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] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to LU Patent Application No. LU102299, filed December 17, 2020. This application is a divisional application based on Japanese Patent Application No. 2023-561424, which is a national phase entry of International Patent Application PCT / EP2021 / 084473, filed December 7, 2021, and published as WO2022 / 128593 A1.

[0002] The present invention provides Method of manufacturing an energy filter assembly for an ion implantation system Regarding. [Background technology]

[0003] Ion implantation is a method for achieving doping or defect profile creation in materials, such as semiconductor or optical materials, with a predetermined depth profile ranging from a few nanometers to 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.

[0004] There is a need to generate depth profiles by ion implantation having a wider depth distribution of doping or defect concentration peaks than that obtained by monoenergetic ion irradiation, or to generate doping or defect depth profiles that cannot be generated by one or several simple monoenergetic implants. Doping concentration peaks can often be approximately represented by a Gaussian distribution, or more precisely, by a Pearson distribution. However, there are deviations from such distributions, especially when so-called channeling effects are present in crystalline materials. Prior art methods for generating depth profiles using structured energy filters are known, in which the energy of a monoenergetic ion beam is modified as it passes through a finely structured energy filter element. The resulting energy distribution results in the creation of a depth profile ion in the target material. This is described, for example, in European Patent 0014516B1 (Bartko).

[0005] An example of such an ion implantation device 20 is shown in FIG. 1 , in which an ion beam 10 impinges on a structured energy filter 25. The ion beam source 5 can be a cyclotron, a radio frequency linear accelerator, an electrostatic tandem accelerator, or a single-ended electrostatic accelerator. In other aspects, 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 one particular embodiment, the ion beam source produces an ion beam 10 at 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 some preferred aspects between 4 MeV and 40 MeV, and in preferred aspects between 8 MeV and 30 MeV. The frequency of the ion beam 10 can be between 1 Hz and 2 kHz, for example 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.

[0006] 1, it can be seen that the energy filter 25 is made from a membrane having a triangular cross-sectional configuration on the right hand side, however, this type of cross-sectional configuration is not a limitation of the present invention and other cross-sectional configurations can be used. min However, since the left-hand side has a minimum thickness of the membrane of the energy filter 25, 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 membrane resulting in absorption of at least a portion of the energy of the ion beam 10 in the membrane).

[0007] On the other hand, the lower ion beam 10-2 is focused on the region 25 where the membrane of the energy filter 25 is at its 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, and therefore the energy of the lower ion beam 10-2 on the right hand side is reduced and is less than the energy of the upper ion beam, i.e., E1 > E2. As a result, the higher energy upper ion beam 10-1 can penetrate to a greater depth in the substrate material 30 than the lower energy lower ion beam 10-2. This results in a different depth profile in the substrate material 30 that is part of the wafer.

[0008] This depth profile is shown on the right-hand side of Figure 1. The solid rectangular area indicates that ions penetrate into the substrate material to a depth between d1 and d2. However, the horizontal profile shape is a special case, which is obtained when all energies are considered geometrically equal and the energy filter and substrate material are the same. The Gaussian curve shows an approximate depth profile without the energy filter 25, with a maximum at a depth of d3. It will be appreciated that depth d3 is greater than depth d2 because some of the energy of the ion beam 10-1 is absorbed in the energy filter 25.

[0009] In the prior art, there are several principles known for the fabrication of energy filters 25. Typically, energy filters 25 are made from bulk material with the surface of the energy filter 25 etched to generate a desired pattern, such as the triangular cross-sectional pattern known from FIG. 1. German patent DE 102016106119 B4 (Csato / Krippendorf) describes an energy filter fabricated from layers of material with different ion beam energy reduction properties. The depth profile resulting from the energy filter described in the Csato / Krippendorf patent application depends on the structure of the material layers as well as the structure of the surface.

[0010] A further construction principle is shown in the applicant's co-pending application DE102019120623.5, in which an energy filter comprises spaced apart microstructured layers connected together by vertical walls.

[0011] The maximum power from the ion beam 10 that can be absorbed through the energy filter 25 depends on three factors: the effective cooling mechanism of the energy filter 25, the thermomechanical properties of the film from which the energy filter 25 is made, and the choice of material from which the energy filter 25 is made. In a typical ion implantation process, approximately 50% of the power is absorbed in the energy filter 25, but this can go up to 80% depending on the process conditions and filter geometry.

[0012] An example of an energy filter is shown in Figure 2, where the energy filter 25 is made from a triangular structured membrane mounted on a frame 27. In one non-limiting example, the energy filter 25 can be made from a single piece of material, such as silicon-on-insulator, comprising an insulating layer of silicon dioxide 22, e.g., having a thickness of 0.2-1 μm, sandwiched between a silicon layer 21 (up to 200 μm thick, typically between 2 μm and 20 μm thick) and bulk silicon 23 (approximately 400 μm thick). The structured membrane is made from, for example, silicon, but can also be made from silicon carbide, other silicon or carbon-based materials, or ceramics.

[0013] In order to use the ion beam 10 efficiently by optimizing the wafer throughput in the ion implantation process for a given ion current for the ion beam 10, it is preferable to irradiate only the membrane of the energy filter 25 and not the frame 27 on which the membrane is held in place. In practice, it is likely that at least part of the frame 27 will also be irradiated by the ion beam 10 and therefore heat up. In fact, it is possible for the frame 27 to be completely irradiated. The membrane forming the energy filter 25 will be heated, but because it is thin (i.e., between 2 μm and 20 μm, but up to 200 μm), it has a very low thermal conductivity. The membrane has dimensions of 2×2 cm 2 From 35x35cm 2 and corresponds to the size of the target wafer. There is almost no heat conduction between the film and the frame 27. Therefore, 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.

[0014] Localized heating of the membrane in the energy filter 25 occurs in addition to thermal stresses between the heated portion of the membrane and the frame that forms the energy filter 25. Furthermore, localized heating of the membrane due to absorption of energy from the ion beam 10 in only a portion of the membrane, for example, due to electrostatic or mechanical scanning of the beam or mechanical movement of the filter relative to the beam, can also result in thermal stresses in the membrane, potentially resulting in mechanical deformation or damage to the membrane. Heating of the membrane also occurs within a very short time period, i.e., less than one second, often on the order of milliseconds. A cooling effect occurs during or immediately after the localized momentary irradiation, as adjacent or more distant regions of the filter have a lower temperature than the momentarily irradiated area. The problem is that there is little heat conduction to provide thermal equalization. This non-uniform temperature distribution is particularly pronounced for pulsed and scanned ion beams 10. These temperature gradients can lead to the formation of defects and segregated phases in the material from which the membrane of the energy filter 25 is made, and can even result in unexpected modifications of the material.

[0015] Previously, the problem was that tension and the associated risk of damage to the film due to cracking or increased brittleness could occur more frequently during all stages of the ion implantation process (i.e., the time before irradiation, the stage of heating the film by the ion beam (local or global), the actual irradiation (local or global), the cooling stage after removal of the ion beam (local or global), and the end of the implantation process).

[0016] The main drawback of energy filter assemblies for monolithic edge ion implantation systems is the transition from the edge (full wafer thickness, approximately 100 μm) to the actual energy filter membrane (typical thickness about 20 μm). If the filter frame and energy filter have the same irradiance power, the resulting heat at the transition will be greater than the heating of the thin membrane due to the high thermal conductivity of the rigid edge and the resulting large heat capacity. As a result, temperature gradients in the transition region can increase, leading to thermomechanical stresses. The practical aspect is further complicated by the fact that always irradiating the filter frame and membrane with the same power is not a favorable process change for reasons of maximizing wafer throughput, since losses of untransmitted ions would be too great. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] European Patent No. 0014516 [Patent Document 2] German patent number 102016106119 [Patent Document 3] German Patent Application Publication No. 102019120623 Summary of the Invention [Problem to be solved by the invention]

[0018] It is therefore an object of the present invention to provide an energy filter assembly for an ion implantation system with a mechanically decoupled energy filter to reduce or avoid stresses or their effects during aspects of processing and the associated risk of damage to the energy filter membrane through membrane cracking, increased membrane brittleness, or similar problems.

[0019] Therefore, there is a need for improved energy filter assemblies for ion implantation systems to improve the mechanical and thermomechanical stability of the energy filter. [Means for solving the problem]

[0020] The present invention 1 According to an aspect of the present invention, a method for manufacturing an energy filter assembly for an ion implantation system is provided. For thoseThe method includes the steps of: providing a silicon-on-insulator (SOI) wafer as a substrate material having a first surface and a second surface, wherein a thickness of a 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 processing steps and at least one wet or dry etching patterning step; cleaning the first surface and the second surface after patterning the mask material layer; performing a first wet chemical etching on the first surface or the second surface using a KOH or TMAH etching solution; applying a third mask material layer to the first surface of the SOI wafer to mask a KOH or TMAH wet or dry etching step on the first surface; patterning the third mask material layer on the first surface using a third lithography processing step and at least one wet or dry etching patterning step; applying a KOH or TMAH wet or dry etching step to the first surface of the SOI wafer remaining at the BOX layer; performing a second wet chemical etching of the first surface or the second surface using a KOH or TMAH etchant; performing a third wet chemical or dry etching of the second surface so that the etching is remaining at the BOX layer; removing the BOX layer; and removing the mask layers on the first and second surfaces.

[0021] In one aspect of the method for manufacturing an energy filter assembly, the method further includes applying a first protective layer to the 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.

[0022] The present invention 2 According to this aspect, there is provided a further method for manufacturing an energy filter assembly for an ion implantation system, the method including the steps of providing a substrate or base layer; depositing a first filter layer to provide an energy filter and a first filter frame layer to provide a first filter frame; patterning the first filter layer and the first filter frame layer using a suitable etching technique, such as masked etching or sequential etching, with a laser or ion beam etching device; sequentially depositing and patterning multiple first filter layers and first filter frame layers; removing, polishing, or etching the substrate or 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 resiliently coupling the first filter frame with the energy filter.

[0023] The present invention 3 According to an aspect of the present invention, there is provided a further method for manufacturing an energy filter assembly for an ion implantation system, the method including 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.

[0024] In one aspect of the method for manufacturing the energy filter assembly, at least the elastic element is a connecting element for elastically connecting the first filter frame to the energy filter.

[0025] In one aspect of the method for manufacturing an energy filter assembly, the energy filter has at least one filter element that absorbs beam energy of an ion beam.

[0026] In one aspect of the method of manufacturing the energy filter assembly, at least one resilient element is disposed on at least one filter element of the energy filter.

[0027] In one aspect of the method for manufacturing the energy filter assembly, the at least one resilient element is configured as a micro-spring element.

[0028] In one embodiment of the method for manufacturing the energy filter assembly, the thickness of the micro-spring elements is 6 μm, 16 μm, or 100 μm.

[0029] In one embodiment of the method for manufacturing the energy filter assembly, the width of the micro-spring elements is 50 μm or 100 μm, and the length is from 100 μm to several mm.

[0030] In one aspect of the method of manufacturing the energy filter assembly, at least one resilient element is integrally formed with at least one of the energy filter and the first filter frame.

[0031] In one aspect of the method of manufacturing the energy filter assembly, at least one of the filters is prismatic, pyramidal, or freeform in shape.

[0032] The present invention will now be described based on the drawings. It will be 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 will be understood that features of certain aspects or embodiments of the present invention can be combined with the drawings of different aspects of other embodiments of the present invention. The present invention will become more apparent when the following detailed description of several examples, which form part of this disclosure, is read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a diagram of the principle of an ion implantation device with an energy filter as known in the prior art; [Figure 2] 1 is a diagram of the structure of an ion implantation device with an energy filter. [Figure 3A] 1 is a top view of an energy filter assembly for an ion implantation system according to a first embodiment of the present invention, with at least one coupling element for resiliently coupling a first filter frame with an energy filter; FIG. [Figure 3B] 3B is a cross-sectional view of the energy filter assembly taken along section line AA' in FIG. 3A. [Figure 4A] FIG. 10 is a top view of an energy filter assembly for an ion implantation system according to a second embodiment of the present invention, with at least one coupling element resiliently coupling a first filter frame with a second filter frame housing the energy filter. [Figure 4B] 4B is a cross-sectional view of the energy filter assembly taken along section line AA' in FIG. 4A. [Figure 5A] FIG. 10 is a cross-sectional view of an energy filter assembly for an ion implantation system according to a third embodiment of the present invention, with at least one aperture element and a substrate, wherein the at least one aperture element is disposed between the energy filter and the substrate. [Figure 5B] FIG. 5B is a top view of the energy filter assembly of FIG. 5A with at least one detection element that scans the ion beam over at least one minimum scan area. [Figure 5C] 5B is a top view of the energy filter assembly of FIG. 5A with at least one detector element scanning the ion beam with a scan region extending beyond the at least one detector element. [Figure 6] FIG. 10 is a top view of an energy filter assembly for an ion implantation system according to another embodiment of the present invention, with preloaded coupling elements for maintaining a connection between a first filter frame and an energy filter under controlled tension. [Figure 7A] 3 is a flow diagram of a method for manufacturing an energy filter assembly for an ion implantation system in accordance with the present invention. [Figure 7B] 3 is a flow diagram of a method for manufacturing an energy filter assembly for an ion implantation system in accordance with the present invention. [Figure 7C] 3 is a flow diagram of a method for manufacturing an energy filter assembly for an ion implantation system in accordance with the present invention. [Figure 7D] 3 is a flow diagram of a method for manufacturing an energy filter assembly for an ion implantation system in accordance with the present invention. [Figure 7E]3 is a flow diagram of a method for manufacturing an energy filter assembly for an ion implantation system in accordance with the present invention. [Figure 8] 3 is a flow diagram of a method for filtering ion implants using an energy filter assembly for an ion implantation system in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0034] The present invention will now 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 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 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 the examples. The examples highlight different aspects of the present invention. It is not necessary to implement all of these combined aspects to practice the teachings of the present technology. Rather, a person skilled in the art will select and combine those aspects that seem useful and are required for the corresponding application and implementation.

[0035] FIG. 3A shows a top view of an energy filter assembly 1 for an ion implantation system according to a first embodiment of the present invention. FIG. 3B shows a cross-sectional view of the energy filter assembly 1 taken along section line A-A′ in FIG. 3A . As seen in FIGS. 3A and 3B , the energy filter assembly 1 includes an energy filter 25 having at least one filter element 25 a that at least partially absorbs the beam energy of the ion beam 10. The energy filter assembly 1 further includes a first filter frame 40 and at least one coupling element 50, which resiliently couples the first filter frame 40 to the energy filter 25. While the at least one filter element 25 a of the energy filter 25 is made from a membrane having a cross section with a triangular prism shape, this type of cross-sectional shape is not a limitation of the present invention, and other cross-sectional shapes can be used as needed and / or desired. For example, the at least one filter element 25 a of the energy filter 25 can be made from a membrane having a pyramidal or freeform shape.

[0036] The at least one filter element 25a can be made of silicon, silicon carbide, or carbon, although this type of material is not a limitation of the present invention and other materials can be used as needed and / or desired. As seen in FIG. 3A , at least one coupling element 50 is disposed on at least one filter element 25a of the energy filter 25. As seen in FIG. 3A , 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 energy filter 25. 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 energy filter 25. 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 may be coupled to the energy filter 25 and the first filter frame 40 by laser welding, bonding techniques, or at least one mechanical fastener, although this type of coupling is not a limitation of the present invention and other coupling techniques may be used as needed and / or desired. As can be seen in Figure 3B, the 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 irradiated via the ion beam source 5 (not shown).

[0037] In a first embodiment of the present invention, the energy filter assembly 1 includes five coupling elements 50, two of which are arranged on the longitudinal sides of each of the energy filters 25, and one of which is arranged on the width side of each of the energy filters 25. However, in the first embodiment of the present invention, two coupling elements 50 may be arranged on the width side of each of the energy filters 25, and one of the coupling elements 50 may be arranged on the longitudinal side of each of the energy filters 25. Furthermore, in the first embodiment of the present invention, the number of coupling elements 50 is not limited by the present invention. The energy filter assembly 1 may include six or more coupling elements 50, or four or fewer coupling elements 50. In a further embodiment of the present invention, the energy filter assembly 1 may include only one coupling element 50, and the coupling element 50 elastically couples the first filter frame 40 to the energy filter 25. In a further embodiment of the present invention, at least one coupling element 50 may be arranged on the top and / or bottom surface of the energy filter 25 to elastically couple the first filter frame 40 to the energy filter 25.

[0038] In 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 micro-spring element. The micro-spring element can have a thickness of 6 μm, 16 μm, or even several hundred μm. The micro-spring element 50 can have a width of 50 μm, 100 μm, and a length from 100 μm up to several mm. However, this type of coupling element 50 is not a limitation of the present invention, and other types of coupling elements can be used as needed and / or desired.

[0039] FIG. 4A shows a top view of an energy filter assembly 100 for an ion implantation system according to a second embodiment of the present invention. FIG. 4B shows a cross-sectional view of the energy filter assembly 100 taken along the line A-A′ in FIG. 4A . The energy filter assembly 100 for an ion implantation system according to the second embodiment of the present invention has the same configuration as the filter assembly 1 according to the first embodiment of the present invention. Therefore, elements having substantially the same functions as those in the first embodiment of the present invention are designated by the same reference numerals and will not be described and / or illustrated in detail 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 resiliently couples the first filter frame 40 to the second filter frame 30.

[0040] As seen in FIG. 4A , in a second embodiment of the present invention, at least one coupling element 50 is disposed on the second filter frame 30, which houses at least one filter element 25 a of the energy filter 25. Also 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 may be integrally formed with at least one portion of the second filter frame 30. The at least one coupling element 50 may also be integrally formed with at least one portion of the first filter frame 40. However, the at least one coupling element 50 may also be formed separately from at least one portion of the second filter frame 30. The at least one coupling element 50 may also be formed separately from at least one portion of the first filter frame 40. The at least one coupling element 50 may be coupled to the second filter frame 30 and the first filter frame 40 by laser welding, bonding, or at least one mechanical fastener; however, this type of coupling is not a limitation of the present invention, and other coupling techniques may be used as needed and / or desired. Furthermore, in the second embodiment of the present invention, the number of coupling elements 50 is not limited by the present invention. The energy filter assembly 100 may include six or more coupling elements 50, or four or fewer coupling elements 50. In a further embodiment of the present invention, the energy filter assembly 100 may include only one coupling element 50, which resiliently couples the first filter frame 40 to the second filter frame 30. In a further embodiment of the present invention, the at least one coupling element 50 may be disposed on the top and / or bottom of the second filter frame 30 to resiliently couple the first filter frame 40 to the energy filter 25 via the second filter frame 30.

[0041] As shown in FIG. 4B, in a second embodiment of the present invention, at least one filter element 25a is arranged in a plane X, Y perpendicular to the beam direction Z of the ion beam 10 irradiated via the ion beam source 5 (not shown). As shown in FIG. 4B, the energy filter assembly 100 includes an insulating silicon dioxide layer 22, e.g., having a thickness of 0.3 to 1.5 μm, sandwiched between the first filter frame 40 and bulk silicon 23 (approximately 400 μm thick). However, the present invention is not limited thereto; the insulating silicon dioxide layer 22 may be omitted, and other connecting layers may be used as needed and / or desired. As shown in FIG. 4B, the energy filter 25 includes at least one filter layer 32 with a layer thickness having a minimum membrane thickness. The energy filter 25 may be configured with only one filter layer 32 or with multiple filter layers 32. For example, the energy filter 25 may be made with five filter layers 32, with each of the five filter layers 32 having a layer thickness with a minimum membrane thickness. The quantity of filter layers 32 is not a limitation of the present invention. Furthermore, as seen in FIG. 4B , the first filter frame 40 has at least one first filter frame layer 43 with a layer thickness with a minimum thickness. The first filter frame 40 may be configured with only one first filter frame layer 43 or with multiple first filter frame layers 43. The quantity of first filter frame layers 43 is not a limitation of the present invention. Furthermore, as seen in FIG. 4B , the second filter frame 30 has at least one second filter frame layer 33 with a layer thickness with a minimum thickness. The second filter frame 30 may be configured with only one second filter frame layer 33 or with multiple second filter frame layers 33. The quantity of second filter frame layers 33 is not a limitation of the present invention.

[0042] FIG. 5A shows a cross-sectional view of an energy filter assembly 200 for an ion implantation system according to a third embodiment of the present invention. FIGs. 5B and 5C show top views of a further embodiment of the energy filter assembly 200 according to the third embodiment of the present invention. The energy filter assembly 200 for an ion implantation system according to the third embodiment of the present invention comprises the same components as the filter assembly 1 according to the first embodiment of the present invention and the same components as the filter assembly 100 according to the second embodiment of the present invention. Accordingly, elements having substantially the same functions as those in the first and second embodiments of the present invention are again numbered the same and will not be described and / or illustrated in detail herein for the sake of brevity.

[0043] 5A , in a third embodiment of the present invention, the energy filter assembly 200 further comprises at least one aperture element 60 arranged in a plane X, Y perpendicular to the beam direction Z of the ion beam 10 irradiated via the 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 arranged between the energy filter 25 and the substrate 70 such that the filtered ion beam 10 a is transmitted to the substrate 70 and the unfiltered ion beam 10 b is blocked by the at least one aperture element 60. As can be seen in FIG. 5A , the substrate 70 may be fixed with respect to the transmitted ion beam 10 a. However, the present invention is not limited thereto, and the substrate 70 may also be movable in at least one of a first direction 70 a and a second direction 70 b, both of which are perpendicular to the beam direction Z of the transmitted ion beam 10 a.

[0044] In a further embodiment 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 detector element 80, which scans the ion beam 10 over at least one minimum scanning area 80a, as best seen in Figures 5A and 5B. The at least one detector element 80 may be a Faraday cup, although the invention is not limited thereto.

[0045] In a further embodiment of the energy filter assembly 200 according to the third embodiment of the present invention, the at least one detector element 80 scans the ion beam 10 in a scanning region 80b, which extends beyond the at least one detector element 80, as best seen in Figure 5C.

[0046] FIG. 6 shows a top view of an energy filter assembly 300 for an ion implantation system according to a fourth embodiment of the present invention. The energy filter assembly 300 for an ion implantation system according to a third embodiment of the present invention includes the same components as the filter assembly 1 according to the first embodiment of the present invention, the same components as the filter assembly 100 according to the second embodiment of the present invention, and the same components as the filter assembly 100 according to the third embodiment of the present invention. Accordingly, elements having substantially the same functions as those in the first, second, and third embodiments of the present invention are designated by the same reference numerals and will not be described and / or illustrated in detail for the sake of brevity. At least one coupling element 50 resiliently couples 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 the at least one coupling element 50 may also resiliently couple the first filter frame 40 directly to the energy filter 25. In the energy filter assembly 300 of the fourth embodiment 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 controlled tension. The membrane of the energy filter 25 has a tendency to "expand," i.e., to form distortions. 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 maintains its "flat stress state" as much as possible regardless of orientation (vertical / upright or horizontal / lying) and external loads (thermal and mechanical influences). Therefore, the membrane of the energy filter 25 is tensioned 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 kept (substantially) smooth or flat by tensile stress, i.e., by controlled tension. The extension spring 50 is further configured so that the maximum withstandable 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 entire temperature range allowed during operation.

[0047] As 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 fit 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 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 seen in FIG. 6 , at least one coupling element 50 is provided to elastically couple 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. As such, the coupling element 50 creates a flexible mechanical connection between the second filter frame 30 and the first filter frame 40 that surround the energy filter 25. The curved contour 35 absorbs the force of the at least one coupling element 50, particularly when the coupling element 50 is configured as a tension spring 50. As such, the effects of thermomechanical stresses can be further reduced.

[0048] 6, holes can be provided in the first filter frame 40 and / or the second filter frame 30 using 3D laser ablation to attach tension springs 50. After installing the tension springs 50, the membrane of the energy filter 25 and the first filter frame 40 are decoupled from each other by a specific cut geometry (which takes into account all mechanical and thermodynamic effects). This cut can also be created using 3D laser ablation.

[0049] In a further aspect of the energy filter assembly 300 according to the fourth aspect of the present invention, the preloaded at least one coupling element 50 is configured such that the controlled tension on the energy filter 25 is less than the maximum allowable tension which includes a safe value within the overall temperature range allowed during operation.

[0050] In a further embodiment 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 tension spring element. However, the present invention is not so limited and other pre-loaded elements may be used as needed and / or desired.

[0051] 7A-7E show a flow diagram of a method for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system in accordance with the present invention.

[0052] According to a fifth aspect of the present invention, there is provided a method 400 for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system. The method 400 includes the steps of: providing 401 an energy filter 25 having at least one filter element 25 that at least partially absorbs beam energy of an ion beam 10; providing 402 a first filter frame 40; and coupling the first filter frame 40 to the energy filter 25 with at least one coupling element 50 for resiliently coupling the first filter frame 40 to the energy filter 25. The method 400 further includes the steps of: providing 403 a second filter frame 30 that houses the energy filter 25; and resiliently coupling 404 the at least one coupling element 50 between the first filter frame 40 and the second filter frame 30.

[0053] According to a sixth aspect of the present invention, a method 500 for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system is provided. The method 500 includes the steps of: providing a silicon-on-insulator (SOI) wafer as a substrate material having a first surface and a second surface, in which a thickness of a 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 in a step 502 for masking a wet chemical potassium hydroxide (KOH) etching or a 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 a first and a second lithography processing step and at least one wet or dry etching patterning step; cleaning the first surface and the second surface after patterning the mask material layer in a step 504; and performing a first wet chemical etching on the first surface or the second surface using a KOH or TMAH etching solution in a step 505. The method includes step 506 of removing the first mask material layer; step 506 of applying a third mask material layer to the first surface of the SOI wafer to mask a KOH or TMAH wet or dry etching step on the first surface; step 507 of patterning the third mask material layer on the first surface using a third lithography processing step and at least one wet or dry etching patterning step; step 508 of applying a KOH or TMAH wet or dry etching step to the first surface of the SOI wafer, stopping at the BOX layer; step 509 of performing a second wet chemical etching of the first or second surface using a KOH or TMAH etchant; step 510 of performing a third wet chemical or dry etching of the second surface, so that the etching stops at the BOX layer; step 511 of removing the BOX layer; and step 512 of removing the mask layers on the first and second surfaces.

[0054] In a further aspect of the method 500 for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system, the method 500 includes applying a first protective layer to the second surface to prevent etching 513. The method 500 may further include applying a second protective layer to the first surface or the second surface to prevent etching of the first surface 514.

[0055] According to a seventh aspect of the present invention, there is provided a method 600 for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system. The method comprises the steps of: providing 601 a volumetric material slab; and successively removing 602 material by a laser etching or mechanical erosion device, the successive removal 602 being in increments of tens of nanometers up to several micrometers per step, with several removal steps for a given structure, the successive removal 602 being performed according to a predetermined 3D layout of the energy filter 25, the first filter frame 40, and at least one coupling element 50 for elastically coupling the first filter frame 40 with the energy filter 25.

[0056] According to an eighth aspect of the present invention, a method 700 for manufacturing an energy filter assembly 1, 100, 200, 300 for an ion implantation system is provided. The method includes step 701 of providing a substrate or base layer; step 702 of depositing a first energy filter layer 32 to provide the energy filter 25 and a first filter frame layer 43 to provide the first filter frame 40; step 703 of patterning the first energy filter layer 32 and the first filter frame layer 43 using a suitable etching technique, such as masked etching or sequential etching, with a laser or ion beam etching device; step 704 of sequentially depositing and patterning multiple first energy filter layers 32 and first filter frame layers 43; step 705 of removing, polishing, or etching the substrate or base layer to a desired substrate layer thickness or base layer thickness; and step 706 of removing, polishing, or etching the first energy filter layer 32 and the first filter frame layer 43 to cut out at least one coupling element 50 for resiliently coupling the first filter frame 40 with the energy filter 25.

[0057] 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 the steps of: providing an energy filter 25 (step 801); providing a first filter frame 40 (step 802); creating at least one elastic element 50 between the energy filter 25 and the first filter frame 40 by laser ablation (step 803); and separating the energy filter 25 from the first filter frame 40 by material ablation (step 804).

[0058] 8 shows a flow chart of a method 900 for filtering ion implants 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 the steps of: providing an energy filter assembly 1, 100, 200, 300 comprising an energy filter 25 with at least one filter element 25a, in which a first filter frame 40 is resiliently coupled 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; providing an ion beam 10 extending across the energy filter 25 and the at least one coupling element 50; and disposing the at least one aperture element 60 relative to a direction of the ion beam 10 to stop unfiltered ions 10b of the ion beam 10 from impinging on the substrate 70. The method 900 may further include the ion beam 10 extending across the energy filter 25 and the at least one coupling element 50, and extending at least partially across the first filter frame 40. Specifically, when the method 900 includes the ion beam 10 extending across the energy filter 25 and the at least one coupling element 50, and extending at least partially across the first filter frame, the scan region extends beyond at least one detection element in the form of a Faraday cup.

[0059] 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 the tenth aspect of the present invention, the method 900 includes a step 904 of scanning the ion beam 10 over 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.

[0060] According to a further aspect of the present invention, there is provided an energy filter assembly for an ion implantation system, the energy filter assembly including an energy filter, a first filter frame, and at least one coupling element, the energy filter having at least one filter element configured to absorb beam energy of an ion beam, the at least one coupling element resiliently coupling the first filter frame to the energy filter.

[0061] In one aspect of the energy filter assembly, at least one coupling element is disposed on at least one filter element of the energy filter.

[0062] In a further 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 resiliently couples the first filter frame with the second filter frame.

[0063] In one embodiment of the energy filter assembly, 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 even several hundred μm. The micro-spring element may also have a width of 50 μm, 100 μm, and a length from 100 μm up to several mm.

[0064] In one aspect of the energy filter assembly, the at least one coupling element is integrally formed with at least one of the energy filter and the first filter frame.

[0065] In one aspect of the energy filter assembly, the at least one coupling element is integrally formed with at least one of the first filter frame and the second filter frame.

[0066] In a further embodiment of the energy filter assembly, the at least one coupling element is coupled to the energy filter, the first filter frame, and the second filter frame by laser welding, a bonding technique, or at least one mechanical fastener.

[0067] In one embodiment of the energy filter assembly, at least one filter element is prism-shaped, pyramidal-shaped, or freeform-shaped.

[0068] In a further aspect of the energy filter assembly, the at least one filter element is disposed in a plane that is perpendicular to the beam direction of the ion beam.

[0069] In a further aspect of the energy filter assembly, the energy filter assembly further comprises at least one aperture element and a substrate, the at least one aperture element being disposed in a plane perpendicular to the beam direction of the ion beam, the at least one aperture element being further disposed between the energy filter and the substrate such that the filtered ion beam is transmitted to the substrate only through the filter.

[0070] In a further aspect of the energy filter assembly, the substrate is fixed relative 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.

[0071] In another aspect of the energy filter assembly, the energy filter assembly further comprises at least one detector element that scans the ion beam over at least one minimum scan area. The at least one detector element scans the ion beam over the scan area, the scan area extending beyond the at least one detector element. The detector element may be a Faraday cup.

[0072] In a further embodiment of the energy filter assembly, at least one filter element is made from silicon, silicon carbide, or carbon.

[0073] In a further aspect of the energy filter assembly, at least one coupling element is preloaded to maintain a connection between the first filter frame and the energy filter under controlled tension. The at least one coupling element is preloaded to maintain a connection between the first filter frame and the energy filter under controlled tension, particularly in the event of thermal expansion of the filter during ion bombardment. The preloaded at least one coupling element is configured such that the controlled tension on the energy filter is less than a maximum withstandable tension that includes a safety value within the entire temperature range allowed during operation. The at least one coupling element may be provided as a micro-tension spring element.

[0074] According to a further aspect of the invention, the second filter frame has a curved outer shape and the first filter frame has an inner contour that matches the curved outer shape, and a gap is provided between the outer shape of the second filter frame and the inner contour of the first filter frame.

[0075] According to a further aspect of the present invention, there is provided a method for manufacturing an energy filter assembly for an ion implantation system, the method including the steps of providing an energy filter having at least one filter element that at least partially absorbs beam energy of an ion beam, providing a first filter frame, and coupling the first filter frame to the energy filter with at least one coupling element for resiliently coupling the first filter frame to the energy filter.

[0076] In one aspect of the method for manufacturing the energy filter assembly, the method further includes providing a second filter frame that houses the energy filter, and resiliently coupling at least one coupling element between the first filter frame and the second filter frame.

[0077] According to a further aspect of the present invention, there is provided a method for filtering ion implantation, the method including the steps of: providing an energy filter assembly including an energy filter having at least one filter element, wherein a first filter frame is resiliently coupled to the energy filter by at least one coupling element, and at least one aperture element is positioned between the energy filter and a substrate; providing an ion beam extending across the energy filter and the at least one coupling element; and positioning the at least one aperture element relative to a direction of the ion beam to stop unfiltered ions of the ion beam from impinging on the substrate.

[0078] In one aspect of the method for filtering ion implantation, the method further includes scanning the ion beam over the energy filter, the at least one coupling element, and the first filter frame such that the at least one detection element is illuminated.

[0079] According to a further aspect of the present invention, there is provided a further method for manufacturing an energy filter assembly for an ion implantation system, comprising the steps of providing a volumetric material slab and successively removing material by a laser etching or mechanical erosion device, the removal being in increments of tens of nanometers up to several micrometers per step, involving several removal steps for a given structure, the successive removal being performed according to a predetermined 3D layout of the energy filter, a first filter frame, and at least one coupling element for elastically coupling the first filter frame with the energy filter.

[0080] From the foregoing description of the invention, those skilled in the art will perceive improvements, changes, and modifications in the present invention. Such improvements, changes, and modifications within the skill in the art are intended to be covered by the appended claims. [Explanation of symbols]

[0081] 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 Outline 40 First Filter Frame 41 Inner Contour 43 First filter layer 50 Bonding Elements 60 Aperture Elements 70 boards 70a First Direction 70b Second Direction 80 detection elements 80a Minimum scanning area 80b Scanning area 90 Gap 100 Energy filter assembly 200 Energy filter assembly 300 Energy filter assembly

Claims

1. 1. A method for manufacturing an energy filter assembly for an ion implantation system, the energy filter assembly including 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 a buried oxide (BOX) thickness 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 a wet chemical potassium hydroxide (KOH) etch or a tetramethylammonium hydroxide (TMAH) etch; patterning the first and second mask material layers on the first and second surfaces using first and second lithographic processing steps and at least one wet or dry etching patterning step; cleaning the first surface and the second surface after patterning the mask material layer; a first wet chemical etching of the first surface or the second surface using a KOH or TMAH etchant; removing the first layer of mask material; applying a third mask material layer to the first surface of the SOI wafer to mask a KOH or TMAH wet or dry etching step on the first surface; patterning the third mask material layer on the first surface using a third lithography processing step and at least one wet or dry etching patterning step; applying a KOH or TMAH wet or dry etching step to the first surface of the SOI wafer remaining at the BOX layer; a second wet chemical etching of the first surface or the second surface using a KOH or TMAH etchant; a third wet chemical or dry etch of the second surface such that the etch is stopped at the BOX layer; removing the BOX layer; removing the mask layer at the first surface and the second surface; A method comprising:

2. The method of claim 1 , including applying a first protective layer to the second surface to prevent etching.

3. The method of claim 1 , further comprising applying a second protective layer to the first surface or the second surface to prevent etching of the first surface.

4. 1. A method for manufacturing an energy filter assembly for an ion implantation system, comprising: providing a substrate or base layer; depositing a first filter layer to provide an energy filter and a first filter frame layer to provide a first filter frame; patterning the first filter layer and the first filter frame layer using a suitable etching technique, such as masked etching or sequential etching with a laser or ion beam etching device; sequentially depositing and patterning multiple first filter layers and first filter frame layers; removing, polishing, or etching the substrate or base layer to a desired substrate or base layer thickness; removing, grinding, or etching the first filter layer and the first filter frame layer to remove at least one coupling element for resiliently coupling the first filter frame with the energy filter; A method comprising:

5. 1. 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; A method comprising:

6. The method described in claim 5, wherein the at least one elastic element is a connecting element for elastically connecting the first filter frame to the energy filter.

7. A method as described in claim 5 or 6, wherein the energy filter has at least one filter element that absorbs the beam energy of the ion beam.

8. The method described in claim 7, wherein the at least one elastic element is arranged on the at least one filter element of the energy filter.

9. The method described in claim 5, wherein the at least one elastic element is configured as a micro-spring element.

10. The method described in claim 9, wherein the thickness of the micro-spring element is 6 μm, 16 μm, or 100 μm.

11. A method as described in claim 9 or 10, wherein the width of the micro-spring element is 50 μm or 100 μm and the length is 100 μm to several mm.

12. A method described in any one of claims 5 to 9, wherein the at least one elastic element is integrally formed with at least one of the energy filter and the first filter frame.

13. The method of claim 7, wherein the at least one filter element is in the shape of a triangular prism, a pyramid, or a freeform shape.

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