant-current power supply B (11) are used to neutralize the electrons (12) accumulated thereon, ensuring the stability of the potential on the electrode B.

Description

Technical Field

[0001] The present invention relates to a method for eliminating charge accumulation, which is applied to an ion implanter and belongs to the field of semiconductor device manufacturing. Background Art

[0002] In an ion implanter, which is a semiconductor manufacturing equipment, the first process is to accelerate the ion beam, and the purpose is to enable the ion beam to obtain the initial energy required by the process. This acceleration system generally consists of a high-voltage power supply and an electrode, that is, the high-voltage power supply provides a DC positive high voltage potential to the electrode to generate an electric field for accelerating the ion beam. Since the electrode is in the optical path space of the ion implanter, space charges will inevitably bombard the electrode. When the space charges bombard the electrode, charges will continuously accumulate on the electrode, causing the potential on the electrode to be unstable, resulting in the instability of the ion beam acceleration energy, not meeting the process parameter requirements, causing energy pollution, affecting the uniformity of the beam current and the dose distribution, and thus reducing the qualified rate of the wafer. Therefore, maintaining a stable potential on the electrode is crucial for the acceleration of the ion beam and the improvement of the qualified rate of the wafer. Eliminating the charge accumulation on the electrode is the goal we want to achieve. Summary of the Invention

[0003] As Figure 1 shown, a method for eliminating positive charge accumulation includes a high-voltage power supply A (1), a positive electrode A (2), a ground electrode C (3), a high-voltage resistor A (4), and a constant-current power supply A (5), and is characterized in that:

[0004] The high-voltage power supply A (1) outputs a DC positive voltage to provide a positive potential to the electrode A (2). The electrode A (2) and the ground electrode C (3) form an electric field for accelerating the ion beam, enabling the ion beam to obtain the initial energy meeting the process requirements; since the accelerated ion beam will bombard the electrode A (2), positive charges (6) will accumulate on the electrode A (2), causing the potential thereon to continuously rise and resulting in potential instability; the high-voltage resistor A (4) forms a loop, and electrons (7) provided by the constant-current power supply A (5) continuously flow into the electrode A (2) to neutralize the positive charges (6) accumulated thereon, ensuring the stability of the potential on the electrode A (2).

[0005] As Figure 2 shown, a method for eliminating negative charge accumulation includes a high-voltage power supply B (8), a negative electrode B (9), a ground electrode C (3), a high-voltage resistor (10), and a constant-current power supply (11), and is characterized in that:

[0006] The high-voltage power supply B (8) outputs a DC negative voltage, providing a negative potential to the electrode B (9). The electrode B (9) and the ground electrode C (3) form an electric field for decelerating the ion beam, and the purpose is to suppress the divergence of electrons (12) in the ion beam. Since the electrons in the ion beam will bombard the electrode B, electrons (12) will accumulate on the electrode B (9), which will cause the potential thereon to be unstable. The high-voltage resistor B (8) forms a loop, and the positive charges (13) provided by the constant-current power supply B (9) continuously flow into the electrode B (9) to neutralize the accumulated electrons (12) thereon, ensuring the stability of the potential on the electrode B (9).

[0007] The advantages of the present invention are as follows:

[0008] By an active method, charges are continuously provided to the electrode to neutralize the accumulated opposite charges thereon. This process has real-time performance, which not only improves the stability of the electrode potential, but also effectively prevents energy contamination during ion beam implantation into the wafer, improving the qualification rate of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The specific implementation manners of the present invention are as follows:

[0010] Figure 1 is the schematic diagram of eliminating the accumulation of positive charges on the electrode of the present invention;

[0011] Figure 2 is the schematic diagram of eliminating the accumulation of negative charges on the electrode of the present invention. SPECIFIC IMPLEMENTATION MANNERS

[0012] The following further introduces the present invention with reference to specific embodiments in the drawings, but these descriptions shall not be construed as limiting the present invention.

[0013] Figure 1 Illustrates a method for eliminating the accumulation of positive charges, which includes a high-voltage power supply A (1), a positive electrode A (2), a ground electrode C (3), a high-voltage resistor A (4), and a constant-current power supply A (5). The high-voltage power supply A (1) outputs a DC positive voltage, providing a positive potential to the positive electrode A (2). An electric field for accelerating the ion beam is formed between the electrode A (2) and the electrode C (3), enabling the ion beam to obtain the energy meeting the process requirements. Since the accelerated ion beam will bombard the electrode A (2), positive charges (6) will accumulate thereon, causing the potential thereon to continuously rise and resulting in potential instability. The high-voltage resistor A (4) forms a loop, and the constant-current power supply A (5) continuously provides electrons (7) to the electrode A (2) to neutralize the accumulated positive charges (6) thereon, ensuring the stability of the potential on the electrode A (2).

[0014] Such as Figure 2Disclosed is a method for eliminating negative charge accumulation, which includes a high-voltage power supply B (8), a negative electrode B (9), a ground electrode C (3), a high-voltage resistor B (10), and a constant-current power supply (11). The high-voltage power supply B (8) outputs a DC negative voltage to provide a negative potential to the electrode B (8). The electrode B (8) and the ground electrode C (3) form an electric field for decelerating the ion beam, and the purpose is to suppress the divergence of electrons in the ion beam. Since the electrons in the ion beam will bombard the electrode B (9), electrons (12) will accumulate on it, which will cause the potential on it to be unstable. The high-voltage resistor B (10) forms a loop, and the constant-current power supply B (9) continuously provides positive charges (13) to the electrode B (9) to neutralize the accumulated electrons (12) thereon, ensuring the stability of the potential on the electrode A.

[0015] Specific embodiments of this invention patent have elaborated on the content of this invention patent. For those of ordinary skill in the art, any obvious changes made to it without departing from the spirit of this invention patent will constitute an infringement of this invention patent and will bear corresponding legal responsibilities.

Claims

1. A method for eliminating electrode charge accumulation, characterized in that: When the high-voltage power supply A (1) outputs a DC positive voltage, a positive potential is provided to the positive electrode A (2), and a positive electric field is formed between it and the ground electrode C (3) for accelerating the ion beam and enabling it to obtain an initial energy that meets the process requirements; since the accelerated ion beam will bombard the positive electrode A (2), positive charges (6) will accumulate on the electrode A, making the potential thereon unstable; the high-voltage resistor A (4) forms a loop, and the electrons (7) provided by the constant-current power supply A (5) continuously flow into the positive electrode A (2) to neutralize the positive charges (6) accumulated thereon, ensuring the stability of the potential on the positive electrode A (2); wherein, the positive electrode A (2) is connected to the ground through the high-voltage resistor A (4) and the constant-current power supply A (5) in sequence; When the high-voltage power supply B (8) outputs a DC negative voltage, a negative potential is provided to the negative electrode B (9), and a negative electric field is formed between it and the ground electrode C (3) for suppressing the divergence of the electrons (12) in the ion beam. During this process, the electrons (12) will bombard the negative electrode B (9), causing electrons (12) to accumulate on the negative electrode B (9), making the potential thereon unstable; the high-voltage resistor B (10) forms a loop, and the positive charges (13) provided by the constant-current power supply B (10) continuously flow into the negative electrode B (9) to neutralize the electrons (12) accumulated thereon, ensuring the stability of the potential on the negative electrode B (9); wherein, the negative electrode B (9) is connected to the ground through the high-voltage resistor B (10) and the constant-current power supply B (11) in sequence.

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