Process window structure, manufacturing method thereof and semiconductor processing equipment

Abstract

The invention discloses a process window structure and a manufacturing method thereof, and semiconductor processing equipment. The craft window structure comprises a window body, an ultraviolet light source is arranged in the first direction of the window body, a coated wafer is placed in the second direction of the window body, and the coated wafer is placed perpendicular to the ultraviolet light source; the anti-reflection film is arranged in a first target area of the first face of the window body so as to increase the light transmittance of ultraviolet light irradiated to the surface of a wafer through the first target area, so that the surface of the wafer presents bat-shaped light intensity distribution, and the first target area is determined based on the light intensity of each area of the surface of the wafer. According to the invention, the distribution uniformity of the ultraviolet light intensity received by the wafer surface can be integrally improved under the condition that the irradiation light intensity of partial area of the wafer surface is not reduced, so that the luminous efficiency utilization rate is improved, the film curing uniformity of the wafer surface is improved, the structure is simple, the manufacturing is convenient, an additional complex light path design structure does not need to be added, and the cost is low. Therefore, the equipment cost can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and particularly relates to a process window structure, a process window structure, and a semiconductor processing apparatus. Background Art

[0002] In semiconductor processing, ultraviolet curing treatment (UV Cure) has become a very necessary and effective means. Ultraviolet curing can cause cross-linking reactions of polymer molecules in a thin film to form a three-dimensional network structure, thereby improving the hardness, strength, and wear resistance of the thin film. For some thin films used for functions such as insulation or capacitance, ultraviolet curing can reduce the dielectric constant of the thin film and improve its insulation performance, thereby reducing leakage and crosstalk phenomena during signal transmission, and contributing to improving the performance and stability of semiconductor devices. Moreover, the molecular structure of the cured thin film is more stable, and its tolerance to chemical substances is also enhanced, which is beneficial to resisting the erosion of various chemical reagents and maintaining the integrity and performance of the thin film during subsequent semiconductor processes such as etching and cleaning.

[0003] However, in the prior art, the light intensity distribution of the ultraviolet light provided by an ultraviolet curing device usually shows an uneven distribution with a high center and a low edge, resulting in an excessive ultraviolet curing degree in the central region. The uneven ultraviolet light intensity distribution directly affects the uniformity of film formation process indexes, such as the refractive index (RI) of the thin film.

[0004] In response to this, currently common solutions to improve the uniformity of ultraviolet light irradiation include adding multiple pairs of main reflectors and sub-reflectors around the ultraviolet light source, and through multi-stage reflection, to improve the uniformity of the light intensity distribution of the ultraviolet light irradiated on the wafer surface. However, this method requires introducing a structure with a complex optical path design, which not only has a design load, but also occupies equipment space and increases equipment costs. In addition, common solutions also include setting an absorption layer on the light-receiving surface of the chamber cover to absorb part of the strong light intensity in the central region of the ultraviolet light, thereby improving the uniformity of the light intensity distribution of the ultraviolet light irradiated on the wafer surface. Although this method can simplify the equipment structure, it is necessary to sacrifice the ultraviolet light intensity irradiated on some regions of the wafer surface, reducing the light efficiency utilization rate.

[0005] In order to solve the above problems existing in the prior art, there is an urgent need in the art for an improved process window structure that can improve the uniformity of the ultraviolet light intensity received on the entire wafer surface without reducing the light intensity irradiated on some regions of the wafer surface, thereby improving the light efficiency utilization rate and the uniformity of thin film curing on the wafer surface, and the structure of the present invention is simple and easy to manufacture, without the need to add an additional complex optical path design structure, thereby reducing equipment costs. Summary of the Invention

[0006] A brief overview of one or more aspects is given below to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all contemplated aspects, and is neither intended to identify key or decisive elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that follows.

[0007] In order to overcome the above-mentioned defects existing in the prior art, the present invention provides a process window structure, a manufacturing method of a process window structure, and a semiconductor processing device, which can improve the uniformity of the ultraviolet light intensity distribution received on the wafer surface as a whole without reducing the light intensity irradiated on some areas of the wafer surface, thereby improving the light efficiency utilization rate and the uniformity of film curing on the wafer surface. Moreover, the structure of the present invention is simple and easy to manufacture, without adding additional complex optical path design structures, thus reducing the equipment cost.

[0008] Specifically, the above-mentioned process window structure provided according to the first aspect of the present invention includes: a window body, with an ultraviolet light source arranged in its first direction and a coated wafer placed in its second direction, wherein the coated wafer is placed perpendicular to the ultraviolet light source; and an antireflection film, arranged in a first target area on the first surface of the window body to increase the light transmittance of the ultraviolet light irradiated onto the wafer surface through the first target area, so that the light intensity distribution on the wafer surface presents a bat-shaped pattern, wherein the first target area is determined based on the light intensity of each area on the wafer surface.

[0009] Further, in some embodiments of the present invention, the coated wafer and the window body are concentrically placed, and the first target area is the outer edge area of the window body, wherein the area of the first target area is

[0010] Further, in some embodiments of the present invention, the first target area is an annular outer edge area, and the ratio of the width of the first target area to the radius of the non-target area located at the center of the window body ranges from 1:1 to 2:3.

[0011] Further, in some embodiments of the present invention, the process window structure further includes: an absorption film, arranged in a second target area in the non-target area to reduce the light transmittance of the ultraviolet light irradiated onto the wafer surface through the second target area, so that the ultraviolet light irradiated onto the wafer surface at least through the first target area and the second target area presents the bat-shaped static light intensity distribution.

[0012] Further, in some embodiments of the present invention, the absorption film includes a nickel-chromium-iron alloy layer, and the film thickness of the absorption film is 4 - 6 nm.

[0013] Further, in some embodiments of the present invention, the first surface faces away from the coated wafer, and the antireflection film is a multilayer film structure formed by alternately depositing at least two layers of a first refractive index material and a second refractive index material.

[0014] Further, in some embodiments of the present invention, the first refractive index material is silicon dioxide, the second refractive index material is aluminum oxide, the silicon dioxide and the aluminum oxide are alternately deposited to form a multilayer film structure, and the thickness of each film layer is one quarter of the wavelength of light in the film.

[0015] In addition, a method for manufacturing the above process window structure according to the second aspect of the present invention includes the following steps: obtaining an initial light intensity distribution of each region on the surface of the coated wafer in the second direction of the window body; determining a light intensity boundary range on the surface of the wafer according to the initial light intensity distribution; determining a first target area of the window body based on the light intensity boundary range; and depositing an antireflection film on the first surface of the window body according to the first target area to increase the transmittance of ultraviolet light irradiated onto the surface of the wafer through the first target area, so that a bat-shaped static light intensity distribution is presented on the surface of the wafer, wherein the first target area is determined based on the light intensity of each region on the surface of the wafer.

[0016] Further, in some embodiments of the present invention, the step of determining the light intensity boundary range on the surface of the wafer according to the initial light intensity distribution includes: connecting a plurality of test points on the surface of the wafer corresponding to the outer edge of the maximum light intensity region in the initial light intensity distribution to obtain the light intensity boundary range, and the step of determining the first target area of the window body based on the light intensity boundary range further includes: taking the area of the window body corresponding to outside the maximum light intensity region as the first target area according to the light intensity boundary range; determining a second target area in the non-target area of the window body corresponding to the maximum light intensity region according to the target light intensity; and depositing an absorption film on the first surface of the window body according to the second target area to reduce the transmittance of ultraviolet light irradiated onto the surface of the wafer through the second target area, so that the ultraviolet light irradiated onto the surface of the wafer through at least the first target area and the second target area presents a bat-shaped static light intensity distribution.

[0017] In addition, the above-mentioned semiconductor processing equipment provided according to the second aspect of the present invention includes: a process chamber in which a coated wafer is placed; an ultraviolet light source disposed above the process chamber; a rotation mechanism connected to the ultraviolet light source to drive the ultraviolet light source to rotate and irradiate the coated wafer; and the above-mentioned process window structure provided according to the first aspect of the present invention, located between the process chamber and the ultraviolet light source, so that the ultraviolet light intensity irradiated on the wafer surface presents a bat-shaped static light intensity distribution, and after the ultraviolet light source rotates, the rotating ultraviolet light is irradiated on the wafer surface through the process window structure to present a uniform dynamic light intensity distribution, so as to uniformly cure the films in each area of the wafer surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] After reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings, the above features and advantages of the present invention can be better understood. In the drawings, the components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0019] Figure 1 FIG. shows a schematic structural diagram of a semiconductor processing equipment provided according to some embodiments of the present invention;

[0020] Figure 2A FIG. shows a schematic structural diagram of a process window structure provided according to some embodiments of the present invention;

[0021] Figure 2B FIG. shows a schematic diagram of a static light intensity distribution of a bat shape presented on the wafer surface according to some embodiments of the present invention;

[0022] Figure 3 FIG. shows a graph of the light intensity distribution irradiated on the wafer surface through a conventional process window in the prior art;

[0023] Figure 4 FIG. shows a graph of the light intensity distribution irradiated on the wafer surface through the process window structure according to some embodiments of the present invention;

[0024] Figure 5 FIG. shows a flowchart of a manufacturing method of a process window structure according to some embodiments of the present invention; and

[0025] Figure 6 FIG. shows a schematic diagram of the light intensity test points in each area of the wafer surface according to some embodiments of the present invention.

[0026] Reference Numerals:

[0027] 100 Semiconductor processing equipment;

[0028] 110 Ultraviolet light source;

[0029] 111 Ultraviolet lamp tube;

[0030] 112 Reflector;

[0031] 120 Wafer;

[0032] 200 Process window structure;

[0033] 210 Window body;

[0034] 211 First target area;

[0035] 212 Non-target area;

[0036] 213 Second target area;

[0037] 220 Anti-reflection film;

[0038] 230 Absorbing film;

[0039] 610, 611 to 614 Test points;

[0040] 620 Light intensity demarcation range; and

[0041] S510 to S540 Steps. Detailed implementation manners

[0042] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiments, this does not mean that the features of this invention are limited to this implementation manner. On the contrary, the purpose of introducing the invention in conjunction with the implementation manner is to cover other alternatives or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, many specific details will be included in the following description. The present invention can also be implemented without these details. In addition, in order to avoid confusing or obscuring the key points of the present invention, some specific details will be omitted in the description.

[0043] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0044] In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal", and "vertical" used in the following description should be understood as the orientations shown in this section and the related drawings. Such relative terms are for convenience of description only and do not represent that the devices described need to be manufactured or operated in a specific orientation, and thus should not be construed as a limitation on the present invention.

[0045] It is understood that although terms such as "first", "second", "third", etc. may be used herein to describe various components, regions, layers, and / or parts, these components, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers, and / or parts. Therefore, the first component, region, layer, and / or part discussed below may be referred to as the second component, region, layer, and / or part without departing from some embodiments of the present invention.

[0046] As described above, the currently common solutions for improving the uniformity of ultraviolet light irradiation include adding multiple pairs of main reflectors and sub-reflectors around the ultraviolet light source, and through multi-stage reflection, to improve the uniformity of the light intensity distribution of the ultraviolet light irradiated on the wafer surface. However, this method requires introducing a structure with a complex optical path design, which not only increases the design load, but also occupies the equipment space and increases the equipment cost. In addition, the common solutions also include setting an absorption layer on the light-receiving surface of the chamber cover to absorb the strong light intensity in the central region of part of the ultraviolet light, so as to improve the uniformity of the light intensity distribution of the ultraviolet light irradiated on the wafer surface. Although this method can simplify the equipment structure, it is necessary to sacrifice the ultraviolet light intensity irradiated on part of the wafer surface, reducing the light efficiency utilization rate.

[0047] To solve the above problems existing in the prior art, the present invention provides a process window structure, a manufacturing method of a process window structure, and a semiconductor processing device, which can improve the uniformity of the ultraviolet light intensity received on the wafer surface as a whole without reducing the light intensity irradiated on part of the wafer surface, thereby improving the light efficiency utilization rate and improving the uniformity of the film curing on the wafer surface, and the structure of the present invention is simple and easy to manufacture, without adding an additional complex optical path design structure, thereby reducing the equipment cost.

[0048] In some non-limiting embodiments, the above process window structure provided by the first aspect of the present invention can be obtained by manufacturing the above manufacturing method of the process window structure provided by the second aspect of the present invention and configured in the above semiconductor processing device provided by the third aspect of the present invention.

[0049] The working principle of the above process window structure will be described below in conjunction with some embodiments of semiconductor processing equipment and methods for fabricating the process window structure. Those skilled in the art can understand that these embodiments of semiconductor processing equipment and methods for fabricating the process window structure are only some non-restrictive implementation manners provided by the present invention, aiming to clearly show the main concept of the present invention and provide some specific solutions convenient for the public to implement, rather than restricting all working modes or all functions of the process window structure. Similarly, the process window structure is also a non-restrictive implementation manner provided by the present invention, and does not limit other configuration objects in these semiconductor processing equipment and the implementation subjects of each step in the method for fabricating the process window structure.

[0050] Please refer to Figure 1 , Figure 1 which shows a schematic structural diagram of a semiconductor processing equipment provided according to some embodiments of the present invention.

[0051] As Figure 1 shown, in some embodiments of the present invention, the semiconductor processing equipment 100 mainly may include a process chamber (not shown in the drawings), an ultraviolet light source 110, a rotation mechanism (not shown in the drawings), and a process window structure 200. A coated wafer 120 to be subjected to ultraviolet curing may be placed inside the process chamber. The ultraviolet light source 110 may be disposed above the process chamber and driven by the connected rotation mechanism to rotate and irradiate the coated wafer 120. By rotating the ultraviolet light source 110, the light in both the horizontal and vertical directions will alternately sweep across the wafer 120 below. Therefore, to a certain extent, the light intensity can be complemented for the static light intensity distribution, improving the overall uniformity of the light illumination.

[0052] Specifically, the ultraviolet light source 110 may include an ultraviolet lamp tube 111, such as an electrodeless mercury lamp, and a reflector 112 located above the ultraviolet lamp tube 111. The reflector 112 can reflect the ultraviolet light emitted by the ultraviolet lamp tube 111 in other directions downward so that it irradiates the coated wafer 120 below.

[0053] However, for a traditional process window, the light intensity complementarity achieved only by rotating the ultraviolet light source 110 still cannot achieve an ideal uniform light intensity distribution. Therefore, in the semiconductor processing equipment 100 provided by the present invention, an improved process window structure 200 may be provided between the process chamber and the ultraviolet light source 110 so that the ultraviolet light intensity of the rotating ultraviolet light irradiating each area on the surface of the wafer 120 via the process window structure 200 is equal, thereby uniformly curing the films on each area of the wafer surface. In this embodiment, the process window structure 200 in the process chamber is improved, so that multiple pairs of secondary reflectors for performing multi-stage reflection in the prior art can be omitted, and no additional complex optical path design structure needs to be added, thereby reducing the equipment cost.

[0054] Specifically, please combine Figure 2A and Figure 2B to understand together that Figure 2A FIG. shows a schematic structural diagram of a process window structure provided according to some embodiments of the present invention. Figure 2B FIG. shows a schematic diagram of the static light intensity distribution with a bat shape on the surface of a wafer provided according to some embodiments of the present invention.

[0055] As Figure 2A shown, in some embodiments, the process window structure 200 may mainly include a window body 210 and an antireflection film 220. Combining Figure 1 to understand together, an ultraviolet light source 110 may be provided in the first direction (such as above) of the window body 210, and a coated wafer 120 may be placed in its second direction (such as below), wherein the coated wafer 120 may be placed perpendicular to the ultraviolet light source 110. Herein, "placed perpendicular" may include that the coated wafer 120 is horizontally placed directly below the ultraviolet light source 110, or may also include that the coated wafer 120 is horizontally placed below the ultraviolet light source 110 with a certain offset distance. The antireflection film 220 may be provided in a first target area 211 on the first surface of the window body 210 to increase the transmittance of the ultraviolet light irradiated onto the surface of the wafer 120 through the first target area 211, wherein the first target area 211 may be determined based on the light intensity of each area on the surface of the wafer 120.

[0056] Combining Figure 1 to understand together, the "first direction" in the above embodiments corresponds to above, and specifically may refer to the outside of the process chamber, while the "second direction" corresponds to below, and specifically may refer to the inside of the process chamber. Similarly, the "first surface" in the above embodiments may also be understood as the upper surface facing away from the coated wafer 120, that is, the outside of the process chamber. Since if the antireflection film 220 is provided in the process chamber, the antireflection film 220 in the chamber is likely to be contaminated during the process (such as deposition process, lithography process, etc.) resulting in a change in its transmittance, thereby affecting the stability of the antireflection film 220.

[0057] As Figure 2B shown, in some embodiments, when the wafer 120 is located directly below the ultraviolet light source 110, the light intensity distribution on the surface of the wafer 120 may present a complete "bat-shaped" static light intensity distribution with low light intensity in the central area of the wafer 120 and high light intensity in its surrounding areas. Specifically, as Figure 2B the curve 241 in FIG. represents the first static light intensity distribution on the surface of the wafer 120 in the vertical direction with respect to the ultraviolet lamp tube 111 when the lamp head (including the ultraviolet lamp tube 111 + the reflector 112) is stationary. And the curve 242 represents the second light intensity distribution on the surface of the wafer 120 in the horizontal direction with respect to the ultraviolet lamp tube 111 when the lamp head is stationary.

[0058] In addition, in some alternative embodiments, when the wafer 120 is placed offset below the ultraviolet light source 110, the surface of the wafer 120 may include the above-mentioned partial "bat-shaped" static light intensity distribution.

[0059] Combined with Figure 1 the common understanding, based on the curves 241 and 242 shown in Figure 2B rotating the ultraviolet light source 110 can obtain a rotated uniform dynamic light intensity distribution, thereby uniformly curing the thin films in each area on the surface of the wafer 120.

[0060] Furthermore, combined with Figure 1 and Figure 2A shown in, in some embodiments, due to the restriction of the light energy transmission efficiency of the optical subsystem, the distance between the wafer 120 and the process window structure 200 cannot be too far, and generally can be maintained in the range of 20 - 40 mm. And since the coated wafer 120 can be placed perpendicular to the ultraviolet light source 110, the ultraviolet light similar to parallel light can be adjusted to fall on the surface of the wafer 120. On this basis, preferably, the coated wafer 120 can be placed concentrically with the window body 210. At this time, the first target area 211 can be the outer edge area of the window body 210.

[0061] As Figure 2A shown, the first target area 211 can preferably be the annular outer edge area of the window body 210. Therefore, there can be a 1:1 correspondence between the ring width R1 of the boundary area of the first target area 211 and the radius R2 of the non-target area 212 at the center of the window body 210 inside it.

[0062] Furthermore, please refer to Figure 3 , Figure 3 which shows the light intensity distribution curve graph of the light irradiated onto the wafer surface via the traditional process window in the prior art.

[0063] As Figure 3 shown, in the embodiment where the diameter of the wafer 120 is 300 mm, in the prior art, for the light intensity distribution irradiated onto the wafer 120 through the traditional process window (without an antireflection film), taking the center point of the wafer (point 6) as the origin, 11 test points are selected, and the interval between each test point can be 30 mm. In the range of 0 - 180 mm in diameter corresponding to the center point of the wafer 120, the light intensity distribution is basically in a uniform state, while the light intensity decreases significantly in the range of 180 - 300 mm. In this regard, in some preferred embodiments provided by the present invention, the area of the first target area 211 on the window body 210 can be set to be

[0064] Specifically, combined with Figure 2A and Figure 3As shown, in some alternative embodiments, when the first target area 211 is a relatively standard annular outer edge area, the ratio of the ring width R1 of the first target area 211 to the radius R2 of the non-target area 212 located at the center of the window body 210 can be Therefore, combining the above two embodiments, the range of the ratio of the ring width R1 of the first target area 211 to the radius R2 of the non-target area 212 can be 1:1 to 2:3.

[0065] On this basis, if the first target area 211 determined based on the light intensity of each area on the surface of the wafer 120 is not a relatively standard annular area but an irregular outer edge area, then the specific range of the irregular first target area 211 can be determined based on the range of the area ratio of the annular first target area 211 obtained in the above embodiment of the annular outer edge area to the area of the wafer 120.

[0066] Specifically, when the ratio of the ring width R1 of the first target area 211 to the radius R2 of the non-target area 212 is 1:1, the area ratio S1 of the two is: When the ratio of the ring width R1 of the first target area 211 to the radius R2 of the non-target area 212 is 2:3, the area ratio S1 of the two is: Therefore, in some embodiments where the first target area 211 is an irregular outer edge area, it can be based on the area of the first target area 211 being of the area of the wafer 120 to determine the range of the first target area 211.

[0067] Furthermore, in some embodiments of the present invention, the antireflection film 220 can be a multi-layer film structure formed by alternately depositing at least two layers of a first refractive index material and a second refractive index material. When light is incident on the multi-layer film, reflected light will be generated on the upper and lower surfaces of each layer of the film. These reflected lights will interfere due to the optical path difference and phase difference. If the thickness and refractive index of the film layers are designed properly, the reflected light can undergo destructive interference at a specific wavelength, thereby reducing the intensity of the reflected light and enabling more light to be transmitted through.

[0068] Since ordinary coating materials will absorb in the ultraviolet band, there are not many materials that can be used for ultraviolet antireflection films. In this embodiment, the antireflection film 220 can be made of aluminum oxide (Al2O3) and silicon dioxide (SiO2). The refractive index of Al2O3 is about 1.76, and the refractive index of SiO2 is about 1.45. By alternately using high refractive index (Al2O3) and low refractive index (SiO2) materials, the interference effect can be effectively enhanced.

[0069] In addition, in some preferred embodiments, the antireflection film 220 can adopt a multilayer film structure. By adjusting the number and thickness of the film layers, the antireflection effect for a wider wavelength range can be achieved, rather than just enhancing the antireflection for a single wavelength. Therefore, compared with the single-layer film structure, the multilayer film structure can more effectively reduce the reflection loss and further improve the light transmittance.

[0070] Specifically, the thickness of each layer of the film can usually be one-fourth of the wavelength of light in the film (i.e., λ / 4), so as to ensure that the reflected light has a phase difference of π, thereby achieving destructive interference. Optionally, in some embodiments, the antireflection film 220 can include a multilayer film structure formed by alternately depositing 6 layers of Al2O3 and SiO2, and the thickness of each layer of the film can be 40 - 50 nm. If the thickness of each layer of the film in the antireflection film 220 is too thick, the film cannot form interference and thus cannot play the role of antireflection. In this embodiment, making 6 layers of antireflection is based on the design requirements of the transmittance. If the number of layers is less than this number, the antireflection transmittance effect cannot meet the requirements.

[0071] Please refer to Figure 4 , Figure 4 which shows the light intensity distribution curve of the light irradiated onto the wafer surface via the process window structure according to some embodiments of the present invention.

[0072] Comparing Figure 3 and Figure 4 , in Figure 3 the prior art shown, that is, the light intensity distribution of the ultraviolet light irradiated onto the surface of the wafer 120 via the traditional process window without the antireflection film 220, through the light intensity uniformity calculation formula its uniformity can be determined to be about 18%, where I max represents the maximum light intensity, I min represents the minimum light intensity, represents the average light intensity. And as Figure 4 shown, in the embodiment of the present invention, for the process window structure 200 formed by plating the antireflection film 220 on the window body 210, through the light intensity uniformity calculation formula, it can be obtained that its uniformity has been significantly improved, from the original 18% reduced to about 7%.

[0073] Continuing as Figure 2A shown, in some other alternative embodiments, if the target light intensity on the surface of the wafer 120 is less than the direct light intensity of the ultraviolet light source 110. For example, if the target light intensity on the surface of the wafer 120 is 70 - 80 mW / cm 2 , and the maximum light intensity of the direct irradiation of the ultraviolet light source 110 onto the central area of the surface of the wafer 120 is 100 mW / cm 2 , at this time, a light absorption film can be plated on the first surface of the window body 210 of the process window structure 200 to absorb part of the excess light intensity.

[0074] Specifically, going back to Figure 2A As shown, the process window structure 200 can also be provided with an absorption film 230 according to the target light intensity. The absorption film 230 can be disposed in the second target area 213 of the non-target area 212 to reduce the light transmittance of the ultraviolet light irradiated onto the surface of the wafer 120 through the second target area 213, so that the ultraviolet light irradiated onto the surface of the wafer 120 through at least the first target area 211 and the second target area 213 presents a bat-shaped static light intensity distribution (as shown by the curve 241 in Figure 2B ). Optionally, the range of the second target area 213 can be less than or equal to the non-target area 212 (in the above embodiment, it can also be understood that the range of the second target area 213 is 0). The range of the second target area 213 and the range of the first target area 211 can be enlarged or reduced according to the uniformly distributed target light intensity, so as to uniformly adjust the light intensity irradiated onto the wafer 120 to the target light intensity.

[0075] In this embodiment, by coating the area with low light intensity of the window body 210 with an antireflection film 220 having an ultraviolet light transmittance increasing effect to increase the ultraviolet light intensity on the surface of the wafer corresponding to this area, and coating the area with high light intensity of the window body 210 with an absorption film 230 having an ultraviolet light absorption effect to reduce the ultraviolet light intensity on the surface of the wafer corresponding to this area, through the combined adjustment of the antireflection film 220 and the absorption film 230, the light intensity distribution on the surface of the wafer 120 is further made uniform.

[0076] Furthermore, in some embodiments, the absorption film 230 can include a nickel-chromium-iron alloy layer. Compared with other common materials that can be used as a light absorption layer, such as zinc oxide (ZnO), indium tin oxide (ITO), titanium dioxide (TiO2), and magnesium fluoride (MgF2), nickel-chromium-iron alloy has significant advantages in ultraviolet light absorption, mainly reflected in its wide absorption bandwidth, high absorption coefficient, and good stability. In contrast, the above other materials have limitations in ultraviolet light absorption ability, especially in terms of absorption range and stability.

[0077] Specifically, in terms of absorption characteristics, nickel-chromium-iron alloy is a metal alloy with a high light absorption coefficient, and due to its metal characteristics, nickel-chromium-iron alloy has a wide absorption bandwidth in the ultraviolet light band and can absorb ultraviolet light in a relatively wide range. While ZnO mainly absorbs ultraviolet light with shorter wavelengths (such as 200 - 300 nm) and has weak absorption ability for ultraviolet light with longer wavelengths. ITO is mainly used for the transmission of visible light and infrared light and has limited absorption ability for ultraviolet light. TiO2 mainly focuses on absorbing ultraviolet light in the short wavelength band (such as 300 - 400 nm) and has a worse absorption effect on ultraviolet light in a wider band than nickel-chromium-iron alloy. MgF2 is a low refractive index material mainly used as an antireflection film in optical coating and has extremely low absorption ability for ultraviolet light.

[0078] In terms of stability, nickel-chromium-iron alloy has good chemical stability and thermal stability, is not easily oxidized or corroded, and is suitable for use in a variety of environments. ZnO may undergo chemical reactions in high humidity or strong acid-base environments, affecting its absorption performance. ITO may undergo hydrolysis reactions in high humidity environments, resulting in a decline in its performance. TiO2 may undergo photocatalytic reactions under light, affecting its absorption performance. MgF2 is prone to deliquescence in high humidity environments, leading to a decline in the performance of the film layer. Therefore, nickel-chromium-iron alloy is more suitable for applications that require efficient ultraviolet light absorption.

[0079] Moreover, further, in the embodiment where nickel-chromium-iron alloy is selected as the absorption film 230, the film thickness of the absorption film 230 can be only 4-6 nm, and only one layer of the absorption film 230 needs to be deposited on the first surface of the window body 210. For the above other materials, such as absorption films made of zinc oxide (ZnO), indium tin oxide (ITO), titanium dioxide (TiO2), and magnesium fluoride (MgF2), due to their respective limitations in ultraviolet light absorption ability, the film thickness of the absorption film needs to be increased to about 30 nm - 65 nm. In this embodiment, significant advantages are achieved in the preparation process and preparation duration of the absorption film 230, as well as in the absorption ability for a wide range of ultraviolet light, and it can cooperate with the antireflection film 220 to jointly achieve uniform distribution of the light intensity on the surface of the wafer 120, thereby improving the uniformity of process indicators.

[0080] Next, please refer to Figure 5 , Figure 5 which shows a flowchart of a method for manufacturing a process window structure according to some embodiments of the present invention.

[0081] As Figure 5 shown, in some embodiments of the present invention, the method for manufacturing a process window structure may include the following steps. First, step S510 can be executed to obtain the initial light intensity distribution of each region on the surface of the coated wafer in the second direction of the window body.

[0082] Specifically, please refer to Figure 6 , Figure 6 which shows a schematic diagram of light intensity test points for each region on the surface of the wafer according to some embodiments of the present invention.

[0083] As Figure 6 shown, in some embodiments, a coated wafer 120 is placed inside the process chamber. The radius of the wafer 120 is 150 mm, and a plurality of test points 610 are provided on the surface of the wafer 120. By using a light intensity detection device, such as an energy meter, the light intensity values of these multiple test points 610 on the surface of the wafer 120 are respectively detected, so as to obtain the initial light intensity distribution of each region on the surface of the coated wafer 120. In Figure 6In the illustrated embodiment, with the center position of the wafer (point 6) as the origin, on the surface of a 300 mm diameter wafer 120, 11 light intensity test points can be set on each diameter ( Figure 6 only the test points on two diameters are taken as examples), and the adjacent test points can be spaced 30 mm apart.

[0084] Continuing as Figure 5 shown, then step S520 can be executed: Determine the light intensity demarcation range on the wafer surface according to the initial light intensity distribution.

[0085] Specifically, in some embodiments, multiple test points on the wafer surface corresponding to the outer edge of the maximum light intensity region in the initial light intensity distribution can be connected to obtain the light intensity demarcation range. In Figure 6 the illustrated embodiment, on the wafer diameter corresponding to the x-axis, the maximum light intensity region of the diameter corresponding to the test points 611 and 612 can be determined by an energy meter. From the test points 611 and 612 to the wafer edge, the light intensity of the light irradiated on this diameter gradually decreases. Similarly, on the wafer diameter corresponding to the y-axis, the maximum light intensity test points are 613 and 614. At this time, the maximum light intensity test points 611 to 614 on the x-axis and y-axis diameters can be connected to obtain the light intensity demarcation range 620.

[0086] Continuing as Figure 5 shown, then step S530 can be executed: Determine the first target area of the window body based on the light intensity demarcation range.

[0087] Specifically, with reference to Figure 2A and Figure 6 understood together, in some embodiments, according to the light intensity demarcation range 620, the area of the window body 210 corresponding to outside the maximum light intensity region can be the first target area 211.

[0088] In some alternative embodiments, if the first target area 211 is not a relatively standard annular area but an irregular outer edge area, the range of the first target area 211 can be determined according to the area of the first target area 211 being of the area of the wafer 120, so as to ensure that the first target area 211 can cover the low light intensity regions on the surface of the wafer 120, thereby improving the ultraviolet light transmittance of these low light intensity regions.

[0089] Further, in some preferred embodiments, if the first target area 211 is a relatively standard circular area, the range of the ratio of the ring width R1 of the first target area 211 to the radius R2 located in the non-target area 212 is 1:1 to 2:3, and the range of the first target area 211 can be determined, so as to ensure that the first target area 211 can cover the low light intensity area on the surface of the wafer 120, thereby improving the ultraviolet transmittance of these low light intensity areas.

[0090] After that, continue to return to Figure 5 , step S540 can be executed: deposit an antireflection film on the first surface of the window body according to the first target area, so as to increase the transmittance of the ultraviolet light irradiated onto the surface of the wafer through the first target area, so that the surface of the wafer presents a bat-shaped static light intensity distribution.

[0091] Specifically, in combination with Figure 1 and Figure 2A Understood together, it can be on the outer side (i.e., the first direction) of the process chamber, that is, on the upper surface (i.e., the first surface) of the window body 210 facing away from the coated wafer 120. According to the previously determined first target area 211, deposit an antireflection film 220 on the first target area 211, so that the surface of the wafer 120 presents a bat-shaped static light intensity distribution (as shown by the curve 241 in Figure 2B ).

[0092] Optionally, the antireflection film 220 is preferably a multilayer film structure formed by alternately depositing alumina and silica. By alternately depositing these two materials with different refractive indexes to form the multilayer film structure of the antireflection film 220, the interference effect can be effectively enhanced, and further the reflection loss can be reduced more effectively, and the light transmittance can be further improved, so that the ultraviolet light intensity irradiated onto each area of the surface of the wafer 120 is evenly distributed, so that the film can be cured evenly and the process index uniformity can be improved. In this embodiment, without reducing the light intensity of some areas on the surface of the wafer, the uniformity of the ultraviolet light intensity received on the surface of the wafer can be improved as a whole, thereby improving the light efficiency utilization rate and improving the uniformity of the film curing on the surface of the wafer. And the structure of the present invention is simple and easy to manufacture, without adding additional complex optical path design structures, so that the equipment cost can be reduced.

[0093] After that, even further, in combination with Figure 1 shown, in some embodiments, the ultraviolet light source 110 can also be rotated so that the light in the horizontal and vertical directions alternately sweeps across the wafer 120 below, thereby further enhancing the effect of light intensity complementarity, so that the irradiated surface of the wafer 120 presents a uniform dynamic light intensity distribution (as shown by the light intensity curve in Figure 4 ). Comparing Figure 3 and Figure 4, in this embodiment, by combining the process window structure 200 of the antireflection film 220 with the rotating ultraviolet light source 110, the uniformity of the ultraviolet light intensity irradiated on the surface of the wafer 120 can be greatly improved, which is reduced from 18% to 7% originally.

[0094] In addition, as Figure 2A shown, in some other alternative embodiments, if the target light intensity on the surface of the wafer 120 is less than the direct light intensity of the ultraviolet light source, in the above step S530, after determining the first target area 211, the second target area 213 can also be determined in the non-target area 212 of the window body 210 corresponding to the maximum light intensity area according to the target light intensity on the surface of the wafer 120. Then, according to the second target area 213, the absorption film 230 is deposited on the first surface of the window body 210 to reduce the transmittance of the ultraviolet light irradiated on the surface of the wafer 120 via the second target area 213, so that the ultraviolet light irradiated on the surface of the wafer 120 via at least the first target area 211 and the second target area 213 presents a bat-shaped static light intensity distribution (as shown by the curve 241 in Figure 2B ). After that, the rotating ultraviolet light source 110 can also be used to further improve the effect of light intensity complementarity, so that the irradiated light intensity distribution on the surface of the wafer 120 is uniform dynamically (as shown by the light intensity curve in Figure 4 ), thereby improving the illumination uniformity on the surface of the wafer 120.

[0095] Although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and / or concurrently with other actions that are illustrated and described herein or that are not illustrated and described herein but are understandable to those skilled in the art.

[0096] In summary, the present invention provides a process window structure, a manufacturing method of a process window structure, and a semiconductor processing device, which can improve the uniformity of the ultraviolet light intensity distribution received on the surface of the wafer as a whole without reducing the light intensity irradiated on some areas of the wafer surface, thereby improving the light efficiency utilization rate and the uniformity of film curing on the wafer surface. Moreover, the structure of the present invention is simple and easy to manufacture, without the need to add additional complex optical path design structures, thus reducing the equipment cost.

[0097] The previous description of the present disclosure is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A process window structure, characterized in that, Comprising: A window body, which is provided with an ultraviolet light source in a first direction, and a coated wafer is placed in a second direction thereof, wherein the coated wafer is placed perpendicular to the ultraviolet light source; and An anti-reflection film, which is arranged in a first target area on a first surface of the window body to increase the light transmittance of the ultraviolet light irradiated onto the wafer surface through the first target area, so that the wafer surface presents a bat-shaped static light intensity distribution, wherein the first target area is determined based on the light intensity of each area on the wafer surface.

2. The process window structure according to claim 1, characterized in that The coated wafer is placed concentrically with the window body, and the first target area is the outer edge area of the window body, wherein the area of the first target area is 3. The process window structure according to claim 2, wherein, The first target area is an annular outer edge area, and the range of the ratio of the ring width of the first target area to the radius of the non-target area located at the center of the window body is 1:1 to 2:

3.

4. The process window structure according to claim 3, wherein The process window structure further comprises: An absorption film, which is arranged in a second target area in the non-target area to reduce the light transmittance of the ultraviolet light irradiated onto the wafer surface through the second target area, so that the ultraviolet light irradiated onto the wafer surface at least through the first target area and the second target area presents the bat-shaped static light intensity distribution.

5. The process window structure according to claim 4, characterized in that The absorption film includes a nickel-chromium-iron alloy layer, and the film thickness of the absorption film is 4 to 6 nm.

6. The process window structure according to claim 1, wherein The first surface is the surface facing away from the coated wafer, and the anti-reflection film is a multi-layer film structure formed by alternately depositing at least two layers of a first refractive index material and a second refractive index material.

7. The process window structure according to claim 6, characterized in that, The first refractive index material is silicon dioxide, the second refractive index material is aluminum oxide, the silicon dioxide and the aluminum oxide are alternately deposited to form a multi-layer film structure, and the thickness of each film layer is one quarter of the wavelength of light in the film.

8. A manufacturing method of a process window structure, characterized in that, Including the following steps: Obtain the initial light intensity distribution of each area on the surface of the coated wafer located in the second direction of the window body; Determine the light intensity demarcation range on the wafer surface according to the initial light intensity distribution; Determine the first target area of the window body based on the light intensity demarcation range; And Deposit an anti-reflection film on the first surface of the window body according to the first target area to increase the light transmittance of the ultraviolet light irradiated onto the wafer surface through the first target area, so that the wafer surface presents a bat-shaped static light intensity distribution, wherein the first target area is determined based on the light intensity of each area on the wafer surface.

9. The manufacturing method according to claim 8, characterized in that, The step of determining the light intensity demarcation range on the wafer surface according to the initial light intensity distribution includes: Connect a plurality of test points on the wafer surface corresponding to the outer edge of the maximum light intensity area in the initial light intensity distribution to obtain the light intensity demarcation range. The step of determining the first target area of the window body based on the light intensity demarcation range further includes: According to the light intensity demarcation range, the area of the window body corresponding to the area outside the maximum light intensity area is the first target area; Determine a second target area in the non-target area of the window body corresponding to the maximum light intensity area according to the target light intensity; and Deposit an absorption film on the first surface of the window body according to the second target area to reduce the light transmittance of the ultraviolet light irradiated onto the wafer surface through the second target area, so that the ultraviolet light irradiated onto the wafer surface at least through the first target area and the second target area presents the bat-shaped static light intensity distribution.

10. A semiconductor processing device, characterized in that, Comprising: A process chamber, inside which a coated wafer is placed; An ultraviolet light source, disposed above the process chamber; A rotation mechanism, connected to the ultraviolet light source to drive the ultraviolet light source to rotate and irradiate the coated wafer; And The process window structure according to any one of claims 1 to 7, located between the process chamber and the ultraviolet light source, so that the ultraviolet light intensity irradiated on the surface of the wafer presents a bat-shaped static light intensity distribution, and after the ultraviolet light source rotates, the rotating ultraviolet light is irradiated on the surface of the wafer through the process window structure to present a uniform dynamic light intensity distribution, so as to uniformly cure the films in each area on the surface of the wafer.

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