Mask, photolithography device, method for manufacturing mask, and photolithography method based on mask

Abstract

The present disclosure relates to a mask, a lithography device, a method for manufacturing the mask, and a lithography method based on the mask, wherein the mask comprises: a substrate, which is configured to be transparent to an exposure beam used for lithography, wherein the exposure beam is in a first frequency band; and a photochromic layer, which is disposed on one side of the substrate and comprises a photochromic material, and the photochromic layer is configured to generate a corresponding mask pattern under irradiation of a modulated light beam having a spatial structure, wherein the photochromic material is in a non-transparent state or a transparent state to the exposure beam based on whether it is irradiated by modulated light in the modulated light beam, and the modulated light beam is in a second frequency band separated from the first frequency band.

Description

Technical Field

[0001] The present disclosure generally relates to the field of photolithography technology, and more specifically, to a mask, a photolithography device, a method for manufacturing a mask, and a photolithography method based on the mask. Background Art

[0002] In photolithography, masks are usually used to form patterned structures. However, once the mask is made, the pattern is not easy to change. Moreover, if there are defects in the mask or defects are introduced during the use of the mask, it is difficult to repair these defects. In addition, masks are usually very expensive. All of the above factors will lead to higher costs for chips produced using masks and cumbersome processes for mask defect monitoring. Therefore, there is a demand for new masks in chip production technology. Summary of the invention

[0003] The purpose of the present disclosure is to provide a mask, a lithography apparatus, a method for manufacturing the mask, and a lithography method based on the mask.

[0004] According to a first aspect of the present disclosure, a mask is provided, comprising: a substrate, the substrate being configured to be transparent to an exposure beam used for photolithography, wherein the exposure beam is in a first frequency band; and a photochromic layer, the photochromic layer being disposed on one side of the substrate and comprising a photochromic material, the photochromic layer being configured to generate a corresponding mask pattern under irradiation of a modulated light beam having a spatial structure, wherein the photochromic material is in a non-transparent state or a transparent state to the exposure beam based on whether it is irradiated by modulated light in the modulated light beam, and the modulated light beam is in a second frequency band separated from the first frequency band.

[0005] In some embodiments, the substrate includes at least one of quartz and calcium fluoride.

[0006] In some embodiments, the photochromic material is configured to be in a non-light-transmitting state to the exposure beam when irradiated by the modulated light in the modulated light beam; and the photochromic material is configured to be in a light-transmitting state to the exposure beam when not irradiated by the modulated light in the modulated light beam.

[0007] In some embodiments, the photochromic material is configured to be in a light-transmitting state with respect to the exposure beam when irradiated by the modulated light in the modulated light beam; and the photochromic material is configured to be in a light-non-transmitting state with respect to the exposure beam when not irradiated by the modulated light in the modulated light beam.

[0008] In some embodiments, when the photochromic material is in a light-transmitting state, the light transmittance to the exposure light beam is 60% to 99%.

[0009] In some embodiments, when the photochromic material is in a non-light-transmitting state, the light transmittance to the exposure light beam is 5% to 30%.

[0010] In some embodiments, the wavelength corresponding to the first frequency band includes 193-405 nm.

[0011] In some embodiments, the wavelength corresponding to the first frequency band includes at least one of 193 nm, 248 nm, 325 nm, 365 nm and 405 nm.

[0012] In some embodiments, the wavelength corresponding to the second frequency band includes 500-580 nm, or 580-1100 nm, or a portion of 500-580 nm, or a portion of 580-1100 nm.

[0013] In some embodiments, the wavelength corresponding to the second frequency band includes 633 nm.

[0014] In some embodiments, the photochromic layer includes the photochromic material in a continuous film.

[0015] In some embodiments, the photochromic layer has a thickness of 50 to 200 nm or 200 to 5000 nm.

[0016] In some embodiments, the photochromic material includes at least one of an organic photochromic material and an inorganic photochromic material.

[0017] In some embodiments, the photochromic material includes 1,2-bis(5,5'-dimethyl-2,2'-diphenylthio)perfluorocyclopent-1-ene.

[0018] In some embodiments, the mask further includes: a modulated light source configured to generate a modulated light beam having a spatial structure.

[0019] In some embodiments, the modulated light source includes: a first light generator, which is configured to generate an initial light beam in a second frequency band, and the initial light beam has a uniform light intensity distribution in a cross section perpendicular to its traveling direction; and a spatial light modulator, which is configured to convert the initial light beam into a modulated light beam with a spatial structure under the action of a control signal, wherein the control signal is generated according to a mask pattern.

[0020] In some embodiments, the modulated light beam is a near-field light beam relative to the photochromic layer.

[0021] In some embodiments, the mask further includes: a temperature controller, the temperature controller includes a temperature maintaining unit, and the temperature maintaining unit is configured to be disposed adjacent to the substrate or the photochromic layer to maintain the temperature of the mask within a preset temperature range.

[0022] According to a second aspect of the present disclosure, a lithography device is proposed, which includes: a mask as described above; and a control module, wherein the control module is configured to generate a control signal according to a design layout, and the control signal is used to generate a modulated light beam having a spatial structure corresponding to the design layout.

[0023] In some embodiments, the lithography apparatus further comprises: a modulated light source configured to generate a modulated light beam having a spatial structure.

[0024] In some embodiments, the modulated light source includes: a first light generator, which is configured to generate an initial light beam in a second frequency band, and the initial light beam has a uniform light intensity distribution in a cross section perpendicular to its traveling direction; and a spatial light modulator, which is configured to convert the initial light beam into a modulated light beam with a spatial structure under the action of a control signal, wherein the control signal is generated according to a mask pattern.

[0025] In some embodiments, the lithography apparatus further includes: a temperature controller, the temperature controller including a temperature maintaining unit, the temperature maintaining unit being configured to be disposed adjacent to the substrate or the photochromic layer to maintain the temperature of the mask within a preset temperature range.

[0026] In some embodiments, the lithography apparatus further includes: a second light generator configured to generate an exposure light beam in the first frequency band.

[0027] In some embodiments, the exposure light beam has a uniform light intensity distribution in a cross section perpendicular to its traveling direction.

[0028] According to a third aspect of the present disclosure, a method for manufacturing a mask is proposed, the manufacturing method comprising: providing a substrate, the substrate being configured to be transparent to an exposure beam used for photolithography, wherein the exposure beam is in a first frequency band; and forming a photochromic layer on one side of the substrate, the photochromic layer comprising a photochromic material, the photochromic layer being configured to generate a corresponding mask pattern under irradiation of a modulated light beam having a spatial structure, wherein the photochromic material is in a non-transparent state or a transparent state to the exposure beam based on whether it is irradiated by modulated light in the modulated light beam, and the modulated light beam is in a second frequency band separated from the first frequency band.

[0029] According to the fourth aspect of the present disclosure, a mask-based lithography method is proposed, wherein the mask is the mask as described above, and the lithography method comprises: irradiating a modulated light beam having a spatial structure onto the mask to generate a corresponding mask pattern in the mask; after generating the mask pattern, irradiating an exposure light beam onto a wafer through the mask to expose the wafer; after completing the exposure of the wafer, turning off the exposure light beam; and after turning off the exposure light beam, turning off the modulated light beam.

[0030] In some embodiments, the intensity of the modulated light beam is greater than the intensity of the exposure light beam.

[0031] In some embodiments, the photolithography method further includes: operating a temperature controller to maintain the temperature of the mask within a preset temperature range. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0033] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0034] Figure 1 is a schematic structural diagram of a mask according to an exemplary embodiment of the present disclosure;

[0035] Figure 2 is a schematic diagram of a mask irradiated by an exposure beam and a modulated beam according to an exemplary embodiment of the present disclosure;

[0036] Figure 3 is a cross-sectional schematic diagram of a mask irradiated by an exposure beam and a modulated beam according to an exemplary embodiment of the present disclosure;

[0037] Figure 4 is a schematic structural diagram of a lithography apparatus according to an exemplary embodiment of the present disclosure;

[0038] Figure 5 is a schematic flow chart of a method for manufacturing a mask according to an exemplary embodiment of the present disclosure;

[0039] Figure 6 It is a schematic flow chart of a mask-based lithography method according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0040] The present disclosure will be described below with reference to the accompanying drawings, wherein the accompanying drawings illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in a variety of different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure of the present disclosure more complete and fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide more additional embodiments.

[0041] It should be understood that the same reference numerals represent the same elements throughout the drawings. In the drawings, the dimensions of certain features may be distorted for clarity.

[0042] It should be understood that the terms used in the specification are only used to describe specific embodiments and are not intended to limit the present disclosure. All terms (including technical terms and scientific terms) used in the specification have the meanings commonly understood by those skilled in the art unless otherwise defined. For the sake of simplicity and / or clarity, well-known functions or structures may not be described in detail.

[0043] The terms "include", "comprises", and "comprising" used in the specification indicate the presence of the claimed features, but do not exclude the presence of one or more other features. The term "and / or" used in the specification includes any and all combinations of one or more of the relevant listed items. The terms "between X and Y" and "between approximately X and Y" used in the specification should be interpreted as including X and Y. The term "between approximately X and Y" used in this specification means "between approximately X and approximately Y", and the term "from approximately X to Y" used in this specification means "from approximately X to approximately Y".

[0044] In the specification, when an element is said to be "on", "attached", "connected", "coupled", or "contacting" another element, the element may be directly on, attached, connected, coupled, or contacting another element, or there may be an intermediate element. In contrast, when an element is said to be "directly" "on", "directly attached", "directly connected", "directly coupled", or "directly contacting" another element, there will be no intermediate element. In the specification, a feature is arranged "adjacent" to another feature, which may refer to a feature having a portion that overlaps with an adjacent feature or a portion that is located above or below an adjacent feature.

[0045] In the specification, spatial relational terms such as "upper", "lower", "left", "right", "front", "back", "higher", "lower", etc. may describe the relationship of one feature to another feature in the drawings. It should be understood that the spatial relational terms include different orientations of the device in use or operation in addition to the orientation shown in the drawings. For example, when the device in the drawings is turned over, features previously described as being "below" other features may now be described as being "above" the other features. The device may also be oriented in other ways (rotated 90 degrees or in other orientations), and the relative spatial relationships will be interpreted accordingly.

[0046] In the research of micro-nano devices and the production process of semiconductor chips, mask-based lithography technology is usually used to form the desired device or chip structure. In order to form the desired structure, one or more masks can be pre-fabricated according to the layout of the device or chip to be processed and the corresponding process steps. The pattern on each mask can correspond to a layer in the layout or to multiple layers that can be prepared in the same step. Generally, the mask can include a substrate (for example, quartz glass) that can allow an exposure beam (for example, an ultraviolet beam, etc.) that changes the properties of the etchant (photoresist) to pass through, and a coating (for example, a metal chromium film) deposited on the substrate to prevent the above exposure beam from passing through.

[0047] In a method for manufacturing a mask, a chromium film with a thickness of tens of nanometers and an etchant on the chromium film are sequentially deposited on quartz glass, and then a desired pattern is formed on the etchant by laser direct writing or electron beam exposure, and then the chromium exposed from the etchant is wet etched or dry etched to form a pattern corresponding to the desired structure on the chromium film. Among them, the laser direct writing method is usually used to form a mask with a minimum line width of more than 300nm, while the electron beam exposure method can be used to form a mask with a minimum line width of less than 300nm.

[0048] Using the above preparation method, the cost of a single mask is about tens of thousands of dollars, while the cost of a complete set of masks for a complete device or chip production process may be as high as millions of dollars. Moreover, once such a mask is made, its structure is difficult to change. In traditional application scenarios, single batches of chips including central processing units (CPUs), dynamic random access memories (DRAMs), flash memories, etc. are usually in the millions or even hundreds of millions, so the cost of manufacturing masks can be well shared, so that mask-based lithography processes can be widely used in the manufacturing and production of these devices or chips. However, with the development of industries such as the Internet of Things, artificial intelligence, and personalized life and health, more and more small batches of devices or chips are currently involved, and the number of these devices or chips may be only tens of thousands or even less. If the mask is prepared in advance and then these devices or chips are produced based on the mask, it is difficult to share the cost of manufacturing the mask with a sufficient number of devices or chips, resulting in a significant increase in the cost of devices or chips. In addition, if laser direct writing is used to directly manufacture these devices or chips, on the one hand, its yield is very low and it is difficult to meet the needs of mass production. On the other hand, the minimum line width of laser direct writing of about 300nm also limits the way of miniaturizing devices to improve the integration and performance of chips and reduce chip costs. Similarly, if electron beam exposure is used to directly manufacture these devices or chips, although smaller and more integrated devices or chips can be manufactured, its yield is still extremely low and it is difficult to meet production requirements. In addition, the process cost is also very high, which hinders the market penetration of devices and chips.

[0049] In addition, defects in the mask may also lead to a significant increase in the cost of producing devices or chips. Specifically, if there are small defects in the mask, it will take time to detect and repair the defects; and if there are large defects in the mask, the entire mask may have to be discarded.

[0050] In order to solve the above problems, meet the needs of small-batch chip production and related products to develop towards high integration, and enable future technologies such as the Internet of Things and artificial intelligence to have better social penetration, the present disclosure proposes a programmable, erasable and reusable digital photolithography mask. In such a mask, the light transmittance state of the corresponding pixel area in the mask can be reversibly changed by controlling a modulated light beam with a spatial structure to irradiate the mask with a photochromic material, so that the pattern on the same mask can be changed as needed, thereby realizing the reuse of the mask, thereby reducing the production cost of the device or chip.

[0051] In an exemplary embodiment of the present disclosure, Figure 1 As shown, the reticle may include a substrate 110 and a photochromic layer 120 .

[0052] Among them, the substrate 110 can be configured to be transparent to the exposure beam used for lithography to avoid interfering with the lithography process. The exposure beam can be in a first frequency band, which usually corresponds to the frequency band where part of the ultraviolet light is located. For example, the wavelength corresponding to the first frequency band may include 193 to 405 nm. In some specific examples, the wavelength corresponding to the first frequency band may include at least one of 193 nm, 248 nm, 325 nm, 365 nm and 405 nm. The substrate 110 can be made of a material with a certain structural strength to support the other layers of the mask plate disposed thereon. In some embodiments, the substrate 110 can be made of quartz glass or calcium fluoride glass, etc.

[0053] The photochromic layer 120 may be disposed on one side of the substrate 110, and the photochromic layer 120 may include a photochromic material and generate a corresponding mask pattern under the irradiation of a modulated light beam having a spatial structure. Figure 2 and Figure 3 As shown, the modulated light beam 930 with a spatial structure specifically refers to a light beam with a non-uniform intensity distribution on a cross section perpendicular to its traveling direction. For example, on a cross section perpendicular to the traveling direction of the modulated light beam 930, the modulated light intensity of some areas may be zero, while other areas may have a non-zero modulated light intensity. The photochromic material will be in a non-light-transmitting state or a light-transmitting state with respect to the exposure light beam based on whether it is irradiated by the modulated light in the modulated light beam, and will accordingly form a non-light-transmitting area and a light-transmitting area in the mask, thereby generating a desired mask pattern.

[0054] In a specific example, when the photochromic material is opposite to the region with non-zero modulated light intensity on the cross section of the modulated light beam 930, that is, when the photochromic material is irradiated by the modulated light in the modulated light beam 930, this portion of the photochromic material absorbs the modulated light and is in a non-light-transmitting state with respect to the exposure light beam (for example, the organic photochromic material absorbs the modulated light as the de-excitation light and generates a high absorption rate for the ultraviolet light as the exposure light beam, resulting in this portion of the organic photochromic material being in a non-light-transmitting state with respect to the exposure light beam), corresponding to Figure 3 920 of the photochromic material; and when the photochromic material is opposite to the region where the modulated light intensity is zero on the cross section of the modulated light beam 930, that is, when the photochromic material is not irradiated by the modulated light in the modulated light beam 930, this portion of the photochromic material will be in a light-transmitting state to the exposure beam, corresponding to Figure 3The light-transmitting region 121 of the photochromic material for the exposure beam 920 shown in FIG. Therefore, by controlling the spatial distribution of the intensity of the modulated light beam, or in other words, by controlling the spatial structure of the modulated light beam, the light-transmitting region 121 and the non-light-transmitting region 122 for the exposure beam 920 can be formed in the photochromic layer 120, and the combination of these regions can form a desired mask pattern in the mask.

[0055] Of course, it can be understood that in some other specific examples, when the photochromic material is opposite to the area with non-zero modulated light intensity on the cross section of the modulated light beam, that is, when the photochromic material is irradiated by the modulated light in the modulated light beam, this part of the photochromic material may also be in a light-transmitting state with respect to the exposure light beam; and when the photochromic material is opposite to the area with zero modulated light intensity on the cross section of the modulated light beam, that is, when the photochromic material is not irradiated by the modulated light in the modulated light beam, this part of the photochromic material may be in a non-light-transmitting state with respect to the exposure light beam.

[0056] In addition, under normal circumstances, only when the modulated light is irradiated on the photochromic material, its non-light-transmitting state (or light-transmitting state) can be maintained, and once the modulated light is removed, the photochromic material will return to its default state. Therefore, when performing photolithography using a mask including such a photochromic material, it is necessary to keep the modulated light beam irradiated on the mask while exposing the wafer / sample with the exposure light beam, so as to maintain the light-transmitting area and the non-light-transmitting area in the mask unchanged, or to keep the mask pattern unchanged until the photolithography is completed. Due to the above requirements, it is necessary to avoid the interference of the modulated light beam 930 with the exposure process, that is, the modulated light beam 930 cannot change the properties of the anti-etching agent (for example, photoresist), which requires that the modulated light beam 930 is in a second frequency band separated from the first frequency band of the exposure light beam 920. Here, the separated first and second frequency bands refer to that any frequency in the first frequency band is different from any frequency in the second frequency band. In some embodiments, the wavelength corresponding to the second frequency band may include 500-580 nm, or 580-1100 nm, or a portion of 500-580 nm, or a portion of 580-1100 nm. In a specific example, the wavelength corresponding to the second frequency band may be 633 nm.

[0057] In order to ensure that the photochromic material in the mask can allow enough exposure light beam to pass through for exposing the sample when it is in the light-transmitting state, and can block the exposure light beam enough to avoid exposure of the wafer / sample when it is in the light-impermeable state, the light transmittance of the photochromic material in the light-transmitting state and the light-impermeable state should meet certain requirements. In a specific example, when the photochromic material is in the light-transmitting state, its light transmittance to the exposure light beam can be 60% to 99%; and when the photochromic material is in the light-impermeable state, its light transmittance to the exposure light beam can be 5% to 30%.

[0058] In some embodiments, the photochromic material may include at least one of an organic photochromic material and an inorganic photochromic material. Common organic photochromic materials may include liquid tetracene solutions, benzalphenylhydrazines solutions, osazones solutions, etc., and solid 2,3,4,4-tetrachloronaphthalen-1-(4H)-one, spironaphthoxazines organic materials, diarylethene materials, azobenzene derivatives, 1,2-bis(5,5'-dimethyl-2,2'-bithiophen-yl)perfluorocyclopent-1-ene, etc., while inorganic photochromic materials may include a variety of transition metal oxides and their composite materials, such as tungsten oxide (WO x ), molybdenum trioxide (MoO3), vanadium pentoxide (V2O5), titanium dioxide (TiO2), etc.

[0059] However, considering that in the current common photolithography applications, the photochromic materials that can be used should have at least the following properties: (1) the light-transmitting state and the light-non-transmitting state of the photochromic material can be reversibly switched under the control of the modulated light beam to realize an erasable and reusable mask, that is, when not irradiated by the modulated light in the modulated light beam, the photochromic material has a sufficiently high transmittance to the exposure light beam in the first frequency band, and when irradiated by the modulated light in the modulated light beam, it has a sufficiently low transmittance to the exposure light beam in the first frequency band, or when not irradiated by the modulated light in the modulated light beam, it has a sufficiently low transmittance to the exposure light beam in the first frequency band, and when irradiated by the modulated light in the modulated light beam, it has a sufficiently high transmittance to the exposure light beam in the first frequency band; and (2) the second frequency band in which the modulated light beam used to reversibly switch the light-transmitting state and the light-non-transmitting state of the photochromic material is located is separated from the first frequency band in which the exposure light beam (ultraviolet light) is located to avoid interfering with the photolithography process. Based on the above considerations, in the existing process of photolithography using ultraviolet light as the exposure beam, 1,2-bis(5,5'-dimethyl-2,2'-diphenylthio)perfluorocyclopent-1-ene can be used as the photochromic material in the mask. However, it is understandable that when using exposure beams or modulated beams in other frequency bands, other photochromic materials corresponding to the corresponding frequency bands can also be selected, and there is no limitation here. Furthermore, a photochromic material with good heat dissipation and a lower required modulated beam intensity can be selected to reduce the substantial increase in the mask temperature caused by the irradiation of the modulated beam, thereby improving the reliability of photolithography.

[0060] Under normal circumstances, the photochromic layer 120 may include a photochromic material in a continuous film form, so that the mask can be prepared by deposition methods such as lamination, spin coating, and spraying. In order to enable the photochromic material to effectively block the exposure beam when it is in a non-light-transmitting state, the thickness of the photochromic layer 120 can be 50 to 200 nm or 200 to 5000 nm. In some other cases, a patterned photochromic layer can also be formed as needed, and the patterned photochromic layer can be formed by laser direct writing, electron beam direct writing, photolithography based on another mask, etc. Alternatively, in other cases, a photochromic material in a liquid state can also be used as needed. At this time, a barrier layer can be set above the photochromic layer 120 so that the liquid photochromic material is confined between the substrate 110 and the barrier layer to maintain the stable nature of the structure of the mask, thereby ensuring the exposure effect.

[0061] In some embodiments, Figure 4 As shown, a modulated light source 200 may also be included, which may be regarded as a part of the mask, or may be set independently of the mask in a lithography device including the mask. The modulated light source 200 may be configured to generate a modulated light beam with a spatial structure. Specifically, the modulated light source 200 may include a first light generator 210 and a spatial light modulator 220, wherein the first light generator 210 may be configured to generate an initial light beam in a second frequency band, the initial light beam having a uniform light intensity distribution on a cross section perpendicular to its traveling direction; and the spatial light modulator 220 may be configured to convert the initial light beam into a modulated light beam with a spatial structure under the action of a control signal, wherein the control signal may be generated according to a mask pattern. The spatial structure of the modulated light beam corresponds to the desired mask pattern to form corresponding light-transmitting areas and non-light-transmitting areas by irradiating the modulated light beam onto the photochromic material in the mask. In a specific example, the spatial light modulator may be an optical phase modulator.

[0062] In a specific example, the spatial light modulator can achieve a number of 4160x2464 pixels and a pixel period of 3.74μm. With such a spatial light modulator, a modulated light beam with a wavelength of 633nm can be used to form a pattern consisting of tiny light spots with a size of 3 to 4μm and a period of 6 to 8μm on the mask. Using such a mask and combining it with four-fold (4x) reduction projection lithography technology, the minimum line width that can be processed is about 1μm, and the area of ​​a single exposure is 1x1cm 2 In the case of projection exposure, the photolithography yield of this mask can reach 600 cm2, based on the time required for a single exposure of 100 ms. 2 / min. For an exposure accuracy of 1μm, the above yield is 100 times that of laser direct writing, so it can meet the lithography requirements of next-generation printed circuit boards and chip packaging. In addition, when the wavelength of the modulated beam is 633nm, the pattern with the minimum resolution that can be produced is around 400nm. Combined with four-fold reduction projection lithography technology and using a 248nm exposure beam, a lithography line width of about 100nm can be achieved, which can meet the lithography requirements of many back-end processes of the chip. If it is desired to further improve the line width accuracy of the mask while increasing the yield, a spatial light modulator with 10000x10000 or more pixels can also be developed. In addition, although the mask of the present invention may be limited by the diffraction effect of the modulated light beam, the minimum line width on the mask is usually around 400nm, but by combining it with higher-magnification reduction projection lithography, such as ten-fold (10x) reduction projection lithography technology, and using, for example, a 193nm deep ultraviolet (DUV) exposure beam for exposure, the minimum line width of lithography can be further improved to below 45nm to meet the production requirements of advanced chips.

[0063] In addition, in the photolithography process, in order to improve the photolithography accuracy and the accuracy of the photolithography pattern, the exposure light beam generated by the second light generator 300 can be a near-field light beam relative to the mask. Similarly, the modulated light beam generated by the modulated light source 200 can also be a near-field light beam relative to the photochromic layer in the mask to avoid the influence on the accuracy caused by the optical diffraction effect of the far-field light beam, and improve the accuracy of the mask pattern.

[0064] In some embodiments, considering that the modulated light beam used to control the light-transmitting state or the light-non-transmitting state of the photochromic material usually has a large optical power, in order to avoid excessive light irradiation on the mask and the sample, which may cause the temperature of the mask or the sample to rise, such as Figure 4 As shown, a temperature controller 400 may also be included. The temperature controller 400 may be considered to be included in the mask or be provided independently of the mask in the lithography device including the mask. The temperature controller 400 may include a temperature maintaining unit, which may be configured to be provided adjacent to the substrate 110 or the photochromic layer 120 to maintain the temperature of the mask within a preset temperature range. The temperature controller may be a liquid-cooled temperature controller, a thermoelectric semiconductor temperature controller, etc., which is not limited here. In general, the light intensity of the exposure beam required during the exposure process is usually 10 to 10,000 mW / cm 2 The intensity of the modulated light beam used to change the light transmission state of the photochromic material usually needs to be between 10 and 10,000 W / cm 2 For example, in the photolithography process, the intensity of the modulated light beam with a wavelength of 633 nm may be more than 1000 times the intensity of the exposure light beam with a wavelength of 325 nm. By using the temperature controller 400 to keep the mask within the preset temperature range, the mask can be prevented from being damaged by the strong modulated light beam, and even a higher intensity (e.g., 100 kW / cm 2 ) is used to excite the photochromic material in the mask to quickly change the light transmittance of the photochromic material and obtain the desired and most ideal light transmittance.

[0065] In the mask disclosed in the present invention, the photochromic material therein is used to control the reversible change of the light transmission state of each pixel area. In this way, the corresponding mask pattern can be directly formed based on the data file of the required device or chip structure, and the mask pattern on the same mask can be erased and written, so that the mask can be reused, the use efficiency of the mask is improved, the manufacturing cost of the device or chip is reduced, and a series of problems caused by the high cost of the mask in traditional photolithography are avoided.

[0066] In an exemplary embodiment of the present disclosure, a photolithography apparatus is also provided. Figure 4As shown, the lithography apparatus may include the plate body 100 of the mask as described above and the control module 500. In some embodiments, the lithography apparatus may also include at least one of the modulated light source 200 as described above, the second light generator 300 configured to generate an exposure beam in the first frequency band (the exposure beam generally has a uniform light intensity distribution on a cross section perpendicular to its traveling direction, or at least a uniform light intensity distribution in the central area of ​​the cross section), and the temperature controller 400 as described above. Among them, the control module 500 may be configured to generate a control signal according to the layout, and the control signal is used to generate a modulated light beam having a spatial structure corresponding to the layout. Specifically, the control module 500 may be used to generate a plurality of mask patterns corresponding to one or more layers in the layout of the device or chip, and generate corresponding control signals according to each mask pattern. Further, the control module 500 may transmit the control signal to the spatial light modulator 220, so that the spatial light modulator 220 changes the light transmittance state of each pixel area in the mask according to the control signal.

[0067] In the lithography apparatus of the disclosed embodiment, the data file of the pattern to be exposed can be used to directly make the corresponding reversible mask, and combined with technologies such as ten-fold reduction projection and LELE, it can meet the production needs of small batch chips at 14nm or even more advanced process nodes. Through only one or a few reusable and erasable masks, the manufacture of complex devices or chips can be completed efficiently and accurately, reducing the manufacturing cost of devices or chips, which is conducive to the rapid update, mass production and better market penetration of devices or chips.

[0068] In an exemplary embodiment of the present disclosure, a method for manufacturing a mask is also provided, such as Figure 5 As shown, the manufacturing method may include:

[0069] Step S610, providing a substrate;

[0070] Step S620: forming a photochromic layer on the substrate.

[0071] The substrate may be configured to be transparent to an exposure beam used for photolithography, wherein the exposure beam is in a first frequency band, the photochromic layer may include a photochromic material, and the photochromic layer is configured to generate a corresponding mask pattern under the illumination of a modulated light beam having a spatial structure, wherein the photochromic material is in a non-transparent state or a transparent state to the exposure beam based on whether it is illuminated by modulated light in the modulated light beam, and the modulated light beam is in a second frequency band separated from the first frequency band.

[0072] In an exemplary embodiment of the present disclosure, a photolithography method based on the mask as described above is also proposed, such as Figure 6 As shown, the photolithography method may include:

[0073] Step S710, irradiating the modulated light beam with a spatial structure onto the mask to generate a corresponding mask pattern in the mask;

[0074] Step S720, after the mask pattern is generated, an exposure beam is irradiated onto the wafer / sample coated with photoresist through the mask to expose the sample;

[0075] Step S730, after the exposure of the wafer / sample is completed, the exposure beam is turned off; and

[0076] Step S740, after turning off the exposure light beam, turning off the modulated light beam.

[0077] That is, during the entire exposure process, the modulated light beam should be kept in an open state to ensure the correctness of the mask pattern. The light intensity of the modulated light beam may be greater than the light intensity of the exposure light beam. Accordingly, the photolithography method may further include operating a temperature controller to keep the temperature of the mask within a preset temperature range.

[0078] Although the exemplary embodiments of the present disclosure have been described, it will be appreciated by those skilled in the art that various changes and modifications can be made to the exemplary embodiments of the present disclosure without departing from the spirit and scope of the present disclosure in essence. Therefore, all changes and modifications are included in the scope of protection of the present disclosure as defined by the claims. The present disclosure is defined by the appended claims, and the equivalents of these claims are also included.

Claims

1. A mask, characterized in that: The mask plate comprises: a substrate configured to be transparent to an exposure beam for photolithography, wherein the exposure beam is in a first frequency band; and A photochromic layer, the photochromic layer is arranged on one side of the substrate and includes a photochromic material, the photochromic layer is configured to generate a corresponding mask pattern under the irradiation of a modulated light beam with a spatial structure, wherein the modulated light beam is a light beam with a non-uniform intensity distribution on a cross section perpendicular to its traveling direction, the photochromic material is in a non-light-transmitting state or a light-transmitting state with respect to the exposure light beam based on whether it is irradiated by the modulated light in the modulated light beam, and the modulated light beam is in a second frequency band separated from the first frequency band, the modulated light beam is generated by converting an initial light beam in the second frequency band according to a control signal, the initial light beam has a uniform light intensity distribution on a cross section perpendicular to its traveling direction, the control signal is generated according to the mask pattern, and the photochromic material is configured to restore from a light-transmitting state to a non-light-transmitting state or from a non-light-transmitting state to a light-transmitting state when the modulated light irradiating the photochromic material is removed.

2. The mask according to claim 1, characterized in that: The substrate includes at least one of quartz and calcium fluoride.

3. The mask according to claim 1, characterized in that: The photochromic material is configured to be in a non-light-transmitting state to the exposure light beam when being irradiated by the modulated light in the modulated light beam; and The photochromic material is configured to be in a light-transmitting state with respect to the exposure light beam when not irradiated by the modulated light in the modulated light beam.

4. The mask according to claim 1, characterized in that: The photochromic material is configured to be in a light-transmitting state to the exposure light beam when being irradiated by the modulated light in the modulated light beam; and The photochromic material is configured to be in a non-light-transmitting state with respect to the exposure light beam when not irradiated by the modulated light in the modulated light beam.

5. The mask according to claim 1, characterized in that: When the photochromic material is in a light-transmitting state, the light transmittance to the exposure light beam is 60% to 99%.

6. The mask according to claim 1, characterized in that: When the photochromic material is in a non-light-transmitting state, the light transmittance to the exposure light beam is 5% to 30%.

7. The mask according to claim 1, characterized in that: The wavelength corresponding to the first frequency band includes 193~405 nm.

8. The mask according to claim 1, characterized in that: The wavelength corresponding to the first frequency band includes at least one of 193 nm, 248 nm, 325 nm, 365 nm and 405 nm.

9. The mask according to claim 1, characterized in that: The wavelength corresponding to the second frequency band includes 500-580 nm, or 580-1100 nm, or a part of 500-580 nm, or a part of 580-1100 nm.

10. The mask according to claim 1, characterized in that: The wavelength corresponding to the second frequency band includes 633 nm.

11. The mask according to claim 1, characterized in that: The photochromic layer includes a photochromic material in a continuous film form.

12. The mask according to claim 1, characterized in that: The thickness of the photochromic layer is 50-200 nm or 200-5000 nm.

13. The mask according to claim 1, characterized in that: The photochromic material includes at least one of an organic photochromic material and an inorganic photochromic material.

14. The mask according to claim 1, characterized in that: The photochromic material includes 1,2-bis(5,5'-dimethyl-2,2'-diphenylthio)perfluorocyclopent-1-ene.

15. The mask according to claim 1, characterized in that: The mask also includes: A modulated light source is configured to generate a modulated light beam with a spatial structure.

16. The mask according to claim 15, characterized in that: The modulated light source comprises: A first light generator configured to generate an initial light beam; and The spatial light modulator is configured to convert the initial light beam into a modulated light beam with a spatial structure under the action of a control signal.

17. The mask according to claim 1, characterized in that: The modulated light beam is a near-field light beam relative to the photochromic layer.

18. The mask according to claim 1, characterized in that: The mask also includes: A temperature controller includes a temperature maintaining unit, wherein the temperature maintaining unit is configured to be disposed adjacent to the substrate or the photochromic layer to maintain the temperature of the mask within a preset temperature range.

19. A photolithography apparatus, characterized in that: The lithography apparatus comprises: The mask according to any one of claims 1 to 14; and A control module is configured to generate a control signal according to the layout, wherein the control signal is used to generate a modulated light beam having a spatial structure corresponding to the layout.

20. The lithographic apparatus according to claim 19, characterized in that The lithography apparatus further comprises: A modulated light source is configured to generate a modulated light beam with a spatial structure.

21. The lithographic apparatus according to claim 20, characterized in that The modulated light source comprises: A first light generator configured to generate an initial light beam; and The spatial light modulator is configured to convert the initial light beam into a modulated light beam with a spatial structure under the action of a control signal.

22. The lithographic apparatus according to claim 19, characterized in that The lithography apparatus further comprises: A temperature controller includes a temperature maintaining unit, wherein the temperature maintaining unit is configured to be disposed adjacent to the substrate or the photochromic layer to maintain the temperature of the mask within a preset temperature range.

23. The lithographic apparatus according to claim 19, characterized in that The lithography apparatus further comprises: A second light generator is configured to generate an exposure light beam in a first frequency band.

24. The lithographic apparatus according to claim 23, characterized in that The exposure beam has a uniform light intensity distribution in a cross section perpendicular to its traveling direction.

25. A photolithography apparatus, characterized in that: The lithography apparatus comprises: The mask according to any one of claims 15 to 18; and A control module is configured to generate a control signal according to the layout, wherein the control signal is used to generate a modulated light beam having a spatial structure corresponding to the layout.

26. A method for manufacturing a mask, characterized in that: The manufacturing method comprises: providing a substrate configured to be transparent to an exposure beam for photolithography, wherein the exposure beam is in a first frequency band; and A photochromic layer is formed on one side of the substrate, the photochromic layer comprising a photochromic material, the photochromic layer being configured to generate a corresponding mask pattern under irradiation of a modulated light beam having a spatial structure, wherein the modulated light beam is a light beam having a non-uniform intensity distribution on a cross section perpendicular to its traveling direction, the photochromic material is in a non-light-transmitting state or a light-transmitting state with respect to the exposure light beam based on whether it is irradiated by modulated light in the modulated light beam, and the modulated light beam is in a second frequency band separated from the first frequency band, the modulated light beam is generated by converting an initial light beam in the second frequency band according to a control signal, the initial light beam having a uniform light intensity distribution on a cross section perpendicular to its traveling direction, the control signal being generated according to the mask pattern, and the photochromic material being configured to restore from a light-transmitting state to a non-light-transmitting state or from a non-light-transmitting state to a light-transmitting state when the modulated light irradiating the photochromic material is removed.

27. A mask-based lithography method, characterized in that: The mask is a mask according to any one of claims 1 to 18, and the photolithography method comprises: irradiating a modulated light beam having a spatial structure onto the mask to generate a corresponding mask pattern in the mask; After generating the mask pattern, irradiating the sample with an exposure beam through the mask to expose the sample; After the exposure of the sample is completed, turning off the exposure beam; and After the exposure beam is turned off, the modulating beam is turned off.

28. The photolithography method according to claim 27, characterized in that: The light intensity of the modulated light beam is greater than the light intensity of the exposure light beam.

29. The photolithography method according to claim 27, characterized in that: The photolithography method further comprises: The temperature controller is operated to maintain the temperature of the mask within a preset temperature range.

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