Energy filter assembly for ion injection system with at least one coupling element

Abstract

To provide an energy filter assembly for an ion injection system using a mechanically decoupled energy filter, in order to reduce or avoid stress or its effect during an aspect of processing and associated risk of damage to an energy filter membrane through cracking of the membrane, increase in brittleness of the membrane, or similar issues.SOLUTION: An energy filter assembly (1, 100, 200, 300) for an ion implantation system is provided, comprising an energy filter (25), a first filter frame (40), and at least one coupling element (50). The energy filter (25) has at least one filter element (25a) that absorbs beam energy of an ion beam (10). The at least one coupling element (50) elastically couples the first filter frame (40) to the energy filter (25).SELECTED DRAWING: Figure 3A

Description

Technical Field

[0001] The present invention relates to an energy filter assembly for an ion implantation system comprising at least one coupling element for elastically coupling a first filter frame to an energy filter. The present invention also relates to a method for manufacturing such an energy filter assembly. The present invention further relates to a method for filtering ion implantation by means of such an energy filter assembly.

Background Art

[0002] Ion implantation is a method for achieving doping or defect profile generation in materials such as semiconductor materials or optical materials with a predetermined depth profile in a depth range from several nanometers to several tens of micrometers. Examples of such semiconductor materials include, but are not limited to, silicon, silicon carbide, and gallium nitride. Examples of such optical materials include, but are not limited to, LiNbO3, glass, and PMMA.

[0003] There is a need to generate a depth profile by ion implantation having a depth distribution broader than the depth distribution of a doping concentration peak or a defect concentration peak obtained by single-energy ion irradiation, or to generate a doping depth profile or a defect depth profile that cannot be generated by one or several simple single-energy implantations. The doping concentration peak can often be approximated by a Gaussian distribution, or more precisely by a Pearson distribution. However, there are also deviations from such distributions, especially when the so-called channeling effect is present in the crystalline material. Prior art methods for generating depth profiles using a structured energy filter that changes the energy of a single-energy ion beam as the single-energy ion beam passes through a microstructured energy filter element are known. The resulting energy distribution results in the creation of depth profile ions in the target material. This is described, for example, in European Patent 0014516 B1 (Bartko).

[0004] An example of such an ion implantation device 20 is shown in FIG. 1, where in this example, an ion beam 10 impinges on a structured energy filter 25. The ion beam source 5 can also be a cyclotron, a radio frequency linear accelerator, an electrostatic tandem accelerator, or a single-ended electrostatic accelerator. In other embodiments, the energy of the ion beam source 5 is between 0.5 MeV / nucleon and 3.0 MeV / nucleon, or preferably between 1.0 MeV / nucleon and 2.0 MeV / nucleon. In certain embodiments, the ion beam source generates an ion beam 10 with an energy between 1.3 MeV / nucleon and 1.7 MeV / nucleon. The total energy of the ion beam 10 is between 1 MeV and 50 MeV, in a preferred embodiment between 4 MeV and 40 MeV, and in a preferred embodiment between 8 MeV and 30 MeV. The frequency of the ion beam 10 can be between 1 Hz and 2 kHz, such as between 3 Hz and 500 Hz, and in some embodiments between 7 Hz and 200 Hz. The ion beam 10 can be a continuous ion beam 10. Examples of ions in the ion beam 10 include, but are not limited to, aluminum, nitrogen, hydrogen, helium, boron, phosphorus, carbon, arsenic, and vanadium.

[0005] In FIG. 1, it can be seen that the energy filter 25 is made of a film having a triangular cross-sectional shape on the right hand side, but this type of cross-sectional shape is not a limitation of the present invention and other cross-sectional shapes can be used. The region 25 through which the upper ion beam 10-1 passes through the energy filter 25 min has the minimum thickness of the film of the energy filter 25, so the upper ion beam 10-1 passes through the energy filter 25 with little reduction in energy. In other words, if the energy of the upper ion beam 10-1 on the left hand side is E1, the energy of the upper ion beam 10-1 will have substantially the same value E1 on the right hand side (due to a small energy loss due to the stopping power of the film that results in at least partial absorption of the energy of the ion beam 10 in the film).

[0006] On the one hand, the lower ion beam 10-2 passes through the region 25 where the film of the energy filter 25 is thickest. max The energy E2 of the lower ion beam 10-2 on the left hand side is substantially absorbed by the energy filter 25. Thus, the energy of the lower ion beam 10-2 on the right hand side is reduced and is smaller than the energy of the upper ion beam, that is, E1>E2. As a result, the upper ion beam 10-1 with higher energy can penetrate deeper into the substrate material 30 with respect to the lower ion beam 10-2 with lower energy. This results in different depth profiles in the substrate material 30 which is part of the wafer.

[0007] This depth profile is shown on the right hand side of FIG. 1. The solid line rectangular region shows that the ions penetrate the substrate material at a depth between d1 and d2. However, the shape of the horizontal profile is a special case which is obtained when all energies are considered geometrically equal and the energy filter and the material of the substrate are the same. The Gaussian curve shows an approximate depth profile having a maximum value at a depth d3 without the energy filter 25. Since part of the energy of the ion beam 10-1 is absorbed in the energy filter 25, it is understood that the depth d3 is larger than the depth d2.

[0008] In the prior art, there are several known principles for the fabrication of the energy filter 25. Typically, the energy filter 25 is made from a bulk material with an etched surface of the energy filter 25 to produce a desired pattern, such as the triangular cross-sectional pattern known from FIG. 1. German Patent DE102016106119B4 (Csato / Krippendorf) describes an energy filter manufactured from layers of materials with different ion beam energy reduction characteristics. The depth profile resulting from the energy filter described in the Csato / Krippendorf patent application depends on both the structure of the layer of material and the structure of the surface.

[0009] A further structural principle is shown in the applicant's co-pending application DE102019120623.5, where the energy filter comprises spaced microstructured layers integrally connected by vertical walls.

[0010] The maximum output from the ion beam 10 that can be absorbed through the energy filter 25 depends on three factors, namely, an effective cooling mechanism for the energy filter 25, the thermo-mechanical properties of the film from which the energy filter 25 is made, and the selection of the material from which the energy filter 25 is made. In a typical ion implantation process, approximately 50% of the output is absorbed in the energy filter 25, but this can be increased up to 80% depending on the processing conditions and the filter shape.

[0011] An example of an energy filter is shown in FIG. 2, and the energy filter 25 is made of a film having a triangular structure mounted on the frame 27. In one non-limiting example, the energy filter 25 may be, for example, a silicon-on-insulator comprising a silicon dioxide layer 22 of an insulating layer having a thickness of 0.2 to 1 μm sandwiched between a silicon layer 21 (up to 200 μm maximum, typically between 2 μm and 20 μm thick) and bulk silicon 23 (about 400 μm thick). The structured film can be made of, for example, silicon, but can also be made of silicon carbide, other silicon- or carbon-based materials, or ceramics.

[0012] To efficiently use the ion beam 10, by optimizing the wafer throughput in the ion implantation process for a given ion current of the ion beam 10, it is preferable to irradiate only the film of the energy filter 25 and not irradiate the frame 27 on which the film is held in place. In practice, at least a part of the frame 27 may also be irradiated by the ion beam 10 and thus may be heated. In fact, it is possible for the frame 27 to be completely irradiated. The film forming the energy filter 25 is heated, but because the film is thin (i.e., between 2 μm and 20 μm, but up to 200 μm maximum), it has a very low thermal conductivity. The film has a size between 2x2 cm 2 and 35x35 cm 2 and corresponds to the size of the target wafer. There is little heat conduction between the film and the frame 27. Thus, the monolithic frame 27 does not contribute to cooling the film, and the only cooling mechanism for the associated film is thermal radiation from the film.

[0013] Local heating of the film in the energy filter 25 occurs in addition to the thermal stress between the heated portion of the film forming the energy filter 25 and the frame. Further, local heating of the film due to absorption of energy from the ion beam 10 in only a portion of the film, such as, for example, by electrostatic or mechanical scanning of the beam, or by mechanical movement of the filter with respect to the beam, also introduces thermal stress into the film and can result in mechanical deformation or damage to the film. Heating of the film also occurs within a very short time period, i.e., less than 1 second, and often on the order of milliseconds. The cooling effect occurs during or immediately after local transient radiation because adjacent or more remote regions of the filter have a lower temperature than the instantaneously irradiated region. The problem is that there is little heat conduction to provide heat equalization. This non-uniform temperature distribution is particularly pronounced for the pulsed ion beam 10 and the scanned ion beam 10. These temperature gradients can result in the formation of defects and segregation phases within the material from which the film of the energy filter 25 is made, and can even result in unexpected modification of the material.

[0014] Previously, the problem was that in all aspects of the ion implantation process (i.e., the time prior to irradiation, the aspect of heating the film by the ion beam (locally or globally), the actual irradiation (locally or globally), the cooling aspect (locally or globally) after removal of the ion beam, and the end of the implantation process), the associated risk of damage to the film due to tension, and increased cracking and brittleness, could occur more frequently.

[0015] A major drawback of the energy filter assembly for an ion implantation system with a monolithic edge is the transition from the edge (full wafer thickness, approximately 100 μm) to the actual energy filter membrane (typical thickness of about 20 μm). When the filter frame and the energy filter have the same irradiation output, the heat generated during the transition is greater than the heating of the thin membrane due to the high thermal conductivity of the hard edge and the resulting large heat capacity. As a result, the temperature gradient in the transition region increases, which may lead to thermomechanical stress. Practical aspects are further complicated by the fact that irradiating the filter frame and the membrane at the same output all the time is not a preferred process modification for maximizing wafer throughput because the loss of non-transmitted ions becomes very large.

Prior Art Documents

Patent Documents

[0016]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0017] Therefore, it is an object of the present invention to provide an energy filter assembly for an ion implantation system using a mechanically decoupled energy filter in order to reduce or avoid the associated risks of stress or its effects between process aspects and damage to the energy filter membrane through membrane cracking, increased membrane brittleness, or similar problems.

[0018] Therefore, there is a need to improve the energy filter assembly for an ion implantation system in order to improve the mechanical stability and thermomechanical stability of the energy filter.

Means for Solving the Problem

[0019] According to a first aspect of the present invention, there is provided an energy filter assembly for an ion implantation system, comprising an energy filter, a first filter frame, and at least one coupling element. The energy filter has at least one filter element that absorbs the beam energy of an ion beam. The at least one coupling element elastically couples the first filter frame to the energy filter.

[0020] In one aspect of the energy filter assembly, the at least one coupling element is disposed on at least one filter element of the energy filter.

[0021] In a second aspect of the energy filter assembly, the energy filter assembly further comprises a second filter frame that houses the energy filter, and the at least one coupling element elastically couples the first filter frame to the second filter frame.

[0022] In one aspect of the energy filter assembly, the at least one coupling element is configured as a micro spring element. The micro spring element may have a thickness of 6 μm, 16 μm, or several hundred μm. The micro spring element may also have a width of 50 μm, 100 μm and a length ranging from 100 μm to a maximum of several millimeters.

[0023] In one aspect of the energy filter assembly, the at least one coupling element is formed integrally with at least one of the energy filter and the first filter frame.

[0024] In one aspect of the energy filter assembly, the at least one coupling element is formed integrally with at least one of the first filter frame and the second filter frame.

[0025] In a further aspect of the energy filter assembly, at least one coupling element couples the energy filter, the first filter frame, and the second filter frame by laser welding, bonding techniques, or at least one mechanical fixture.

[0026] In one aspect of the energy filter assembly, at least one filter element is in the shape of a triangular prism, a pyramid, or a free form.

[0027] In a further aspect of the energy filter assembly, at least one filter element is disposed in a plane perpendicular to the beam direction of the ion beam.

[0028] In a third aspect of the energy filter assembly, the energy filter assembly further comprises at least one opening element and a substrate. The at least one opening element is disposed in a plane perpendicular to the beam direction of the ion beam. The at least one opening element is further disposed between the energy filter and the substrate such that the filtered ion beam is transmitted to the substrate only through the filter.

[0029] In a further aspect of the energy filter assembly, the substrate is fixed with respect to the transmitted ion beam or is movable in at least one of a first direction and a second direction perpendicular to the beam direction of the transmitted ion beam.

[0030] In another aspect of the energy filter assembly, the energy filter assembly further comprises at least one detection element that scans the ion beam in at least one minimum scan region. The at least one detection element scans the ion beam in the scan region, and the scan region extends beyond the at least one detection element. The detection element can be a Faraday cup.

[0031] In a further aspect of the energy filter assembly, at least one filter element is made of silicon, silicon carbide, or carbon.

[0032] In a fourth aspect of the energy filter assembly, at least one coupling element is pre-loaded to maintain the connection between the first filter frame and the energy filter under a controlled tension. At least one coupling element is specifically pre-loaded to maintain the connection between the first filter frame and the energy filter under a controlled tension in the case of thermal expansion of the filter during ion irradiation. At least one pre-loaded coupling element is configured such that the controlled tension applied to the energy filter is less than the maximum tolerable tension that includes a safety value within the overall temperature range allowed during operation. At least one coupling element can be provided as a micro-tension spring element.

[0033] According to a fifth aspect of the present invention, there is provided a method for manufacturing an energy filter assembly for an ion implantation system, the method comprising: providing an energy filter having at least one filter element that at least partially absorbs the beam energy of an ion beam; providing a first filter frame; and connecting the first filter frame to the energy filter by at least one coupling element for elastically connecting the first filter frame to the energy filter.

[0034] In one aspect of the method for manufacturing an energy filter assembly, the method further comprises providing a second filter frame for housing the energy filter and elastically connecting at least one coupling element between the first filter frame and the second filter frame.

[0035] According to a sixth aspect of the present invention, there is provided a method for filtering ion implantation, the method comprising the step of providing an energy filter assembly comprising an energy filter having at least one filter element, wherein a first filter frame is elastically coupled to the energy filter by at least one coupling element, and at least one aperture element is disposed between the energy filter and the substrate; the step of providing an ion beam extending across the energy filter and at least one coupling element; and the step of disposing at least one aperture element with respect to the direction of the ion beam so as to stop non-filtered ions of the ion beam from colliding with the substrate.

[0036] In one aspect of a method for filtering ion implantation, the method further comprises the step of scanning an ion beam beyond an energy filter, at least one coupling element, and a first filter frame such that at least one detection element is irradiated.

[0037] According to a seventh aspect of the present invention, a further method for manufacturing an energy filter assembly for an ion implantation system, the method comprising: providing a silicon-on-insulator (SOI) wafer as a substrate material having a first surface and a second surface, wherein the thickness of the buried oxide (BOX) varies between 30 nm and 1.5 μm; applying a first mask material layer and a second mask material layer to the first surface and the second surface of the SOI wafer for masking wet chemical potassium hydroxide (KOH) etching or tetramethylammonium hydroxide (TMAH) etching; patterning the first mask material layer and the second mask material layer on the first surface and the second surface by using first and second lithography processes and at least one wet or dry etching pattern formation process; cleaning the first surface and the second surface after patterning the mask material layer; performing a first wet chemical etching of the first surface or the second surface using an etching solution of KOH or TMAH; removing the first mask material layer; applying a third mask material layer to the first surface for masking a wet etching step or a dry etching step of KOH or TMAH on the first surface of the SOI wafer; patterning the third mask material layer on the first surface by using a third lithography process and at least one wet or dry etching pattern formation process; applying a wet etching step or a dry etching step of KOH or TMAH to the first surface of the SOI wafer remaining in the BOX layer; performing a second wet chemical etching of the first surface or the second surface using an etching solution of KOH or TMAH; performing a third wet chemical or dry etching of the second surface so that the etching is stopped at the BOX layer; removing the BOX layer; and removing the mask layers on the first surface and the second surface.

[0038] In one aspect of a method for manufacturing an energy filter assembly, the method further includes applying a first protective layer to a second surface to prevent etching and / or applying a second protective layer to the first surface or the second surface to prevent etching of the first surface.

[0039] According to an eighth aspect of the present invention, there is provided a further method for manufacturing an energy filter assembly for an ion implantation system, the method comprising providing a bulk material slab and continuously removing material by a laser etching or mechanical corrosion device, the removal being in increments from tens of nanometers to a maximum of several micrometers per step and involving several removal steps for a given structure, the continuous removal being carried out according to a predetermined 3D layout of an energy filter, a first filter frame, and at least one coupling element for elastically coupling the first filter frame to the energy filter.

[0040] According to a ninth aspect of the present invention, there is provided a further method for manufacturing an energy filter assembly for an ion implantation system, the method comprising providing a substrate or a base layer, depositing a first filter layer for providing an energy filter and a first filter frame layer for providing a first filter frame, patterning the first filter layer and the first filter frame layer using an appropriate etching technique such as masked etching or continuous etching by a laser or ion beam etching device, continuously depositing and patterning multiple layers of the first filter layer and the first filter frame layer, removing, polishing, or etching the substrate or the base layer to a desired substrate layer thickness or base layer thickness, and removing, polishing, or etching the first filter layer and the first filter frame layer to cut out at least one coupling element for elastically coupling the first filter frame to the energy filter.

[0041] According to a tenth aspect of the present invention, there is provided a further method for manufacturing an energy filter assembly for an ion implantation system, the method comprising the steps of providing an energy filter, providing a first filter frame, creating at least one elastic element between the energy filter and the first filter frame by laser ablation, and separating the energy filter from the first filter frame by material ablation.

[0042] Hereinafter, the present invention will be described with reference to the drawings. It is understood that the embodiments and aspects of the present invention described in the drawings are merely examples and do not limit the scope of protection of the claims in any way. The present invention is defined by the claims and their equivalents. It is understood that the features of one aspect or embodiment of the present invention can be combined with different aspects of other embodiments of the present invention. The present invention will become more apparent when the following detailed description of some examples as part of the present disclosure is read in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0043]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 5C

Figure 6

Figure 7A

Figure 7B

Figure 7C

Figure 7D

Figure 7E

Figure 8

Embodiments for Carrying Out the Invention

[0044] Here, the present invention will be described based on the drawings. It is understood that the embodiments and aspects of the present invention described herein are merely examples and do not limit the scope of claim protection in any way. The present invention is defined by the claims and their equivalents. It is understood that the features of one aspect or embodiment of the present invention can be combined with the features of different aspects and / or embodiments of the present invention. The object of the present invention is fully described below using examples for the purpose of this disclosure without limiting the disclosure to those examples. The examples present different aspects of the present invention. It is not necessary to implement all of these combined aspects to practice the teachings of this technology. Rather, a person skilled in the art will select and combine those aspects that are considered useful and required for the corresponding applications and implementations.

[0045] FIG. 3A shows a top view of an energy filter assembly 1 for an ion implantation system according to a first aspect of the present invention. FIG. 3B is a cross-sectional view of the energy filter assembly 1 taken along the cutting line A-A' of FIG. 3A. As seen in FIGS. 3A and 3B, the energy filter assembly 1 comprises an energy filter 25 having at least one filter element 25a that at least partially absorbs the beam energy of the ion beam 10. The energy filter assembly 1 further comprises a first filter frame 40 and at least one coupling element 50, and the at least one coupling element 50 elastically couples the first filter frame 40 to the energy filter 25. At least one filter element 25a of the energy filter 25 is made of a film having a cross-section with a triangular prism shape, but this type of cross-sectional form is not a limitation of the present invention, and other cross-sectional forms can be used according to needs and / or requirements. For example, at least one filter element 25a of the energy filter 25 can be made of a film having a pyramidal or free-form shape.

[0046] At least one filter element 25a can be made of silicon, silicon carbide, or carbon, but this type of material is not a limitation of the present invention, and other materials can be used according to needs and / or requirements. As can be seen in FIG. 3A, at least one coupling element 50 is disposed on at least one filter element 25a of the energy filter 25. Further, as can be seen in FIG. 3A, at least one coupling element 50 is also disposed on the first filter frame 40. At least one coupling element 50 can be formed integrally with at least one part of the energy filter 25. At least one coupling element 50 can also be formed integrally with at least one part of the first filter frame 40. However, at least one coupling element 50 can also be formed separately from at least one part of the energy filter 25. At least one coupling element 50 can also be formed separately from at least one part of the first filter frame 40. At least one coupling element 50 can be connected to the energy filter 25 and the first filter frame 40 by laser welding, bonding techniques, or at least one mechanical fixture, but this type of connection is not a limitation of the present invention, and other connection techniques can be used according to needs and / or requirements. As can be seen in FIG. 3B, at least one filter element 25a is disposed in a plane X, Y that is perpendicular to the beam direction Z of the ion beam 10 that is irradiated through an ion beam source 5 (not shown).

[0047] In a first aspect of the present invention, the energy filter assembly 1 comprises five coupling elements 50, two of the coupling elements 50 being arranged on each longitudinal side of the energy filter 25, and one of the coupling elements 50 being arranged on each width side of the energy filter 25. However, in the first aspect of the present invention, two of the coupling elements 50 may be arranged on each width side of the energy filter 25, and one of the coupling elements 50 may be arranged on each longitudinal side of the energy filter 25. Further, in the first aspect of the present invention, the number of coupling elements 50 is not limited by the present invention. The energy filter assembly 1 can comprise six or more coupling elements 50, or four or fewer coupling elements 50. In a further aspect of the present invention, the energy filter assembly 1 can also comprise only one coupling element 50, the coupling element 50 elastically connecting the first filter frame 40 to the energy filter 25. In a further aspect of the present invention, at least one coupling element 50 can be arranged on the upper surface and / or the bottom surface of the energy filter 25 in order to elastically connect the first filter frame 40 to the energy filter 25.

[0048] For the energy filter assembly 1 for an ion implantation system according to the first aspect of the present invention, at least one coupling element 50 can be configured as a microspring element. The microspring element can have a thickness of 6 μm, 16 μm, or several hundreds of μm. The microspring element 50 can have a width of 50 μm, 100 μm and a length from 100 μm up to a maximum of several millimeters. However, this type of coupling element 50 is not a limitation of the present invention, and other types of coupling elements can be used according to needs and / or requirements.

[0049] FIG. 4A shows a top view of an energy filter assembly 100 for an ion implantation system according to a second aspect of the present invention. FIG. 4B shows a cross-sectional view of the energy filter assembly 100 taken along the cutting line A-A' of FIG. 4A. The energy filter assembly 100 for an ion implantation system according to the second aspect of the present invention has the same configuration as the filter assembly 1 according to the first aspect of the present invention. Therefore, elements having substantially the same functions as those in the first aspect of the present invention are also denoted by the same reference numerals here and are not described and / or illustrated in detail here for the sake of brevity. As can be seen in FIG. 4A, the energy filter assembly 100 further includes a second filter frame 30 that houses the energy filter 25, and at least one coupling element 50 elastically connects the first filter frame 40 to the second filter frame 30.

[0050] As can be seen in FIG. 4A, in a second aspect of the present invention, at least one coupling element 50 is disposed on a second filter frame 30 that houses at least one filter element 25a of the energy filter 25. Further as seen in FIG. 4A, at least one coupling element 50 is also disposed on the first filter frame 40. The at least one coupling element 50 can be integrally formed with at least one portion of the second filter frame 30. The at least one coupling element 50 can also be integrally formed with at least one portion of the first filter frame 40. However, the at least one coupling element 50 can also be formed separately from at least one portion of the second filter frame 30. The at least one coupling element 50 can also be formed separately from at least one portion of the first filter frame 40. The at least one coupling element 50 can be connected to the second filter frame 30 and the first filter frame 40 by laser welding, bonding techniques, or at least one mechanical fixture, but this type of connection is not a limitation of the present invention and other connection techniques can be used depending on the needs and / or requirements. Further, in the second aspect of the present invention, the number of coupling elements 50 is not limited by the present invention. The energy filter assembly 100 can comprise six or more coupling elements 50, or four or fewer coupling elements 50. In a further aspect of the present invention, the energy filter assembly 100 can also comprise only one coupling element 50, and the coupling element 50 elastically connects the first filter frame 40 to the second filter frame 30. In a further aspect of the present invention, the at least one coupling element 50 can be disposed on the upper surface and / or the bottom surface of the second filter frame 30 to elastically connect the first filter frame 40 to the energy filter 25 via the second filter frame 30.

[0051] As can be seen in FIG. 4B, in a second aspect of the present invention, at least one filter element 25a is disposed in planes X, Y that are perpendicular to the beam direction Z of the ion beam 10 irradiated through an ion beam source 5 (not shown). As can be seen in FIG. 4B, the energy filter assembly 100 includes a silicon dioxide layer 22 of an insulating layer. For example, the silicon dioxide layer 22 has a thickness of 0.3 to 1.5 μm sandwiched between a first filter frame 40 and bulk silicon 23 (having a thickness of about 400 μm). However, the present invention is not limited thereto, and the silicon dioxide layer 22 of the insulating layer may be omitted, and other connecting layers may be used according to requirements and / or demands. As can be seen in FIG. 4B, the energy filter 25 has at least one filter layer 32 with a layer thickness having a minimum thickness of the film. The energy filter 25 can be configured to have only one filter layer 32 or a plurality of filter layers 32. For example, the energy filter 25 can be made to have five filter layers 32, each having a layer thickness with a minimum thickness of the film. The amount of the filter layer 32 is not a limitation of the present invention. Further, as can be seen in FIG. 4B, the first filter frame 40 has at least one first filter frame layer 43 with a layer thickness having a minimum thickness. The first filter frame 40 can be configured to have only one first filter frame layer 43 or a plurality of first filter frame layers 43. The amount of the first filter frame layer 43 is not a limitation of the present invention. Further, as can be seen in FIG. 4B, the second filter frame 30 has at least one second filter frame layer 33 with a layer thickness having a minimum thickness. The second filter frame 30 can be configured to have only one second filter frame layer 33 or a plurality of second filter frame layers 33. The amount of the second filter frame layer 33 is not a limitation of the present invention.

[0052] FIG. 5A shows a cross-sectional view of an energy filter assembly 200 for an ion implantation system according to a third aspect of the present invention. FIGS. 5B and 5C show top views of further aspects of the energy filter assembly 200 according to the third aspect of the present invention. The energy filter assembly 200 for an ion implantation system according to the third aspect of the present invention comprises the same configuration as the filter assembly 1 according to the first aspect of the present invention and the same configuration as the filter assembly 100 according to the second aspect of the present invention. Therefore, elements having substantially the same functions as those in the first and second aspects of the present invention are also denoted by the same reference numerals herein and are not described and / or illustrated in detail herein for the sake of brevity.

[0053] As can be seen in FIG. 5A, in the third aspect of the present invention, the energy filter assembly 200 further comprises at least one aperture element 60 disposed in planes X, Y perpendicular to the beam direction Z of the ion beam 10 irradiated through an ion beam source 5 (not shown). The energy filter assembly 200 further comprises a substrate 70, and the at least one aperture element 60 is disposed between the energy filter 25 and the substrate 70 such that the filtered ion beam 10a is transmitted to the substrate 70 and the unfiltered ion beam 10b is shielded by the at least one aperture element 60. As can be seen in FIG. 5A, the substrate 70 can be fixed with respect to the transmitted ion beam 10a. However, the present invention is not limited thereto, and the substrate 70 can also be movable in at least one of a first direction 70a and a second direction 70b both perpendicular to the beam direction Z of the transmitted ion beam 10a.

[0054] In a further aspect of the energy filter assembly 200 according to the third aspect of the present invention, the energy filter assembly 200 further comprises at least one detection element 80, and the detection element 80 scans the ion beam 10 in at least one minimum scan region 80a as best seen in FIGS. 5A and 5B. The at least one detection element 80 can be a Faraday cup, but the present invention is not limited thereto.

[0055] In a further aspect of the energy filter assembly 200 according to the third aspect of the present invention, at least one detection element 80 scans the ion beam 10 in a scanning region 80b, which extends beyond at least one detection element 80, as best seen in FIG. 5C.

[0056] FIG. 6 shows a top view of an energy filter assembly 300 for an ion implantation system according to a fourth aspect of the present invention. The energy filter assembly 300 for an ion implantation system according to a third aspect of the present invention includes the same configuration as the filter assembly 1 according to the first aspect of the present invention, the same configuration as the filter assembly 100 according to the second aspect of the present invention, and the same configuration as the filter assembly 100 according to the third aspect of the present invention. Therefore, elements having substantially the same functions as those in the first, second, and third aspects of the present invention are also denoted by the same reference numerals here and are not described and / or illustrated in detail here for the sake of brevity. At least one coupling element 50 elastically connects the first filter frame 40 to the energy filter 25 via the second filter frame 30. However, the present invention is not limited thereto, and at least one coupling element 50 can also directly and elastically connect the first filter frame 40 to the energy filter 25. In the energy filter assembly 300 according to the fourth aspect of the present invention, at least one coupling element 50 is preloaded to maintain the connection between the first filter frame 40 and the energy filter 25 under a controlled tension. The membrane of the energy filter 25 has a tendency to "expand", that is, a tendency to form a strain. For example, at least one coupling element 50 can be configured as a tension spring 50. The purpose is to ensure that the membrane of the energy filter 25 retains its "flat stress state" as much as possible regardless of the orientation (vertical / upright or horizontal / lying) and external loads (thermal and mechanical effects). Therefore, the membrane of the energy filter 25 is pulled by the uniformly distributed preloaded tension springs 50 in the first filter frame 40 and the second filter frame 30. Therefore, the membrane of the energy filter 25 can be (substantially) smoothed or flattened by tensile stress, that is, by controlled tension. The tension spring 50 is further configured such that the maximum tolerable tensile stress (depending on the material) with a corresponding safety factor (depending on the type and magnitude of the external load) is not exceeded within the overall temperature range allowed during operation.

[0057] As can be seen in the top view of the energy filter assembly 300 in FIG. 6, the second filter frame 30 has a curved outer shape 35. For example, the second filter frame 30 has a wavy outer shape 35. The first filter frame 40 is configured to conform to the curved outer shape of the second filter frame 30. Thus, for example, the first filter frame 40 has a wavy or curved inner contour 41. As can be seen in FIG. 6, a gap 90 is provided between the outer shape 35 of the second filter frame 30 and the inner contour 41 of the first filter frame 40. As can be seen in FIG. 6, at least one coupling element 50 is provided to elastically connect the outer shape 35 of the second filter frame 30 and the inner contour 41 of the first filter frame 40. For example, the gap 90 is removed by laser ablation. By providing the gap 90, the energy filter 25 is separated from the first filter frame 40. Thus, the coupling element 50 creates a flexible mechanical connection between the second filter frame 30 surrounding the energy filter 25 and the first filter frame 40. The curved outer shape 35 specifically absorbs the force of at least one coupling element 50 when the coupling element 50 is configured as a tension spring 50. Thus, the influence of thermomechanical stress can be further reduced.

[0058] As can be seen in FIG. 6, holes may be provided in the first filter frame 40 and / or the second filter frame 30 for attaching the tension spring 50 using 3D laser ablation. After installing the tension spring 50, the membrane of the energy filter 25 and the first filter frame 40 are decoupled from each other by a specific cut shape (taking into account all mechanical and thermodynamic effects). This cut can also be generated using 3D laser ablation.

[0059] In a further aspect of the energy filter assembly 300 according to the fourth aspect of the present invention, at least one coupling element 50 pre-loaded is configured such that a controlled tensile force to the energy filter 25 is less than the maximum allowable tensile force including a safety value within the overall temperature range allowed during operation.

[0060] In a further aspect of the energy filter assembly 300 according to the fourth aspect of the present invention, at least one coupling element 50 may be provided as a fine tensile spring element. However, the present invention is not limited thereto, and other pre-loaded elements may be used as required and / or requested.

[0061] Figures 7A - 7E show flowcharts of a method for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system according to the present invention.

[0062] According to a fifth aspect of the present invention, a method 400 for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system is provided. The method 400 includes a step 401 of providing an energy filter 25 having at least one filter element 25 that at least partially absorbs the beam energy of the ion beam 10, a step 402 of providing a first filter frame 40, and a step of connecting the first filter frame 40 to the energy filter 25 by at least one coupling element 50 for elastically connecting the first filter frame 40 to the energy filter 25. The method 400 further includes a step 403 of providing a second filter frame 30 for housing the energy filter 25, and a step 404 of elastically connecting at least one coupling element 50 between the first filter frame 40 and the second filter frame 30.

[0063] According to a sixth aspect of the present invention, there is provided a method 500 for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system. The method 500 includes a step 501 of providing a silicon-on-insulator (SOI) wafer as a substrate material having a first surface and a second surface, wherein the thickness of the buried oxide (BOX) varies between 30 nm and 1.5 μm; a step 502 of applying a first mask material layer and a second mask material layer to the first surface and the second surface of the SOI wafer for masking wet chemical potassium hydroxide (KOH) etching or tetramethylammonium hydroxide (TMAH) etching; a step 503 of patterning the first mask material layer and the second mask material layer on the first surface and the second surface by using first and second lithography processing steps and at least one wet or dry etching pattern forming step; a step 504 of cleaning the first surface and the second surface after patterning of the mask material layer; a step 505 of performing a first wet chemical etching of the first surface or the second surface using an etching solution of KOH or TMAH; a step 506 of removing the first mask material layer; a step 506 of applying a third mask material layer to the first surface for masking a wet etching step or a dry etching step of KOH or TMAH on the first surface of the SOI wafer; a step 507 of patterning the third mask material layer on the first surface by using a third lithography processing step and at least one wet or dry etching pattern forming step; a step 508 of applying a wet etching step or a dry etching step of KOH or TMAH to the first surface of the SOI wafer remaining in the BOX layer; a step 509 of performing a second wet chemical etching of the first surface or the second surface using an etching solution of KOH or TMAH; a step 510 of performing a third wet chemical or dry etching of the second surface so that the etching is stopped at the BOX layer; a step 511 of removing the BOX layer; and a step 512 of removing the mask layers on the first surface and the second surface.

[0064] In a further aspect of method 500 for manufacturing energy filter assemblies 1, 100, 200, 300 for an ion implantation system, method 500 includes step 513 of applying a first protective layer to a second surface to prevent etching. Method 500 may further include step 514 of applying a second protective layer to the first surface or the second surface to prevent etching of the first surface.

[0065] According to a seventh aspect of the present invention, there is provided a method 600 for manufacturing energy filter assemblies 1, 100, 200, 300 for an ion implantation system. The method includes step 601 of providing a bulk material slab and step 602 of continuously removing material by a laser etching or mechanical erosion device, wherein the continuous removal 602 is in increments from several tens of nanometers to a maximum of several micrometers per step, involves several removal steps for a given structure, and the continuous removal 602 is carried out according to a predetermined 3D layout of an energy filter 25, a first filter frame 40, and at least one coupling element 50 for elastically connecting the first filter frame 40 to the energy filter 25.

[0066] According to an eighth aspect of the present invention, there is provided a method 700 for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system. The method includes a step 701 of providing a substrate or a base layer, a step 702 of depositing a first energy filter layer 32 for providing an energy filter 25 and a first filter frame layer 43 for providing a first filter frame 40, a step 703 of patterning the first energy filter layer 32 and the first filter frame layer 43 using an appropriate etching technique such as masked etching or continuous etching by an etching device of a laser or an ion beam, a step 704 of continuously depositing and patterning multiple layers of the first energy filter layer 32 and the first filter frame layer 43, a step 705 of removing, polishing, or etching the substrate or the base layer to a desired substrate layer thickness or base layer thickness, and a step 706 of cutting out at least one coupling element 50 for elastically connecting the first filter frame 40 to the energy filter 25 by removing, polishing, or etching the first energy filter layer 32 and the first filter frame layer 43.

[0067] According to a ninth aspect of the present invention, there is provided a method 800 for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system. The method 800 includes a step 801 of providing an energy filter 25, a step 802 of providing a first filter frame 40, a step 803 of creating at least one elastic element 50 between the energy filter 25 and the first filter frame 40 by laser ablation, and a step 804 of separating the energy filter 25 from the first filter frame 40 by material ablation.

[0068] FIG. 8 shows a flowchart of a method 900 for filtering ion implantation using an energy filter assembly 1, 100, 200, 300 for an ion implantation system according to a tenth aspect of the present invention. The method 900 includes a step 901 of providing an energy filter assembly 1, 100, 200, 300 including an energy filter 25 with at least one filter element 25a, wherein a first filter frame 40 is elastically connected to the energy filter 25 by at least one coupling element 50, and at least one aperture element 60 is disposed between the energy filter 25 and a substrate 70; a step 902 of providing an ion beam 10 extending across the energy filter 25 and at least one coupling element 50; and a step 903 of disposing at least one aperture element 60 in the direction of the ion beam 10 so as to stop unfiltered ions 10b of the ion beam 10 from colliding with the substrate 70. The method 900 may further include that the ion beam 10 extends across the energy filter 25 and at least one coupling element 50 and at least partially across the first filter frame 40. Specifically, when the method 900 includes that the ion beam 10 extends across the energy filter 25 and at least one coupling element 50 and at least partially across the first filter frame, the scanning region extends beyond at least one detection element in the form of a Faraday cup.

[0069] In a further aspect of the method 900 for filtering ion implantation using an energy filter assembly 1, 100, 200, 300 for an ion implantation system according to a tenth aspect of the present invention, the method 900 includes a step 904 of scanning the ion beam 10 beyond the energy filter 25, at least one coupling element 50, and the first filter frame 40 so that at least one detection element 80 is irradiated.

[0070] From the foregoing description of the present invention, those skilled in the art will recognize improvements, changes, and modifications to the present invention. Such improvements, changes, and modifications within the skill in the art are intended to be covered by the appended claims.

Description of Symbols

[0071] 1 Energy filter assembly 5 Ion beam source 10 Ion beam 20 Ion implantation device 21 Silicon layer 22 Silicon dioxide layer 23 Bulk silicon 25 Energy filter 25a Filter element 30 Second filter frame 32 Energy filter layer 33 Second filter frame layer 35 Curved outer shape 40 First filter frame 41 Inner contour 43 First filter layer 50 Coupling element 60 Aperture element 70 Substrate 70a First direction 70b Second direction 80 Detection element 80a Minimum scanning area 80b Scanning area 90 Gap 100 Energy filter assembly 200 Energy filter assembly 300 Energy filter assembly

Claims

1. An energy filter assembly for an ion implantation system, comprising: an energy filter having at least one filter element that absorbs the beam energy of an ion beam; a first filter frame; and at least one coupling element for elastically connecting the first filter frame to the energy filter. The energy filter assembly comprising the above.

2. The energy filter assembly according to claim 1, wherein the at least one coupling element is disposed on the at least one filter element of the energy filter.

3. The energy filter assembly according to claim 1, further comprising a second filter frame for housing the energy filter, wherein the at least one coupling element elastically connects the first filter frame to the second filter frame.

4. The energy filter assembly according to any one of claims 1 to 3, wherein the at least one coupling element is configured as a microspring element.

5. The energy filter assembly according to claim 4, wherein the microspring element has a thickness of 6 μm, 16 μm, or 100 μm.

6. The energy filter assembly according to claim 4 or 5, wherein the microspring element has a width of 50 μm, 100 μm and a length ranging from 100 μm to a maximum of several millimeters.

7. The energy filter assembly according to claim 1, wherein the at least one coupling element is integrally formed with at least one of the energy filter and the first filter frame.

8. The energy filter assembly according to claim 3, wherein the at least one coupling element is integrally formed with at least one of the first filter frame and the second filter frame.

9. The energy filter assembly according to claim 3, wherein the at least one coupling element is connected to the energy filter, the first filter frame, and the second filter frame by laser welding, bonding technology, or at least one mechanical fixture.

10. The energy filter assembly according to claim 1, wherein the at least one filter element is in the shape of a triangular prism, a pyramid, or a free form.

11. The energy filter assembly according to claim 10, wherein the at least one filter element is arranged in a plane perpendicular to the beam direction of the ion beam.

12. At least one aperture element arranged in a plane perpendicular to the beam direction of the ion beam, and a substrate further comprising: The energy filter assembly according to claim 1, wherein the at least one aperture element is arranged between the energy filter and the substrate such that the filtered ion beam is transmitted to the substrate.

13. The energy filter assembly according to claim 12, wherein the substrate is fixed to the transmitted ion beam or is movable in at least one of a first direction and a second direction perpendicular to the beam direction of the transmitted ion beam.

14. The energy filter assembly according to claim 12 or 13, further comprising at least one detection element for scanning the ion beam in at least one minimum scanning region.

15. The energy filter assembly according to claim 14, wherein the at least one detection element scans the ion beam in a scanning region, and the scanning region extends beyond the at least one detection element.

16. The energy filter assembly according to claim 14 or 15, wherein the detection element is a Faraday cup.

17. The energy filter assembly according to claim 1, wherein the at least one filter element is made of silicon, silicon carbide, or carbon.

18. The energy filter assembly according to claim 1, wherein the at least one coupling element is pre-loaded to maintain the connection between the first filter frame and the energy filter under a controlled tension.

19. The energy filter assembly according to claim 18, wherein the at least one pre-loaded coupling element is configured such that the controlled tension to the energy filter is less than the maximum tolerable tension including a safety value within the overall temperature range allowed during operation.

20. The energy filter assembly according to claim 18 or 19, wherein the at least one coupling element is provided as a fine tension spring element.

21. The second filter frame has a curved outer shape, the first filter frame has an inner contour, and the inner contour is adapted to the curved outer shape such that a gap is provided between the outer shape of the second filter frame and the inner contour of the first filter frame. The energy filter assembly according to claim 3.

22. A method for manufacturing an energy filter assembly for an ion implantation system, comprising: providing an energy filter having at least one filter element that absorbs the beam energy of an ion beam; providing a first filter frame; connecting the first filter frame to the energy filter by at least one coupling element for elastically connecting the first filter frame to the energy filter; A method comprising.

23. providing a second filter frame for housing the energy filter; elastically connecting the at least one coupling element between the first filter frame and the second filter frame; The method according to claim 22, further comprising.

24. A method for filtering ion implantation, comprising: providing an energy filter assembly comprising an energy filter having at least one filter element, wherein a first filter frame is elastically connected to the energy filter by at least one coupling element, and at least one aperture element is disposed between the energy filter and a substrate; providing an ion beam extending across the energy filter and the at least one coupling element; positioning the at least one aperture element with respect to the direction of the ion beam to stop unfiltered ions of the ion beam from impinging on the substrate; A method comprising.

25. The method according to claim 24, further comprising scanning the ion beam beyond the energy filter, the at least one coupling element, and the first filter frame such that the at least one detection element is irradiated.

26. A method for manufacturing an energy filter assembly for an ion implantation system, wherein the energy filter assembly includes a first filter frame and at least one coupling element, the method comprising: Providing a silicon-on-insulator (SOI) wafer as a substrate material having a first surface and a second surface, wherein the thickness of the buried oxide (BOX) varies between 30 nm and 1.5 µm; Applying a first mask material layer and a second mask material layer to the first surface and the second surface of the SOI wafer for masking wet chemical potassium hydroxide (KOH) etching or tetramethylammonium hydroxide (TMAH) etching; Pattern-forming the first mask material layer and the second mask material layer on the first surface and the second surface by using first and second lithography processing steps and at least one wet or dry etching pattern-forming step; Cleaning the first surface and the second surface after pattern-forming the mask material layer; Performing a first wet chemical etching on the first surface or the second surface using an etching solution of KOH or TMAH; Removing the first mask material layer; Applying a third mask material layer to the first surface for masking a wet etching step or a dry etching step of KOH or TMAH on the first surface of the SOI wafer; Pattern-forming the third mask material layer on the first surface by using a third lithography processing step and at least one wet or dry etching pattern-forming step; Applying a wet etching step or a dry etching step of KOH or TMAH to the first surface of the SOI wafer remaining in the BOX layer; Performing a second wet chemical etching on the first surface or the second surface using an etching solution of KOH or TMAH; Performing a third wet chemical or dry etching on the second surface so that the etching is stopped at the BOX layer; Removing the BOX layer; The step of removing the mask layer on the first surface and the second surface A method comprising the same. **Claim 27** The method according to claim 26, comprising the step of applying a first protective layer to the second surface to prevent etching. **Claim 28** The method according to claim 26, comprising the step of applying a second protective layer to the first surface or the second surface to prevent etching of the first surface. **Claim 29** A method for manufacturing an energy filter assembly for an ion implantation system, comprising: Providing a bulk material slab; Continuously removing the bulk material by a laser etching or mechanical corrosion device, wherein the removal is an increment from several tens of nanometers to a maximum of several micrometers per step, and involves several removal steps for a given structure, and the continuous removal is performed according to a predetermined 3D layout of an energy filter, a first filter frame, and at least one coupling element for elastically connecting the first filter frame to the energy filter. A method comprising the same. **Claim 30** A method for manufacturing an energy filter assembly for an ion implantation system, comprising: Providing a substrate or a base layer; Depositing a first filter layer for providing an energy filter and a first filter frame layer for providing a first filter frame; Pattern-forming the first filter layer and the first filter frame layer using an appropriate etching technique such as masked etching or continuous etching by a laser or ion beam etching device; Continuously depositing and pattern-forming multiple layers of the first filter layer and the first filter frame layer; Removing, polishing, or etching the substrate or the base layer to a desired substrate layer thickness or base layer thickness; Cutting out at least one coupling element for elastically connecting the first filter frame to the energy filter by removing, polishing, or etching the first filter layer and the first filter frame layer. A method comprising the same. **Claim 31** A method for manufacturing an energy filter assembly for an ion implantation system, comprising: Providing an energy filter; providing a first filter frame; creating at least one elastic element between the energy filter and the first filter frame by laser ablation; separating the energy filter from the first filter frame by material ablation and a method including the same.

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