High-precision miniature electric field sensor based on photoetching process and preparation method thereof

Abstract

The invention relates to the technical field of micro-nano machining and sensors, and discloses a high-precision micro electric field sensor based on a photoetching technology and a preparation method thereof.The micro electric field sensor comprises a structure formed by stacking multiple layers of photoetching patterns, and the structure comprises an electrode layer, an insulating layer and an induction layer which are sequentially connected; the electrode layer adopts a micron-order gap design, and the electric field measurement precision is optimized by adjusting the structural parameters of the induction layer. When the sensor is prepared, a mask pattern is designed through a photoetching process, and the line width, the spacing and the shape are adjusted to control the electrode gap and the electric field distribution characteristic; selecting a photoresist model according to the performance requirement of the sensor and adjusting spin-coating parameters so as to control the thickness of the photoresist; a high-precision microstructure is formed by optimizing exposure intensity and development parameters, the exposure dose is determined through experiments, and when multiple layers of structures are stacked, accurate alignment of photoetching patterns is achieved through mark pattern alignment or coordinate conversion. According to the invention, microminiaturization and high precision of the sensor are realized through a photoetching process.

Description

Technical Field

[0001] The present invention relates to the field of micro-nano processing and sensor technology, and in particular to a high-precision micro electric field sensor based on a photolithography process and a preparation method thereof. Background Art

[0002] Traditional micro electric field sensor fabrication relies heavily on manual assembly, mechanical processing, or low-precision microfabrication techniques (such as screen printing and chemical etching). These methods often result in larger sensors, lower measurement accuracy, and unstable quality during mass production. Manual fabrication makes it difficult to achieve micron / nanoscale structures, resulting in large sensors and low sensitivity. Insufficient process precision leads to poor device consistency and susceptibility to environmental interference. Traditional methods require redesigning molds or process parameters to adjust sensor performance, which is costly and time-consuming. Relying on manual operation makes large-scale manufacturing difficult. While existing photolithography technology can achieve high-precision microstructure processing, it has not yet been fully applied to the adjustable design and functional optimization of electric field sensors. In particular, there is a lack of innovative solutions for dynamically controlling sensor performance through photolithography parameters.

[0003] Furthermore, existing technologies have limitations in achieving tunability and customization of sensor performance, making it difficult to flexibly adjust to different application requirements. This is particularly true for the accuracy, stability, and functionality of micro electric field sensors. Therefore, a new, high-precision, highly tunable fabrication method is urgently needed to meet the increasingly diverse application needs. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-precision miniature electric field sensor based on photolithography technology and a preparation method thereof, so as to realize miniaturization and high precision of the sensor through photolithography technology, and utilize the adjustability of photolithography parameters to realize flexible customization of sensor structure and performance and parameter correspondence to meet the needs of different application scenarios.

[0005] In order to achieve the above purpose, the technical solutions adopted are as follows:

[0006] In the first aspect, the present invention provides a high-precision miniature electric field sensor based on a photolithography process, comprising a structure formed by superimposing multiple layers of photolithography patterns, wherein the structure includes an electrode layer, an insulating layer, and a sensing layer connected in sequence, wherein the electrode layer adopts a micron-level gap design, and the electric field measurement accuracy is optimized by adjusting the structural parameters of the sensing layer.

[0007] As a preferred technical solution, the micro electric field sensor satisfies the transconductance proportional to Wherein, W is the width of the electric field sensing area, L is the channel length, and d is the thickness; sensor performance optimization is achieved by adjusting at least one parameter among W, L, and d.

[0008] As a preferred technical solution, the micro electric field sensor is a planar structure.

[0009] As a preferred technical solution, the micro electric field sensor is a vertical structure.

[0010] In a second aspect, the present invention provides a method for preparing a high-precision micro electric field sensor based on a photolithography process as described above, the method comprising:

[0011] Designing mask patterns through photolithography processes to adjust line width, spacing, and shape to control electrode gaps and electric field distribution characteristics;

[0012] Select the photoresist type and adjust the spin coating parameters according to the sensor performance requirements to control the photoresist thickness;

[0013] High-precision microstructures are formed by optimizing exposure intensity and development parameters, where the exposure dose is determined experimentally;

[0014] When multi-layer structures are stacked, precise alignment of lithography patterns is achieved through mark pattern alignment or coordinate conversion.

[0015] As a preferred technical solution, the photoresist models include S1813 and AZ10XT, wherein S1813 is used for the first photolithography and AZ10XT is used for the second photolithography. The spin coating speed ranges from 1000 to 5000 rpm, and the photoresist thickness is 0.5 to 5 μm.

[0016] As a preferred technical solution, the exposure intensity of S1813 is 100-150mJ / cm 2 , development time is 30-90 seconds; exposure intensity of AZ10XT is 200-450mJ / cm 2 , the developing time is 360-420 seconds, and the developer concentration is 2.38%-4.0%.

[0017] As a preferred technical solution, the preparation method further comprises:

[0018] A performance optimization model is established based on experimental data. The performance optimization model is used to characterize the quantitative relationship between lithography parameters and sensor performance. The quantitative relationship between lithography parameters and sensor performance includes the relationship between the line width, spacing and shape of the mask pattern and the electric field sensitivity, the relationship between the exposure dose and the microstructure morphology, and the relationship between development parameters and structural clarity.

[0019] As a preferred technical solution, the preparation method further includes using the performance optimization model to predict sensor performance under different lithography parameters, thereby guiding the design and manufacturing process.

[0020] As a preferred technical solution, the preparation method further includes calling optimal lithography parameters from the performance optimization model according to target sensitivity, dynamic range or linearity.

[0021] The beneficial effects of the present invention are:

[0022] The present invention realizes a high-precision micro electric field sensor through a photolithography process, which has the following advantages:

[0023] 1. Miniaturization: The electrode gap accuracy reaches micron level, meeting the miniaturization requirements.

[0024] 2. High precision: The photolithography process ensures the high precision and stability of the sensor.

[0025] 3. Customizability: Flexible customization of sensor structure and performance. By adjusting the lithography parameters, the sensor structure can be customized, and then the sensor frequency response range, linearity and dynamic range can be adjusted to meet the needs of different application scenarios; achieving a correspondence between lithography parameters and sensor structure, function or performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The structure of a high-precision micro electric field sensor based on a photolithography process according to an embodiment of the present invention is shown.

[0027] Figure 2 Schematic diagrams of photolithography patterns of a planar structure and a vertical structure according to an embodiment of the present invention are shown, wherein (a) is a planar structure; (b) is a vertical structure.

[0028] Figure 3 The flowchart of manufacturing a high-precision micro electric field sensor according to an embodiment of the present invention is shown.

[0029] Figure 4 The flowchart of the preparation of the high-precision micro electric field sensor according to the embodiment of the present invention is shown.

[0030] Figure 5 A schematic diagram showing a marking pattern according to an embodiment of the present invention is shown.

[0031] Figure 6 A schematic diagram of labeling conversion according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0032] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0033] The specific implementation of the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0034] Example 1:

[0035] The embodiment of the present invention provides a high-precision micro electric field sensor based on photolithography technology, such as Figure 1 As shown, the sensor is composed of multiple layers of photolithographic patterns, including an electrode layer 101, an insulating layer 102, and a sensing layer 103. The electrode layer 101 adopts a micron-level gap design, and the electric field measurement accuracy is significantly improved by adjusting the structural parameters of the sensing layer 103.

[0036] In this embodiment, for example only, the electrode layer 101 may be made of metal (e.g., gold), with a micron-level gap (e.g., 5 μm) between the electrodes to capture external electric field signals. The insulating layer 102 may be made of Parylene or other organic polymer materials to isolate the electrode layer 101 from the sensing layer 103 to prevent leakage current. The sensing layer 103 may be made of an organic semiconductor material (e.g., PEDOT:PSS, P(g2T-TT)) to convert electric field changes into electrical signal output.

[0037] In some embodiments, the electric field sensing area (ie, the area radiated or covered by the sensing layer 103) is optimized: the transconductance of the sensor is proportional to Related to the size of the electric field sensing area, changing the three parameters of the sensor's electric field sensing area, namely, width W, channel length L, and thickness d, can optimize the sensor's performance.

[0038] Specifically, W (width) is the longitudinal dimension of the electric field sensing region. Increasing W can expand the effective area for electric field capture and enhance signal acquisition capabilities. d (thickness) is the vertical dimension of the sensing layer 103, which directly affects the electric field penetration depth and charge distribution density. Increasing d can increase the volume of the electric field sensitive material and enhance the charge accumulation effect. L (channel length) generally refers to the electrode spacing or the length of the carrier propagation path in the sensing layer. Reducing L can shorten the carrier transmission distance and improve the current response.

[0039] Transconductance G represents the efficiency of the sensor in converting electric field changes into electrical signals. The formula for transconductance G is:

[0040]

[0041] As the above formula shows, increasing W expands the sensing area and improves signal strength. Increasing d increases the thickness of the sensing layer and increases the number of carriers. Reducing L shortens the electrode spacing, shortens the carrier transmission distance, and improves current response.

[0042] Based on the above analysis, this embodiment also provides a specific optimization strategy. Specifically, to improve sensitivity, increasing W and d or reducing L can significantly increase the transconductance, thereby enhancing the sensor's ability to detect weak electric fields. Adjusting the W / L / W / L or d / L / d / L ratios can expand the sensor's linear operating range and avoid saturation distortion. Shortening L can reduce carrier migration time and improve the sensor's high-frequency response characteristics.

[0043] In some embodiments, the high-precision micro electric field sensor can be designed as a planar or vertical structure according to application requirements. The planar structure is suitable for conventional electric field measurement, and the vertical structure significantly improves the transconductance performance by multi-layer stacking, which is suitable for high-sensitivity measurement scenarios. The lithographic patterns of the planar structure and the vertical structure are as follows: Figure 2 shown.

[0044] Example 2:

[0045] The embodiment of the present invention provides a method for preparing a high-precision micro electric field sensor based on a photolithography process as described in any embodiment of embodiment 1, such as Figure 3 and Figure 4 As shown, the preparation method includes:

[0046] S10: Design the mask pattern through the photolithography process and adjust the line width, spacing and shape to control the electrode gap and electric field distribution characteristics.

[0047] It should be noted that in step S10, the line width and spacing directly determine the geometric parameters of the electrode layer after photolithography by adjusting the line width (such as 5μm) and spacing (such as 3μm) on the mask. Reducing the line width and spacing can reduce the electrode gap (for example, 1-10μm), thereby improving sensitivity. Shape optimization designs the mask pattern according to the sensor type (planar or vertical). For example, the planar type adopts a parallel electrode design, and the vertical type expands the sensing area through a multi-layer staggered structure. Electric field distribution control simulates the electric field distribution under different mask patterns through finite element simulation (such as COMSOL), and selects the optimal design to balance sensitivity and linearity.

[0048] S20: Select the photoresist type and adjust the spin coating parameters according to the sensor performance requirements to control the photoresist thickness.

[0049] It should be noted that in step S20, when selecting photoresists, for example, S1813 and AZ10XT, S1813 is suitable for single-layer high-precision structures (thickness 0.5-1μm), has high development resolution, and is suitable for micron-level electrode processing. AZ10XT is suitable for multi-layer stacking (thickness 2-5μm), has strong etching resistance, and reduces interlayer interference.

[0050] The spin speed is controlled as follows: The spin coating speed (1000-5000 rpm) is inversely proportional to the photoresist thickness. For example, at 4000 rpm, the S1813 thickness is approximately <1 μm, which meets the requirements of planar sensors.

[0051] Considering the influence of thickness, thinner photoresist (<1μm) can achieve finer lines, but is easily affected by substrate roughness; thicker photoresist layer (>3μm) is suitable for multi-layer structure, but requires longer development time.

[0052] For example, the planar sensor uses S1813 with a spin coating speed of 3000 rpm; the vertical sensor uses AZ10XT with a spin coating speed of 2000 rpm to form a 3 μm thick adhesive layer.

[0053] S30: forming a high-precision microstructure by optimizing exposure intensity and development parameters, wherein the exposure dose is determined by experiments.

[0054] It should be noted that in step S30, the exposure dose (mJ / cm 2 ) Determine the optimal value (such as 120mJ / cm 2 Too low a dose will result in incomplete photolithography and blurred structure boundaries; too high a dose may cause excessive cross-linking, resulting in narrowing of lines. High exposure intensity (such as 300mJ / cm 2 ) is suitable for thick photoresist layers. Developer concentrations, such as 2.38% TMAH (tetramethylammonium hydroxide), are used for high-resolution development, while 4.0% is used for rapid removal of unexposed photoresist layers. Developing times vary depending on the thickness of the photoresist, with thin photoresists requiring approximately 60 seconds and thick photoresists requiring approximately 400 seconds to ensure thorough development of deep layers.

[0055] S40: When stacking multi-layer structures, precise alignment of lithography patterns is achieved through mark pattern alignment or coordinate conversion.

[0056] It should be noted that, in step S40, when the marking pattern is aligned, Figure 5 As shown, a cross alignment mark (size 5×5μm) is designed in each layer of exposure pattern, and the lithography machine platform is adjusted to achieve inter-layer alignment (error <1μm). This method is suitable for aligning the insulating layer and electrode layer of planar sensors.

[0057] like Figure 6As shown, during coordinate conversion, the coordinates of the previous pattern layer are mapped to the current layer through affine transformation (such as translation and rotation) to compensate for deviations in substrate placement. This method is suitable for multi-layer sensor stacking, achieving precise alignment of three-dimensional structures through coordinate conversion. For example, a vertical sensor retains alignment marks after the first layer is processed, and the second layer is staggered through coordinate conversion offset (X + 10μm, Y - 5μm), expanding the sensing area.

[0058] In some embodiments, in order to mass-produce high-precision micro electric field sensors, the preparation method also includes: establishing a performance optimization model through experimental data, and the performance optimization model is used to characterize the quantitative relationship between lithography parameters and sensor performance; wherein, the quantitative relationship between lithography parameters and sensor performance includes the relationship between the line width, spacing and shape of the mask pattern and the electric field sensitivity, the relationship between the exposure dose and the microstructure morphology, and the relationship between development parameters and structural clarity.

[0059] Specifically, a quantitative relationship between lithography parameters and sensor performance is established through experimental data, achieving the following correspondence:

[0060] Mask pattern: Adjusting the line width, spacing, and shape of the mask pattern changes the sensor electrode gap and electric field distribution characteristics. Reducing the line width and spacing can improve electric field sensitivity, but it is necessary to balance manufacturing difficulty and performance stability.

[0061] Photoresist spin coating parameters: The thickness of the spin coating can be controlled by selecting different types of photoresist (such as S1813, AZ10XT) and adjusting the coating speed. Thicker photoresist layers are suitable for multi-layer stacking, while thinner layers are suitable for high-precision single-layer structures.

[0062] Exposure parameters: Adjust exposure intensity and time based on precision requirements to optimize microstructure morphology. High exposure intensity can increase the degree of photoresist crosslinking, but avoid overexposure, which can cause structural distortion. A dose test is performed to determine the optimal exposure dose for optimal lithography results.

[0063] Development parameters: Controlling the development time, temperature, and developer concentration allows for selective removal of the photoresist, resulting in high-precision microstructures. Longer development times can improve structural clarity, but overdevelopment, which can lead to structural loss, must be avoided.

[0064] Based on the performance optimization model, the following functions can be achieved:

[0065] Parameter optimization: Directly call the optimal lithography parameters based on the sensor's sensitivity, dynamic range, and linearity to achieve rapid customization of sensor structure and function to meet the needs of different application scenarios.

[0066] Performance prediction: The model predicts sensor performance under different lithography parameters to guide the design and manufacturing process.

[0067] Process simplification: Optimize the lithography process based on the model to improve preparation efficiency and reduce manufacturing costs.

[0068] The above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the present invention. The scope of patent protection of the present invention should be defined by the claims.

Claims

1. A high-precision micro electric field sensor based on photolithography, characterized in that: The invention comprises a structure formed by superimposing multiple layers of photolithographic patterns, which includes an electrode layer, an insulating layer and a sensing layer connected in sequence. The electrode layer adopts a micron-level gap design, and the electric field measurement accuracy is optimized by adjusting the structural parameters of the sensing layer.

2. The high-precision micro electric field sensor based on photolithography process according to claim 1, characterized in that: By adjusting the structural parameters of the sensing layer, the micro electric field sensor satisfies the transconductance proportional to Wherein, W is the width of the electric field sensing area, L is the channel length, and d is the thickness; sensor performance optimization is achieved by adjusting at least one parameter among W, L, and d.

3. The high-precision micro electric field sensor based on photolithography process according to claim 1, characterized in that: The micro electric field sensor is a planar structure.

4. The high-precision micro electric field sensor based on photolithography process according to claim 1, characterized in that: The micro electric field sensor has a vertical structure.

5. A method for preparing a high-precision micro electric field sensor based on a photolithography process according to any one of claims 1 to 4, characterized in that: The preparation method comprises: Designing mask patterns through photolithography processes to adjust line width, spacing, and shape to control electrode gaps and electric field distribution characteristics; Select the photoresist type and adjust the spin coating parameters according to the sensor performance requirements to control the photoresist thickness; High-precision microstructures are formed by optimizing exposure intensity and development parameters, where the exposure dose is determined experimentally; When multi-layer structures are stacked, precise alignment of lithography patterns is achieved through mark pattern alignment or coordinate conversion.

6. The preparation method according to claim 5, wherein The photoresist models include S1813 and AZ10XT, wherein S1813 is used for the first photolithography and AZ10XT is used for the second photolithography. The spin coating speed ranges from 1000 to 5000 rpm, and the photoresist thickness is 0.5 to 5 μm.

7. The preparation method according to claim 6, wherein The exposure intensity of S1813 is 100-150mJ / cm 2 , development time is 30-90 seconds; exposure intensity of AZ10XT is 200-450mJ / cm 2 , the developing time is 360-420 seconds, and the developer concentration is 2.38%-4.0%.

8. The preparation method according to any one of claims 5 to 7, characterized in that The preparation method further comprises: A performance optimization model is established based on experimental data. The performance optimization model is used to characterize the quantitative relationship between lithography parameters and sensor performance. The quantitative relationship between lithography parameters and sensor performance includes the relationship between the line width, spacing and shape of the mask pattern and the electric field sensitivity, the relationship between the exposure dose and the microstructure morphology, and the relationship between development parameters and structural clarity.

9. The preparation method according to claim 8, wherein The preparation method also includes using the performance optimization model to predict sensor performance under different lithography parameters, thereby guiding the design and manufacturing process.

10. The preparation method according to claim 8, characterized in that The preparation method further includes calling optimal lithography parameters from the performance optimization model according to target sensitivity, dynamic range or linearity.

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