CN100541326C - Method and device for imprinting and manufacturing nanoscale graphics - Google Patents

Abstract

An imprinting manufacturing method of nanometer-level graphics is characterized in that the hardness of the template and the object to be imprinted is improved by sucker adsorption, and the pre-pressing of the sucker is used to make the pressure distribution uniform during imprinting. When loading the template and the object to be imprinted, the optical sensor can be used to align the template and the object to be imprinted. The device applying the method of the present invention includes a movement guarantee controllable component that ensures that the surfaces of the upper and lower vacuum suction cups are relatively parallel and can move in a single direction, so that the template and the object to be imprinted can move relatively controllably to ensure uniform pressure and prevent graphic dislocation and deformation; The rotation torque becomes the pressure between the adsorption components, and the pressure control component can be constant pressure; the heating temperature and adiabatic temperature control component can be controlled; the template and the object to be imprinted can be adsorbed, and the adsorption of the appropriate shape can be changed according to the needs components. The invention can reduce equipment cost, is reliable and practical, and is easy to operate.

Description

Method and device for imprinting and manufacturing nanoscale graphics

technical field

The invention relates to an embossing manufacturing method and a device thereof, in particular to a pattern imprinting manufacturing method and a device thereof for preparing a pattern with super high resolution and a characteristic size of nanometer level.

Background technique

Since the 1960s, integrated circuits have been constantly updated according to Moore's Law, which states that the number of transistors integrated into a single chip doubles every 18 months. As the size of devices in circuits continues to shrink, conventional optical lithography approaches physical limits. The wavelength of ultraviolet light used in the current popular photolithography process is about 250nm. If you want to manufacture a pattern structure much smaller than half of this scale, the diffraction effect will make the characteristics of various parts of the pattern mixed together and blurred. It is used to manufacture optical lithography tools with a line width of less than 100nm, each costing tens of millions to hundreds of millions of dollars. Complex microelectronic structures with line widths of 70nm have been fabricated, but this fabrication method is very expensive.

The nano-lithography technology proposed in US Patent No. 5772905 is "Nano-imprint Lithography" (Nano-imprint Lithography, or NIL), which has the advantages of simple operation, high resolution, good repeatability, less time-consuming, extremely low cost, and can be mass-produced. Advantages of reproducing nanopatterned structures. In this method, a photoresist (also referred to as a resist layer) on a substrate is applied pressure through a stencil having a nanoscale microstructure, thereby forming a micropattern on the photoresist. The preparation of a template with a fine pattern is usually to spin-coat a layer of electron beam-sensitive polymer (such as PMMA) on the substrate, and then use the electron beam direct writing exposure technology to etch the required pattern on its surface. The current highest resolution can be Up to 1 ~ 5nm. The nanoimprint manufacturing method requires the base material of the template to have sufficient hardness so that it is not easily deformed and damaged during the process of pressing and removing the mold.

The hot embossing process in the existing nanoimprint manufacturing method is shown in Figure 4a. Before imprinting, the template 1, the photoresist 2 to be imprinted, and the substrate 3 (usually made of Si, SiO ₂ , Metal, etc.) placed horizontally, vertically up and down. The surface of the template 1 has fine structures with nanometer-level feature sizes. The photoresist 2 in hot embossing is a traditional photoresist PMMA (polymethyl methacrylate), which has been evenly spin-coated on the substrate 3 before embossing. As shown in Figure 4b, when heating and pressing, the template 1, the photoresist 2 to be imprinted, and the substrate 3 will be heated and pressed up and down. The specific process is to first heat the photoresist 2 to the glass transition temperature ( Tg) or above, in the softened state, apply pressure to transfer the pattern, and cool and solidify after the transfer is completed. As shown in Figure 4c, when the mold is released and separated, a concave-convex pattern is formed on the photoresist layer 2 covering the substrate 3, which corresponds to the pattern of the template; the template and the object to be imprinted are in a single direction facing up and down Separation, and the graphic damage caused by the left and right and rotational movements of the two cannot occur during separation. There is also a thin film with a thickness of 40-50 nm on the bottom surface of the patterned concave of the photoresist layer 2 and the substrate 3 , which is usually removed by oxidation reactive ion etching (Reactive Ion Etching) or the like.

The pressure of the above embossing method is generally 40-100 bar, and the pressure distribution is large in the middle, while the imprinting force is small near the edge of the template; when the area of the template is larger, it is more difficult to ensure uniform pressure. Therefore, it is easy to deform the template due to uneven pressure, deform the embossed pattern, and the uniformity of pattern distribution is poor; when the template is a brittle material (such as a silicon wafer, glass), it is easy to cause cracks due to uneven pressure. At present, the following methods are mainly used to solve such problems:

1. Choose a high-hardness material for the template base or treat the surface to enhance the surface hardness. However, brittle materials are prone to cracking when the pressure is uneven. The usual method is to electroform the silicon wafer template into a nickel mold, and then use the nickel template to imprint the pattern. However, the electroforming process is an electrochemical reaction, which requires a lot of heavy metal electroforming acid solutions and various additives (such as stress relievers, detergents, wetting agents, etc.). These chemical solutions are not easy to handle after use, not only expensive but also easy to pollute. environment. Electroforming itself has many defects, such as replication efficiency, pinholes, warping, surface accuracy, and poor thickness uniformity.

2. Improve the uniformity of pressure by improving the pressurization method. The roller-type nanoimprinting method shown in FIG. 5 a is to manufacture the template 101 in the shape of a roller, and fine patterns are distributed on the roller. Patterns are embossed on the photoresist 2 on the substrate 3 by rolling. However, during rolling, the template 101 is in contact with the photoresist 2 to form a line. Although the uniformity of the line is improved, it is difficult to control the imprinting of the entire surface. In the buffer pad method shown in FIG. 5 b , the upper embossing plate 102 and the lower embossing plate 103 respectively hold the template 1 , the photoresist 2 and the substrate 3 to be imprinted. A buffer pad 104 (usually a silicone rubber plate) is placed between the template 1 and the upper platen 102 to ease and balance the impact of the pressure on the template 1 and the object to be imprinted to achieve uniformity. forming. However, the silicone plate is easily stretched and deformed, and limited by the stretching characteristics of the solid material itself, the imprinting force cannot achieve an ideal and uniform distribution state. Especially in the stage of cooling and holding pressure, uneven pressure will cause uneven shrinkage of silica gel, which seriously affects the size of the microstructure of the finished product after transfer.

Fig. 5c is the gas micro-thermal embossing molding method that Chinese patent application number 02131969.3 proposes, adopts to cover one deck with elastic sealing film 105 (such as plastics) on template 1, presses a metal cover 107 and sealing film to form a The pressure-tight air chamber is pressurized by the high-pressure gas source 106. Due to the equal-pressure distribution characteristics of gas molecules, the sealing film pushes the template down evenly. However, the template 1 in this method cannot be fixed during imprinting, so the positioning between the template 1 and the substrate 3 to be imprinted is easily affected by the sealing film, and other methods are needed to assist.

The overlay alignment of multi-layer graphics in nanoimprint technology is to perform multiple imprints on the substrate, which requires that the substrate and the template are parallel to each other and their relative positions can be controlled during each imprint. At present, optical alignment is usually used, and the highest alignment accuracy in the horizontal direction can reach the level of 100nm. Affected by material deformation caused by temperature changes, pressure unevenness, size changes, and graphic area, it will also affect the alignment accuracy. For example, the alignment accuracy of the current 4-inch stencil reaches the level of 1 micron. The use of different imprinting methods will also have a great impact on the accuracy of overlay alignment. For the three methods shown in Figure 5, it is easy to cause uneven movement of the stencil during the imprinting of the roller-type nano-imprinting method. Alignment accuracy, the sealing film covered by the upper template in the gas micro-hot embossing method affects the observation of the optical lens, resulting in complex equipment and low alignment accuracy. The deformation of the silicone plate material in the cushion method will affect the alignment accuracy.

Contents of the invention

The object of the present invention is to provide a nano-imprint method and an imprint device that can distribute the imprint pressure evenly and can be used for overlay alignment, which can reduce the equipment cost, be reliable and practical, and be easy to operate.

The present invention adopts following technical scheme:

In the present invention, the template and the object to be imprinted are respectively fixed on the adsorption surfaces of the upper and lower suction cups by means of suction cup adsorption, so that the template and the upper suction cup, and the object to be imprinted and the lower suction cup are respectively integrated. That is, the hardness of the suction cup is used to strengthen the hardness of the template and the object to be imprinted, which is conducive to the uniform distribution of pressure during imprinting. The suction cup is made of high-hardness materials such as stainless steel, with a smooth adsorption surface and an annular groove. The suction cup can absorb the stencil and the object to be imprinted by extracting the vacuum from the groove. Before embossing, pre-press the upper and lower vacuum suction cups, and the upper and lower mutual pressure reaches the imprinting pressure of 40-100bar, so that the adsorption surfaces are completely in contact. Since the upper and lower vacuum suction cups are made of high-hardness materials and the contact surface is perpendicular to the direction of force, it shows that at this time The adsorption surfaces are parallel and the pressure distribution is uniform. Then, tighten and lock the lower vacuum suction cup and the stand with bolts through the four bolt holes uniformly distributed in the circumferential direction of the lower vacuum suction cup, and use bolts to connect the upper vacuum suction cup with the other through the four bolt holes uniformly distributed in the circumferential direction of the circular sleeve of the upper vacuum suction cup. The splined guide rod that the sleeve fits is tightened and locked. The movement ensures that the controllable component ensures that the spline guide rod moves up and down in a single direction, while the upper vacuum suction cup is locked and fixed on the lower top of the spline guide rod, and the lower vacuum suction cup is fixed on the stand and does not move. Therefore, the spline guide rod drives the upper vacuum suction cup to move up and down in a single direction, and finally the upper and lower vacuum suction cups can move in a single direction up and down. Finally, lift the upper vacuum suction cup and separate it from the lower vacuum suction cup by a certain distance, usually 1-2 cm, and start imprinting after loading the template and the object to be imprinted.

The upper and lower vacuum suction cups can change the appropriate shape according to the needs, so that materials of different shapes and sizes can be embossed. Since the pressure can be adjusted evenly before imprinting, the silicon wafer can be directly imprinted without turning the silicon wafer into a metal template, which can simplify the processing method and reduce the cost.

After the pre-pressing of the upper and lower suction cups is completed, lift the upper suction cup 1-2 cm and then install the template and the object to be imprinted. At this time, the optical sensor can be used to align the template and the object to be imprinted. The specific method is as follows: the template can be fixed by adsorption first, and then the object to be imprinted can be moved manually or with an auxiliary tool, and the alignment can be carried out through optical sensor observation. After the alignment, the object to be imprinted can be adsorbed and fixed, and finally the imprinting can start. The alignment method can also first absorb and fix the object to be imprinted, and then perform alignment by moving the template, or through the alignment of the clamping tool itself, to realize the alignment between the template and the object to be imprinted.

The device applying the manufacturing method of nanometer-level graphic imprinting of the present invention is composed of a pressure control component, a motion assurance controllable component, a temperature control component and an adsorption component. The pressure control component is located at the middle and upper part of the pressure guide cylinder installed on the support plate of the bench, and the motion assurance control component is installed at the lower part of the pressure guide cylinder through the spline guide cylinder. The upper vacuum suction cup of the adsorption component is connected with the spline guide rod of the motion assurance controllable component, and the lower vacuum suction cup is connected with the support plate on the base of the platform. The temperature control component is located under the lower vacuum chuck part of the adsorption component, wherein the upper surface of the heating device is in close contact with the lower surface of the lower vacuum chuck.

The pressure control assembly includes a pressure generating mechanism and a pressure restoring mechanism. The pressure generating mechanism consists of a pressure threaded rod and a pressure guiding cylinder. The pressure threaded rod is installed on the upper part of the pressure guiding cylinder and connected by threads, so that the rotating torque acting on the pressure threaded rod can be transformed into a downward pressure by using the principle of the screw nut. And can make the pressure constant. The pressure recovery mechanism mainly includes a pressure spring, which is set between the spline guide rod and the pressure guide cylinder, and between the spring stopper under the pressure threaded rod and the spline guide cylinder; the recovery force of the pressure spring is used to generate Larger draft force and upward movement of the upper vacuum suction cup. The present invention calculates the pressure transmitted on the spring stopper by measuring the torque applied to the pressure threaded rod, and then subtracts the elastic force of the spring itself during the compression process to obtain the real imprinting force, that is, the pressure applied on the template . Usually, during embossing, the embossing pressure on the control template is controlled at 40-100bar, and the conversion formula is as follows:

Fb (real impression force) = Fn (torque conversion pressure) - Ft (spring force)

Ft (spring force) = k (spring coefficient) × L (spring compression length)

Pb (template imprint pressure) = Fb (true imprint force) / S (template area)

The movement guarantee controllable component is a controllable device that guarantees movement in a single direction up and down, including: a spline guide cylinder installed at the lower part of the pressure guide cylinder, and a spline guide rod connected by splines to form a single direction controllable movement mechanism. Since the spline guide rod is double restricted by the spline guide cylinder and the upper end spring stopper, if the interference fit is adopted, it can finally ensure the controllable movement of the suction cup relative to the vertical up and down (or in a single direction), especially to prevent the ejection process Graphic damage caused by the left and right and rotational movements; the upper part of the upper vacuum suction cup is a circular sleeve with a certain height, which is nested with the lower part of the spline guide rod above it, and there are four evenly distributed around the circumference of the circular sleeve. The bolt holes are connected with the lower part of the spline guide rod by four bolts through the four bolt holes evenly distributed in the circumferential direction on the upper part. The surfaces of the upper and lower vacuum suction cups are relatively parallel and can controllably move in a single direction.

The temperature control assembly includes a heating device, a temperature control device and a thermal insulation device. The heating device is located at the lower part of the lower vacuum suction cup, and is heated by a hot plate so that the temperature is uniform and the heating is rapid. The temperature control device adopts electronic temperature control to control the temperature of the heating object within the required range, and the accuracy meets the requirements. The effect of heat insulation device is to prevent the place temperature that does not need heating such as bench too high during heating process. The invention adopts air heat insulation and heat insulation material heat insulation when the upper and lower vacuum suction cups are connected with other devices, so as to prevent the peripheral temperature from overheating.

The adsorption assembly includes an upper vacuum suction cup and a lower vacuum suction cup. The upper vacuum suction cup looks like a "⊥" shape when viewed from the top. The upper part is a circular sleeve with a certain height and four bolt holes are evenly distributed around the circumference of the circular sleeve. The lower part is a flat plate with a certain thickness. The lower vacuum suction cup is a certain height. Thickness plate, four bolt holes evenly distributed around its circumference. The suction cup is made of high-hardness materials such as stainless steel, with a smooth adsorption surface and grooves for vacuuming. The groove is usually 1 mm deep and 1 mm wide. Multiple annular grooves are distributed in a concentric manner. The number of annular grooves is determined according to the size of the required adsorption force, and then the grooves in the vertical and horizontal directions are used to connect the annular grooves. The groove and the template or the object to be imprinted form a closed space. An air suction circular hole is opened on the side of the suction cup to communicate with the enclosed space, and the air in the enclosed space is drawn from the air suction circular hole to tightly absorb the template or the object to be imprinted. During the contact and separation process between the template and the object to be imprinted during the imprinting process, it is necessary to ensure that it is closely connected with the surface of the upper and lower suction cups.

Since customers need to emboss materials of different sizes, in order to ensure good embossing effects (such as uniform pressure, etc.), the size of the vacuum suction cup itself can be changed and the appropriate shape can be changed according to needs, so that materials of different shapes and sizes can be embossed .

During the embossing process, the key is that the template and the surface of the object to be imprinted should be relatively parallel and can be controlled in a single direction up and down, and then the surface of the upper and lower vacuum suction cups should be relatively parallel and can be controlled in a single direction up and down. Due to limited conditions, it is difficult to ensure that they are relatively parallel. The present invention uses a motion-guaranteed controllable component to ensure that they are relatively parallel during the embossing process. Motion Assurance Controllable components are mechanically hand leveled. Before embossing, the upper vacuum suction cup and the spline guide rod are connected flexibly, that is, the connecting bolts are loosened, and then pressurized so that the upper and lower vacuum suction cups are in close contact; at this time, the sleeve connected with the spline guide rod on the suction surface of the upper vacuum suction cup is used Four screws evenly distributed in the circumferential direction lock and rigidly connect it with the spline guide rod. Then remove the pressure and lift the upper vacuum suction cup, install the template to be imprinted and the object to be imprinted on the upper and lower vacuum suction cups. At this time, the imprint can be started by controlling the temperature control component to heat and press, and the template is parallel to the object to be imprinted. And the movement can be controlled in one direction.

Description of drawings

Figures 1a, b, c, and d are schematic diagrams of the principle of the imprint manufacturing method for nanoscale graphics of the present invention. In the figure, Figure 1a shows the preloading and leveling of the upper and lower vacuum suction cups, Figure 1b shows the clamping template and the object to be imprinted, Figure 1c shows heating and pressing, and Figure 1d shows the demoulding and separation. In the figure: 1 template, 2 photoresist, 3 substrate, 17 upper vacuum chuck, 18 lower vacuum chuck;

FIG. 2 is a cross-sectional view of an imprinting device for nanoscale patterns of the present invention. In the figure: 4 vacuum suction cup heat insulation materials, 5 bench support columns, 6 bench support plates, 7 is the pressure guide cylinder of the bench, 8 is the pressure threaded rod, 9 is the torsion bar, and 10 is the upper support plate of the bench base , 11 spring stopper, 12 pressure spring, 13 spline guide cylinder, 14 spline guide rod, 15 bench base support plate, 17 upper vacuum suction cup, 18 lower vacuum suction cup, 19 heating device, 20 bench base support plate;

Fig. 3 is a schematic diagram of the connection method between the upper part of the upper vacuum suction cup and the spline guide rod in the present invention. In the figure: 14 spline guide rod, 16 upper vacuum suction cup insulation material, 17 upper vacuum suction cup, 301 bolt hole, 302 suction round hole, 303 groove;

Figure 4a, b, c are schematic diagrams of the existing nanoimprint lithography technology. Figure 4a in the figure shows the mutual positional relationship between the template and the object to be imprinted when it is not imprinted, Figure 4b shows the mutual positional relationship between the template and the object to be imprinted during imprinting, and Figure 4c shows the template and the object to be imprinted when the imprinting is completed mutual positional relationship. In the figure: 1 template, 2 photoresist, 3 substrate;

Figure 5a, b, c are diagrams of different imprinting methods. Figure 5a in the figure shows the roller-type nanoimprinting method, Figure 5b shows the cushion pad method, and Figure 5c shows the gas micro-hot embossing method. In the figure: 1 template, 2 photoresist, 3 substrate, 101 template, 102 upper embossing plate, 103 lower embossing plate, 104 buffer pad, 105 elastic sealing film, 106 high-pressure air source, 107 metal cover.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1a, b, c, d are schematic diagrams of the principle of the imprinting manufacturing method of nano-level graphics of the present invention. As shown in Figure 1a, the upper and lower vacuum chucks are pre-pressed before imprinting so that the adsorption surfaces are in full contact. Since the upper and lower vacuum chucks are made of high-hardness materials and the contact surface is perpendicular to the force direction, it indicates that the adsorption surfaces are parallel and the pressure Evenly distributed, and then lock the relevant connection mechanism. Through the four bolt holes uniformly distributed in the circumferential direction of the lower vacuum chuck 18, the lower vacuum chuck 18 and the upper support plate 10 of the stand base are tightened and locked with bolts, and the four bolt holes 301 uniformly distributed in the circumferential direction of the circular sleeve on the upper part of the vacuum chuck 17 are used. The bolt tightens and locks the upper vacuum suction cup 17 and the spline guide rod 14 that is sleeved with its sleeve.

As shown in FIG. 1 b , the template 1 , the object to be imprinted—the photoresist 2 and the substrate 3 are loaded, and an optical sensor is used to align the template 1 and the objects to be imprinted 2 and 3 . Adopting the sucker adsorption method can increase the hardness of the template 1 and the object to be imprinted, and improve the uniformity of the imprinting pressure distribution. The controllable assembly ensures that the spline guide rod 14 moves in a single direction up and down through the movement, while the upper vacuum suction cup 17 is locked and fixed on the bottom top of the spline guide rod 14, and the lower vacuum suction cup 18 is fixed on the stand and does not move. Therefore, the spline guide rod 14 drives the upper and lower vacuum suction cups 17 to move in a single direction up and down, and finally the upper and lower vacuum suction cups can move in a single direction up and down relative to each other. Finally, the upper vacuum chuck 17 is lifted and separated from the lower vacuum chuck 18 by a certain distance, usually 1-2 cm, and the template and the object to be imprinted are loaded.

As shown in Figure 1c, when heating and pressing, the template 1, the object to be imprinted: the photoresist 2 and the substrate 3 will be heated and pressed up and down, wherein the temperature and pressure should be controlled according to needs, for example, to ensure that the temperature is heated Uniform and constant, high pressure and constant.

As shown in FIG. 1d, when the mold is released and separated, the template 1 and the object to be imprinted: the photoresist 2 and the substrate 3 are separated in a single direction up and down. And the graphic damage caused by the left and right and rotational movements of the two cannot occur during separation.

FIG. 2 is a cross-sectional view of the imprinting device for nanoscale patterns of the present invention. In FIG. 2 , the lower support plate 20 of the platform base is a square iron plate located at the bottom of the device, and the upper support plate 10 of the platform base is supported by two left and right platform base support plates 15 erected thereon. The shape of the support plate 10 on the platform base is square, and the center is a round hole. Three stand support columns 5 are uniformly distributed around the center of support plate 10 on the stand base, and the stand support plate 6 with holes in the center of the circle is installed on the three stand support columns 5 . The platform support plate 6, the platform support column 5, the upper support plate 10 of the platform base, the lower support plate 20 of the platform base, and the platform base support plate 15 are connected by bolts to form a nanoimprint lithography machine platform for supporting The role of the device. Bench pressure guiding cylinder 7 is installed in the round hole in the middle of bench support plate 6 by bolt connection, and lower vacuum sucker 18 is installed in the center round hole of support plate 10 on the bench base by bolt connection.

As shown in FIG. 2 , the pressure control assembly is located on the upper part of the device, including a pressure threaded rod 8 , a torsion rod 9 and a pressure spring 12 . The pressure threaded rod 8 is installed on the top of the bench pressure guiding cylinder 7, and is threadedly connected with the pressure guiding cylinder 7. The torsion bar 9 passes through the circular hole on the top of the pressure guiding cylinder 7 of the stand, and the torsion bar 9 is rotated by the principle of the lead screw nut to drive the pressure threaded bar 8, so that the rotational torque becomes downward pressure. The pressure spring 12 is sleeved between the spline guide rod 14 and the pressure guide cylinder 7 and between the spring catch 11 on the top of the pressure threaded rod 8 and the spline guide cylinder 13 . When the pressure spring 12 is pressed and restored, the spring stopper 11 is pushed upward, and then the spline guide rod 14 is driven upward to generate a larger draft force, thereby forming a pressure recovery mechanism. The pressure can be calculated by measuring the torque on the torsion bar 9 .

The motion assurance controllable assembly is a single up and down movement assurance controllable device, which is located at the lower part of the pressure control assembly and includes a spline guide cylinder 13 . The spline guide cylinder 13 is installed on the lower part of the pressure guide cylinder 7 through bolt connection, and the spline guide rod 14 connected with the spline can only move up and down in the spline guide cylinder 13, thereby forming a single direction controllable movement mechanism . It can finally ensure the controllable movement of the suction cup up and down (or in a single direction), especially to prevent damage to the graphics caused by the left, right and rotational movements during the demoulding process. The upper vacuum suction cup 17 looks like a "⊥" shape when viewed from a plane, and the upper part is a circular sleeve with a certain height. The hole is equipped with four locking bolts, and four bolts connect it with the splined guide rod 14 bottoms. The orientation installed on the lower part of the splined guide rod 14 can be adjusted as required, thereby forming a suction cup leveling mechanism, which can ensure relatively parallel and single-direction controllable movement of the upper and lower vacuum suction cup surfaces.

The temperature control assembly is located between the upper support plate 10 of the platform base and the lower support plate 20 of the platform base, including a heating device 19 , an upper vacuum chuck heat insulating material 16 and a lower vacuum chuck heat insulating material 4 . The heating device 19 is located directly below the lower vacuum chuck 18, and is in close contact with the surface of the vacuum chuck 18, and is heated by a hot plate so that the temperature is uniform and the heating is rapid. The lower vacuum chuck heat insulating material 4 is a metal gasket, which is placed between the lower vacuum chuck 18 and the bolt of the stand, so that the lower vacuum chuck 18 is isolated from the support plate 10 on the base of the stand, and heat can be prevented from spreading from the lower vacuum chuck 18 to The lower part of the stand. Between the upper vacuum chuck 17 and the spline guide rod 14, a heat insulating material 16 is placed to prevent heat from spreading to the spline guide rod 17 top platform.

The adsorption assembly is located between the spline guide rod 14 and the upper support plate 10 of the platform base, including: the upper vacuum suction cup 17 connected with the lower part of the spline guide rod 14 by bolts, and the lower vacuum suction cup 17 connected with the upper support plate 10 of the platform base by bolts. sucker18. During the contact and separation process of the template and the object to be imprinted during the imprinting process, it is necessary to ensure that it is closely connected with the surface of the upper and lower vacuum suction cups. The present invention adopts vacuum adsorption. The vacuum chuck can also change the appropriate shape according to the needs, so as to imprint materials of different shapes and sizes.

Manually turn the torsion bar 9 to make the pressure threaded rod 8 rotate, and according to the principle of the lead screw nut, the rotating torque becomes downward pressure through the bench pressure guide cylinder 7 . The spring catch 11 is subjected to downward pressure, compresses the pressure spring 12, and drives the spline guide rod 14 to move downward together through the spline guide cylinder 13 . The spline guide bar 14 and the upper vacuum chuck 17 are actively connected by the upper vacuum chuck heat insulating material 16 and the locking bolt, and the lower vacuum chuck 18 is also connected with the stand by the lower vacuum chuck heat insulating material 4 . When embossing, the upper vacuum chuck 17 and the lower vacuum chuck 18 absorb the template and the object to be imprinted respectively. The heating device 19 can monitor the temperature of the template and the imprinting material in real time according to the imprinting conditions. Thus, under the pressure of the splined guide rod 14 , the upper vacuum chuck 17 can interact with the lower vacuum chuck 18 to squeeze the stencil and the imprinting material. When the embossing is finished, by turning the torsion bar 9 manually, the pressure threaded rod 8 is rotated and withdrawn from the downward pressure applied to the spring catch 11 . At the same time, under the spring restoring force of the pressure spring 12, the spline guide rod 14 is driven upward by the spring catch 11, and finally the upper vacuum suction cup 17 and the lower vacuum suction cup 18 move up and down relatively, and at the same time, the template is separated from the object to be imprinted .

The present invention adopts a manual method and utilizes the principle of a screw nut to transform the torque into a downward pressure, and can use this principle to automatically lock the position during embossing, thereby keeping the pressure constant. And when the pressure is removed, the upper vacuum suction cup 17 can be returned to its original position by the restoring force of the pressure spring 12, and a larger draft force can be produced at the moment of demoulding.

According to the principle of nano-thermal embossing, the present invention ensures that the template and the object to be imprinted must remain parallel during the embossing process, and the relative movement must be strictly controlled relative to vertical up and down (or a single direction), especially to prevent left and right in the demoulding process. and graphics corruption due to rotational motion. The specific measures are to connect the spline guide rod 14 on the top of the vacuum suction cup 17 with the spline guide cylinder 13, so as to ensure that the spline guide rod 14 only has a single direction controllable movement and prevents left and right and rotational movement.

Fig. 3 is a schematic diagram of the connection method between the upper part of the upper vacuum suction cup and the spline guide rod in the present invention. The upper vacuum suction cup 17 is in the shape of "⊥" when viewed from above. The upper part is a circular sleeve with a certain height and four bolt holes 301 are uniformly distributed around the circumference of the circular sleeve, and the lower part is a flat plate with a certain thickness. The adsorption surface is smooth, and there is a groove 303 for vacuuming, and a suction circular hole 302 is opened on the side of the suction cup to communicate with the groove 303 . As shown in Figure 3, before imprinting, the upper vacuum suction cup 17 is flexibly connected with the spline guide rod 14, and then pressurized so that the upper and lower vacuum suction cups are in close contact; The four bolt holes 301 evenly distributed are rigidly connected with the spline guide rod 14 by locking. Then the pressure is lifted to lift the upper vacuum chuck 17, and the clamp template 1 and the objects to be imprinted 2, 3 can be heated and pressurized to start imprinting, and the upper and lower vacuum chucks can move in parallel and in a single direction. The upper vacuum suction cup heat insulation material 16 is organic matter and other materials, which can prevent heat from spreading to the top of the stand from the upper vacuum suction cup 17. At the same time, because the upper vacuum suction cup heat insulation material 16 itself has certain elasticity, it can play an elastic connection role when leveling. Easier to level.

The heating device 19 of the present invention is heated by a hot plate. In the heating process, the temperature is too high in places where the platform and the like do not need to be heated. The present invention adopts air heat insulation and heat insulation material heat insulation when the upper and lower vacuum chucks 17, 18 are connected with other devices, so as to prevent the peripheral recent temperature from heating up.

In the present invention, the embossing method is from top to bottom, and the pressure mechanism that generates pressure can be used in the bottom-to-top embossing method, and this only needs to install the device upside down. Manual pressurization can also be changed to mechanical electric pressurization.

In the present invention, in order to ensure that the template 1 and the objects to be imprinted 2 and 3 are kept parallel during the imprinting process and that the relative movement is strictly guaranteed to be relatively vertical and up-down (or in a single direction) controllable movement, a spline guide rod 14 and The spline connection of the spline guide cylinder 13, on this basis, the accuracy of the guide can be ensured by changing the number of splines, or the gap between the spline guide rod 14 and the spline guide cylinder 13 can be adjusted by bolts to control the guiding accuracy.

In the present invention, the upper and lower vacuum chucks 17, 18 use vacuum adsorption to absorb the template and the object to be imprinted, and the heating is also indirectly passed through the upper and lower vacuum chucks 17, 18. The functions of the upper and lower vacuum chucks 17, 18 can also be expanded on this basis, for example, they can change appropriate shapes as required, so that materials of different shapes and sizes can be embossed.

Experiments were carried out using the imprinting method and device for nanoscale patterns of the present invention. In this experiment, the hardness of the template 1, substrate 2 and photoresist 3 to be imprinted is improved through the adsorption method of the planar vacuum suction cup, and the pressure distribution during imprinting is made uniform by using the pre-pressure of the suction cup. When loading the template 1 and the objects to be imprinted 2, 3, an optical sensor is used to align the template 1 and the objects to be imprinted 2, 3. Finally, the photoresist 2 is heated above the glass transition temperature (Tg) by heating, and then pressurized in a softened state. The fine pattern is transferred to the photoresist 2 on the substrate 3 by applying pressure to the template 1 having the nanoscale fine concave-convex pattern. The specific operation method is as follows:

First the upper vacuum suction cup 17 is movably connected with the spline guide rod 14, and the lower vacuum suction cup is movably connected with the support plate 10 on the stand base, that is, the connecting bolts are not tightened earlier, so that the upper and lower vacuum suction cups 17, 18 can still move slightly up and down. When starting preloading, manually rotate the torsion bar 9, thereby turning the pressure threaded rod 8, so that the rotational torque becomes downward pressure. Push the spline guide rod 14 to move downward by the spring catch 11 again. Finally, the upper and lower vacuum chucks 17, 18 are brought into contact with the adsorption surfaces, and the mutual pressure rises to the pressure range of 40-100 bar during actual imprinting, which can be calculated by the torque applied to the pressure threaded rod 8 . At this time, due to the complete contact of the adsorption surface, the upper and lower vacuum chucks are made of high hardness material and the contact surface is perpendicular to the force direction, which indicates that the adsorption surface is parallel and the pressure distribution is uniform at this time. Then lock the relevant connecting mechanism, tighten the four bolts that are uniformly distributed in the circumferential direction of the lower vacuum suction cup 18, lock the lower vacuum suction cup 18 and the stand, and tighten the four bolts that are evenly distributed in the circumferential direction of the upper circular sleeve of the upper vacuum suction cup 17. Locked with the spline guide rod 14 that is sleeved with its sleeve. Finally, the torsion bar 9 is rotated, and the pressure spring 12 pushes the spring stopper 11 to move upward when the pressure spring 12 is pressed back, thereby driving the upper vacuum suction cup to lift and separate from the lower vacuum suction cup by a certain distance, usually 1-2 cm.

Install the template 1, the photoresist 2 and the substrate 3 on the adsorption surfaces of the upper and lower vacuum chucks 17 and 18 respectively, so that the upper vacuum chuck 17 absorbs the template 1 and the lower vacuum chuck 18 absorbs the photoresist of the object to be imprinted. The resist 2, the substrate 3, the upper vacuum chuck 17 and the adsorption template 1, the lower vacuum chuck 18, the printed photoresist 2, and the substrate 3 are respectively integrated.

When loading the template 1 and the photoresist 2 and substrate 3 of the object to be imprinted, the template 1 and the objects to be imprinted 2 and 3 are aligned by an optical sensor. The specific method is as follows: first use the vacuum chuck 17 to absorb and fix the template 1, then move the objects 1 and 3 to be imprinted manually or with an auxiliary tool, and perform alignment through optical sensor observation. The highest level of alignment accuracy is 100nm. Finally, the object to be imprinted is adsorbed and fixed on the lower vacuum chuck 18 .

When heating and pressing, the template 1 is first moved down to contact with the photoresist 2 to facilitate heat transfer, but at this time the pressure between the two is zero. Then the heating device 19 heats the lower vacuum chuck 18 with a hot plate, so that the template 1, the photoresist 2, and the substrate 3 are heated rapidly, and the temperature control component adopts electronic temperature control to control the temperature of the heating object within the required range, and the accuracy meets the requirements 1 ℃. Finally, the photoresist PMMA is heated to a glass transition temperature of 190-200°C above 105°C, so that the photoresist has good fluidity. Then start to pressurize, so that the pressure between the template and the object to be imprinted reaches between 40 and 100 bar. The pressure can be kept constant through the pressure generating mechanism, so that the photoresist 2 made of polymer PMMA glue penetrates into the nanoscale fine structure of the template 1 .

After the pattern transfer is completed, the temperature of the template 1, the photoresist 2, and the substrate 3 is lowered to 80°C. Then the pressure is gradually eliminated, so that the pressure between the template 1 and the photoresist 2 is zero. Due to the return action of the pressure spring 12, the template 1 and the substrate 3 are respectively adsorbed on the upper and lower vacuum chucks 17, 18, and a larger drawing force is generated under the return action of the pressure spring, thereby separating the template 1 and the photoresist 2.

The substrate 3 is taken out from the lower vacuum chuck 18 . Observing the pattern of the photoresist 2 of this embodiment with a scanning electron microscope (SEM), it can be seen that the pattern on the stencil 1 is almost faithfully reproduced.

In this experiment, the template 1 is a quartz glass plate with a length and width of 2.5 inches and a thickness of 3mm. On its surface, metal Cr with a thickness of 140nm is plated, and the required pattern is etched with an electron beam on the Cr layer. The pattern is 140nm in height, minimum The protrusions on the glass surface with a line width of 200 nm are fine patterns of Cr. The material of the substrate 2 is a circular silicon wafer with a thickness of 1 mm and a diameter of 2 inches. The photoresist 2 is conventional photoresist of PMMA, and the thickness of the photoresist 2 is 2 μm.

Utilizing the method of the invention, the brittle material will be greatly reduced when the pressure is uneven.

The embossing device adopting the nanometer-level pattern of the present invention can realize pattern transfer with a characteristic size below 10nm, can form fine patterns and mass-produce them, and can also meet the needs of scientific researchers who study nanostructures and devices. The manufacturing cost of the device of the invention is low, which is only one percent of the price of a common electron beam lithography machine. The invention can be used to prepare various nanometer electronic devices, optical devices, memories, nanofluid channels, biochips and the like.

Claims (6)

1, a kind of impression manufacture method of Nano grade figure, it is characterized in that: adopt area vacuum sucker suction type that masterplate [1] and thing to be impressed [2,3] are installed on two vacuum cups [17,18] absorption surface up and down respectively, upward vacuum cup [17], following vacuum cup [18] adsorb masterplate [1] and thing to be impressed [2,3] respectively when making impression, last vacuum cup [17] and masterplate [1], following vacuum cup [18] forms one respectively with thing to be impressed [2,3]; Before the impression, vacuum cup [17 up and down at first pressurizes, 18], its absorption surface is contacted fully, use four circumferential uniform bolts of circular sleeve upper groove that vacuum cup [17] top is connected with spline guide pole [14] this moment with itself and locked being rigidly connected of spline guide pole [14], to descend vacuum cup [18] and locked being rigidly connected of stand base upper backup pad [10] with circumferential four the uniform bolts of following vacuum cup [18], sucker can only be made unidirectional motion relatively up and down about making, cancel pressure then and lift vacuum cup [17], masterplate [1] and thing [2 to be impressed are installed on vacuum cup absorption surface up and down, 3], just can carry out heating and pressurizing and begin impression this moment by the control temperature-controlling module; In masterplate that is installed [1] and thing to be impressed [2,3], can utilize optical sensor that masterplate [1] and thing to be impressed [2,3] are aimed at, by adsorbing fixedly masterplate [1] earlier, move thing to be impressed [2,3] again and aim at; Also can adsorb thing fixedly to be impressed [2,3] earlier, mobile again masterplate [1] is aimed at.

2, the impression manufacture method of Nano grade figure according to claim 1, it is characterized in that: utilize feed screw nut principle and spline guiding principle, by the combination control impression pressure of pressure threaded rod [8], stand pressure guide cylinder [7], spline guide pole [14], spline guide cylinder [13], spring washer [11] and pressure spring [12] and the size and Orientation of withdrawing pattern power; The spline guide pole [14] on last vacuum cup [17] top is connected with the spline of spline guide cylinder [13], makes spline guide pole [14] and last vacuum cup [17] have only the controlled motion of single direction; Pressure threaded rod [8] rotary torque becomes downward pressure during impression, promotes spline guide pole [14] and moves downward, and impresses; During the demoulding, remove pressure, utilize the restoring force of pressure spring, produce bigger withdrawing pattern power vacuum cup [17] is moved upward.

3, application rights requires the device of the impression manufacture method of 1 described Nano grade figure, it is characterized in that: device comprises that pressure control assembly, motion guarantee controllable components, temperature-controlling module and absorbent module; Pressure control assembly is positioned at the middle and upper part of the stand pressure guide cylinder that is installed on the stand back up pad [6], motion guarantees that Control Component is installed in stand pressure guide cylinder [7] bottom by spline guide cylinder [13], absorbent module is positioned between spline guide pole [14] and the stand base upper backup pad [10], last vacuum cup [17] guarantees that with motion the spline guide pole [14] of controllable components is connected, following vacuum cup [18] is connected with stand base upper backup pad [10], temperature-controlling module is positioned between stand base upper backup pad [10] and the stand base lower supporting plate [20], the below of the following vacuum cup [18] of absorbent module, wherein heating arrangement [19] upper surface closely contacts with following vacuum cup [18] lower surface.

4, device according to claim 3 is characterized in that: pressure control assembly comprises pressure threaded rod [8], torque arm [9], stand pressure guide cylinder [7], spring washer [11] and pressure spring [12]; Pressure threaded rod [8] is installed in the top of stand pressure guide cylinder [7], adopts with stand pressure guide cylinder [7] to be threaded; Torque arm [9] passes the circular hole on pressure threaded rod [8] top; Pressure spring [12] is enclosed between the spring washer [11] and spline guide cylinder [13] between spline guide pole [14] and the stand pressure guide cylinder [7], below pressure threaded rod [8]; Described motion guarantees that controllable components comprises the spline guide cylinder [13] that is installed in stand pressure guide cylinder [7] bottom, with the spline guide pole [14] that spline guide cylinder [13] spline is connected, spline guide cylinder [13] and spline guide pole [14] are formed single direction controlled motion mechanism; Absorbent module comprises vacuum cup [17] and following vacuum cup [18], the bottom of the circular sleeve on last vacuum cup [17] top and its top spline guide pole [14] is nested, on circular sleeve, circumferentially be evenly equipped with four bolts hole [301], with four bolts it is connected with spline guide pole [14] bottom, can adjusts the orientation that is installed in spline guide pole [14] bottom as required; Temperature-controlling module comprises heating arrangement [19], last vacuum cup heat-barrier material [16] and following vacuum cup heat-barrier material [4], heating arrangement [19] be positioned at following vacuum cup [18] under, closely contact with following vacuum cup [18] surface, adopt hot plate to heat; Following vacuum cup heat-barrier material [4] is a metallic gasket, is placed on down between the bolt of vacuum cup [18] and stand, and vacuum cup [18] and stand base upper backup pad [10] are isolated; Between last vacuum cup [17] and spline guide pole [14], be placed with vacuum cup heat-barrier material [16]; Absorbent module comprise with spline guide pole [14] bottom by bolted go up vacuum cup [17], with the bolted vacuum cup [18] down of stand base upper backup pad [10].

5, according to claim 3 or 4 described devices, it is characterized in that: vacuum cup [17,18] is the area vacuum sucker up and down, absorption surface has in order to the annular groove that vacuumizes [303], and a plurality of annular grooves distribute with concentric manner, and the groove of direction is connected annular groove [303] in length and breadth; Last vacuum cup [17] is looked squarely the shape as ⊥, and the bottom is for there being certain thickness flat board, and top is the circular sleeve that is positioned at dull and stereotyped central authorities; Vacuum cup [17,18] adopts high hardness material up and down, and absorption surface has very high flatness; Vacuum cup [17,18] can change suitable shape according to the needs of impression difformity and big or small material up and down.

6, according to claim 3 or 4 described devices, it is characterized in that: pressure control assembly becomes pressure threaded rod [8] rotary torque into downward pressure by stand pressure guide cylinder [7], promotes spline guide pole [14] and moves downward; When removing pressure, be contained in pressure spring [12] on the spline guide pole [14] can be replied spline guide pole [14] under the effect of spring washer [11] reference position.

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