A double mask structure for thin film electrodes

Abstract

The utility model provides a kind of double mask plate structure for thin film electrode, four sample patterns are integrated in double mask plate, realize single-time synchronous production four samples, save preparation cost, simplify process flow simultaneously, improve thin film electrode preparation efficiency;In 400 DEG C environment, stainless steel mask plate deformation amount is ≤1 μm for 3 hours, can be repeatedly and stably used, further reduce cost, especially applicable to high-precision thin film electrode preparation.

Description

Technical Field

[0001] This invention belongs to the field of micro-nano fabrication and vacuum coating technology, and particularly relates to a dual-mask structure for thin film electrodes. Background Technology

[0002] Topological materials possess unique topologically protected dissipative transport properties on their surface states, showing great promise in low-power electronic devices and quantum bits. Fabricating high-precision electrodes on thin films of topological materials allows for the measurement of their electrical, magnetic, and optical properties, which is crucial for obtaining accurate material properties.

[0003] In current thin-film electrode fabrication technologies, photomask technology is widely used. Its principle involves tightly bonding a photomask to the substrate during deposition or etching processes. The photomask blocks certain areas, allowing material to be deposited or etched only in specific regions, thus forming the desired electrode pattern. However, existing technologies have several drawbacks. For example, a single photomask suffers from poor adhesion to the substrate and low positioning accuracy. Flexible photomasks, such as those made of polyimide, are prone to decomposition at high temperatures exceeding 200°C, releasing impurities that severely contaminate the film. Furthermore, while dual-photomask designs have been attempted, they have not yet effectively solved a series of challenges, including interlayer alignment stability, multi-sample preparation, and material compatibility.

[0004] In sample transfer, conventional operations require 30-45 minutes to break the vacuum and open the vacuum chamber. This process not only disrupts the vacuum environment, allowing a large amount of external impurities to enter the chamber, but also takes a long time to rebuild the vacuum environment, greatly reducing experimental efficiency. Frequent such operations can damage critical equipment such as the deposition system, significantly increasing equipment maintenance costs and failure rates. Utility Model Content

[0005] To address the problems of large electrode pattern deviation, low fabrication efficiency, and high vacuum transfer costs, this invention provides a dual-mask structure for thin-film electrodes, which simplifies the process and improves the fabrication efficiency of thin-film electrodes.

[0006] A dual-mask structure for thin-film electrodes includes a first mask and a second mask;

[0007] The surface of the first mask is provided with a rectangular cutout area that matches the outline of the electrode to be prepared. Four right-angled cutout marks for positioning are symmetrically distributed at the four corners, and a blank surrounding area for accommodating high-temperature resistant tape is reserved outside each right-angled cutout mark.

[0008] The second photomask has a six-electrode pattern cutout area at the center of its surface, and alignment frames matching the right-angle cutout marks of the first photomask are provided at its four corner edges.

[0009] Furthermore, the first mask is planar in shape, with a flatness of ≤2μm and a surface roughness Ra≤0.1μm.

[0010] Furthermore, the first photomask is made of 304 stainless steel.

[0011] Furthermore, by attaching high-temperature resistant tape to the blank surrounding area of ​​the first mask, interlayer bonding is achieved between the first mask and the second mask.

[0012] Furthermore, the second photomask is made of 304 stainless steel.

[0013] Furthermore, the masks on both the first and second mask plates are prepared using a vacuum sample transfer device;

[0014] The vacuum sample transfer device includes a sample transfer rod 51, an operating handle 52, a flange 53, a pre-evacuation chamber 54, a reaction chamber 55, a partition 56, a sample stage 57, a sample holder 58, and a spring 59; wherein the pre-evacuation chamber 54 and the reaction chamber 55 are isolated by the partition 56; the sample stage 57 is located in the reaction chamber 55;

[0015] One end of the sample transfer rod 51 is connected to the operating handle 52, and the other end extends into the flange 53, the pre-extraction chamber 54, and the reaction chamber 55 in sequence. The operating handle 52 is used to control the movement of the sample transfer rod 51. The moving distance of the sample transfer rod 51 can be from the pre-extraction chamber 54 to the sample stage 57 in the reaction chamber 55.

[0016] The first or second mask is fixed to the sample holder 58 by the spring clip 59; the end of the sample transfer rod 51 that extends into the reaction chamber 55 has a V-shaped groove structure, so the sample holder 58 is placed in the V-shaped groove structure, thereby realizing the sample holder 58 holding the first or second mask back and forth between the pre-extraction chamber 54 and the reaction chamber 55.

[0017] Furthermore, the round-trip process of the sample holder 58 holding the first or second mask in the pre-extraction chamber 54 and the reaction chamber 55 is as follows:

[0018] The pre-extraction chamber 54 and the reaction chamber 55 are isolated by the partition 56. When the pre-extraction chamber 54 is opened, the sample holder 58 is placed from the pre-extraction chamber 54 into the V-groove structure of the sample transfer rod 51.

[0019] Close the pre-evacuation chamber 54 and evacuate the pre-evacuation chamber 54 until the difference between the vacuum degree of the pre-evacuation chamber 54 and the vacuum degree of the reaction chamber 55 is less than the set threshold. Then open the partition between the pre-evacuation chamber 54 and the reaction chamber 55 and transfer the sample holder 58 to the sample stage 57 of the reaction chamber 55 using the sample transfer rod 51.

[0020] Once the masking on the first or second mask is completed, the sample transfer rod 51 retracts the sample holder 58 to the pre-extraction chamber 54, then closes the partition 56, re-isolating the pre-extraction chamber 54 and the reaction chamber 55.

[0021] Reopen the pre-evacuation chamber 54, remove the current first or second mask, replace it with the next mask, and repeat the process of closing the pre-evacuation chamber 54, evacuating the vacuum, and opening and closing the partition 56 until the first and second masks are prepared.

[0022] Furthermore, the sample transfer rod 51 is machined from stainless steel 310 bar stock.

[0023] Beneficial effects:

[0024] 1. This utility model provides a dual-mask structure for thin film electrodes. The dual-mask integrates four sample patterns, enabling the simultaneous production of four samples in a single operation, saving preparation costs, simplifying the process, and improving the efficiency of thin film electrode preparation. The stainless steel mask can be deformed by ≤1μm after 3 hours at 400℃, and can be reused stably, further reducing costs. It is especially suitable for the preparation of high-precision thin film electrodes.

[0025] 2. This utility model provides a double mask structure for thin film electrodes. The sample transfer rod clamping end has a V-groove structure. This structural design can ensure that the sample holder is clamped firmly and reliably. The end is provided with a threaded interface to connect the operating handle, which facilitates the operator to accurately control the sample transfer rod. The sample holder is connected to the sample transfer rod through the clamping end to ensure the stability of the sample transfer process.

[0026] 3. This utility model provides a dual mask structure for thin film electrodes. The sample holder surface has screw holes and spring clips for fixing the sample and preventing sample displacement during sample transfer.

[0027] 4. This utility model provides a double mask structure for thin film electrodes. The sample transfer rod has high mechanical strength and can maintain a stable shape in a vacuum environment. The rotating partition set between the pre-evacuation chamber and the reaction chamber can achieve precise control of the chamber connection state during vacuum sample transfer.

[0028] 5. This invention provides a dual-mask structure for thin-film electrodes, which only requires evacuation of the smaller pre-evacuation chamber, while the vacuum level of the larger reaction chamber remains basically unchanged. This allows the present invention to complete vacuum sample transfer in about 10 minutes, compared to the traditional sample transfer which takes 45 minutes (including 30 minutes of evacuation), thus improving vacuum transfer efficiency and providing an efficient solution for the vacuum environment in the thin-film electrode preparation process. Attached Figure Description

[0029] Figure 1A schematic diagram of the first photomask provided by this utility model;

[0030] Figure 2 A schematic diagram of the second mask provided by this utility model;

[0031] Figure 3 A schematic diagram showing the alignment relationship between the first and second photomasks provided for this utility model;

[0032] Figure 4 A schematic diagram showing four sample patterns integrated on a mask provided by this utility model;

[0033] Figure 5 A schematic diagram of the vacuum sample transfer device provided by this utility model;

[0034] Among them, 11-sample hollow area, 12-right angle positioning mark, 21-six electrode hollow area, 22-edge positioning mark, 51-sample transfer rod, 52-operating handle, 53-flange, 54-pre-extraction chamber, 55-reaction chamber, 56-rotating partition, 57-sample stage, 58-sample rack, 59-spring sheet. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0036] A dual-mask structure for thin-film electrodes includes a first mask and a second mask;

[0037] like Figure 1 As shown, the surface of the first mask is provided with a rectangular cutout area that matches the outline of the electrode to be prepared. Four right-angled cutout marks for positioning are symmetrically distributed at the four corners, and a blank surrounding area for accommodating high-temperature resistant tape is reserved outside each right-angled cutout mark.

[0038] like Figure 2 As shown, the second mask has a six-electrode pattern cutout area at the center of its surface, and alignment frames matching the right-angle cutout marks of the first mask are provided at the four corner edges.

[0039] Specifically, the first mask 1 is planar in shape and made of 304 stainless steel, ensuring structural strength without compromising pattern accuracy due to excessive thickness. Its thickness is 100μm ± 5μm, and its flatness is ≤2μm, which helps improve the uniformity of thin film deposition and the accuracy of the pattern. The surface roughness Ra ≤ 0.1μm reduces impurity adsorption and interference with the thin film formation process. The surface of the first mask 1 has a rectangular cutout area 11, 4mm × 0.8mm in size, precisely matching the contour of the electrode to be prepared. Its shape and size are strictly designed according to the target electrode, accurately defining the thin film deposition area and laying the foundation for forming a specific electrode shape. To achieve precise alignment, four right-angled cutout marks 12 with sides of 1.5mm are symmetrically distributed at the four corners of the first mask 1. These marks play a crucial positioning role in practical applications. A 1mm blank area is reserved around the marking for attaching high-temperature resistant tape. The high-temperature resistant tape can firmly fix the first mask 1 onto the second mask 2, maintaining good adhesion even in high-temperature environments and preventing mask displacement. The processing accuracy of the sample cutout area 11 and the right-angle mark 12 is as high as ±1μm, ensuring the high accuracy of the size and position of each part.

[0040] Furthermore, the second mask 2 has an overall size of 8mm × 8mm, and its material properties are consistent with the first mask 1, using 304 stainless steel, which has good corrosion resistance and mechanical properties. The surface is polished to reduce the roughness Ra≤0.1μm. The second mask 2 has a six-electrode pattern cutout area 21 at its center, with each electrode measuring 0.8mm × 1mm. This electrode pattern layout is determined according to experimental requirements such as Hall effect testing, and can meet the electrode fabrication requirements of various application scenarios. The four corner edges are designed as alignment frames 22 that precisely match the right-angle cutout marks 12 of the first mask 1, with an alignment tolerance ≤5μm. In actual use, such as... Figure 3 and Figure 4 As shown, the alignment frame 22 can quickly and accurately align with the right-angled cutout mark 12 of the first mask, greatly improving the positioning efficiency and accuracy when the two masks work together.

[0041] It should be noted that the masks on both the first and second photomasks were prepared using a vacuum transfer device.

[0042] Among them, such as Figure 5 As shown, the vacuum sample transfer device includes a sample transfer rod 51, an operating handle 52, a flange 53, a pre-evacuation chamber 54, a reaction chamber 55, a partition 56, a sample stage 57, a sample holder 58, and a spring 59; wherein, the pre-evacuation chamber 54 and the reaction chamber 55 are isolated by the partition 56; the sample stage 57 is located in the reaction chamber 55; the volume of the reaction chamber 55 is at least twice the volume of the pre-evacuation chamber 54.

[0043] One end of the sample transfer rod 51 is connected to the operating handle 52, and the other end extends into the flange 53, the pre-extraction chamber 54, and the reaction chamber 55 in sequence. The operating handle 52 is used to control the movement of the sample transfer rod 51. The moving distance of the sample transfer rod 51 can be from the pre-extraction chamber 54 to the sample stage 57 in the reaction chamber 55.

[0044] The first or second mask is fixed to the sample holder 58 by the spring clip 59; the end of the sample transfer rod 51 that extends into the reaction chamber 55 has a V-shaped groove structure, so the sample holder 58 is placed in the V-shaped groove structure, thereby realizing the sample holder 58 holding the first or second mask back and forth between the pre-extraction chamber 54 and the reaction chamber 55.

[0045] The process of the sample holder 58, which holds the first or second mask, moving back and forth between the pre-extraction chamber 54 and the reaction chamber 55 is as follows:

[0046] The pre-extraction chamber 54 and the reaction chamber 55 are isolated by the partition 56. When the pre-extraction chamber 54 is opened, the sample holder 58 is placed from the pre-extraction chamber 54 into the V-groove structure of the sample transfer rod 51.

[0047] Close the pre-evacuation chamber 54 and evacuate the pre-evacuation chamber 54 until the difference between the vacuum degree of the pre-evacuation chamber 54 and the vacuum degree of the reaction chamber 55 is less than the set threshold. Then open the partition between the pre-evacuation chamber 54 and the reaction chamber 55 and transfer the sample holder 58 to the sample stage 57 of the reaction chamber 55 using the sample transfer rod 51.

[0048] Once the masking on the first or second mask is completed, the sample transfer rod 51 retracts the sample holder 58 to the pre-extraction chamber 54, then closes the partition 56, re-isolating the pre-extraction chamber 54 and the reaction chamber 55.

[0049] Reopen the pre-evacuation chamber 54, remove the current first or second mask, replace it with the next mask, and repeat the process of closing the pre-evacuation chamber 54, evacuating the vacuum, and opening and closing the partition 56 until the first and second masks are prepared.

[0050] Optionally, the sample transfer rod body 51 is made of 310 stainless steel bar with a diameter of 5cm and a length of 1.2m. This material has good high temperature resistance, corrosion resistance, and high mechanical strength, and can meet the operational requirements in a vacuum environment. The clamping end has a V-groove structure. When the sample holder is placed in the V-groove, it can fit tightly against the sample holder from both sides, providing a stable clamping force and effectively preventing the sample holder from shaking or shifting during sample transfer, ensuring the stability and safety of sample transfer. The end is provided with a threaded interface, which is specifically used to connect the operating handle 52. The sample holder 57 has specially designed screw holes and spring clips 59 on its surface. The screw holes are evenly distributed at the sample holder position, and the sample can be fixed to the sample holder 57 with matching screws. The sample holder 57 is tightly connected to the V-groove clamping end of the sample transfer rod through its specific connection part. During connection, the connection part of the sample holder 57 can accurately fit into the V-groove, forming a stable connection structure, ensuring a reliable connection between the sample holder and the sample transfer rod during sample transfer, thereby ensuring the stability of sample transfer.

[0051] The vacuum flange 53 is sized to fit the body interface of the pre-evacuation chamber 54 and is equipped with a fluororubber O-ring vacuum seal. A rotating partition 58 is provided between the pre-evacuation chamber and the reaction chamber to connect and isolate the pre-evacuation chamber 54 and the reaction chamber 55, for transferring samples and maintaining a stable vacuum environment in their respective chambers.

[0052] The working principle of the dual-mask structure of this utility model is as follows:

[0053] The first mask 1 has right-angled cutout marks 12 symmetrically distributed at its four corners, and the second mask has precisely matching alignment frames 22 at its four corner edges. In terms of spatial relationship, when the first mask 1 is fixed to a substrate such as a silicon wafer, its right-angled cutout marks 12 will form a positioning reference on the substrate surface.

[0054] When the second mask 2 is close to the substrate, visual assistance (such as observation under an optical microscope) is used to ensure that the alignment frame 22 and the right-angled cutout mark 12 are spatially aligned. Due to the extremely high dimensional accuracy of both, with an alignment tolerance ≤5μm, this high-precision matching design ensures the accurate position of the second mask 2 relative to the first mask 1, thus laying the foundation for the precise superposition of subsequent electrode patterns. Figure 4 As shown, the first mask has four sample patterns, and the second mask has four six-electrode patterns. The edge alignment frame of the second mask matches the size of the right-angle cutout mark on the first mask.

[0055] Since the fabrication of thin-film electrode structures requires the sequential use of a dual-mask structure, the vacuum sample transfer device needs to perform two sample injections. A clamping structure ensures that the sample holder, carrying the substrate with a single fixed mask, can be stably transferred to the fabrication area in a vacuum environment during each injection, providing a reliable guarantee for obtaining high-quality thin-film electrodes. The dual-mask structure and the sample transfer device together constitute a complete and efficient novel system for thin-film electrode fabrication.

[0056] In summary, this invention provides a thin-film electrode fabrication device integrating a dual-mask cooperative positioning structure and vacuum sample transfer. Through the dual-mask structure, the average interlayer alignment error measured using an optical microscope is 2μm, which is 80% higher than the traditional process (error ±10μm), effectively improving alignment accuracy. Furthermore, this invention integrates four sample patterns on top of a single mask that only has one sample pattern, thereby achieving simultaneous production of four samples in a single operation, saving costs while enhancing the comparability and reliability of experimental data.

[0057] Of course, there may be other embodiments of this utility model. Without departing from the spirit and essence of this utility model, those skilled in the art can make various corresponding changes and modifications based on this utility model. However, these corresponding changes and modifications should all fall within the protection scope of the appended claims of this utility model.

Claims

1. A dual-mask structure for thin-film electrodes, characterized in that, Including the first mask and the second mask; The surface of the first mask is provided with a rectangular cutout area that matches the outline of the electrode to be prepared. Four right-angled cutout marks for positioning are symmetrically distributed at the four corners, and a blank surrounding area for accommodating high-temperature resistant tape is reserved outside each right-angled cutout mark. The second photomask has a six-electrode pattern cutout area at the center of its surface, and alignment frames matching the right-angle cutout marks of the first photomask are provided at its four corner edges.

2. The dual-mask structure for thin-film electrodes as described in claim 1, characterized in that, The first mask is planar in shape, with a flatness of ≤2μm and a surface roughness Ra≤0.1μm.

3. The dual-mask structure for thin-film electrodes as described in claim 1, characterized in that, The first photomask is made of 304 stainless steel.

4. The dual-mask structure for thin-film electrodes as described in claim 1, characterized in that, By attaching high-temperature resistant tape to the blank surrounding area of ​​the first mask, interlayer bonding is achieved between the first mask and the second mask.

5. The dual-mask structure for thin-film electrodes as described in claim 1, characterized in that, The second photomask is made of 304 stainless steel.

6. The dual-mask structure for thin-film electrodes as described in claim 1, characterized in that, The masks on the first and second photomasks are both prepared using a vacuum sample transfer device; The vacuum sample transfer device includes a sample transfer rod (51), an operating handle (52), a flange (53), a pre-evacuation chamber (54), a reaction chamber (55), a partition (56), a sample stage (57), a sample holder (58), and a spring (59); the pre-evacuation chamber (54) and the reaction chamber (55) are isolated by the partition (56); the sample stage (57) is located in the reaction chamber (55); One end of the sample transfer rod (51) is connected to the operating handle (52), and the other end extends into the flange (53), the pre-extraction chamber (54), and the reaction chamber (55) in sequence. The operating handle (52) is used to control the movement of the sample transfer rod (51). The moving distance of the sample transfer rod (51) can be from the pre-extraction chamber (54) to the sample stage (57) in the reaction chamber (55). The first or second mask is fixed to the sample holder (58) by a spring clip (59); the end of the transfer rod (51) that extends into the reaction chamber (55) has a V-groove structure, so the sample holder (58) is placed in the V-groove structure, thereby enabling the sample holder (58) holding the first or second mask to move back and forth between the pre-extraction chamber (54) and the reaction chamber (55).

7. A dual-mask structure for thin-film electrodes as described in claim 6, characterized in that, The sample transfer rod (51) is made of stainless steel 310 bar.

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