Main reflector and ultraviolet curing equipment

Abstract

The invention relates to the technical field of ultraviolet curing, in particular to a main reflector and ultraviolet curing equipment. The invention provides a main reflector which is applied to ultraviolet curing equipment and used for reflecting light rays emitted by an ultraviolet curing light source to the surface of a semiconductor wafer. The surface type curve of the inner concave surface of the main reflecting mirror accords with a specific polynomial curved surface equation; and the polynomial curved surface equation is used for optimizing the illumination uniformity of ultraviolet rays on the surface of a semiconductor wafer. According to the main reflector and the ultraviolet curing equipment provided by the invention, by optimizing the surface type and the reflectivity of the main reflector, high uniformity and high efficiency of UV illumination are realized, and the process effect and the product quality are improved while the specific process specification requirements are met.

Description

Technical Field

[0001] The invention relates to the technical field of ultraviolet curing, and more particularly to a main reflector and ultraviolet curing equipment. Background Art

[0002] In the UV Cure process, the uniformity and efficiency of the light source are important factors affecting the quality of curing. Usually, UV Cure equipment is used in processes such as photoresist curing and packaging material curing in semiconductor manufacturing, which requires the UV light to have a uniform light intensity distribution on the wafer surface to ensure consistent curing effect in the entire curing area. In addition, the accuracy of the UV Cure process also directly affects the subsequent process steps, so it places high demands on the design and optimization of the UV light source system.

[0003] In UV Cure equipment, the UV light generated by the UV curing light source is usually reflected by a main reflector to the surface of the wafer to be processed, thereby achieving uniform irradiation.

[0004] There are still many deficiencies in the design of the primary reflector in the prior art, including:

[0005] 1) It is difficult to achieve uniform irradiation over a large area with traditional plane, spherical or parabolic reflectors. After reflection, the light will form uneven spots on the surface of the wafer, resulting in inconsistent curing effects within the curing area.

[0006] 2) The reflectivity of the main reflector to UV light is limited, and part of the light energy is lost during reflection, resulting in energy waste of the light source. In addition, the traditional reflector has poor control over the reflection of different wavelengths of the light beam, and fails to efficiently concentrate the light energy in the target area, further reducing the utilization rate of light energy. Summary of the invention

[0007] The purpose of the present invention is to provide a main reflector and ultraviolet curing equipment to solve the problem that the main reflector in the prior art forms uneven light spots on the wafer surface, resulting in inconsistent curing effects in the curing area.

[0008] Another object of the present invention is to provide a main reflector and ultraviolet curing equipment to solve the problem that the main reflector in the prior art has poor reflection control ability for different wavelength bands of the light beam, thereby reducing the energy utilization rate of the light source and the ultraviolet curing effect.

[0009] In order to achieve the above-mentioned object, the present invention provides a main reflector, which is applied to ultraviolet curing equipment, wherein the main reflector is used to reflect the light emitted by the ultraviolet curing light source to the surface of the semiconductor wafer;

[0010] The surface curve of the inner concave surface of the primary reflector conforms to a specific polynomial surface equation:

[0011] The polynomial surface equation is used to optimize the illumination uniformity of ultraviolet rays on the surface of the semiconductor wafer.

[0012] In some embodiments, the polynomial surface equation of the primary reflector is a quintic polynomial, and the corresponding expression is:

[0013] y=A+B1*x+B2*x 2 +B3*x 3 +B4*x 4 +B5*x 5 ;

[0014] Among them, x is the horizontal coordinate of the concave surface of the main reflector, and y is the height coordinate of the concave surface of the main reflector;

[0015] A is the intercept, and B1, B2, B3, B4, and B5 are the coefficient values ​​of each item.

[0016] In some embodiments, the intercept A of the polynomial surface equation is 2.21195, the coefficient values ​​B1 are 1.29659, B2 are 0.04614, B3 are 7.59899E-04, B4 are 7.46533E-06, and B5 are 3.06779E-08.

[0017] In some embodiments, the reflectivity of the main reflector is set within a specific range to optimize the reflection efficiency of light in the ultraviolet band and improve the ultraviolet curing effect on the wafer surface.

[0018] In some embodiments, the reflectivity of the primary reflector satisfies the following conditions:

[0019] In the 220-480nm band, the average reflectivity reaches over 85%.

[0020] In some embodiments, the reflectivity of the primary reflector satisfies the following conditions:

[0021] In the 220-450nm band, the minimum reflectivity reaches 80%;

[0022] In the 200-220nm band, the minimum reflectivity reaches 50%.

[0023] In some embodiments, the reflectivity of the primary reflector satisfies the following conditions:

[0024] When the reflectivity of the rising edge is greater than or equal to 50%, the wavelength range is within 205nm±5nm;

[0025] When the reflectivity of the falling edge is greater than or equal to 50%, the wavelength range is within 520nm±10nm.

[0026] In order to achieve the above object, the present invention provides an ultraviolet curing device, which at least includes an ultraviolet curing light source and a main reflector:

[0027] The ultraviolet curing light source is arranged in the main reflector at the top of the cavity and is used to generate ultraviolet rays;

[0028] The main reflector is used to reflect the ultraviolet rays of the ultraviolet curing light source to the surface of the semiconductor wafer.

[0029] In some embodiments, the UV curing equipment further includes a quartz optical window, which is disposed below the main reflector and the UV light source and above the semiconductor wafer, and is used to protect the semiconductor wafer while transmitting UV light to the surface of the semiconductor wafer.

[0030] In some embodiments, the ultraviolet curing equipment further includes a wafer temperature control stage:

[0031] The wafer temperature control platform is arranged at the bottom of the semiconductor wafer and is used to control and adjust the temperature of the semiconductor wafer.

[0032] The primary reflector and ultraviolet curing equipment proposed in the present invention achieve high uniformity and high efficiency of UV lighting by optimizing the surface shape and reflectivity of the primary reflector, and can provide stable and uniform lighting in the UV Cure process, thereby meeting specific process specification requirements and improving process effects and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always represent the same features, wherein:

[0034] Figure 1 A schematic diagram of the structure of an ultraviolet curing device according to an embodiment of the present invention is disclosed;

[0035] Figure 2a A simulation result diagram on a wafer when a main reflector of a first surface type according to an embodiment of the present invention is disclosed;

[0036] Figure 2b A simulation result diagram on a wafer when a primary reflector of a first surface type according to an embodiment of the present invention is disclosed;

[0037] Figure 3a A simulation result diagram on a wafer when a main reflector of a second surface type according to an embodiment of the present invention is disclosed;

[0038] Figure 3b A simulation result diagram on a wafer when a main reflector of a second surface type according to an embodiment of the present invention is disclosed;

[0039] Figure 4a A simulation result diagram on a wafer when a main reflector of a third surface type according to an embodiment of the present invention is disclosed;

[0040] Figure 4b A simulation result diagram on a wafer when a main reflector of a third surface type according to an embodiment of the present invention is disclosed;

[0041] Figure 5 A first surface profile graph of a primary reflector according to an embodiment of the present invention is disclosed;

[0042] Figure 6 A reflectivity graph of a primary reflector according to an embodiment of the present invention is disclosed.

[0043] The meanings of the reference numerals in the figures are as follows:

[0044] 1UV electrodeless mercury lamp;

[0045] 2 main reflector;

[0046] 3 quartz optical window;

[0047] 4Semiconductor wafers;

[0048] 5. Wafer temperature controlled stage. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the invention and are not used to limit the invention.

[0050] In the prior art, the surface shape and reflectivity of the primary reflector lack precise specification design, resulting in poor reflection effect in practical applications. The lack of uniformity and reliability of the UV Cure process can easily have a negative impact on key parameters such as UV Cure shrinkage and refractive index (RI), thus failing to meet specific process specifications (SPEC) requirements.

[0051] The main reflector and ultraviolet curing equipment proposed in the present invention make the illumination more uniform by precisely controlling the surface shape and reflectivity of the main reflector, concentrate the reflectivity in the effective UV band, improve the stability and efficiency of the process, and solve the above-mentioned deficiencies in the prior art.

[0052] On the one hand, the present invention provides an ultraviolet curing device, which at least includes an ultraviolet curing light source and a main reflector:

[0053] The ultraviolet curing light source is arranged in the main reflector at the top of the cavity and is used to generate ultraviolet rays;

[0054] The main reflector is used to reflect the ultraviolet rays of the ultraviolet curing light source to the surface of the semiconductor wafer.

[0055] On the other hand, a main reflector proposed by the present invention is applied to the above-mentioned ultraviolet curing equipment, and the main reflector is used to reflect the light emitted by the ultraviolet curing light source to the surface of the semiconductor wafer;

[0056] The surface curve of the inner concave surface of the primary reflector conforms to a specific polynomial surface equation:

[0057] The polynomial surface equation is used to optimize the illumination uniformity of ultraviolet rays on the surface of the semiconductor wafer.

[0058] Furthermore, the reflectivity of the main reflector is set within a specific range to optimize the reflection efficiency of light in the ultraviolet band and improve the ultraviolet curing effect on the wafer surface.

[0059] Figure 1 The schematic diagram of the structure of a UV curing device according to the present invention is disclosed. Figure 1 The ultraviolet curing device proposed by the present invention shown in the figure comprises a UV electrodeless mercury lamp 1, a main reflector 2, a quartz optical window 3 and a wafer temperature control stage 5:

[0060] The UV electrodeless mercury lamp 1 is located in the main reflector 2 at the top of the equipment cavity.

[0061] The UV electrodeless mercury lamp 1, as an ultraviolet curing light source, is used to generate ultraviolet light (UV light). Its electrodeless characteristics can achieve stable UV light output, and is suitable for ultraviolet curing processes that require uniform illumination.

[0062] The main reflector 2 is used to reflect the ultraviolet light from the UV electrodeless mercury lamp 1 to the surface of the semiconductor wafer 4 .

[0063] Furthermore, the main reflector 2 can rotate, or rotate synchronously with the rotation of the UV electrodeless mercury lamp 1, so as to form a circular uniform light area.

[0064] The quartz optical window 3 is disposed below the main reflector 2 and the UV electrodeless mercury lamp 1 and above the semiconductor wafer 4 , and is used to protect the semiconductor wafer 4 while transmitting ultraviolet rays to the surface of the semiconductor wafer 4 .

[0065] Quartz material has high light transmittance, especially high transmittance to ultraviolet light. The function of the quartz optical window 3 is to protect the semiconductor wafer 4 below and prevent dust or impurities in the environment from interfering with the lighting effect, while ensuring that UV light can pass efficiently.

[0066] The semiconductor wafer 4 is the subject of the UV curing process. After being irradiated with UV light, the wafer will undergo a curing process and its properties, such as shrinkage and refractive index (RI), will be adjusted.

[0067] The wafer temperature control stage 5 is arranged at the bottom of the semiconductor wafer 4 and is used to control and adjust the temperature of the semiconductor wafer 4 to ensure the accuracy and stability of the ultraviolet curing process and avoid unnecessary thermal stress or temperature gradient of the semiconductor wafer 4 during UV light irradiation.

[0068] Each component is supported and fixed by the equipment frame, wherein the installation positions of the UV electrodeless mercury lamp 1 and the main reflector 2 are precisely designed to ensure that the UV light energy is evenly distributed on the wafer surface after reflection.

[0069] The surface shape of the primary reflector 2 is optimized through design and simulation to ensure uniformity of illumination and to ensure that the wavelength band of the reflected light is suitable for the specific process specification (SPEC) requirements of the UV curing process.

[0070] In this embodiment, the surface curve of the inner concave surface of the primary reflector 2 conforms to a specific polynomial surface equation, and the polynomial surface equation is a quintic polynomial, and the corresponding expression is:

[0071] y=A+B1*x+B2*x 2 +B3*x 3 +B4*x 4 +B5*x 5 ;

[0072] Among them, x is the horizontal coordinate of the concave surface of the main reflector, and y is the height coordinate of the concave surface of the main reflector;

[0073] A is the intercept, and B1, B2, B3, B4, and B5 are the coefficient values ​​of each item.

[0074] The above parameters determine the shape of the curve, such as the depth of the depression, the curvature distribution, etc., which in turn affects the distribution and uniformity of the ultraviolet light.

[0075] like Figure 1 In the coordinate system shown, the x-axis of the main reflector 2 represents the width direction of the main reflector, the y-axis represents its height direction, and the z-axis is perpendicular to the xy plane and points to the inside of the drawing.

[0076] In this embodiment, it is assumed that each xy cross section of the primary reflector along the Z axis is the same. Therefore, in this embodiment, the polynomial surface equation composed of the above x and y is used to describe the surface curve of the primary reflector.

[0077] The following shows three surface types that conform to the above polynomial surface equation and their simulation results.

[0078] Figure 2a The simulation result diagram on the wafer when the main reflector of the first surface type according to one embodiment of the present invention is disclosed. Figure 2a On the left is a simulation diagram of the wafer's illumination uniformity. The color in the diagram gradually changes from the center to the edge, indicating the distribution of the illumination intensity.

[0079] The color changes from light to dark, indicating the light intensity in different areas. The brightest area has the strongest light, and the darker it gets as it goes outward, indicating a decreasing light intensity. The color transition indicates that the light uniformity is high in a static state, with concentrated light in the center and attenuated light at the edges.

[0080] Figure 2a The right side is a simulation curve of the illumination intensity of the wafer when the main reflector of the first type is stationary. The red and blue curves represent the changes in illumination intensity in the X-axis and Y-axis directions of the semiconductor wafer, respectively. The X-axis and Y-axis of the semiconductor wafer are perpendicular to each other to form the surface plane of the wafer. The peak and distribution in the curve reflect the uniformity of illumination. It can be seen that the curve reaches a peak in the central area and gradually decreases to both sides, indicating that the illumination center intensity of the wafer is higher when stationary, but the edge illumination is slightly attenuated. The curve can further discover the problem of illumination uniformity and provide data basis for further optimization of the reflector surface type.

[0081] Figure 2b The simulation result diagram on the wafer when the main reflector of the first surface type according to one embodiment of the present invention is disclosed. Figure 2b The left side is the corresponding wafer illumination uniformity simulation diagram. The color in the diagram gradually darkens from the inside to the outside. The brightest area indicates that the illumination intensity is strong in the center of the wafer, which gradually weakens toward the edge. It can be seen that rotation makes the illumination intensity cover the entire wafer surface more evenly, and the color distribution is more uniform, indicating that the rotation state can improve the illumination uniformity. This is very important for processes that require consistent illumination.

[0082] Figure 2b The right side of the figure shows the X-axis (red) and Y-axis (blue) light intensity distribution curves of the semiconductor wafer when the main reflector rotates. Compared with the static state, the light intensity distribution during rotation is flatter and more uniform, and the light intensity on the X-axis and Y-axis is almost the same, indicating that rotation can effectively eliminate the intensity difference between the center and the edge, ensuring the uniformity of the light on the wafer surface.

[0083] Figure 3a The simulation result diagram on the wafer when the main reflector of the second surface type according to one embodiment of the present invention is still is disclosed. Figure 3a The left side is a simulation diagram of the illumination uniformity of the wafer when the main reflector is stationary. Figure 2aFor the first type of surface, the color transition shows that the central light concentration is higher and the edge attenuation is more obvious, indicating that the lighting uniformity in the static state is not as good as the first type of surface design.

[0084] Figure 3a The right side is the simulation curve of the light intensity of the wafer when the main reflector of the second type is stationary. Figure 2a ,The curve has an obvious peak in the center and drops rapidly toward the edge, indicating that the illumination distribution is concentrated in the center in the static state and has poor uniformity.

[0085] Figure 3b The simulation result diagram on the wafer when the main reflector of the second surface type according to one embodiment of the present invention is rotated is disclosed. Figure 3b The left side shows the uniform distribution of light on the wafer when the main reflector rotates. Although the rotation improves the uniformity, there is still some uneven light at the edge due to the different surface design. The color change shows that the rotation effect improves the distribution uniformity to a certain extent, but it is slightly insufficient compared to the first surface type.

[0086] Figure 3b The right side shows the curve of the main reflector when it rotates. The curve is relatively flat, but there is still a certain center deviation, indicating that although the rotation improves the uniformity, the effect is not as good as the first type of surface design.

[0087] Figure 4a The simulation result diagram on the wafer when the main reflector of the third surface type according to one embodiment of the present invention is disclosed. Figure 4a The left side is a simulation diagram of the illumination uniformity of the wafer when the main reflector is stationary. The illumination distribution of the wafer when the main reflector is stationary is high in the center and decays toward the edge, and the uniformity is not ideal.

[0088] Figure 4a The right side is a simulation curve of the light intensity of the wafer when the main reflector of the third type is stationary. There are obvious peaks in the center of the curves of the X-axis and Y-axis, indicating that the light uniformity is poor in the stationary state.

[0089] Figure 4b The simulation result diagram on the wafer when the main reflector of the third surface type according to an embodiment of the present invention rotates is disclosed, such as Figure 4b As shown in the figure, the left side shows the simulation results of the illumination uniformity of the wafer during the rotation of the main reflector. It can be seen from the figure that as the main reflector rotates, the illumination distribution on the wafer surface becomes more uniform. However, compared with the distribution of the first surface type, the stability of the overall illumination intensity is slightly insufficient.

[0090] Figure 4bOn the right is a simulation curve of the light intensity of the wafer when the main reflector of the third surface type is rotated. Although the rotation makes the distribution curve flatter, there is still unevenness at the edge, which shows that the design of the third surface type has limitations in improving the uniformity of light.

[0091] Among the three types of surfaces mentioned above, the first type performs best in terms of illumination uniformity. The simulation images of the second and third types of surfaces show areas of uneven illumination, especially in the curves in the X-axis and Y-axis directions, where there may be obvious fluctuations or irregular changes, resulting in the concentration or lack of illumination intensity, which in turn affects the process quality.

[0092] In this embodiment, the coordinate point data of the concave surface of the first type of primary reflector is shown in Table 1:

[0093] Table 1

[0094] X Y X Y -2.542 -0.795 -37.37 -9.169 -4.623 -2.859 -41.233 -8.175 -7.837 -5.462 -45.011 -6.99 -11.425 -7.606 -48.738 -5.647 -15.303 -9.18 -52.418 -4.168 -19.325 -10.125 -57.855 -1.74 -23.397 -10.543 -63.19 0.895 -27.453 -10.55 -68.46 3.715 -31.464 -10.213 -72.631 60.58

[0095] The surface equation of the first surface curve of the main reflector is shown in Table 2:

[0096] Table 2

[0097]

[0098] Figure 5 A curve diagram of a first surface type primary reflector according to an embodiment of the present invention is disclosed, such as Figure 5 As shown in the figure, it shows the coordinate point data of the concave surface of the main reflector, reflecting the curve characteristics of its concave shape. The curve is deeply concave at the center, indicating that the curvature at this position is large, and gradually becomes shallower towards the edge. This concave characteristic affects the distribution of light on the reflector, thereby determining the uniformity of illumination.

[0099] The abscissa (X-axis) in the figure represents the horizontal coordinate of the concave surface inside the primary reflector.

[0100] The ordinate (Y-axis) represents the height coordinate of the concave surface inside the primary reflector.

[0101] By controlling the concave depth and shape of the reflective mirror surface, it is ensured that the light can be converged in a specific area during the reflection process to achieve uniform distribution, thereby improving the accuracy and imaging quality of the optical system.

[0102] In addition to the above-mentioned design of the surface shape and surface curve of the main reflector, the main reflector of the present invention is also designed for reflectivity. The reflectivity design of the main reflector is mainly to optimize the reflectivity of light in different bands, especially to design high reflectivity for the UV band.

[0103] In this embodiment, the reflectivity of the main reflector is set within a specific range to optimize the UV curing effect on the wafer surface. The specific definitions of the reflection band of the main reflector and its specific reflectivity are shown in the following table:

[0104] Table 3

[0105] project definition Average reflectivity(@220-480nm) ≥85％ Minimum reflectivity (@220-450nm) ≥80％ Minimum reflectivity (@200-220nm) ≥50％ Rising edge reflectivity (reflectivity R ≥ 50%) 205nm≤±5nm Lower rising edge reflectivity (reflectivity R ≥ 50%) 520nm≤±10nm

[0106] Reflectivity plays an important role in the UV Cure process and the reflection band should be within the effective range. The table above lists the key optical reflectivity indicators of the primary reflector to define its optical performance in different bands.

[0107] The reflectivity of the primary reflector satisfies one or all of the following conditions:

[0108] In the 220-480nm band, the average reflectivity is over 85%;

[0109] In the 220-450nm band, the minimum reflectivity reaches 80%;

[0110] In the 200-220nm band, the minimum reflectivity reaches 50%.

[0111] When the reflectivity of the rising edge is greater than or equal to 50%, the wavelength range is within 205nm±5nm;

[0112] When the reflectivity of the falling edge is greater than or equal to 50%, the wavelength range is within 520nm±10nm.

[0113] Among them, the average reflectivity requirement is that the average reflectivity in the 220-480nm band must reach more than 85%, ensuring that the reflector has a high reflection efficiency in this range.

[0114] The minimum reflectivity requirement is 80% in the 220-450nm band to ensure the reflection stability within this range; the minimum reflectivity requirement in the 200-220nm band is 50%, that is, the reflectivity at shorter wavelengths can also be maintained at a certain level.

[0115] The requirement for the reflectivity at the rising edge is that the wavelength range from the lowest reflectivity to the wavelength where the reflectivity reaches 50% is within 205nm±5nm, thereby controlling the initial reflection efficiency of the light.

[0116] The requirement for the reflectivity at the falling edge is that the wavelength range where the reflectivity drops from 50% is within 520nm±10nm, thereby limiting the reflection cutoff point of the light.

[0117] This table is used to ensure that the main reflector has stable and efficient reflection performance at different wavelengths, so that the light uniformity meets the design requirements, and ensure stable reflection effects in different bands to meet the reflection requirements of light of different wavelengths, thereby improving light utilization efficiency and UV curing effects.

[0118] Figure 6 The reflectivity curve of the main reflector in different wavelength ranges is shown. The horizontal axis represents the wavelength range and the vertical axis represents the reflectivity. The reflectivity curve is the average result after multiple tests. Reflectivity plays an important role in the UV curing process. Figure 6 It can be observed that the main reflector of the present invention exhibits a high reflectivity in the ultraviolet light band, which ensures that the effective UV light band required in the ultraviolet curing process is fully reflected. The reflectivity gradually decreases near 500-550nm, indicating that the main reflector has a strong selective reflection characteristic for the band and can achieve efficient reflection within the specified band.

[0119] The main reflector and ultraviolet curing equipment proposed in the present invention achieve high uniformity and high efficiency of UV illumination by optimizing the surface shape and reflectivity of the main reflector. The main reflector can provide stable and uniform illumination in the UV Cure process, which not only meets the requirements of specific specifications (SPEC), but also significantly improves the process effect and product quality.

[0120] The primary reflector and ultraviolet curing device proposed in the present invention have the following beneficial effects:

[0121] 1) High uniformity of UV illumination is achieved through optimization of the main reflector surface design;

[0122] 2) The reflectivity design of the main reflector ensures high reflection efficiency in the UV band, reduces the loss of UV light, and enhances the effect of UV Cure.

[0123] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0124] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0125] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0126] In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and "vertical" are used interchangeably.

[0127] The directions or positional relationships indicated by “inside”, “clockwise”, “counterclockwise”, etc. are based on the directions or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0128] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise clearly specified.

[0129] The above embodiments are provided for persons familiar with the art to implement or use the present invention. Personnel familiar with the art can make various modifications or changes to the above embodiments without departing from the inventive concept of the present invention. Therefore, the protection scope of the present invention is not limited to the above embodiments, but should be the maximum scope of the innovative features mentioned in the claims.

Claims

1. A primary reflector, used in ultraviolet curing equipment, characterized in that: The main reflector is used to reflect the light emitted by the ultraviolet curing light source to the surface of the semiconductor wafer; The surface curve of the inner concave surface of the primary reflector conforms to a specific polynomial surface equation: The polynomial surface equation is used to optimize the illumination uniformity of ultraviolet rays on the surface of the semiconductor wafer.

2. The primary reflector according to claim 1, characterized in that: The polynomial surface equation of the primary reflector is a quintic polynomial, and the corresponding expression is: y=A+B1*x+B2*x 2 +B3*x 3 +B4*x 4 +B5*x 5 ; Among them, x is the horizontal coordinate of the concave surface of the main reflector, and y is the height coordinate of the concave surface of the main reflector; A is the intercept, and B1, B2, B3, B4, and B5 are the coefficient values ​​of each item.

3. The primary reflector according to claim 2, characterized in that: The intercept A of the polynomial surface equation is 2.21195, the coefficient values ​​B1 are 1.29659, B2 are 0.04614, B3 are 7.59899E-04, B4 are 7.46533E-06, and B5 are 3.06779E-08.

4. The primary reflector according to claim 1 or claim 2, characterized in that: The reflectivity of the main reflector is set within a specific range to optimize the reflection efficiency of light in the ultraviolet band.

5. The primary reflector according to claim 4, characterized in that: The reflectivity of the primary reflector satisfies the following conditions: In the 220-480nm band, the average reflectivity is over 85%.

6. The primary reflector according to claim 4, characterized in that: The reflectivity of the primary reflector satisfies the following conditions: In the 220-450nm band, the minimum reflectivity reaches 80%; In the 200-220nm band, the minimum reflectivity reaches 50%.

7. The primary reflector according to claim 4, characterized in that The reflectivity of the primary reflector satisfies the following conditions: When the reflectivity of the rising edge is greater than or equal to 50%, the wavelength range is within 205nm±5nm; When the reflectivity of the falling edge is greater than or equal to 50%, the wavelength range is within 520nm±10nm.

8. An ultraviolet curing device, characterized in that: At least includes a UV curing light source and a primary reflector: The ultraviolet curing light source is arranged in the main reflector at the top of the cavity and is used to generate ultraviolet rays; The main reflector is the main reflector as claimed in any one of claims 1 to 7, and is used to reflect ultraviolet rays from an ultraviolet curing light source to the surface of a semiconductor wafer.

9. The ultraviolet curing device according to claim 8, characterized in that: It also includes a quartz optical window, which is arranged below the main reflector and the ultraviolet light source and above the semiconductor wafer, and is used for protecting the semiconductor wafer while transmitting ultraviolet rays to the surface of the semiconductor wafer.

10. The ultraviolet curing device according to claim 8, characterized in that: Also includes wafer temperature control stage: The wafer temperature control carrier is arranged at the bottom of the semiconductor wafer and is used to control and adjust the temperature of the semiconductor wafer.

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