CN-121282075-B - Ion beam processing device and method with adjustable beam energy

CN121282075BCN 121282075 BCN121282075 BCN 121282075BCN-121282075-B

Abstract

The invention discloses an ion beam processing device with adjustable beam energy, which comprises a base, a bracket, a negative electrode plate, a positive electrode plate, a diaphragm and an electric energy control module, wherein a circular through hole is formed in the middle of the base, one ends of the negative electrode plate and the positive electrode plate are fixed on the base, a cylindrical ion beam channel is enclosed between the negative electrode plate and the positive electrode plate, the diaphragm is fixed on the base through the bracket, a conical channel is arranged in the diaphragm, the large end of the conical channel is aligned with one end of the cylindrical ion beam channel far away from the circular through hole, the small end faces outwards, and the positive electrode of the electric energy control module is respectively connected with the negative electrode plate and the positive electrode plate through wires. An ion beam processing method with adjustable beam energy is also disclosed. The ion beam processing device and the ion beam processing method with adjustable beam energy have the advantages of reducing the speed regulation frequency of the machine tool, meeting the large-span removal amount regulation requirement, improving the processing efficiency and the precision, reducing the dynamic performance requirement of the machine tool and the like.

Inventors

PENG XIAOQIANG
GUAN CHAOLIANG
LIU MENG
LAI TAO
HU HAO
DU CHUNYANG
DAI YIFAN

Assignees

中国人民解放军国防科技大学

Dates

Publication Date: 20260508
Application Date: 20251211

Claims (10)

1. The ion beam processing device with the adjustable beam energy is characterized by comprising a base (1), a bracket (2), a negative electrode plate (3), a positive electrode plate (4), a diaphragm (5) and an electric energy control module (6), wherein a circular through hole (11) is formed in the middle of the base (1), one ends of the negative electrode plate (3) and the positive electrode plate (4) are fixed on the base (1), a cylindrical ion beam channel (7) is formed by encircling between the negative electrode plate (3) and the positive electrode plate (4), the diaphragm (5) is fixed on the base (1) through the bracket (2), a conical channel (8) is arranged in the diaphragm (5), the conical channel (8) is coaxial with the cylindrical ion beam channel (7), the large end of the conical channel (8) is aligned with one end of the cylindrical ion beam channel (7) far away from the circular through hole (11), the small end of the conical channel is outwards used for sending out the surface to be processed of an ion beam processing optical element (9), the positive electrode and the negative electrode of the electric energy control module (6) is connected with the negative electrode plate (3) and the positive electrode plate (4) through a wire, the electric energy control module (6) is used for controlling the on-off frequency of the positive electrode plate (4) and the electric energy control module (4), the position of the ion beam processing device relative to the optical element (9) is obtained in real time, the ion beam processing device passes through each processing point (92) according to the corresponding speed and the on-off frequency of each processing point (92), the negative electrode plate (3) and the positive electrode plate (4) are used for generating potential difference in the cylindrical ion beam channel (7) when being electrified so as to deflect the passing ion beam, the negative electrode plate (3) is used for absorbing deflected ions, and the conical channel (8) is used for intercepting the ion beam passing through the cylindrical ion beam channel (7) so as to obtain the ion beam diameter meeting the actual processing requirement.
2. The ion beam processing apparatus according to claim 1, wherein the electric power control module (6) comprises a DC power box (61), an electronic switch (62) and a control unit (63), the positive electrode plate (4) is connected with the positive electrode of the DC power box (61) through the electronic switch (62), the negative electrode plate (3) is connected with the negative electrode of the DC power box (61), and the control unit (63) is connected with the electronic switch (62).
3. The ion beam processing device with adjustable beam energy according to claim 1, wherein the negative electrode plate (3) and the positive electrode plate (4) are both arranged in the bracket (2), and two sides of the bracket (2) are respectively provided with a wire passing window (21).
4. The ion beam processing apparatus according to claim 1, wherein an insulating pad (12) is provided between the negative electrode plate (3) and the positive electrode plate (4) and the base (1).
5. The ion beam processing apparatus according to claim 4, wherein the insulating pad (12) is a ceramic pad.
6. The ion beam processing apparatus according to claim 1, wherein the taper angle of the tapered passage (8) is 60 ° to 80 °, and the diameter of the cylindrical ion beam passage (7) is larger than that of the circular through hole (11).
7. The ion beam processing apparatus according to any one of claims 1 to 6, wherein the base (1), the bracket (2), the negative electrode plate (3), the positive electrode plate (4) and the diaphragm (5) are all made of graphite materials.
8. Ion beam processing method with adjustable beam energy, characterized in that the ion beam processing device with adjustable beam energy of any one of claims 1 to 7 is adopted, the circular through hole (11) is abutted with an ion source, the small end of the conical channel (8) is aligned to the surface to be processed of the optical element (9) on the machine tool, the electric energy control module (6) is connected with the machine tool, and the ion beam processing method with adjustable beam energy comprises the following steps: s1, detecting error morphology distribution of a surface to be processed of an optical element (9); S2, obtaining a processing path (91) of the ion beam processing device relative to the optical element (9) and the amount to be removed of each processing point (92) on the processing path (91) according to the error morphology distribution of the surface to be processed of the optical element (9); S3, according to the amount to be removed of each processing point (92) on the processing path (91), the speed of the ion beam processing device passing through each processing point (92) along the processing path (91) and the on-off frequency of the negative electrode plate (3) and the positive electrode plate (4) are obtained; S4, enabling the ion source to emit ion beams to the cylindrical ion beam channel (7) according to constant power, enabling the ion beam processing device to sequentially process all processing points (92) along a processing path (91) relative to the optical element (9), enabling the electric energy control module (6) to obtain the positions of the ion beam processing device relative to the optical element (9) in real time, and enabling the ion beam processing device to pass through all the processing points (92) according to the speeds and the on-off frequencies corresponding to all the processing points (92) obtained in the S3.
9. The beam energy adjustable ion beam processing method as set forth in claim 8, wherein S3, the speed of the ion beam processing device passing through each processing point (92) along the processing path (91) is divided into a first ladder, a second ladder and a third ladder from small to large, when the processing point (92) corresponds to the passing speed of the ion beam processing device in the first ladder, the on-off frequency of the corresponding negative electrode plate (3) and the positive electrode plate (4) is 0 even if the ion beam processing device passes through all ion beams emitted by the ion source, when the processing point (92) corresponds to the passing speed of the ion beam processing device in the second ladder, the on-off frequency of the corresponding negative electrode plate (3) and the positive electrode plate (4) is 0.5 even if the ion beam processing device passes through half of the ion beam emitted by the ion source, and when the processing point (92) corresponds to the passing speed of the ion beam processing device in the third ladder, the on-off frequency of the corresponding negative electrode plate (3) and the positive electrode plate (4) is 0.33 even if the ion beam processing device passes through one third of the ion source.
10. The method of ion beam processing with adjustable beam energy according to claim 8, wherein S3, a resident speed threshold V is set, when the passing speed of the processing point location (92) corresponding to the ion beam processing device is equal to or smaller than V, the on-off frequency of the corresponding negative electrode plate (3) and positive electrode plate (4) is 0, even if the ion beam processing device passes through all ion beams emitted by the ion source, when the passing speed of the processing point location (92) corresponding to the ion beam processing device is larger than V, the passing speed of the processing point location (92) corresponding to the ion beam processing device is adjusted to V, and the on-off frequency of the processing point location (92) corresponding to the negative electrode plate (3) and the positive electrode plate (4) is determined according to V.

Description

Ion beam processing device and method with adjustable beam energy Technical Field The invention relates to the technical field of optical element processing equipment, in particular to an ion beam processing device and method with adjustable beam energy. Background In the high-end optical field, the surface shape accuracy of the optical element directly determines the working performance of an optical imaging system, a laser weapon device and an extreme ultraviolet lithography system. To meet the requirements of nano-scale or even picometer-scale manufacturing of such optical elements, ion beam polishing equipment is often used to correct the surface shape errors of the surfaces of the optical elements in the final link of ultra-precise manufacturing. Ultra-precise ion beam polishing technology achieves atomic scale material removal by ion sputtering, namely when high-energy ion beam current bombards the surface of an optical element, surface layer atoms are sputtered after reaching the sputtering threshold of the material, and macroscopically show a material removal contour with a Gaussian shape. The non-contact manufacturing process has the advantages of picometer-level material removal resolution, time linear relation of material removal rate, stability, no damage and the like, and has become an ultra-high precision processing means accepted in the field of modern optical manufacturing. To correct the millimeter-scale dimensional error of the surface of the optical element, the beam diameter of the ion beam generated in theory should be smaller than the spatial wavelength of the error, and the smaller the beam diameter of the ion beam, the stronger the correction capability of the spatial error of the frequency band. This places higher demands on the dynamic performance of the machine tool, since the removal function produced by the small-size ion beam has a large aspect ratio. At present, a method for reducing the dynamic performance requirement of a machine tool in the ion beam shaping process is to add a layer of assumed additional removed material on the surface of a workpiece in the residence time solving stage, the method optimizes the dynamic performance of the machine tool by increasing the material removal amount of the whole workpiece, and the method inevitably increases the time of an ion beam polishing process. Especially for small-size ion beam diameter, the removal function has the characteristics of extremely high peak efficiency and weak volume removal rate, the conventional machine tool is difficult to meet the frequent acceleration and deceleration requirements and the adjustment requirements of large-span removal amount in the ion beam shaping process, and the time of ion beam shaping is doubled by only adding an additional removal layer with a few nanometers. In addition, as the overall process time increases, there is a great uncertainty in the overall shaping process, and the long-term ion beam shaping process places more stringent demands on the stability of the ion source, and adding additional removal layers in excess increases the likelihood of surface deterioration. In the whole ion beam shaping process of the existing ion beam polishing equipment, the energy of the ion beam is constant, the profile of removed materials in unit time is constant, the processing energy of the ion beam cannot be dynamically adjusted in the processing process, the final processing effect depends on the surface shape error distribution of an actual optical element, and the effective correction of the surface shape error of the ion beam on the ultra-high precision optical element is difficult to meet. The prior art patent document 201910340903.7 discloses an ion beam energy control device, which comprises an inlet end and an outlet end, wherein the inlet end is used for injecting an ion beam, the outlet end is used for injecting the ion beam, a plurality of electrode pairs are respectively arranged, each electrode pair comprises a first electrode and a second electrode which are oppositely arranged, each first electrode and each second electrode are rod-shaped, a space between each first electrode and each second electrode is used for allowing the ion beam to pass through, at least one electrode pair among the plurality of electrode pairs forms a first electrode group, a voltage applied to the first electrode group deflects the ion beam in a first direction, at least one electrode pair among the plurality of electrode pairs forms a second electrode group, and a voltage applied to the second electrode group deflects the ion beam in a second direction, and the second direction is opposite to the first direction. The ion beam energy control device has more advantages in the aspects of electrode shape, electrode layout, beam current adjustment and the like. However, the purpose of changing the direction of the ion beam by the ion beam energy control device is to reduce energy pollution, avoid the loss of