CN116031124A - An arc chamber structure and working method for an ion source of an ion implanter - Google Patents

Abstract

The invention provides an arc starting chamber structure and working method for an ion source of an ion implanter, which is suitable for an ion source of an ion implanter, and the ion source of the ion implanter includes a filament assembly, a cathode assembly, a semicircular Cylindrical arc starting chamber components, process gas inlet components, and reflector components; semi-cylindrical arc starting chamber components adopt a semi-cylindrical chamber design, and the reflector component adopts a suspended reflector design. The structure of the arcing chamber of the ion source used in the ion implanter of the present invention is a semi-cylindrical arcing chamber, which simplifies the assembly and maintenance process of the ion source; The service life of the ion source greatly improves the productivity of the ion implanter. Through a new R&D design, the invention reduces the energy consumption of the ion source, improves the efficiency of ion extraction and the intensity of the beam, and thus improves the yield rate of process products.

Description

An arc chamber structure and working method for an ion source of an ion implanter

technical field

The invention belongs to the technical field of semiconductor equipment, and in particular relates to an arc-starting chamber structure and a working method for an ion source of an ion implanter.

Background technique

There are many problems in the use of the traditional ion source of the ion implanter, including 1. The service life of the ion source is short (usually about 100 hours), and the traditional ion source often has filament breakage and cathode breakdown at the end of its service life. Phenomenon. At the same time, it will also cause a sudden interruption of the process operation, and unnecessary troubles such as follow-up reprinting are required. 2. The current of the ion beam is too small and cannot meet the technological requirements of advanced manufacturing. It is relatively difficult to start the arc during the use of the traditional ion source, and it is necessary to apply relatively large energy to each part of the ion source to extract a relatively small amount of ion beam. . This reduces the utilization efficiency of the entire ion implanter, thereby affecting the production of products. 3. The uniformity of the ion beam is poor, and there is a missing corner above the ion beam. Traditional ion sources have a great impact on the uniformity of the ion beam, and towards the end of the life of the ion source, the uniformity of the ion beam becomes more difficult to control. This shortens the lifetime of the ion source even further, causing more downtime headaches. 4. The bottom of the arcing chamber is planar, so that the volume of the entire arcing chamber is relatively small, and the ionization rate of the process gas is relatively low. The traditional ion source arcing chamber adopts a planar design, which cannot optimize the reaction volume of the arcing chamber to the greatest extent, so that the process gas passing into the arcing chamber cannot be fully ionized. Not only is a large amount of process gas wasted, but also the by-products produced by a large amount of process gas passed into the arcing chamber are attached to the surface of the ion source, further reducing the service life of the ion source and the quality of the ion beam.

With the development of semiconductor process technology and the improvement of process requirements, it is of great significance to design and transform an ion source with low energy consumption, low maintenance, high stability, and capable of producing high-quality ion beams.

Contents of the invention

Based on the problems existing in the prior art, the present invention provides an arc-starting chamber structure and working method for an ion source of an ion implanter.

According to the first aspect of the technical solution of the present invention, the present invention provides an arcing chamber structure for the ion source of the ion implanter, which is suitable for the ion source of the ion implanter, and the ion source of the ion implanter includes Filament assembly, cathode assembly, semi-cylindrical arc-starting chamber assembly, process gas inlet assembly, and reflector assembly; the semi-cylindrical arc-starting chamber assembly adopts a semi-cylindrical chamber design, and the reflector assembly adopts a suspended reflector design .

Further, the filament assembly generates free electrons when the filament is heated, and the free electrons enter the cathode under the action of an electric field, and then bombard the cathode assembly. After the cathode assembly receives the bombardment from the filament electrons, a large number of free electrons are generated and enter the arc chamber assembly under the action of the electric field.

Furthermore, the structure of the arcing chamber for the ion source of the ion implanter includes a filament clamp, a cathode insulator, a filament, a heat-resistant bolt and a filament energy supply rod. The heat-resistant bolts fix the two filament clamps to the outside of the cathode insulator, the filament is connected to the filament clamp, and the corresponding energy is applied to the filament through the filament energy supply rod to complete the heating of the filament and generate electrons.

Preferably, the arc-starting chamber structure for the ion source of the ion implanter further includes a cathode, which is inserted into the ring of the bracket and locked with a set screw. Adjust the position of the cathode so that the set bolt is completely close to the semicircular hole on the upper channel of the filament clamp, and lock the bolt. Slowly push the filament into the cathode, press the two positioning pins on the bracket into the pin holes of the cathode insulator, so that the bracket and the cathode insulator are close together without gaps in between.

According to the second aspect of the technical solution of the present invention, the present invention provides a working method for an arcing chamber structure of an ion source of an ion implanter, which includes the following steps:

Step S1, the filament assembly is heated to generate electrons to bombard the cathode;

Step S2, the cathode assembly generates a large amount of electrons and enters the arcing chamber;

Step S3, the process gas is passed into the arcing chamber;

Step S4, free electrons and reaction gas collide to generate plasma;

In step S5, the reflector assembly continuously reflects electrons and collides with the process gas.

Compared with the prior art, the beneficial technical effect of the arcing chamber structure used for the ion source of the ion implanter of the present invention is as follows:

1. The structure of the arcing chamber for the ion source of the ion implanter of the present invention is a semi-cylindrical arcing chamber, which simplifies the assembly and maintenance process of the ion source.

2. The invention adopts the optimized filament and cathode assembly, which effectively prolongs the service life of the ion source and greatly improves the productivity of the ion implanter.

3. The present invention reduces the energy consumption of the ion source through a new research and development design, improves the efficiency of ion extraction and the intensity of the beam, and further improves the yield rate of the process product.

Description of drawings

FIG. 1 is a schematic diagram of an exploded structure of an arcing chamber structure used in an ion source of an ion implanter according to the present invention.

FIG. 2 is a schematic structural view of the filament assembly in the arc-starting chamber structure of the ion source of the ion implanter in FIG. 1 .

FIG. 3 is a schematic structural view of the cathode assembly in the arcing chamber structure of the ion source of the ion implanter in FIG. 1 .

FIG. 4 is a structural schematic diagram of the semi-cylindrical arcing chamber assembly used in the arcing chamber structure of the ion source of the ion implanter in FIG. 1 .

FIG. 5 is a schematic structural view of the reflector assembly in the arcing chamber structure used in the ion source of the ion implanter in FIG. 1 .

FIG. 6 is a structural schematic diagram of a gas inlet component in the arcing chamber structure used in the ion source of the ion implanter in FIG. 1 .

Fig. 7 is a schematic working flow diagram of the structure of the arcing chamber for the ion source of the ion implanter.

Explanation of the reference signs in the accompanying drawings:

Filament clamp 1; cathode insulator 2; filament 3; cathode 4; cathode sleeve 5; first cathode terminal plate 6; second cathode terminal plate 7; calibration balance pin 8; cathode inner bushing 9; cathode side isolation plate 10; Ceramic nut 11; reflector 12; reflector side isolation plate 13; reflector end plate 14, reflector insulator 15; reflector clip 16; semi-cylindrical isolation plate 17; arcing chamber 18; heat-resistant bolt 19; cathode Bracket 20; process gas inlet pipe 21; locking bolt 22; filament energy supply rod 23; cathode energy supply rod 24; arc starting outer layer cover plate 25; arc starting inner layer cover plate 26.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention , but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should also be noted that, for the convenience of description, only the parts related to the related invention are shown in the drawings. In the case of no conflict, the embodiments and the features in the embodiments of the present invention can be combined with each other.

It should be noted that concepts such as "first" and "second" mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the sequence of functions performed by these devices, modules or units or interdependence.

It should be noted that the modifications of "one" and "multiple" mentioned in the present invention are illustrative and not restrictive, and those skilled in the art should understand that unless the context clearly indicates otherwise, it should be understood as "one or more" multiple".

The present invention provides an arc-starting chamber structure and working method for an ion source of an ion implanter. The ion source equipped with the arc-starting chamber structure of an ion source for an ion implanter is a kind of low energy consumption, low Maintenance-free, high-stability ion source that produces a high-quality ion beam. The ion source includes an optimized filament assembly, a cathode assembly, a semi-cylindrical arc-starting chamber assembly, a process gas inlet assembly, a reflector assembly and an insulator for isolating each assembly.

As shown in Figure 2, the filament in the filament assembly in the ion source adopts a larger size and more optimized material, which greatly improves the heat resistance of the filament and the ability to generate electrons. As shown in Figure 3, the cathode assembly adopts a thicker The unique cathode design and more optimized material and structure adjustment greatly improve the ability of the cathode to generate electrons, and the effective extension of the service life is also a highlight of this design. As shown in Figure 4, the semi-cylindrical arc striking chamber assembly abandons the inherent planar design and adopts a new semi-cylindrical chamber design, which makes the capacity of the reaction chamber larger, the gas distribution is more uniform, and the gas ionization rate can be effectively improved. improve. The reflector assembly shown in FIG. 5 adopts a suspended reflector design, so that the reflection efficiency is increased. As shown in Figure 6, the optimized gas inlet assembly makes the distribution of the process gas more uniform and the pressure distribution more reasonable when it enters the arcing chamber, effectively improving the utilization rate of the process gas.

Further, the filament assembly is the source of heating the filament to generate free electrons, and the generated free electrons enter the cathode under the action of an electric field, and then bombard the cathode assembly. The cathode assembly generates a large number of free electrons after being bombarded by electrons from the filament and enters the arcing chamber assembly under the action of an electric field. And the ingenious design of the cathode assembly makes the distance control between the cathode and the filament more simple and reliable, so that the repetition rate and success rate of the ion source assembly process are greatly improved. And the appropriate filament size and cathode thickness can greatly improve the life of the filament and cathode. The semi-cylindrical arcing chamber assembly effectively increases the volume of the arcing chamber, and the ingenious semi-cylindrical design is more conducive to the full collision of process gas molecules and atoms with free electrons in the arcing chamber. This in turn generates more ions. This design not only increases the ionization rate of the process gas, but also reduces the amount of process gas used, thereby reducing the by-products attached to the surface of the ion source, improving the service life of the ion source and improving the quality of the ion beam. The process gas inlet assembly optimizes the pressure distribution and uniformity of the process gas fed into the arcing chamber, thereby improving the degree of ionization of the process gas. The repellent assembly enables the electrons in the arc starting chamber to bounce back more effectively and timely when they run to the vicinity of the reflex electrode, and continue to collide with the process gas in the arc starting chamber to generate more ions. The insulators of the isolation components provide high-efficiency potential isolation, so that the potentials among the filament, the cathode and the arcing chamber are independent of each other and operate reliably.

As shown in Figure 1, the structure of the arcing chamber for the ion source of the ion implanter in this embodiment includes a filament clamp 1, a cathode insulator 2, a filament 3, a cathode 4, a cathode sleeve 5, and a first cathode terminal plate 6 , second cathode terminal plate 7, calibration balance pin 8, cathode inner bushing 9, cathode side separator 10, ceramic nut 11, reflector 12, reflector side separator 13, reflector end plate 14, reflector insulator 15 , reflector clip 16, semi-cylindrical isolation plate 17, arcing chamber 18, heat-resistant bolt 19, cathode support 20, process gas inlet tube 21, locking bolt 22, filament energy supply rod 23, cathode energy supply rod 24 , The outer layer cover plate 25 of arc starting and the inner layer cover plate 26 of arc starting.

The heat-resistant bolts 19 fix the two filament clamps 1 to the outside of the cathode insulator 2, the filament 3 is connected to the filament clamp 1, and the corresponding energy is applied to the filament through the filament energy supply rod 23 to complete heating of the filament and generate electrons. Insert the cathode 4 into the ring of the bracket 20 and lock it with a set screw 22 . Adjust the position of the cathode 4 so that the set bolt 22 is completely close to the semicircular hole on the upper channel of the filament clamp 1, and the bolt 22 is locked. Slowly push the filament into the cathode, press the two positioning pins on the bracket into the pin holes of the cathode insulator, so that the bracket and the cathode insulator are close together without gaps in between. Use bolts to lock the bracket and the cathode insulator, and screw the bushing 5 onto the bracket. When screwing in, the bushing and the cathode should be pushed in concentrically. Open the filament clamp, adjust the position of the filament, and push the filament 1 inward until it is close to the inside of the cathode 2. Loosen the bolt 22, adjust the position of the cathode 2, move the bolt 22 from the semicircular hole to the position of the elongated hole, form a distance between the inside of the filament 1 and 2, and tighten the screw 22. , Insert the alignment balance pin 8 into the positioning pin hole at the reflective end of the arcing chamber 18 . Install the reflector end plate 14 on the arc starting chamber. When assembling, the positioning pin holes on the reflector end plate 14 are aligned with the positioning pins on the arc starting chamber. Install the reflector insulator 15 on the arcing chamber with bolts and ceramic nuts 11, align the positioning pin holes on the reflector insulator 15 with the positioning pins, and press them in so that the reflector insulator 15 is in close contact with the end plate. The repeller clip 16 is mounted on the repeller insulator with heat-resistant bolts 19 . Insert two locating pins 8 into the locating pin holes of the arcing chamber, push them to the inside of the holes when inserting, and press the cathode inner bushing 9 into the cathode inner end plate 7 . Align the two locating pin holes on the cathode inner end plate 7 with the two locating pins on the arcing chamber and insert them, and stick to the cathode side of the arcing chamber. Align the two locating pin holes on the cathode end plate 6 with the two locating pins on the arcing chamber and insert them, so as to be close to the inner end plate of the cathode. Press and stabilize the two end plates on the cathode side, insert the cathode side isolation plate 10 into the groove between the arc starting chamber and the cathode inner end plate, insert the reflector side isolation plate 13 into the arc starting chamber and the reflector end plate In the groove between, the semi-cylindrical separating plate 17 is packed into the arcing chamber, and the circular holes on the two will be aligned. Pass the reflector 12 through the hole of the 0.5mm plug plate, install the reflector 12 and the plug plate on the arcing chamber, and close to the reflector isolation plate. Take out the 0.5mm plug, and the distance between the reflector 12 and the arcing chamber-ion source reflector isolation plate is 0.5mm. Install the arcing inner layer cover plate 26 and the outer layer cover plate 25 on the arcing chamber. When assembling, the arcing inner layer cover plate 26 and the outer layer cover plate 25 are centered and aligned with the arcing chamber. Insert the process gas inlet pipe 21 into the circular hole on one side of the arcing chamber, turn the process gas inlet pipe 21, adjust the position so that the gas hole is downward, and insert the gas pipe into the gas hole of the process gas inlet pipe 21.

The filament assembly is composed of a filament clamp 1, a filament 3, a heat-resistant bolt 19 and a filament energy supply rod 23. The main function of the filament assembly is to generate the original electron source under the action of the filament power supply, thereby bombarding the cathode assembly. The main material of the filament 3 is high temperature resistant tungsten.

The cathode assembly is composed of cathode 4 , cathode sleeve 5 , first cathode terminal plate 6 , second cathode terminal plate 7 , cathode inner bushing 9 , cathode bracket 20 , locking bolt 22 , and cathode energy supply rod 24 . The main function of the cathode assembly is to generate a large number of electrons from the cathode 4 after being bombarded by the electrons generated by the filament assembly and enter the arcing chamber. The main material of the cathode 4 is also high temperature resistant tungsten.

The semi-cylindrical arc-starting chamber assembly consists of a cathode-side separator 10, a reflector-side separator 13, a semi-cylindrical separator 17, an arc-starting chamber 18, an arc-starting outer layer cover 25 and an arc-starting inner layer cover 26 Composed together. The main function of the semi-cylindrical arcing chamber assembly is to serve as a reaction chamber for the electrons and process gas generated by the cathode assembly to pass into the process gas fed by the assembly, so that the process gas is ionized to generate plasma.

The process gas inlet assembly is mainly composed of a process gas inlet pipe 21 and other accessories, and its main function is to feed process gas and provide reaction gas with uniform distribution and stable pressure.

The reflector assembly is composed of the reflector 12, the reflector plate 14 and the reflector clip 16. Its main function is to reflect the moving electrons in the arcing chamber, so that they can continuously collide with the process gas in the arcing chamber and improve the process gas temperature. dissociation efficiency. The insulators for isolating each component include: a cathode insulator 2 , a calibration balance pin 8 , a ceramic nut 11 and a reflector insulator 15 . Its main function is to isolate different potentials applied between different components.

When using the ion source of the arcing chamber structure of the ion source of the ion implanter according to the present invention to operate, the electrons generated by the heating of the filament all gather at the cathode 4 under the action of the electric field, and bombard the cathode, causing it to be heated and generate a large amount of electrons. Electrons, so a large number of electrons enter the arcing chamber 18 under the action of the electric field. When the reactive gas enters the arcing chamber through the intake pipe 21, a large number of electrons generated by the cathode will collide violently with the incoming process gas under the action of the electric field, so that the outermost valence electrons of the process gas are peeled off, forming the corresponding charged ions. Therefore, the energy required to peel off the outer valence electrons of different elements is different, and the rule generally followed is that elements with smaller relative atomic masses require higher energy. This is because the closer the outer valence electrons are to the nucleus, the more energy is required to free the outer valence electrons from the nucleus.

In order to transfer sufficient energy to the process gas atoms or molecules passing into the arc chamber, the ion source requires a large number of free electrons. These free electrons are accelerated by the electrostatic potential, the accelerated free electrons strike and transfer energy to the corresponding process gas atoms or molecules, only a small part of the energy (about 1/5 to 1/10 of the acceleration) is transferred to the dopant on target. At the same time, in order to increase the probability of free electrons colliding with process gas atoms or molecules in the arcing chamber, the function of the reflector 12 in this embodiment is to form a corresponding line by accumulating a certain amount of electrons on the surface of the reflector. Negative potential, thereby repelling free electrons and causing a large number of free electrons to reflect back to the arc starting chamber and continue to collide with process gas atoms or molecules in the reflex arc chamber to form more target ions.

The working steps of the arcing chamber structure for the ion source of the ion implanter are as follows:

Step S1, the filament assembly is heated to generate electrons to bombard the cathode;

Step S2, the cathode assembly generates a large amount of electrons and enters the arcing chamber;

Step S3, the process gas is passed into the arcing chamber;

Step S4, free electrons and reaction gas collide to generate plasma;

In step S5, the reflector assembly continuously reflects electrons and collides with the process gas.

Compared with the prior art, the present invention adopts an integrated arcing chamber and designs a corresponding inner protective layer, which not only increases the reliability of the ion source, but also makes the ion source easier to assemble and maintain. In addition, the optimized design of the process gas inlet pipe enables the pressure and uniformity of the process gas to enter the arc chamber to be effectively controlled. The purpose is to increase the ionization rate of the process gas and improve the extraction from the ion source. The number of ions, thereby increasing the process throughput. In addition, this embodiment adopts an optimally designed filament, which is improved to a certain extent in terms of material and size, so that the service life of the filament is greatly increased. The upgraded cathode installation and fixing device have greatly improved the stability and service life of the cathode.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (8)

1. An arcing chamber structure for an ion source of an ion implanter, characterized in that it is suitable for the ion source of an ion implanter, and the ion source of the ion implanter includes a filament assembly, a cathode assembly, a half cylinder Type arc starting chamber assembly, process gas inlet assembly, reflector assembly; The semi-cylindrical arc starting chamber assembly adopts a semi-cylindrical chamber design, and the reflector assembly adopts a suspended reflector design. 2. The arcing chamber structure for the ion source of an ion implanter as claimed in claim 1, wherein the filament assembly is to make the filament heated to generate free electrons, and the free electrons produced enter the cathode under the action of an electric field, And then bombard the cathode assembly. 3. The arcing chamber structure for the ion source of an ion implanter as claimed in claim 2, wherein the cathode assembly generates a large amount of free electrons and enters under the action of an electric field after receiving bombardment from filament electrons. Arc chamber assembly. 4. The arcing chamber structure for the ion source of the ion implanter as claimed in claim 3, characterized in that, the arcing chamber structure for the ion source of the ion implanter comprises a filament clamp, a cathode insulator, Filament, heat-resistant bolt and filament power supply rod. 5. The arc-starting chamber structure for the ion source of an ion implanter as claimed in claim 4, wherein two filament clamps are fixed to the outside of the cathode insulator by heat-resistant bolts, the filament is connected to the filament clamp, and is passed through The filament energy supply rod applies corresponding energy to the filament to complete heating of the filament and generate electrons. 6 . The arc-starting chamber structure for the ion source of an ion implanter as claimed in claim 5 , further comprising a cathode, which is inserted into the ring of the bracket and locked with a set screw. 7 . Adjust the position of the cathode so that the set bolt is completely close to the semicircular hole on the upper channel of the filament clamp, and lock the bolt. 7. The arcing chamber structure for the ion source of an ion implanter as claimed in claim 6, wherein the filament is slowly pushed into the cathode, and the two positioning pins on the bracket are pressed into the cathode insulator In the pin hole of the , so that the bracket and the cathode insulator fit snugly with no gap in between. 8. A working method for an arcing chamber structure of an ion source of an ion implanter, characterized in that it comprises the following steps: Step S1, the filament assembly is heated to generate electrons to bombard the cathode; Step S2, the cathode assembly generates a large amount of electrons and enters the arcing chamber; Step S3, the process gas is passed into the arcing chamber; Step S4, free electrons and reaction gas collide to generate plasma; In step S5, the reflector assembly continuously reflects electrons and collides with the process gas.

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