Nanoimprint device for scanning microprobe alignment and control method thereof

Abstract

The present invention relates to a nanoimprinting device for scanning microprobe alignment. The device includes a sample stage, a heatable microprobe, a first pressure sensor provided on the heatable microprobe, an alignment optical path, a light source system, a nanoimprint head, a second pressure sensor provided on the nanoimprint head, a three-axis drive mechanism, and a computer. The heatable microprobe, the first pressure sensor, the alignment optical path, the light source system, the nanoimprint head, the second pressure sensor, and the three-axis drive mechanism are all connected to the computer for communication to form a closed-loop feedback system. The computer acquires position coordinate data of the heatable microprobe and the nanoimprint head, as well as pressure data of the first and second pressure sensors in real time, to calculate the error data between corresponding points after two imprints by the nanoimprint head and perform compensatory imprinting. The present invention has the advantages of improving micro-nano patterning efficiency, realizing multiple splicing and imprinting of small-area imprint master templates to achieve large-area micro-nano patterning, and reducing process costs and improving alignment accuracy.

Description

Technical Field

[0001] The present invention relates to the field of micro-nano device processing, and in particular to a nanoimprint device for aligning a scanning microprobe and a control method thereof. Background Art

[0002] With the rapid development of semiconductor micro-nano integrated circuit devices, various micro-nano processing technologies are widely used in the field of micro-nano structure processing. To ensure the precision and quality of micro-nano chip processing, photolithography, electron beam scanning, laser direct writing, scanning microprobe technology, and nanoimprinting technology have become the core technologies in this field.

[0003] At present, micro-nanostructure graphic schemes such as heated probe direct writing, parallel laser direct writing, parallel electron beam direct writing and rolling nanoimprinting have been gradually developed. Among them, high-precision nanoscale processing can be achieved based on heated probe direct writing, parallel electron beam direct writing and rolling nanoimprinting. At present, heated probe direct writing in the above schemes can achieve processing without damaging the material, but due to the characteristics of the working principle, there is a problem of low efficiency. Among them, parallel electron beam direct writing technology can improve the processing efficiency of patterning, but due to the characteristics of using electron beams, it will cause the properties of the processed material to change. For rolling nanoimprinting that can achieve large-area nanopatterning, the imprint master template area is large, and the commonly used production technology is heated microprobe and electron beam direct writing, which also takes a lot of time.

[0004] Therefore, there is an urgent need for a nanoimprinting device and a control method for scanning microprobe alignment, which can effectively solve the difficulty of splicing multiple micro-nano patterns to form large-area micro-nano patterns, and provide an efficient and high-precision processing technology for the manufacture of semiconductor micro-nano devices. Summary of the Invention

[0005] The object of the present invention is to address the above-mentioned problems existing in the prior art and to provide a nanoimprint device for aligning a scanning microprobe and a control method thereof.

[0006] To achieve the above-mentioned object, the present invention adopts the following technical solution: a nanoimprinting device for scanning microprobe alignment includes a sample stage for placing a sample, a heatable microprobe for ablating a mark on the sample surface, a first pressure sensor provided on the heatable microprobe, an alignment optical path for coarse alignment of the heatable microprobe and the nanoimprinting device, a light source system for providing light of different wavelengths, a nanoimprinting head for imprinting the surface of a material, a second pressure sensor provided on the nanoimprinting head, a three-axis drive mechanism for driving the heatable microprobe and the nanoimprinting head to move along the X, Y, and Z axes, and a computer for processing calculations;

[0007] The heatable microprobe, the first pressure sensor, the alignment optical path, the light source system, the nanoimprint head, the second pressure sensor and the three-axis driving mechanism are all connected to the computer for communication to form a closed-loop feedback system;

[0008] The computer acquires the position coordinate data of the heatable microprobe and the nanoimprint head, as well as the pressure data of the first pressure sensor and the second pressure sensor in real time, so as to calculate the error data between the corresponding points after two imprints of the nanoimprint head and perform compensatory imprinting.

[0009] Working principle and beneficial effects: 1. Compared with the existing technology, the present application first performs marking and alignment through a heatable microprobe, and then obtains the position coordinate data of the heatable microprobe and the nanoimprint head, as well as the pressure data of the first pressure sensor and the second pressure sensor in real time, so as to calculate the error data between the corresponding points after two imprints of the nanoimprint head and perform compensatory imprinting, thereby improving the efficiency of micro-nano patterning and realizing the micro-nano patterning of a large area by splicing and imprinting a small-area imprint master template multiple times;

[0010] 2. Compared with the existing technology, the present application can combine a computer to perform edge alignment through a scanning probe, replacing manual alignment, reducing process costs, eliminating manual alignment operations, reducing the operator's difficulty of use, and improving alignment accuracy.

[0011] Furthermore, the distance between the heatable microprobe and the nanoimprint head in the horizontal and vertical directions is fixed. In this way, after the heatable microprobe is positioned, the nanoimprint head can be easily adjusted because the absolute position between the two is fixed.

[0012] Furthermore, the minimum resolution of the relative position of the heatable microprobe and the nanoimprint head in the horizontal direction is 10nm. In this way, the error in the entire adjustment process is within ±10nm. Therefore, the designed photolithography mask pattern can be efficiently processed onto the silicon wafer to make a mother template, and the flexible material is transferred as a patterned film on the imprint head. The electrode width can be less than 10 nanometers. The heatable microprobe is used to scan and locate the area to be imprinted on the silicon wafer and then perform imprinting. Through the above process, multiple alignment imprinting can be performed to achieve precise alignment imprinting (similar to overlay in photolithography), and finally multiple precise overlays can be achieved to achieve patterning, and the verification of semiconductor device development and design can be quickly realized.

[0013] Furthermore, the first pressure sensor detects the slight pressure change when the heatable microprobe contacts the sample, and simultaneously analyzes the slight pressure change through a computer to obtain the characteristics of the material morphology. The characteristics of the material morphology can be conveniently calculated.

[0014] Furthermore, the diameter of the heatable microprobe tip is 5-10 nm, and the tip is provided with an electric heating structure.

[0015] Furthermore, the light source of the light source system adopts a 405nm semiconductor laser light source.

[0016] Furthermore, the light source of the light source system is connected to the nanoimprint head via an optical coupling optical path.

[0017] Furthermore, the alignment light path is a transmission type or episcopic microscope system composed of microscope objective lenses with different magnifications.

[0018] Furthermore, the computer determines the first contact point between the nanoimprint head and the interface of the imprint adhesive and the change in pressure after the nanoimprint head contacts the imprint adhesive by detecting the first turning point of the pressure change curve of the second pressure sensor.

[0019] A nanoimprint control method for scanning microprobe alignment, using the above-mentioned nanoimprint device for scanning microprobe alignment, comprises the following steps:

[0020] The sample is placed on the sample stage, and the relative position of the sample and the heatable microprobe is adjusted by a three-axis drive mechanism;

[0021] Inputting an embossed pattern distribution into a computer, the embossed pattern distribution including embossed patterns, distances between patterns, and distribution of embossed dot arrays;

[0022] The computer drives a heatable microprobe to scan the starting point of the sample where the imprint is to be made, obtains the outline and marks the starting point;

[0023] Based on the relative distance between the heatable microprobe and the nanoimprint head, the position of the nanoimprint head is adjusted by a three-axis driving mechanism to perform imprinting;

[0024] The relative error between each marking starting point and the nanoimprint head reference point is analyzed by computer and compensated;

[0025] According to the distribution of the imprint pattern, the sample surface is pressed by the nanoimprint head;

[0026] After each pressing is completed, the imprint pattern boundary is scanned by a heatable microprobe and the relative error is recalculated to improve the alignment accuracy until the imprint task is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention;

[0028] Figure 2 yes Figure 1 A magnified image of the heatable microprobe;

[0029] Figure 3 is a flow chart of Example 2 of the present invention;

[0030] Figure 4 This is a flowchart of Example 3 of the present invention.

[0031] In the figure, 1. heatable microprobe; 2. first pressure sensor; 3. alignment optical path; 4. light source; 5. optical coupling optical path; 6. second pressure sensor; 7. displacement control; 8. computer; 9. nanoimprint head. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention are within the scope of protection of the present invention.

[0033] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms cannot be understood as limiting the present invention.

[0034] Example 1

[0035] like Figure 1-2 As shown, the nanoimprinting device for scanning microprobe alignment includes:

[0036] Sample stage, used to place samples.

[0037] In this embodiment, the sample stage is located on the device body, which is equivalent to the sample stage being stationary. Of course, it can also be placed on the X-axis or Y-axis translation stage of the three-axis drive mechanism. In this way, the three-axis drive mechanism only needs to drive the heatable microprobe 1 and the nanoimprint head 9 to move and the sample stage respectively, so that the heatable microprobe 1 and the sample stage, as well as the nanoimprint head 9 and the sample stage, can move relative to each other. This is equivalent to the sample stage being able to move along the X-axis, and the heatable microprobe 1 and the like being able to move along the Y-axis and the Z-axis; or the sample stage being able to move along the Y-axis, and the heatable microprobe 1 and the like being able to move along the X-axis and the Z-axis; or the sample stage being able to move along the X-axis and the Y-axis, and the heatable microprobe 1 and the like being able to move along the Z-axis.

[0038] A heatable microprobe 1 is used to ablate marks on the sample surface;

[0039] Preferably, the diameter of the tip of the heatable microprobe 1 is 5-10 nm, and an electric heating structure is provided on the tip.

[0040] In this embodiment, the heatable microprobe 1 is heated by passing an electric current through a resistance wire on the cantilever beam at the rear end of the probe tip, and the heat is transferred to the probe tip to ablate an alignment mark or mark on the sample surface. The current size and other control are achieved by the computer 8 or the control circuit. This is a conventional technical means, and its principle will not be elaborated here.

[0041] A first pressure sensor 2 is provided on the heatable microprobe 1 and is used to detect minute pressure changes when the heatable microprobe 1 contacts the sample. A computer 8 analyzes the pressure changes (minor pressure changes) to obtain characteristics of the material morphology.

[0042] In this embodiment, the first pressure sensor 2 is a stress gauge on the cantilever beam at the upper end of the heatable microprobe 1 tip. Its resistance changes as the contour of the sample to be imprinted changes. This resistance change signal represents minute pressure changes. This allows the computer 8 to acquire real-time positional coordinate data of the heatable microprobe 1 and nanoimprint head 9, as well as pressure data from the first and second pressure sensors 2 and 6. This allows the computer 8 to calculate the error between corresponding points after two impressions by the nanoimprint head 9 and perform compensatory imprinting.

[0043] Alignment optical path 3, used for coarse alignment of the heatable microprobe 1 and nanoimprinting;

[0044] In this embodiment, the alignment optical path 3 may be a transmissive or episcopic microscope system composed of microscope objective lenses of different magnifications, which can be used to assist in the rough alignment of the heatable microprobe 1 and the nano-imprint.

[0045] A light source 4 system for providing light of different wavelengths;

[0046] In this embodiment, the light source 4 system includes a light source 4 and a coupling optical path. The light source 4 of the nanoimprint head 9 can determine different light wavelengths according to the type of photoinitiator selected for the photoresist, such as using a 405nm semiconductor laser light source 4. The optical coupling optical path 5 can be spatial optical coupling or optical fiber coupling. The optical fiber coupling is not limited to the optical fiber type and interface type.

[0047] A nanoimprint head 9, used for imprinting the surface of the material;

[0048] In this embodiment, the ultraviolet light nanoimprint module in the nanoimprint head 9 can achieve a 90° rotation angle of the ultraviolet light through a beam splitting cubic mirror, and the ultraviolet light used for exposure is coupled through an optical fiber.

[0049] Preferably, the heatable microprobe 1 and the nanoimprint head 9 (divided into an ultraviolet nanoimprint module and a heating nanoimprint module) are fixed in place on an X-axis piezoelectric stage (part of a three-axis drive mechanism), and the probe used for calibration is located on the same horizontal line as the center points of the two imprint heads.

[0050] Preferably, the distance between the tip of the heatable microprobe 1 and the center of the nanoimprint head 9 is fixed and the distance accuracy is about 10nm, which is equivalent to the distance between the heatable microprobe 1 and the nanoimprint head 9 in the horizontal vertical direction being fixed, and the minimum resolution of the relative position of the heatable microprobe 1 and the nanoimprint head 9 in the horizontal direction is 10nm. In this way, the error in the entire adjustment process is within ±10nm. Thus, the designed photolithography mask pattern can be efficiently processed onto the silicon wafer to make a mother template, and the flexible material is transferred as a patterned film on the imprint head. The electrode width can be less than 10nm, and the heatable microprobe 1 is used to scan and locate the area to be imprinted on the silicon wafer and then imprint. Through the above process, multiple alignment imprints can be performed to achieve precise alignment imprinting (similar to overlay in photolithography), and finally multiple precise overlays are achieved to achieve patterning, and the verification of semiconductor device development and design is quickly realized. Reduce the difficulty and workload of manual operation.

[0051] A second pressure sensor 6 is provided on the nanoimprint head 9 and is used to detect the pressure of the imprint adhesive applied by the nanoimprint head 9 to the surface of the material. The computer 8 determines the first contact point between the nanoimprint head 9 and the imprint adhesive interface and the pressure change after the nanoimprint head 9 contacts the imprint adhesive by detecting the first turning point of the pressure change curve of the second pressure sensor 6.

[0052] A three-axis driving mechanism for driving the heatable microprobe 1 and the nanoimprint head 9 to move along the XYZ three axes;

[0053] In this embodiment, the three-axis drive mechanism itself is conventional technology, implemented by multiple linear modules or multiple motors, and can be divided into three stages: X, Y, and Z. The X and Y stages are used to adjust the relative X and Y positions of the nanoimprint head 9 and the sample, respectively. The Z-axis stage is used to control the relative Z position of the nanoimprint head 9 and the sample, and serves to apply pressure to the heatable microprobe 1 or the nanoimprint head 9.

[0054] The computer 8 is used for processing calculations.

[0055] In this embodiment, the heatable microprobe 1, the first pressure sensor 2, the alignment optical path 3, the light source 4 system, the nanoimprint head 9, the second pressure sensor 6 and the three-axis drive mechanism are all connected to the computer 8 for communication to form a closed-loop feedback system. The computer 8 can be installed with corresponding programs to control each part.

[0056] Example 2

[0057] like Figure 3 As shown, the nanoimprint control method for scanning microprobe alignment uses the nanoimprint device for scanning microprobe alignment of Example 1, including the following steps:

[0058] S1, placing the sample on the sample stage and adjusting the relative position of the sample and the heatable microprobe 1 through the three-axis drive mechanism;

[0059] S2. Inputting the embossed pattern distribution into the computer 8, the embossed pattern distribution including the embossed patterns, the distance between the patterns, and the distribution of the embossed dot matrix;

[0060] S3, the computer 8 drives the heatable microprobe 1 to scan the starting point of the sample where the imprint is to be made, obtains the contour, and marks the starting point;

[0061] S4, adjusting the position of the nanoimprint head 9 by a three-axis driving mechanism based on the relative distance between the heatable microprobe 1 and the nanoimprint head 9 to perform imprinting;

[0062] S5, using the computer 8 to analyze the relative error between each marking starting point and the reference point of the nanoimprint head 9 and compensate for it;

[0063] In this embodiment, when the nanoimprint head 9 imprints the imprint glue on the surface of the material, the heatable microprobe 1 can be used to scan and image the starting point of the material to be imprinted or the position to be spliced ​​in advance, and the reference can be determined. Then, the imprint head is moved to the reference position obtained by the scan to perform imprinting; since the resolution of the displacement stage along the X-axis is 10nm, the error in this process is within ±10nm.

[0064] S6, pressing the sample surface by the nanoimprint head 9 according to the imprint pattern distribution;

[0065] S7. After each pressing is completed, the heatable microprobe 1 is used to scan the boundary of the imprinted pattern and recalculate the relative error to improve the alignment accuracy until the imprinting task is completed.

[0066] Example 3

[0067] The difference between this embodiment and embodiment 2 is that the sample is directly placed on the three-axis moving stage (the X or Y moving stage in the three-axis driving mechanism). Figure 4 The specific steps are as follows:

[0068] Step 1: Place the sample on the three-axis stage;

[0069] Step 2: Input the intended embossing pattern into the computer 8 and set the error compensation parameters;

[0070] Step 3: The probe scans the sample to determine the reference and mark the starting position;

[0071] Step 4: Imprint and measure the error, and compare the error compensation parameters;

[0072] Step 5: Determine whether the error range is greater than or equal to 20nm;

[0073] Step 6: If yes, then emboss the corresponding pattern according to the patterning program of computer 8; if no, then repeat step 2;

[0074] The parts not described in detail in the present invention are prior art, so the present invention does not describe them in detail.

[0075] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the elements may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0076] Although this document frequently uses terms such as heatable microprobe 1, first pressure sensor 2, alignment optical path 3, light source 4, optical coupling optical path 5, second pressure sensor 6, displacement control 7, computer 8, and nanoimprint head 9, the use of other terms is not excluded. These terms are used solely to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations would be contrary to the spirit of the present invention.

[0077] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, any technical solution that is the same or similar to that of the present application falls within the scope of protection of the present invention.

Claims

1. A nanoimprinting apparatus for scanning microprobe alignment, characterized in that: The system comprises a sample stage for placing a sample, a heatable microprobe for ablating a mark on the sample surface, a first pressure sensor provided on the heatable microprobe, an alignment optical path for coarse alignment of the heatable microprobe and the nanoimprinting machine, a light source system for providing light of different wavelengths, a nanoimprinting head for imprinting the surface of a material, a second pressure sensor provided on the nanoimprinting head, a three-axis drive mechanism for driving the heatable microprobe and the nanoimprinting head to move along the X, Y, and Z axes, and a computer for processing calculations; The heatable microprobe, the first pressure sensor, the alignment optical path, the light source system, the nanoimprint head, the second pressure sensor, and the three-axis drive mechanism are all connected to the computer for communication to form a closed-loop feedback system; The computer acquires in real time the position coordinate data of the heatable microprobe and the nanoimprint head, as well as the pressure data of the first pressure sensor and the second pressure sensor, so as to calculate the error data between corresponding points after two imprints by the nanoimprint head and perform compensatory imprinting; Wherein, an electric heating structure is provided on the tip of the heatable microprobe; and the light source of the light source system is connected to the nanoimprint head via an optical coupling optical path.

2. The nanoimprinting device for scanning microprobe alignment according to claim 1, characterized in that: The heatable microprobe and the nanoimprint head are fixed in a horizontal and vertical distance.

3. The nanoimprinting device for scanning microprobe alignment according to claim 2, characterized in that: The minimum resolution of the relative position of the heatable microprobe and the nanoimprint head along the horizontal direction is 10 nm.

4. The nanoimprinting device for scanning microprobe alignment according to claim 1, characterized in that: The first pressure sensor detects a small pressure change when the heatable microprobe contacts the sample, and the computer analyzes the small pressure change to obtain the characteristics of the material morphology.

5. The nanoimprinting device for scanning microprobe alignment according to claim 1, characterized in that: The tip diameter of the heatable microprobe is 5-10 nm.

6. The nanoimprinting device for scanning microprobe alignment according to any one of claims 1 to 5, characterized in that: The light source of the light source system adopts a 405 nm semiconductor laser light source.

7. The nanoimprinting device for scanning microprobe alignment according to any one of claims 1 to 5, characterized in that: The alignment light path is a transmission type or episcopic type microscope system composed of microscope objective lenses with different magnifications.

8. The nanoimprinting device for scanning microprobe alignment according to any one of claims 1 to 5, characterized in that: The computer determines the first contact point between the nanoimprint head and the embossing adhesive interface and the pressure change after the nanoimprint head contacts the embossing adhesive by detecting the first turning point of the pressure change curve of the second pressure sensor.

9. A nanoimprint control method for scanning microprobe alignment, characterized in that: The nanoimprinting device for scanning microprobe alignment according to any one of claims 1 to 8 comprises the following steps: The sample is placed on the sample stage, and the relative position of the sample and the heatable microprobe is adjusted by a three-axis drive mechanism; Inputting an embossed pattern distribution into a computer, the embossed pattern distribution including embossed patterns, distances between patterns, and distribution of embossed dot arrays; The computer drives a heatable microprobe to scan the starting point of the sample where the imprint is to be made, obtains the outline and marks the starting point; Based on the relative distance between the heatable microprobe and the nanoimprint head, the position of the nanoimprint head is adjusted by a three-axis driving mechanism to perform imprinting; The relative error between each marking starting point and the nanoimprint head reference point is analyzed by computer and compensated; According to the distribution of the imprint pattern, the sample surface is pressed by the nanoimprint head; After each pressing is completed, the imprint pattern boundary is scanned by a heatable microprobe and the relative error is recalculated to improve the alignment accuracy until the imprint task is completed.

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