CN202210213U - An adaptive wafer stage for whole wafer nanoimprinting - Google Patents

Abstract

The utility model discloses an self-adaptive film-supporting platform suitable for whole wafer nano-imprinting, which comprises a fixed base, a floating base, a vacuum sucker and a vacuum pipeline. Wherein, the vacuum suction cup is fixed on the upper plane of the floating base; the fixed base has a concave spherical structure, the floating base has a convex spherical structure, and the fixed base and the floating base are in hemispherical contact. The utility model realizes the parallel self-adaptive adjustment of the template and the substrate and the compensation of the wedge error through the spherical contact and cooperation between the fixed base and the floating base; the locking and locking of the floating base on the fixed base is realized by vacuum negative pressure. Fix, maintain the relative pose between the substrate and the template after leveling, and ensure the parallelism between the template and the substrate during the imprinting process. The utility model has the advantages of simple structure, convenient adjustment, low cost, wide adaptability, high flexibility, etc., and can be applied to nano-imprinting of whole wafers, especially suitable for the whole nano-imprinting process and equipment of large-sized wafers.

Description

An adaptive wafer stage for whole wafer nanoimprinting

technical field

The utility model relates to a chip holder for nano-imprinting, in particular to an self-adaptive chip holder suitable for a nano-imprint lithography machine for large-sized wafers, and belongs to the technical fields of micro-nano manufacturing and precision machinery.

Background technique

Nanoimprint lithography (Nanoimprint Lithography, NIL) is a new micro-nano patterning method, which is a technology that uses a mold to realize its patterning through the force deformation of the resist. Compared with other micro-nano manufacturing methods, NIL has the characteristics of high resolution, ultra-low cost and high productivity, especially in the manufacture of large-area micro-nano structures and complex three-dimensional micro-nano structures. At present, there are mainly three schemes for implementing the nanoimprint process: step-and-repeat nanoimprint process, roll imprint process and whole wafer nanoimprint process. With the growing demand of micro-nano technology for the manufacture of large-area micro-nano structures, especially in recent years, high-brightness LED patterning technology, micro-lens and other device manufacturing have more urgent needs for large-area wafer-scale micro-nano structures. Therefore, the development of whole wafer nanoimprinting process and equipment has become more and more important and urgent. Unlike the existing step-and-repeat nanoimprinting process and roll imprinting process, the wafer stage (also known as the wafer workbench), the whole wafer nanoimprinting is carried out through the template (mold) and the entire wafer (substrate) at the same time. The contact and imprinting of the resist on the wafer) with complete uniformity, and the replication of large-area patterns on the wafer scale can be realized in one step (single step). Therefore, the structure, function and form of the wafer stage used in the whole wafer nanoimprinting are very different from the wafer stage used in the existing nanoimprint lithography and various other lithography equipment.

Due to the error of the nanoimprint structure itself and the unevenness of the substrate itself (warping and deformation, especially for LED epitaxial wafers), there are non-parallel errors and wedge errors during the nanoimprint process. If the non-parallelism error and wedge error are compensated, it is impossible to ensure a completely uniform and consistent contact between the template and the substrate during the imprinting process, and to obtain a uniform residual layer thickness. If the non-parallelism between the template and the substrate exceeds a certain level, the thickness difference of the wedge-shaped film exceeds the height of the embossed feature, which will cause the failure of the pattern transfer, and may also cause damage to the template. In addition, the non-parallel between the template and the substrate may also cause relative slippage between the template and the substrate during the nanoimprinting process, and lateral expansion occurs, which affects the accuracy of the imprinted pattern; the template may also affect the imprinted features during demolding. cause havoc. Therefore, the parallelism between the template and the substrate must be guaranteed during the nanoimprint process; in addition, compared with the step-and-repeat nanoimprint process, for whole wafer nanoimprinting, the parallelism between the template and the substrate must be maintained. This is especially important because the step-and-repeat nanoimprint process has a relatively small contact area between the template and the substrate in each step of the imprinting process, but the simultaneous contact between the template and the substrate during the entire wafer nanoimprinting process is relatively small. The area is very large (the entire wafer area). Compared with the small-area step-and-repeat nanoimprint process, the whole wafer nanoimprint has the effect of error amplification. Therefore, the whole wafer nanoimprint process is very important for maintaining the template and substrate. The parallelism between slices has more stringent requirements. Therefore, the whole wafer nanoimprint lithography machine must have the functions of template and substrate parallelism adjustment and wedge error compensation. For nanoimprinting of the whole wafer, this function is completed by the wafer stage, that is, during the imprinting process, by adjusting the change of the space position of the wafer stage, the wedge-shaped error between the template and the substrate is compensated, and the distance between the template and the substrate is maintained. parallel to avoid relative lateral sliding between them. Achieve uniform and consistent contact between the template and the substrate, and obtain a uniform and consistent residual layer thickness. Enables high-fidelity pattern transfer and replication across the entire wafer imprint area.

There are two ways to adjust the parallelism between the template and the substrate and the wedge-shaped error through the carrier table: passive adjustment (also called self-adaptive adjustment) and active control adjustment. Adaptive adjustment is to use the flexibility of the mechanism itself to passively adapt to the non-parallelism between the template and the substrate. When the imprinting force acts on the substrate through the template, the substrate carrying the substrate will produce a corresponding slight rotation to compensate for the wedge error. , so that the entire substrate is evenly stressed. And this tiny rotation can be accommodated by the flexibility of the mechanism itself. The methods of self-adaptive adjustment mainly include: flexible hinge mechanism, elastic support, universal floating ball, wedge-shaped compensation module, etc. Self-adaptive adjustment has the obvious advantages of simple structure, convenient adjustment and low cost. Active control adjustment is to detect the position and non-parallelism of the template and the substrate through the measurement system, and according to the feedback result, actively adjust the pose between the template and the substrate through the actuator to achieve parallel positioning between the two. Active control has the obvious advantages of high adjustment accuracy and quick response, but it is costly and complicated to control.

Utility model content

The purpose of this utility model is to solve the problem of non-parallel and wedge-shaped errors between the substrate and the template in the process of nano-imprinting of the entire wafer, and to provide an adaptive bearing suitable for nano-imprinting of the entire wafer. The film stage is used to realize the parallel adjustment and wedge error compensation between the substrate and the template.

In order to achieve the above object, the utility model takes the following technical solutions:

An adaptive wafer stage suitable for nanoimprinting of a whole wafer, comprising: a fixed base, a floating base, a vacuum suction cup and a vacuum pipeline, wherein the floating base is located on the fixed base; the vacuum suction cup is fixed on the On the upper plane of the floating base, the vacuum suction cup is used to place and fix the substrate (wafer); the fixed base is provided with a horizontal pipeline, the vacuum pipeline includes vacuum pipeline I and vacuum pipeline II, and the vacuum suction cup is provided with a horizontal air inlet ; The horizontal pipeline is connected to the vacuum pipeline I, and the horizontal air inlet is connected to the vacuum pipeline II.

The fixed base has a concave spherical structure, the floating base has a convex spherical structure, and the fixed base and the floating base are in hemispherical contact and fit. The parallel adaptive adjustment of the template and the substrate and the compensation of the wedge error are realized through the spherical contact fit between the fixed base and the floating base.

The fixed base is also provided with a vertical pipeline, the center of the fixed base is provided with a central circular through hole, and an inner circular through hole is provided below the central circular through hole, and the inner circular through hole is connected with the central circular through hole respectively. The hole, the horizontal pipeline and the vertical pipeline are connected; the uppermost end of the vertical pipeline is connected with the concave spherical structure, and the lowermost end of the vertical pipeline is connected with the inner circular through hole.

The working principle of the utility model is: through the spherical contact and cooperation between the fixed base and the floating base, the parallel self-adaptive adjustment of the template and the substrate and the compensation of the wedge error are realized; Locking and fixing, maintain the relative posture between the substrate and the template after leveling, ensure the parallelism between the template and the substrate during the imprinting process, and maintain uniformity.

During application, by opening the vacuum pipeline I, under the action of vacuum negative pressure, the locking and fixing of the floating base on the fixed base after leveling is realized, and the relative pose between the substrate and the template after leveling is maintained. Ensure that the template and substrate are parallel to each other during the imprinting process. By opening the vacuum pipeline II, the vacuum chuck generates a gas pressure difference between the upper and lower planes of the substrate, and realizes the clamping and fixing of the substrate under the action of negative pressure. The entire wafer stage system realizes the locking and fixing of the fixed base and the floating base after leveling through the negative pressure generated by the vacuum pipeline, and the fixing of the substrate on the vacuum chuck.

The utility model is used for the whole wafer nano-imprinting self-adaptive chip holder, and a relatively large central circular through hole is arranged in the center of the fixed base, on the one hand, the contact area between the fixed base and the floating base is reduced, Thereby reducing the friction force during self-adaptive adjustment, so that the two are easy to produce relative sliding or rotation, so that the wedge-shaped error between the template and the substrate is fully compensated; on the other hand, the adsorption force during locking and fixing is increased , to avoid relative sliding between the fixed base and the floating base during the imprinting process.

The method for realizing self-adaptive leveling and wedge error compensation of the substrate and the template by adopting the self-adaptive substrate for nanoimprinting of the whole wafer of the present utility model is as follows:

(1) Place the substrate on the vacuum chuck, turn on the vacuum pipeline system of the vacuum chuck, and the vacuum chuck realizes the clamping of the substrate under the action of negative pressure through the gas pressure difference generated between the upper and lower planes of the substrate and fixed;

(2) The embossing head is pressed down, and the template is in contact with the substrate. With the continuous increase of the imprinting force, the fixed base and the floating base cooperate through spherical contact to realize the parallel adaptive adjustment of the template and the substrate and the compensation of the wedge error. ;

(3) The embossing force is increased to the maximum, and the maximum imprinting force is kept unchanged, and the template and the substrate are fully parallel and adaptively adjusted through a delay of 2-5s;

(4) Open the vacuum pipeline system on the fixed base, and realize the locking and fixing of the floating base on the fixed base under the action of vacuum negative pressure, and maintain the relative posture between the substrate and the template after leveling, Ensure parallelism between template and substrate during imprinting.

The self-adaptive chip holder for nano-imprinting of a whole wafer of the utility model is used for nano-imprinting of a whole wafer, and can also be used in a bonding machine to realize wafer-level bonding, and has the following beneficial effects:

(1) Simple structure, convenient adjustment and low cost.

(2) Complete wedge-shaped error compensation: Since there is a relatively large central circular through hole in the center of the fixed base to reduce the contact area, and the spherical contact between the fixed base and the floating base is rolling friction, the difference between the fixed base and the floating base There is very little friction between them, and it is easy to produce relative sliding and rolling, so the compensation is sufficient and complete.

(3) Vacuum negative pressure locking and fixing is adopted between the fixed base and the floating base, which has the advantages of simple and fast, high precision, easy operation and low cost.

(4) The system has wide adaptability and high flexibility. With different wafer sizes, the entire wafer carrier system has little variability, and can adapt to the requirements of the whole wafer nanoimprinting process with different wafer sizes.

(5) The self-adaptive substrate for whole wafer nanoimprinting of the present utility model is especially suitable for whole wafer nanoimprinting of large size wafers, and provides a tool for the development of whole wafer nanoimprinting process and equipment of large size wafers an effective solution.

Description of drawings

FIG. 1 is a schematic structural diagram of an adaptive wafer stage for nanoimprinting of a whole wafer in an embodiment.

Fig. 2 is a schematic diagram of a three-dimensional structure of an adaptive wafer stage for nanoimprinting of a whole wafer in an embodiment.

Fig. 3a is a schematic diagram of a three-dimensional structure of a fixed base in an embodiment.

Fig. 3b is a schematic cross-sectional view of the three-dimensional structure of the fixed base in the embodiment.

Fig. 4 is a schematic diagram of a three-dimensional structure of the floating base in the embodiment.

Among them, 1. Fixed base; 101. Concave spherical structure; 102. Vertical pipeline; 103. Horizontal pipeline; 104. Central circular through hole; 105. Inner circular through hole; 2. Floating base; 201. 3. Vacuum sucker; 4. Vacuum pipeline; 401. Vacuum pipeline I; 402. Vacuum pipeline II; 5. Screw.

Detailed ways

Below in conjunction with accompanying drawing and the embodiment that the utility model person provides according to the technical scheme of the utility model, the utility model is described in further detail.

Example

An adaptive wafer stage for whole wafer nanoimprinting, including: a fixed base 1, a floating base 2, a vacuum chuck 3 and a vacuum pipeline 4, as shown in Figures 1, 2, 3a, 3b, and 4, wherein the floating base 2 is located on the fixed base 1; the vacuum chuck 3 is fixed on the upper plane of the floating base 2 by screws 5, and the vacuum chuck 3 is used to place and fix the substrate (wafer); the fixed base 1 is provided with horizontal pipeline 103, and vacuum pipeline 4 comprises vacuum pipeline I 401 and vacuum pipeline II 402, and vacuum chuck 3 is provided with horizontal air inlet; Horizontal pipeline 103 links to each other with vacuum pipeline I 401, and horizontal air inlet is connected with Vacuum line II 402 is connected.

The fixed base 1 has a concave spherical structure 101 , the floating base 2 has a convex spherical structure 201 , and the fixed base 1 and the floating base 2 are in a hemispherical contact fit. The parallel adaptive adjustment of the template and the substrate and the compensation of the wedge error are realized through the spherical contact fit between the fixed base 1 and the floating base 2 .

The fixed base 1 is also provided with a vertical pipeline 102, the center of the fixed base 1 is provided with a central circular through hole 104, and an inner circular through hole 105 is provided below the central circular through hole 104, and the inner circular through hole 105 respectively communicates with the central circular through hole 104, the horizontal pipeline 103 and the vertical pipeline 102;

The working principle of the utility model is: through the spherical contact and cooperation between the fixed base 1 and the floating base 2, the parallel self-adaptive adjustment of the template and the substrate and the compensation of the wedge error are realized; The locking and fixing on the base 1 maintains the relative posture between the substrate and the template after leveling, ensures the parallelism between the template and the substrate during the imprinting process, and maintains uniformity.

During application, by opening the vacuum pipeline I 401, under the action of vacuum negative pressure, the locking and fixing of the floating base 2 on the fixed base 1 after leveling is realized, and the relative relationship between the substrate and the template after leveling is maintained. pose, to ensure that the template and the substrate are parallel to each other during the imprinting process. By opening the vacuum pipeline II 402, the vacuum chuck 3 generates a gas pressure difference between the upper and lower planes of the substrate, and realizes the clamping and fixing of the substrate under the action of negative pressure. The entire wafer stage system realizes the locking and fixing of the fixed base 1 and the floating base 2 after leveling through the negative pressure generated by the vacuum pipeline, and the fixing of the substrate on the vacuum chuck 3 .

The method for realizing self-adaptive leveling and wedge error compensation of the substrate and the template by adopting the self-adaptive substrate for nanoimprinting of the whole wafer of the present utility model is as follows:

(1) The substrate is placed on the vacuum chuck 3, and the vacuum pipeline system of the vacuum chuck 3 is opened. The vacuum chuck 3 realizes the substrate under negative pressure by the gas pressure difference generated between the upper and lower planes of the substrate. clamping and fixing;

(2) The embossing head is pressed down, and the template is in contact with the substrate. With the continuous increase of the imprinting force, the fixed base 1 and the floating base 2 cooperate through spherical contact to realize parallel self-adaptive adjustment and wedge error between the template and the substrate. compensation;

(3) The embossing force is increased to the maximum, and the maximum imprinting force is kept unchanged, and the template and the substrate are fully parallel and adaptively adjusted through a delay of 2-5s;

(4) Open the vacuum pipeline system on the fixed base 1, under the action of vacuum negative pressure, realize the locking and fixing of the floating base 2 on the fixed base 1, and maintain the relative relationship between the substrate and the template after leveling Pose, which ensures the parallelism between the template and the substrate during the imprinting process.

The upper surface of the concave spherical structure 101 of the fixed base 1 and the lower surface of the convex spherical structure 201 of the floating base 2 should be coated with a wear-resistant coating or heat-treated to have high surface roughness, hardness and wear resistance.

Claims (3)

1. An adaptive wafer stage for nanoimprinting of a whole wafer, characterized in that it comprises: a fixed base (1), a floating base (2), a vacuum chuck (3) and a vacuum pipeline (4) , wherein the floating base (2) is located on the fixed base (1); the vacuum suction cup (3) is fixed on the upper plane of the floating base (2); the fixed base (1) is provided with a horizontal pipeline (103), Vacuum pipeline (4) comprises vacuum pipeline I (401) and vacuum pipeline II (402), and vacuum chuck 3 is provided with horizontal air inlet; Horizontal pipeline (103) links to each other with vacuum pipeline I (401), and horizontal air inlet Connect with vacuum line II (402). 2. A kind of self-adaptive wafer stage for whole wafer nanoimprinting as claimed in claim 1, it is characterized in that, described fixed base (1) has concave spherical structure (101), and floating base ( 2) It has a convex spherical structure (201), and the contact between the fixed base (1) and the floating base (2) is hemispherical. 3. An adaptive wafer stage for nanoimprinting of a whole wafer as claimed in claim 1 or 2, characterized in that, a vertical pipeline (102) is also provided in the fixed base (1) , the center of the fixed base (1) is provided with a central circular through hole (104), and an inner circular through hole (105) is provided below the central circular through hole (104), and the inner circular through hole (105) is connected to the center respectively. The circular through hole (104), the horizontal pipeline (103) and the vertical pipeline (102) communicate; the uppermost end of the vertical pipeline (102) communicates with the concave spherical structure (101), and the lowermost end of the vertical pipeline (102) communicates with the The inner circular through holes (105) communicate with each other.

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