Exposure apparatus and method based on dpp light source

Abstract

The application discloses an exposure device and method based on a DPP light source, comprising a DPP light source, a zirconium film, a multilayer film mirror and a linear grating, wherein the DPP light source is used for generating EUV light; the zirconium film filters the EUV light generated by the DPP light source; the multilayer film mirror collects the EUV light output by the DPP light source, and reflects the EUV light to vertically enter the linear grating; the vertically-entered EUV light interferes through the linear grating, and reaches photoresist to be exposed, wherein the intensity distribution of the EUV light on the photoresist plane is triangular distribution, and the intensity changes linearly with the position. The application can form a small-feature pattern by controlling an exposure dose, and can obtain a periodic pattern with a feature size of less than 25 nanometers by controlling the exposure dose; and smaller exposure linewidth can be realized by optimizing photoresist material.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photolithography, and in particular to an exposure device and method for obtaining a 25nm line width based on a DPP light source. BACKGROUND

[0002] High-resolution nanometer patterning, especially in the region of feature size below 20 nanometers, is still a challenge for most photolithography techniques and has become an important research field in modern nanotechnology.

[0003] Extreme ultraviolet interference lithography has the characteristics of high resolution and high throughput parallel manufacturing. The athermal spatial frequency multiplication (ASFM) technology based on athermal Talbot effect can be used to manufacture 1D and 2D periodic nanostructures with a period of hundreds of nanometers.

[0004] For example, Chinese patent CN111077739A discloses an extreme ultraviolet light exposure device and method and a method for manufacturing a semiconductor device, wherein the extreme ultraviolet light (EUV) exposure device comprises: an EUV source configured to generate and output EUV; a first illumination optical device configured to transmit the EUV to an EUV mask; a projection optical device configured to project the EUV reflected from the EUV mask onto an exposure target; a laser source configured to generate and output a laser beam; and a second illumination optical device configured to irradiate the laser beam onto at least one mirror included in the projection optical device. This patent can reduce or minimize errors caused by the mirror in the EUV exposure process to reduce overlay errors. However, the exposure method used in this patent has a great relevance to the accuracy of the final pattern and the mask, and has a high requirement for the accuracy of the mask. The size of the final pattern will correspond to the mask pattern, and defects in the mask line will also be copied to the final exposed pattern. SUMMARY

[0005] In view of the defects in the prior art, the present application provides an exposure device and method based on a DPP light source, which can simply and effectively obtain an exposure pattern with a smaller feature size, and reduces the requirement for the accuracy of the mask and avoids defects in the mask line being copied to the final exposed pattern.

[0006] In a first aspect, the present application provides an exposure device based on a DPP light source, comprising: a DPP light source, a zirconium film, a multilayer film mirror, and a linear grating, wherein:

[0007] The DPP light source is used to output EUV light;

[0008] The zirconium film filters the EUV light generated by the DPP light source;

[0009] The multilayer film mirror collects the EUV light output by the DPP light source, and reflects the EUV light to be perpendicularly incident on the linear grating, and plays a role of in-band filtering.

[0010] The perpendicularly incident EUV light is interfered by the linear grating, and reaches the photoresist to be exposed, wherein the intensity distribution of the EUV light on the photoresist plane is a triangular section, and the intensity changes linearly with the position.

[0011] Optionally, the exposure device further comprises a micro-nano carrier platform, which carries a wafer loaded with photoresist, and can move the wafer loaded with photoresist to a set distance close to the linear grating, and keep the wafer horizontal with the linear grating; wherein the set distance is the distance between the linear grating and the wafer to meet the requirements of achromatic talbot lithography.

[0012] Optionally, the DPP light source provides EUV light with a wavelength of 13.5 nm and a bandwidth of 4%.

[0013] Optionally, the linear grating has a period of 100 nm, and the image of the light rays interfered on the photoresist plane presents alternating light and dark stripes with a period of 50 nm.

[0014] Optionally, the exposure device further comprises a debris removal device for removing harmful particles generated by the discharge of the light source electrode; the DPP light source generates EUV light, which is filtered by the zirconium film after passing through the debris removal device, and is collected and focused on the linear grating by the multilayer film mirror.

[0015] In a second aspect, the application provides an exposure method based on a DPP light source, comprising:

[0016] The DPP light source outputs EUV light with a set wavelength and bandwidth;

[0017] The zirconium film filters the EUV light generated by the DPP light source;

[0018] The multilayer film mirror collects the EUV light output by the DPP light source, and reflects the EUV light to be perpendicularly incident on the linear grating, and plays a role of in-band filtering;

[0019] The perpendicularly incident EUV light is interfered by the linear grating, and reaches the photoresist to be exposed, wherein the intensity distribution of the EUV light on the photoresist plane is a triangular section, and the intensity changes linearly with the position.

[0020] Optionally, the exposure method further comprises: moving the wafer loaded with photoresist to a set distance close to the linear grating and keeping horizontal with the linear grating by controlling the micro-nano carrier platform, wherein the set distance is the distance between the linear grating and the wafer meeting the requirements of implementing achromatic talbot lithography.

[0021] Optionally, the DPP light source provides extreme ultraviolet light with a wavelength of 13.5 nm and a bandwidth of 4% after filtering.

[0022] Optionally, the linear grating period is 100 nm, and the image of the light rays that interfere on the photoresist plane presents alternating light and dark stripes with a period of 50 nm.

[0023] Optionally, in the exposure method, the exposure intensity and exposure time of the exposure process are controlled to change the etching effect achieved on the photoresist, and finally the line width is controlled.

[0024] Optionally, in the exposure method, the exposure dose in the EUV lithography exposure process is controlled to obtain an exposure pattern with a small line width size, wherein:

[0025] When the exposure dose is large, small intensity has an effect on the photoresist; when the exposure dose is small, only the part with high intensity has an effect on the photoresist, and the line width obtained after exposure is proportional to the exposure dose;

[0026] By controlling the exposure time and the exposure intensity to change the exposure dose, a periodic pattern with a line width size of less than 25 nm is obtained.

[0027] Compared with the prior art, the present application has at least one of the following beneficial effects:

[0028] The present application provides an exposure device and method, EUV emitted by the DPP light source is vertically incident to the grating surface, because the light intensity has a triangular cross section, small feature patterns can be formed by controlling the exposure dose. Based on the Talbot effect, high flux and efficiency can be achieved in large-area and high-resolution patterning processes.

[0029] The present application provides an exposure device and method, by the cooperation between the DPP light source, the multi-layer film mirror and the linear grating, the distance between the grating and the wafer meets the requirements of implementing ASFM, further by controlling the exposure intensity and the exposure time, the etching effect achieved on the photoresist is changed, finally the effect of controlling the line width is achieved, and a periodic pattern with ideal size is obtained. Further, the period of the exposure pattern in the present application can be reduced to half of the grating period, the line width can be controlled by controlling the exposure dose, and the small defects at the edge of the grating will not be recorded on the exposure pattern.

[0030] The present application provides an exposure device and method, by controlling exposure metering, a periodic pattern with a feature size of 25nm or less can be obtained, and optimizing photoresist material is expected to achieve a smaller exposure line width. BRIEF DESCRIPTION OF DRAWINGS

[0031] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments thereof as read in conjunction with the accompanying drawings:

[0032] Figure 1 Figure 1 is a structural diagram of an exposure device according to an embodiment of the present application;

[0033] Figure 2 Figure 2 is a flow chart of an exposure method according to an embodiment of the present application;

[0034] Figure 3 Figure 3 is a partial image of a linear grating according to a preferred embodiment of the present application;

[0035] Figure 4 Figure 4 is a partial distribution diagram of planar light rays of photoresist according to a preferred embodiment of the present application;

[0036] Figure 5 Figure 5 is a distribution diagram of planar light ray intensity of photoresist according to a preferred embodiment of the present application;

[0037] Figure 6 Figure 6 is a general layout diagram of an exposure device according to an application embodiment of the present application;

[0038] Figure 7 Figure 7 is a structural diagram of a debris removal device for a Z-pinch Z-pinch plasma source according to an embodiment of the present application;

[0039] Figure 8 Figure 8 is a structural diagram of a vane trap according to a preferred embodiment of the present application;

[0040] Figure 9 Figure 9 is a structural diagram of a metal trap according to a preferred embodiment of the present application;

[0041] In the drawings: 100 is a DPP light source, 200 is a multi-layer film mirror, 300 is a linear grating, 400 is photoresist, 500 is a zirconium film; 3 is a vane trap, 4 is a buffer air curtain, 5 is a first metal trap, 6 is a second metal trap, 51 is a zirconium foil, and 52 is a nickel mesh. DETAILED DESCRIPTION

[0042] The present application will be described in detail below with specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made. These all belong to the protection scope of the present application.

[0043] High resolution nanometer patterning, especially in the area of feature size below 20 nanometers, is still a challenge for most lithography techniques.

[0044] In order to obtain a smaller feature size exposure pattern, such as a periodic pattern with a line width of less than 25 nm, the present application proposes an exposure device and an exposure method based on the prior art. The exposure device and the exposure method are based on the ASFM technology, by setting the position of the device, further cooperating with the control of the exposure intensity and the exposure time, changing the etching effect realized on the photoresist, finally achieving the effect of controlling the line width, and obtaining the ideal size of the periodic pattern.

[0045] Specifically, referring to Figure 1 The exposure device based on the DPP light source provided by the embodiment of the present application comprises a DPP light source 100, a multilayer film mirror 200, a linear grating 300 and a zirconium film 500, wherein: the DPP light source 100 is used to generate EUV light, which reaches the multilayer film mirror 200 after being filtered by the zirconium film 500; the multilayer film mirror 200 collects the EUV output by the DPP light source 100, and reflects it to be perpendicular to the linear grating 300; the EUV light which is perpendicular to the linear grating 300 interferes and reaches the photoresist 400 to be exposed, wherein the intensity distribution of the EUV light on the plane of the photoresist 400 is a triangular cross section, and the intensity changes linearly with the position.

[0046] In the embodiment, the intensity changes linearly with the position, wherein: the light interferes through the linear grating 300, and the intensity distribution of the EUV on the plane of the photoresist 400 is obtained, the photoresist 400 is etched faster at the position with higher EUV intensity, and when the photoresist 400 at the position of the intensity peak is etched to end, the etching at other positions has not ended, so that the exposure time and the dose are controlled, and the line width of the final exposure pattern is controllable.

[0047] In the above embodiment of the present application, the EUV emitted by the DPP light source 100 is perpendicular to the surface of the linear grating 300, because the light intensity has a triangular distribution, the small feature pattern can be formed by controlling the exposure dose, and based on the Talbot effect, the high flux and efficiency can be obtained in the large-area and high-resolution patterning process.

[0048] In order to better realize the exposure control in the photolithography, in some possible embodiments, the above-mentioned device can further comprise: a micro-nano carrier platform, the micro-nano carrier platform carries a wafer (located at Figure 1The middle part 4 corresponds to the position, and can move the wafer with photoresist to a set distance close to the linear grating 300 and keep horizontal with the linear grating 300; wherein the set distance is the distance between the linear grating and the wafer required to implement ASFM.

[0049] For example, in an embodiment, the wafer with photoresist is moved to 40 microns away from the linear grating 40 and kept horizontal with the grating. Of course, in other embodiments, it can be adjusted according to actual conditions, and is not limited to 40 microns in this embodiment.

[0050] In some possible embodiments, the DPP light source 100 generates extreme ultraviolet light (EUV) by discharging to excite plasma. After filtering through the zirconium film 500 and the multilayer film mirror 200, the EUV light with a wavelength of 13.5 nm and a bandwidth of 4% is obtained. Of course, in other embodiments, it can be adjusted according to actual conditions.

[0051] In some possible embodiments, the multilayer film mirror 200 is covered with Mo / Si multilayer film, and the reflectivity of the light in the 13.5 nm band is much greater than that in other bands, which can achieve the effect of in-band filtering.

[0052] In some possible embodiments, the fineness of the grating has a great influence on the result, and the perpendicularity of the edge of the grating should be ensured as much as possible. In the embodiment of the present application, the multilayer film mirror 200 is arranged to make the DPP light source vertically incident on the surface of the linear grating 300; the distance between the linear grating 300 and the wafer (photoresist) meets the requirements of implementing ASFM, and the adjustment of the distance can be realized by the micro-nano object platform. Through the arrangement of the two parts, the intensity distribution of the light on the photoresist plane can be triangular, so that small feature patterns can be formed by controlling the exposure dose.

[0053] For example, in a more preferred embodiment, the period of the linear grating 300 is 100 nm, and the image of the light that causes the interference phenomenon on the photoresist plane presents alternating light and dark stripes with a period of 50 nm.

[0054] The period of the grating will directly affect the period of the etching pattern on the photoresist. For the linear grating, the period of the etching pattern is half of the period of the grating. Using a grating with a period of 100 nm, it is more difficult to manufacture a grating with a period less than 100 nm, and it is difficult to guarantee the linearity of the edge of the grating. If a larger grating period is selected, it will make it more difficult to realize small feature size patterns and test the performance of the photoresist. Therefore, when selecting a grating, the edge pattern of the grating used should as much as possible meet the rectangular pattern.

[0055] Reference Figure 6As shown, it is the overall layout of the device in a specific preferred application of the present application. In the figure, the DPP light source 100 generates extreme ultraviolet light, which is collected and focused by the multilayer film mirror 200 after the debris removal device, and is focused on the linear grating 300. The photoresist 400 is spin-coated on the wafer and installed in the micro-nano control platform. Among them, the DPP light source 100 is arranged at the frontmost position of the entire device, and the debris removal device is arranged behind the DPP light source 100, followed by the multilayer film mirror 200. On one side of the multilayer film mirror 200, a light source detection device can also be arranged for detecting the quality of the light source. The micro-nano carrier platform is located on one side of the linear grating. In this embodiment, the multilayer film mirror 200 can be fixed in the first box, and the linear grating 300 is fixed in the second box. One input end of the first box faces the DPP light source, and the other output end faces the second box (linear grating). The EUV collected by the multilayer film mirror 200 must be perpendicular to the linear grating 300. Among them, the carrier part of the micro-nano carrier platform (carrying the wafer of the photoresist) is also in the second box. Through this arrangement, the part of the entire device containing the optical path is operated in a vacuum state.

[0056] In order to obtain better results, in some possible embodiments, the exposure device further comprises a debris removal device for removing debris; the DPP light source generates EUV light, which is subjected to subsequent operations after passing through the debris removal device.

[0057] In some preferred embodiments, in order to achieve a more ideal debris removal effect, a debris removal device is designed which adopts a combination scheme of mechanical collision part, gas blowing part, foil filtering part and other removal mechanisms. Under the premise of ensuring the in-band flux of extreme ultraviolet light, it has good debris removal performance and out-of-band filtering performance, and protects the Mo / Si multi-coated collection mirror, so as to meet the requirements of continuously improving the power and conversion efficiency of the electric plasma source and continuously reducing the exposure time.

[0058] Specifically, referring to Figures 7-9 As shown, the debris removal device comprises a mechanical collision part, a gas blowing part and a foil filtering part, wherein: the mechanical collision part blocks and disturbs the movement of high-energy and low-energy debris and charge-neutral debris, thereby reducing the range of debris; the gas blowing part removes debris by using gas molecules to collide with debris and change their trajectories; the foil filtering part filters out-of-band light and has the function of filtering debris. Further, the mechanical collision part, the gas blowing part and the foil filtering part are arranged as follows:

[0059] The first position is a mechanical collision section, the second position is a gas purging section located after the mechanical collision section, and the third position is a foil filter section located after the gas purging section. Alternatively, the first position can be a gas purging section, the second position a mechanical collision section located after the gas purging section, and the third position a foil filter section located after the mechanical collision section.

[0060] The positions of the aforementioned mechanical collision section and gas purging section can be interchanged, depending on the debris removal effect under specific working conditions. That is, if the debris removal effect of the mechanical collision section before the gas purging section is better than that of the gas purging section before the mechanical collision section, it is recommended to choose the layout where the mechanical collision section is before the gas purging section; otherwise, choose the layout where the gas purging section is before the mechanical collision section. Figure 7 The diagram shown illustrates one possible location setting.

[0061] Based on the above preferred embodiments, the structure of the mechanical collision part can be further optimized. (Refer to...) Figure 8 As shown, the mechanical impact section can be a trap (a device / structure for capturing debris or external filtering), which includes multiple thin hexahedrons arranged in a ring array. The debris emission characteristics are approximately isotropic, and the trap's structural design enables radial debris capture, thereby reducing axial dimensions and making the debris removal system more compact.

[0062] In one specific embodiment, the blade trap initially blocks high-energy, low-energy, and charge-neutral debris, extending the lifespan of the foil filter and the reflector. Here, high and low energy primarily describe the kinetic energy of the debris particles, typically characterized in electron volts (eV). Generally, the main high-energy debris ions are Xe+ and Xe+2, while low-energy and charge-neutral particles include the fuel (xenon) used in the light source generator, as well as other ions including buffer gas ions, Ni+, Fe+, Mo+, W+, and Si+.

[0063] Furthermore, in some specific embodiments, the number of blades can be determined by a compromise among factors such as EUV power at the IF focal point, debris removal performance, and machining process. Generally, the number of blades can be 60-90; in this embodiment, the number of blades is 80.

[0064] Mechanical cleaning alone offers limited and weak cleaning effectiveness. To improve cleaning performance, this embodiment includes a gas purging section behind the mechanical impact section. In a preferred embodiment, the gas purging section employs a buffer gas curtain generated by a high-pressure gas pump. This buffer gas curtain contains one or more gases selected from hydrogen, neon, helium, and argon. These gases are relatively transparent to extreme ultraviolet (EUV) light within the band. That is, very little EUV light is absorbed when propagating in this gas phase, meaning that a large portion of the EUV flux can be retained.

[0065] The aforementioned mechanical impact and air curtain dual-cleaning mechanisms are still insufficient to meet the industry demands for contamination removal from the collection mirror and the ever-increasing power of the light source. Therefore, a foil filter section is further placed behind the air curtain. (Refer to...) Figure 8 , 9 As shown, in a preferred embodiment, the foil filter section is configured as a dual structure, consisting of a first metal trap and a second metal trap. The first and second metal traps are two layers of metal sheets, typically forming a "V" or "U" shaped structure. When the two metal sheets are placed opposite each other at a certain angle, the gap between them can capture or filter passing substances. This design utilizes the electrical conductivity or magnetic properties of metals to achieve the adsorption, blocking, or screening of specific substances. In a preferred embodiment, zirconium is selected as the main material for manufacturing the metal traps, which are composed of zirconium foil 51 and nickel mesh 52.

[0066] Based on the same technical concept, another embodiment of the present invention also provides an exposure method based on a DPP light source, which can obtain periodic patterns with feature sizes below 25 nanometers by controlling the exposure metering.

[0067] Reference Figure 1 The exposure structure shown, and Figure 2 The flowchart of the exposure method shown in this embodiment illustrates the exposure method based on a DPP light source, which specifically includes the following steps:

[0068] S1 uses a DPP light source 100 to output EUV with set wavelength and bandwidth;

[0069] S2 is filtered out of band by a zirconium film 500;

[0070] S3, the multilayer film reflector 200 collects the EUV light filtered by the DPP light source, reflects it and then incident perpendicularly onto the linear grating 300.

[0071] S4, the perpendicularly incident EUV is interfered with by the linear grating 300 and reaches the photoresist 400 to be exposed for exposure. The intensity distribution of EUV on the photoresist plane is triangular, and the intensity changes linearly with position.

[0072] In some possible implementations, to achieve precise positional control between the photoresist 400 and the linear grating 300 during the exposure process, a micro / nano platform is used. A wafer carrying the photoresist 400 is mounted on the micro / nano platform, and the platform is controlled to move the photoresist-laden wafer to a predetermined distance close to the linear grating 300, maintaining a horizontal position with the grating. This predetermined distance is the distance between the linear grating and the wafer required for achromatic Taltoi lithography. For example, in one embodiment, the photoresist-laden wafer is moved to a distance of 40 micrometers from the linear grating and kept horizontal. Of course, adjustments can be made in other embodiments depending on the specific circumstances, and the 40 micrometers is not limited to this embodiment.

[0073] In some possible implementations, the EUV light provided by the DPP light source is filtered to 13.5 nm with a bandwidth of 4% extreme ultraviolet light.

[0074] In the above embodiments of the present invention, the DPP light source is incident perpendicularly on the surface of the linear grating, ensuring that the distance between the linear grating 300 and the wafer meets the requirements for implementing ASFM, and ensuring the perpendicularity of the grating edge as much as possible.

[0075] In some possible implementations, the linear grating period is 100 nm, and the image of the interfering light rays on the photoresist plane appears as alternating bright and dark stripes with a period of 50 nm. (Refer to...) Figures 4-6 As shown, a partial image of the raster is as follows: Figure 4 As shown, the image of the interfering light rays on the photoresist plane is as follows: Figure 5 As shown, it exhibits alternating bright and dark stripes with a period of 50 nm, and its intensity distribution is as follows. Figure 6 As shown. According to Figure 6 The intensity distribution of light on the photoresist plane is shown, exhibiting a triangular profile, with the intensity changing linearly with position. At high exposure doses, even lower intensities can affect the photoresist; at low exposure doses, only the higher-intensity regions affect it. The resulting linewidth is directly proportional to the exposure dose. By controlling the exposure time and intensity to alter the exposure dose, periodic patterns with linewidths below 25 nm can be obtained.

[0076] In the embodiment of the present application, the exposure intensity and exposure time of the exposure process are controlled to change the etching effect on the photoresist, and finally to control the line width. For example, the exposure dose of the EUV lithography exposure process is controlled to obtain an exposure pattern with small line width, wherein: when the exposure dose of the exposure is large, small intensity will affect the photoresist; when the exposure dose is small, only the part with high intensity will affect the photoresist; the line width obtained after exposure is proportional to the exposure dose; by controlling the exposure time and exposure intensity to change the exposure dose, a periodic pattern with a line width size of less than 25 nm is obtained.

[0077] Compared with electron beam lithography, focused ion beam lithography, scanning probe lithography and other technologies, according to the definition of Tennant law, reducing the resolution by 2 times will result in a 32 times reduction in throughput, so that the above-mentioned direct writing technology is inefficient for large area and high resolution patterning. The lithography scheme used in the present application can have high flux and efficiency in the process of large area and high resolution patterning based on the Talbot effect; because the light intensity has a triangular distribution, small feature patterns can be formed by controlling the exposure dose. In addition, if the photoresist material is optimized, it is expected to achieve smaller exposure line width.

[0078] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An exposure apparatus based on a DPP light source, characterized in that... include: The components include a DPP light source, a zirconium film, a multilayer mirror, and a linear grating, among which: The DPP light source is used to output EUV light; The zirconium film filters the EUV light generated by the DPP light source; The multilayer film reflector collects the EUV light output from the DPP light source, reflects it, and then incident it perpendicularly onto the linear grating, thus serving as an in-band filter. The perpendicularly incident EUV light is interfered with by the linear grating and reaches the photoresist to be exposed. The intensity distribution of EUV on the photoresist plane is a triangular cross section, and the intensity changes linearly with position.

2. The exposure apparatus according to claim 1, characterized in that, Also includes: A micro-nano platform that carries a wafer loaded with photoresist and can move the wafer loaded with photoresist to a set distance close to the linear grating while maintaining a horizontal position with the linear grating; The set distance is the distance between the linear grating and the wafer that meets the requirements for implementing achromatic Taltbot lithography.

3. The exposure apparatus according to claim 1, characterized in that, The DPP light source provides EUV light, which is filtered out by a zirconium film outside the band and then filtered in the band by a multilayer film reflector to obtain EUV light with a wavelength of 13.5 nm and a bandwidth of 4%.

4. The exposure apparatus according to claim 1, characterized in that, The linear grating has a period of 100nm, and the light rays that interfere with each other produce an image of alternating bright and dark stripes on the photoresist plane with a period of 50nm.

5. The exposure apparatus according to claim 1, characterized in that, It also includes a debris removal device for removing harmful particles generated by electric shock discharge; The DPP light source generates EUV light, which is collected by the multilayer film reflector and focused onto the linear grating after passing through the debris removal device.

6. An exposure method based on a DPP light source, characterized in that... include: The DPP light source is filtered to output EUV light with a set wavelength and bandwidth. Zirconium film filters the EUV light generated by the DPP light source; The multilayer film reflector collects the EUV light output from the DPP light source, reflects it, and then incident it perpendicularly onto the linear grating, thus serving as an in-band filter. The multilayer film reflector collects the EUV output from the DPP light source, reflects it, and then incident it perpendicularly onto the linear grating. The perpendicularly incident EUV is interfered with by the linear grating and reaches the photoresist to be exposed. The intensity distribution of EUV on the photoresist plane is a triangular cross section, and the intensity changes linearly with position.

7. The exposure method according to claim 6, characterized in that, Also includes: By controlling a micro / nano carrier platform, a wafer containing photoresist is moved to a set distance close to the linear grating and kept horizontal with the linear grating; wherein, the set distance is the distance between the linear grating and the wafer that meets the requirements for implementing achromatic Taltbot lithography.

8. The exposure method according to claim 6, characterized in that, The DPP light source provides filtered extreme ultraviolet light with a wavelength of 13.5nm and a bandwidth of 4%. The linear grating has a period of 100nm, and the light rays that interfere with each other produce an image of alternating bright and dark stripes on the photoresist plane with a period of 50nm.

9. The exposure method according to claim 6, characterized in that, By controlling the exposure intensity and exposure time during the exposure process, the etching effect achieved on the photoresist is altered, ultimately controlling the linewidth.

10. The exposure method according to claim 9, characterized in that, By controlling the exposure metering during the EUV lithography exposure process, an exposure pattern with a small linewidth is obtained, wherein: When the exposure dose is large, small intensity will affect the photoresist; when the exposure dose is small, only the high intensity will affect the photoresist. The linewidth obtained after exposure is proportional to the exposure dose. By controlling the exposure time and intensity to change the exposure metering, periodic patterns with linewidths below 25nm can be obtained.

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