System and process for thinning gallium ion processing damaged layer of diamond layer by layer by using helium ion beam
By using a helium ion beam layer-by-layer thinning system and process, and by controlling the beam current and dosage, the problems of damage layer thickness and new defects introduced by the helium ion beam during the processing of diamond with focused gallium ion beams have been solved, resulting in a diamond structure with low defects and high flatness, which is suitable for the fabrication of electronic devices.
Patent Information
- Application Number
- CN202511472074.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-15
- Publication Date
- 2025-11-28
AI Technical Summary
Existing focused gallium ion beam processing of diamond results in thick and inaccurate damage layers, while focused helium ion beam processing is prone to new defects such as helium bubbles and surface bulges.
A helium ion beam layer-by-layer thinning system and process were adopted. By adjusting the beam current and dose to decrease layer by layer with each processing step, the gradient distribution of the diamond damage layer was matched. Layer-by-layer thinning was performed using a Tescan LYRA 3 XMU FIB-SEM and a Zeiss Orion NanoFab HIM system, and the layers were characterized using a Horiba LabRAM HR Evolution and a ThermoFisher Talos F200X G2 TEM.
This method achieves precise thinning of the damaged layer, avoids the introduction of new damage, and obtains a diamond structure with low defects and high flatness, laying the foundation for subsequent electronic device fabrication.
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Figure CN121017757A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of micro-nano processing, and in particular to a system and process for layer-by-layer thinning of a gallium ion processing damage layer of diamond by a helium ion beam. BACKGROUND
[0002] In the prior art, focused gallium ion beam (FIB) technology is currently the mainstream means for diamond processing, but using a focused gallium ion beam for processing introduces a damage layer of about 200 nm on the surface of the diamond. In order to remove the damage layer, traditional methods mostly use means such as heat treatment or chemical etching, but these methods generally have the shortcomings of insufficient precision or easy introduction of new defects. Focused helium ion beam (HIM) technology theoretically has the potential to finely thin the damage layer, but if fixed parameters are directly used for processing, new defects such as helium bubble formation and surface bulging often occur due to excessive ion implantation.
[0003] In summary, the existing focused gallium ion beam rough processing of diamond has the problems of thick damage layer and the traditional processing of focused helium ion beam is prone to cause bulging or incomplete thinning. SUMMARY
[0004] The purpose of the present application is to provide a system and process for layer-by-layer thinning of a gallium ion processing damage layer of diamond by a helium ion beam, which gradually reduces the beam current and dose of the focused helium ion beam along the number of processing times, accurately matches the gradient distribution of the damage layer of the diamond, realizes the effect of thinning only the damage layer without introducing new damage, and ultimately obtains a diamond structure with low defects and high flatness, laying a foundation for subsequent electronic device manufacturing.
[0005] To achieve the above purpose, the present application provides a system for layer-by-layer thinning of a gallium ion processing damage layer of diamond by a helium ion beam, comprising a sample pretreatment module for processing a single crystal diamond substrate; a focused gallium ion beam rough processing module for forming a target structure on the diamond substrate, while forming a damage layer containing amorphous carbon, graphite phase and lattice distortion on the surface of the structure; a focused helium ion beam layer-by-layer decreasing processing module for thinning the damage layer processed by the focused gallium ion beam rough processing module, matching the gradient distribution of the damage layer surface amorphous layer, middle layer lattice damage and deep layer complete crystal of the focused gallium ion beam rough processing module; a damage layer characterization module for analyzing the structural properties of the damage layer of the diamond and observing the microstructure and damage layer thickness of the diamond.
[0006] The application also provides a process for layer-by-layer thinning of a gallium ion processing damage layer of a diamond by a helium ion beam, which adopts the system for layer-by-layer thinning of a gallium ion processing damage layer of a diamond by a helium ion beam and comprises the following steps: S1. Cleaning and positioning of the diamond substrate by a sample pretreatment module; S2. Forming an amorphous damage layer on the surface of the diamond by processing the required structure by a gallium ion beam through a focused gallium ion beam rough processing module; S3. Thinning the amorphous damage layer by a focused helium ion beam layer-by-layer thinning processing module through a layer-by-layer thinning processing method; S4. Characterizing the diamond damage layer by using a damage layer characterization module to confirm that the damage layer is thinned and the surface is free of new damage.
[0007] Preferably, in S1, the cleaning operation is: sequentially performing ultrasonic cleaning with acetone, anhydrous ethanol and deionized water and then blowing dry with nitrogen; The positioning operation is: plating a thin gold layer by an automatic gold plating and carbon plating combined instrument, marking the region to be processed with a marker pen and processing a cross positioning mark beside the marked region by a focused ion beam to remove surface impurities and ensure the processing positioning accuracy.
[0008] Preferably, the specific operation of S2 is: performing rough processing by selecting a Tescan LYRA 3 XMU FIB-SEM system, setting the processing parameters: liquid metal gallium ion source, acceleration voltage 25-40 kV, beam current 1-1.5 nA, S-shaped scanning path, scanning times 1000-1500 times, incident angle 0°, X and Y direction pixel overlap rate both 50%, residence time 1-1.5 μs; selecting a rectangular scanning mode, setting the processing region, processing the required diamond structure and simultaneously forming a damage layer with a thickness of 100-300 nm on the surface of the diamond.
[0009] Further, the focused gallium ion beam rough processing system adopts a Tescan LYRA 3 XMU FIB-SEM device, sets the parameters of acceleration voltage, beam current, scanning path, scanning times, X / Y direction pixel overlap rate and residence time, selects a rectangular scanning mode, forms the target structure on the diamond substrate and simultaneously forms a damage layer containing amorphous carbon, graphite phase and lattice distortion on the surface of the structure.
[0010] Preferably, the specific operation of S3 is: performing thinning processing by selecting a Zeiss Orion NanoFab HIM system, fixing the processing parameters: acceleration voltage 25-40 kV, incident angle 0°, X and Y direction pixel overlap rate both 50%, residence time 1-1.5 μs.
[0011] Preferably, in S3, the layer-by-layer thinning method comprises beam current thinning processing and dose thinning processing.
[0012] Further, the focused helium ion beam layer-by-layer thinning processing system adopts Zeiss Orion NanoFab HIM system, sets parameters such as acceleration voltage, incident angle, X / Y direction pixel overlap rate, residence time, etc., studies the influence of dose on processing by adjusting the dose, studies the influence of beam current on processing by adjusting the beam current, and thins the damage layer after FIB processing in a layer-by-layer decreasing manner, that is, the beam current is gradually reduced along the processing times, the dose is gradually reduced along the processing times, or the beam current and the dose are synchronously gradually reduced along the processing times, to match the gradient distribution of the amorphous surface layer-crystal lattice damage middle layer-intact crystal deep layer of the FIB damage layer.
[0013] Preferably, the specific operation of S4 is that Horiba LabRAM HR Evolution RAMAN is used to analyze the structural characteristics of the diamond, and ThermoFisher Talos F200X G2 TEM system is used to analyze the damage layer thickness, and the diamond cross-section structure is observed by HRTEM.
[0014] Therefore, the system and process for layer-by-layer thinning of a diamond gallium ion processing damage layer by a helium ion beam have the following beneficial effects: (1) By adjusting and controlling the beam current and dose of the focused helium ion beam to gradually decrease along the processing times, the gradient distribution of the diamond damage layer is accurately matched, the effect of only thinning the damage layer without introducing new damage is achieved, and finally a low-defect, high-flatness diamond structure is obtained, laying a foundation for subsequent electronic device manufacturing; (2) The process effectively avoids the formation of helium bubbles and bulges, accurately thins the damage layer, and avoids the introduction of new damage, which is unique in accurately matching the gradient of the damage layer and avoiding new damage.
[0015] The technical solutions of the present application will be further described in detail below with the help of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 is a process flowchart of the present application; Figure 2 is a Raman spectrum diagram of the structural characteristics of the diamond by Horiba LabRAM HR Evolution RAMAN of the present application; Figure 3 is an EDS area scanning picture of the influence of the dose of the focused helium ion beam on the processing area; Figure 4 is an EDS area scanning picture of the influence of the beam current of the focused helium ion beam on the processing area; Figure 5 is an HRTEM image of the damage layer of the diamond before layer-by-layer thinning of the present application; Figure 6 is an HRTEM image of the loss layer of the diamond after layer-by-layer thinning according to the application. DETAILED DESCRIPTION
[0017] The technical solutions of the application are further described below with reference to the drawings and examples.
[0018] Unless otherwise defined, the technical terms or scientific terms used in the application shall have the usual meanings understood by those skilled in the art to which the application belongs.
[0019] Example 1 The application provides a system for layer-by-layer thinning of a gallium ion processing damage layer of a diamond by a helium ion beam, comprising a sample pretreatment module for processing a single crystal diamond substrate; A focused gallium ion beam rough machining module is used to form a target structure on the diamond substrate, and a damage layer containing amorphous carbon, graphite phase and lattice distortion is formed on the surface of the structure; A focused helium ion beam layer-by-layer thinning module is used to thin the damage layer processed by the focused gallium ion beam rough machining module, and match the gradient distribution of the amorphous surface layer-crystal lattice damage middle layer-intact crystal deep layer of the damage layer of the focused gallium ion beam rough machining module; A damage layer characterization module is used to analyze the structural properties of the diamond damage layer and observe the microstructure of the diamond and the thickness of the damage layer.
[0020] As shown in Figure 1 The application also provides a process for layer-by-layer thinning of a gallium ion processing damage layer of a diamond by a helium ion beam, which adopts the above-mentioned system for layer-by-layer thinning of a gallium ion processing damage layer of a diamond by a helium ion beam, and comprises the following steps: S1. Clean and position the diamond substrate by the sample pretreatment module: first, sequentially ultrasonic clean with acetone, anhydrous ethanol and deionized water, and then dry with nitrogen; after cleaning the single crystal diamond, use a Cressington 108auto automatic gold plating and carbon plating instrument to coat a thin gold layer on the surface of the diamond, mark the area to be processed with a marker, and finally use FIB to process a cross-shaped positioning mark beside the marked area.
[0021] S2, the focused gallium ion beam rough machining module processes the required structure by a gallium ion beam to form an amorphous damage layer on the diamond surface: a Tescan LYRA 3 XMU FIB-SEM system is selected to perform rough machining, and the machining parameters are set as follows: liquid metal gallium ion source, acceleration voltage 30 kV, beam current 1 nA, S-shaped scanning path, scanning times 1000 times, incident angle 0°, X and Y direction pixel overlap rate 50%, and residence time 1 μs; a rectangular scanning mode is selected, the machining area is set, and the required diamond structure is machined, and at the same time, a damage layer is formed on the diamond surface, as shown in Figure 5 Fig. 2, the cross-sectional structure of the diamond after layer-by-layer thinning is observed by HRTEM, and a damage layer with a thickness of about 200 nm is formed on the surface of the diamond.
[0022] S3, the focused helium ion beam layer-by-layer decreasing machining module thins the amorphous damage layer by a helium ion beam layer-by-layer decreasing machining method: a Zeiss Orion NanoFab HIM system is used to perform thinning machining, and the machining parameters are fixed as follows: acceleration voltage 30 kV, incident angle 0°, X and Y direction pixel overlap rate 50%, and residence time 1 μs.
[0023] The effect of the helium ion beam dose on the diamond damage layer is studied, and the specific machining parameters are shown in Table 1.
[0024] Table 1: Machining parameter table of focused helium ion beam dose effect
[0025] The effect of the helium ion beam current on the diamond damage layer is studied, and the specific machining parameters are shown in Table 2.
[0026] Table 2: Machining parameter table of focused helium ion beam current effect
[0027] Two layer-by-layer decreasing methods, beam current decreasing machining and dose decreasing machining, are used, and the specific machining parameters are shown in Table 3. The EDS surface scanning picture of the machining area affected by the focused helium ion beam dose is shown in Figure 3 , and the EDS surface scanning picture of the machining area affected by the focused helium ion beam current is shown in Figure 4 . It can be seen from Figure 3 that the thickness of the damage layer in area A is 192.97±1.06 nm, the thickness of the damage layer in area B is 205.62±0.97 nm, the thickness of the damage layer in area C is 215.54±0.36 nm, and the thickness of the damage layer in area D is 200.39±1.46 nm, which indicates that appropriate helium ion beam dose can effectively thin the surface damage layer of the diamond nanowire, and too high or too low dose cannot achieve this effect. It can be seen from Figure 4It can be seen that the thickness of the damage layer in region A is 173.41±0.34nm, the thickness of the damage layer in region B is 183.70±0.95nm, the thickness of the damage layer in region C is 164.50±0.07nm, and the thickness of the damage layer in region D is 144.79±1.74nm. This indicates that high beam current cannot thin the damage layer, and high energy density can easily penetrate deeper regions, which in turn thickens the damage layer.
[0028] Both layer-by-layer decreasing processing methods match the gradient distribution of the FIB damaged layer: surface amorphous layer - middle layer lattice damage layer - deep intact crystal layer, avoiding helium bubble formation or surface bulging.
[0029] Table 3. Parameters for Layer-by-Layer Decreasing Focused Helium Ion Beam Processing
[0030] S4. Characterize the diamond damage layer using the damage layer characterization module to confirm that the damage layer is thinned and there is no new damage on the surface: Damage layer characterization: The structural properties of diamond were analyzed using Horiba LabRAM HR Evolution RAMAN, and the analysis results are as follows. Figure 2 As shown, by Figure 2 It can be seen that the Horiba LabRAM HR Evolution RAMAN was used to examine the diamond after FIB processing, indicating that the diamond was damaged in the FIB. The thickness of the damaged layer was analyzed using a ThermoFisher Talos F200X G2 TEM system, and the cross-sectional structure of the diamond after layer-by-layer thinning was observed using HRTEM. The results are as follows. Figure 6 As shown, by Figure 6 It can be seen that the thickness of the damaged layer after thinning is 20nm, confirming that no new damage is introduced; at the same time, the integrity of the crystal is verified by the SAED function of TEM, and the EDS function eliminates residual contamination of elements such as gallium and tungsten.
[0031] Therefore, the present invention employs the above-mentioned system and process for thinning the damaged layer of diamond gallium ion processing layer by layer using a helium ion beam. By adjusting the beam current and dose of the focused helium ion beam to decrease layer by layer along the processing number, the gradient distribution of the diamond damaged layer is precisely matched, achieving the effect of thinning the damaged layer without introducing new damage. Finally, a diamond structure with low defects and high flatness is obtained, laying the foundation for subsequent electronic device fabrication.
[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A system for layer-by-layer thinning of a damaged layer in diamond gallium ion processing using a helium ion beam, characterized in that: Includes a sample pretreatment module for processing single-crystal diamond substrates; A focused gallium ion beam roughing module is used to form target structures on diamond substrates, while simultaneously forming a damage layer containing amorphous carbon, graphite phases, and lattice distortions on the surface of the structure. The focused helium ion beam layer-by-layer thinning processing module is used to thin the damaged layer processed by the focused gallium ion beam rough processing module, matching the gradient distribution of the damaged layer from the surface amorphous layer to the middle lattice damage layer to the deep intact crystal layer in the focused gallium ion beam rough processing module. The damage layer characterization module is used to analyze the structural characteristics of the diamond damage layer and observe the microstructure and damage layer thickness of the diamond.
2. A process for thinning a damaged layer in diamond gallium ion processing using a helium ion beam layer-by-layer, characterized in that: The system for thinning a damaged layer in diamond gallium ion processing using a helium ion beam as described in claim 1 includes the following steps: S1. The diamond substrate is cleaned and positioned using the sample pretreatment module. S2, the focused gallium ion beam roughing module processes the required structure using gallium ion beams to form an amorphous damage layer on the diamond surface; S3, the focused helium ion beam layer-by-layer thinning module uses the helium ion beam layer-by-layer thinning method to reduce the amorphous damaged layer. S4. Use the damage layer characterization module to characterize the diamond damage layer and confirm that the damage layer is thinned and there is no new damage on the surface.
3. The process for thinning a damaged layer in diamond gallium ion processing using a helium ion beam layer-by-layer method according to claim 2, characterized in that: In S1, the cleaning procedure is as follows: ultrasonic cleaning is performed sequentially with acetone, anhydrous ethanol, and deionized water, followed by drying with nitrogen gas. The positioning operation is as follows: a thin gold layer is deposited using an automatic gold plating and carbon plating combined instrument, the area to be processed is marked with a marker pen, and a cross positioning mark is processed next to the marked area by a focused ion beam to remove surface impurities and ensure processing positioning accuracy.
4. The process for thinning a damaged layer in diamond gallium ion processing using a helium ion beam layer-by-layer method according to claim 2, characterized in that: The specific operation of S2 is as follows: The Tescan LYRA 3 XMU FIB-SEM system is used to perform roughing. The processing parameters are set as follows: liquid metal gallium ion source, accelerating voltage 25-40kV, beam current 1-1.5nA, S-shaped scanning path, 1000-1500 scans, incident angle 0°, pixel overlap rate in both X and Y directions is 50%, and dwell time is 1-1.5μs. The rectangular scanning mode is selected, the processing area is set, the required diamond structure is processed, and a damage layer with a thickness of 100-300nm is formed on the diamond surface.
5. The process for thinning a damaged layer in diamond gallium ion processing using a helium ion beam layer-by-layer method according to claim 2, characterized in that: The specific operation of S3 is as follows: the thinning process is performed using the Zeiss Orion NanoFab HIM system with fixed processing parameters: acceleration voltage 25-40kV, incident angle 0°, pixel overlap rate in both X and Y directions is 50%, and dwell time is 1-1.5μs.
6. The process for thinning a damaged layer in diamond gallium ion processing using a helium ion beam layer-by-layer method according to claim 2, characterized in that: In S3, the layer-by-layer reduction methods include beam reduction processing and dose reduction processing.
7. The process for thinning a damaged layer in diamond gallium ion processing using a helium ion beam layer-by-layer method according to claim 2, characterized in that: The specific operation of S4 is as follows: the structural characteristics of diamond are analyzed using the Horiba LabRAM HR Evolution RAMAN; the thickness of the damaged layer is analyzed using the ThermoFisher Talos F200X G2 TEM system; and the cross-sectional structure of diamond is observed using HRTEM.