Photovoltaic chain type photoetching production system

Abstract

The invention belongs to the technical field of photoetching, and particularly relates to a photovoltaic chain-type photoetching production system, which comprises a chain-type roller coating module, a chain-type roller coating module, a chain-type roller coating module, a chain-type roller coating module and a chain-type roller coating module, the laser positioning point punching module is used for forming a silicon wafer positioning point; the exposure module is used for grabbing the silicon wafer positioning points; the developing module is used for alkali washing of the silicon wafer; the washing system is used for cleaning the surface of the silicon wafer; the photoresist removing module is used for removing photoresist on the surface of the silicon wafer; the drying module is used for drying the surface of the silicon wafer; compared with laser film opening, irradiation of high-power laser, heating of the surface of a thin film to a high temperature and generation of thermal damage to a passive film, the method provided by the invention realizes film masking through photoresist development and exposure by utilizing a photoetching technology, and can realize lossless patterning; and the passivation performance of p < + >-poly-Si and n < + >-poly-Si is not damaged.

Description

Technical Field

[0001] The invention belongs to the technical field of photolithography, and in particular to a photovoltaic chain photolithography production system. Background Art

[0002] Photolithography is widely used in semiconductors and is a precise micro-nano processing technology that transfers designed tiny patterns to the surface of light-sensitive materials. Its core is to use a photolithography machine to transfer precise patterns to a substrate, thereby achieving precise manufacturing of tiny structures.

[0003] Existing semiconductor lithography machines include step-and-scan lithography technology, dry lithography technology, immersion lithography technology, electron beam lithography technology, ion beam lithography technology, laser direct writing lithography technology, grating exposure technology, nanoimprint technology, etc.

[0004] Problems in applying semiconductor lithography machines to photovoltaics: 1. Low production capacity. The production capacity of semiconductor lithography machines is less than 100-200 pieces / h, while the production capacity of photovoltaic laser graphics is greater than 7,000 pieces / h;

[0005] 2. The equipment cost is high, and the price of a single device can be as high as hundreds of millions of dollars. In the process of processing chips, the lithography machine uses a series of light source energy and shape control methods to transmit the light beam through the mask with the circuit diagram drawn on it, and the objective lens compensates for various optical errors, and then scales the circuit diagram down and maps it to the silicon wafer, and then uses chemical methods to develop it to obtain the circuit diagram engraved on the silicon wafer. The more complex the chip, the more layers of the circuit diagram, and the more precise the exposure control process is required;

[0006] 3. The maintenance cost is high, mainly because the equipment is complex and uses a large number of high-precision optical system accessories. Summary of the invention

[0007] In order to make up for the shortcomings of the prior art and solve the above technical problems, the present invention proposes a photovoltaic chain lithography production system, which can replace the IBC (all-back interdigitated back contact cell) laser patterning technology to achieve low cost, high production capacity and high cell photoelectric conversion efficiency. The specifics are as follows;

[0008] A photovoltaic chain lithography production system, comprising:

[0009] A chain roller coating module for coating silicon wafers with photoresist;

[0010] A laser marking module for forming the silicon wafer marking points;

[0011] An exposure module, used for grabbing the positioning points of the silicon wafer;

[0012] a developing module, used for alkaline washing of the silicon wafer;

[0013] A water washing system, used for cleaning the surface of the silicon wafer;

[0014] A degumming module, used for degumming the surface of the silicon wafer;

[0015] A drying module, used for drying the surface of the silicon wafer;

[0016] A computer controller is used to control the operation of the above modules.

[0017] Preferably, the chain roller coating module comprises at least twelve gluing stations, and a single silicon wafer is placed in a single gluing station;

[0018] The upper roller and the lower roller are arranged correspondingly, and are arranged horizontally with the gluing station;

[0019] The interior of the upper roller is a pipeline structure, the photoresist is transmitted and moved inside the upper roller, and a glue outlet is opened on the surface of the upper roller.

[0020] Preferably, the surface of the upper roller is covered with columnar sponge, and the lower roller is made of PP or PVDF material.

[0021] Preferably, the laser marking module includes a single laser and a marble platform. The single laser is used to mark 2-4 points on the surface of the silicon wafer. The points are in the shape of a cross or a circle. The silicon wafer is transmitted between the marble platform and the glue coating station through a transmission mechanism.

[0022] Preferably, the exposure module includes a CCD camera for capturing a cross-shaped or circular point on the surface of the silicon wafer to achieve positioning of the silicon wafer;

[0023] A screen, the screen comprising quartz glass, borosilicate glass or other optical glass, with an exposure pattern, a hollow area and a non-hollow area on its surface;

[0024] Rotating platform, used to achieve precise adjustment of silicon wafer position;

[0025] Light source, the light source is an LED light source, a single wavelength light source with a wavelength range of 100-500nm, and a square light spot with a side length of 182mm-230mm, which is used to irradiate the screen;

[0026] The exposure platform is used to carry the rotating platform.

[0027] Preferably, the developing module comprises a chain roller alkali cleaning tank, a transmission connection is established between the chain roller alkali cleaning tank and the exposure platform via a belt transmission system, and the silicon wafer is corroded in the chain roller alkali cleaning tank via the alkali cleaning roller.

[0028] Preferably, the water washing module includes a No. 1 water washing tank and a No. 2 water washing tank.

[0029] Preferably, the degumming module comprises a chain alkali washing tank, and a cleaning water jet is provided above the chain roller alkali washing tank and the chain alkali washing tank for washing the corroded silicon wafers.

[0030] Preferably, the drying module includes a drying tank, and the chain roller alkali washing tank, the first water washing tank, the chain alkali washing tank, the second water washing tank and the drying tank are all connected through alkali washing rollers, and the surface of the alkali washing rollers is provided with anti-slip textures.

[0031] The beneficial effects of the present invention are as follows:

[0032] 1. Lossless patterning: Compared with laser film opening, the use of high-power laser irradiation heats the film surface to a high temperature, causing thermal damage to the passivation film itself. Photolithography technology realizes masking through photoresist development and exposure, which can achieve lossless patterning without damaging the passivation performance of p+-poly-Si and n+-poly-Si.

[0033] 2. High-precision patterning: Photolithography originates from semiconductor technology. It has higher patterning accuracy and can achieve a smaller pitch (p+ / gap / n+). As the efficiency of BC cells increases, it will gradually develop towards a smaller pitch, and lasers will limit its further development.

[0034] 3. High potential for cell photoelectric conversion efficiency: Combined with lossless mask patterning of poly-Si / Si O2 / n-Si, high-precision patterning, and narrower pitch, the cell conversion efficiency is closer to the theoretical limit of single-cell efficiency, and is estimated to be 0.10%-0.20% higher than the laser process efficiency.

[0035] 4. Solve the difficulty of BC leakage: BC battery has leakage because the pn junction is on the back and the interdigitation is alternating. The main reason is that the laser process cannot completely remove the film, resulting in the inability to completely etch the diffused junction during the wet process. The leakage of BC battery is 50 times that of TOPCon battery (data released by the industry show that there are more than 200 leakage points), and the weak light response is poor in outdoor power generation. Therefore, relying on the chain lithography process to solve the leakage of BC is one of the important advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described below in conjunction with the accompanying drawings.

[0037] Figure 1 It is the overall equipment structure diagram of the present invention.

[0038] In the figure: gluing station 1, upper roller 101, lower roller 102, single laser 2, marble platform 3, screen 4, rotating platform 5, exposure platform 51, light source 6, chain roller alkali cleaning tank 7, belt transmission system 8, alkali cleaning roller 9, No. 1 water washing tank 10, No. 2 water washing tank 11, chain alkali cleaning tank 12, silicon wafer 13, cleaning water knife 14, drying tank 15. DETAILED DESCRIPTION

[0039] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0040] Example 1: Figure 1 As shown, the present invention provides a photovoltaic chain lithography production system, comprising:

[0041] A chain roller coating module, used for coating the silicon wafer 13 with photoresist;

[0042] A laser marking module for forming the positioning points of the silicon wafer 13;

[0043] An exposure module, used for grabbing the positioning points of the silicon wafer 13;

[0044] a developing module, used for alkaline washing of the silicon wafer 13;

[0045] a water washing system, used for cleaning the surface of the silicon wafer 13;

[0046] A degumming module, used for degumming the surface of the silicon wafer 13;

[0047] A drying module, used for drying the surface of the silicon wafer 13;

[0048] A computer controller is used to control the operation of the above modules.

[0049] Embodiment 2: Based on Embodiment 1, the chain roller coating module in the present invention comprises: at least twelve gluing stations 1, each gluing station 1 is provided with a single silicon wafer 13;

[0050] The upper roller 101 and the lower roller 102 are arranged correspondingly and are arranged horizontally with the gluing station 1;

[0051] Among them, the interior of the upper roller 101 is a pipeline structure, and the photoresist is transmitted and moved inside the upper roller 101. A glue outlet is opened on the surface of the upper roller 101. The upper roller 101 and the lower roller 102 are driven by a motor and connected by a worm gear and a worm, so that the upper roller 101 and the lower roller 102 can rotate at the same speed as the motor. Of course, gear transmission, belt transmission, etc. can also be used to achieve the transmission connection between the upper roller 101 and the lower roller 102, so as to achieve the synchronous rotation of the upper roller 101 and the lower roller 102. That is, the present invention is not limited to using a specific method to drive the upper roller 101 and the lower roller 102, as long as the movement and glue coating of the silicon wafer 13 in the present invention can be achieved.

[0052] Specifically, the surface of the upper roller 101 is coated with a columnar sponge, and the lower roller 102 is made of PP or PVDF material, wherein the columnar sponge is used to absorb photoresist, and the photoresist is rolled onto the surface of the silicon wafer 13 through the columnar sponge to achieve the gluing of the silicon wafer 13. The columnar sponge plays a wrapping role, while increasing the contact surface between the upper roller 101 and the silicon wafer 13, and reducing the pressure of the upper roller 101 on the silicon wafer 13. When used specifically, the aperture of the glue outlet on the surface of the upper roller 101 is 0.8 mm, the number of the glue outlets is more than one, and they are arranged every 1-10 cm in the circumferential direction of the upper roller 101, and the photoresist enters the columnar sponge through the glue outlet on the surface of the upper roller 101.

[0053] It should be noted that when it is necessary to replenish the photoresist on the upper roller 101, it can be replenished through the glue replenishing valve set on the upper roller 101, and the glue replenishing method can be electric. The specific method is to set a corresponding glue replenishing container, and the glue replenishing container has a built-in glue replenishing pump. The glue replenishing container is connected to the glue replenishing valve through a glue replenishing tube, and the glue replenishing pump is used to bring the photoresist into the upper roller 101 when glue replenishment is needed. It should be noted that in order not to affect the glue replenishing tube when the upper roller 101 rotates, the glue replenishing tube and the glue replenishing valve can be set to a rotating sealed connection, or the glue replenishing tube and the glue replenishing valve can be connected when glue replenishment is needed. This is manual glue replenishment.

[0054] Specifically, the laser positioning point module includes a single laser 2 and a marble platform 3. The single laser 2 is used to punch 2-4 points on the surface of the silicon wafer 13. The shape of the points is a cross or a circular point. The marble platform 3 and the gluing station 1 are used to transmit the silicon wafer 13 through a transmission mechanism. The single laser 2 emits laser to complete the dotting of the surface of the silicon wafer 13. The change in angle after the laser is emitted is adjusted in real time by the galvanometer, thereby changing the position of the dot on the surface of the silicon wafer 13 and the accuracy of the dot position. When the dot is marked, the distance between the single laser 2 and the silicon wafer 13 is greater than the radius of the silicon wafer 13, that is, 100-200mm. Furthermore, the transmission mechanism between the marble platform 3 and the fixed gluing station 1 uses the marble platform 3 and the fixed gluing station 1 for bearing and fixing to prevent vibration when the silicon wafer 13 is transmitted. The transmission mechanism includes a conveyor belt, a chain conveyor, etc.

[0055] Embodiment 2: Based on Embodiment 1, the exposure module in the present invention includes a CCD camera for capturing a cross-shaped or circular point on the surface of the silicon wafer 13 to achieve positioning of the silicon wafer 13;

[0056] Screen 4, said screen 4 comprising quartz glass, borosilicate glass or other optical glass, with exposure patterns, hollow areas and non-hollow areas on its surface;

[0057] The rotating platform 5 is used to achieve precision adjustment of the position of the silicon wafer 13;

[0058] The light source 6 is an LED light source, a single-wavelength light source with a wavelength range of 100-500nm, and a square light spot with a side length of 182mm-230mm, which is used to irradiate the screen 4;

[0059] The exposure platform 51 is used to carry the rotating platform 5;

[0060] Specifically, the rotating platform 5 has a leveling function. When the silicon wafer 13 is located on the surface of the rotating platform 5, the X-axis, Y-axis and angle rotation R of the rotating platform 5 can be changed by using components such as an air cylinder, an oil cylinder and a leveling instrument, thereby ensuring that the silicon wafer 13 is located in a horizontal position.

[0061] Secondly, the cross-shaped or circular points on the surface of the silicon wafer 13 are captured by a CCD camera, and then the captured information is entered into a computer controller. Specifically, first, an image of the silicon wafer 13 is captured by a CCD camera to obtain an image containing the silicon wafer 13, ensuring that the image is clear and the target object is visible. The position of the obtained image of the silicon wafer 13 is processed using image processing software, including steps such as denoising, filtering, and binarization to enhance the image quality and extract the features of the silicon wafer 13. The features of the silicon wafer 13, i.e., the shapes of the cross-shaped or circular points on the surface of the silicon wafer 13, are extracted by image processing technology. These features will be used for subsequent coordinate positioning. Based on the extracted features, image recognition and other technologies are used to search for the target object in the image of the silicon wafer 13 and determine its coordinate position. This can be accomplished by, for example, comparing the target features with the features in the image. When the coordinate position of the target object in the image is determined, the result can be output as coordinate data by a computer controller.

[0062] Next, the coordinate data is used to determine whether the screen 4 needs to be moved up and down in the vertical direction. If movement is required, the screen 4 is driven to move up and down in the vertical direction by telescopic components such as cylinders and oil cylinders. The purpose of moving the screen 4 up and down is to fix the exposure pattern on its surface on the surface of the silicon wafer 13; when the exposure pattern is fixed on the surface of the silicon wafer 13, the light source 6 is used to complete the exposure of the silicon wafer 13, that is, the exposure pattern in the screen 4 is printed on the surface of the silicon wafer 13.

[0063] Example 3: Based on Example 1, the developing module in the present invention includes a chain roller alkali cleaning tank 7, and a transmission connection is established between the chain roller alkali cleaning tank 7 and the exposure platform 51 through a belt transmission system 8, and the silicon wafer 13 is corroded in the chain roller alkali cleaning tank 7 through the alkali cleaning roller 9.

[0064] After the silicon wafer 13 is exposed in the exposure module, it is transported to the surface of the alkaline cleaning roller 9 through the belt transmission system 8, wherein the belt transmission system 8 includes a conveying structure such as a belt conveyor. The present invention does not specifically limit the specific belt transmission system 8, wherein an alkaline solution is arranged in the chain roller alkaline cleaning tank 7, and the alkaline cleaning roller 9 brings the silicon wafer 13 into the alkaline solution when transmitting the silicon wafer 13, and etches the surface of the silicon wafer 13. The liquid level of the alkaline solution can be adjusted, which can be achieved by replenishing the alkaline cleaning solution into the chain roller alkaline cleaning tank 7 from the outside, so that the alkaline cleaning roller 9 is immersed in the alkaline solution, or half immersed in the alkaline solution, to complete the corrosion of the silicon wafer 13 and realize the development of the silicon wafer 13, that is, etching the photoresist in the non-exposed area of ​​the surface of the silicon wafer 13.

[0065] It should be noted that the power source of the alkali washing roller 9 is a motor, and adjacent alkali washing rollers 9 are driven by belts or transmission components such as transmission chains, that is, one of the alkali washing rollers 9 is driven to rotate by the motor, and then the other alkali washing rollers 9 are driven to rotate by belt transmission or other means, and the transmission speed is controlled at 0-6m / min.

[0066] Embodiment 4: Based on Embodiment 1, the water washing module in the present invention comprises a No. 1 water washing tank 10 and a No. 2 water washing tank 11.

[0067] The degumming module comprises a chain alkali cleaning tank 12 , and a cleaning water jet 14 is provided above the chain roller alkali cleaning tank 7 and the chain alkali cleaning tank 12 for washing the etched silicon wafer 13 .

[0068] The drying module includes a drying tank 15, and the chain roller alkali washing tank 7, the first water washing tank 10, the chain alkali washing tank 12, the second water washing tank 11 and the drying tank 15 are all connected through the alkali washing roller 9, and the surface of the alkali washing roller 9 is provided with anti-slip texture.

[0069] After the silicon wafer 13 is completely etched in the chain roller alkali cleaning tank 7, it is brought into the No. 1 water washing tank 10 by the alkali cleaning roller 9. Before entering the No. 1 water washing tank 10, the surface of the etched silicon wafer 13 is first rinsed by the cleaning water jet 14, and the alkaline solution adhering to the surface of the alkali cleaning roller 9 can be cleaned to reduce the probability of contaminating the cleaning water in the water washing tank. Then, the silicon wafer 13 enters the No. 1 water washing tank 10 for comprehensive rinsing. The alkali cleaning roller 9 is immersed in the cleaning water, or semi-immersed in the cleaning water, to complete the cleaning of the silicon wafer 13. Then, the washed silicon wafer 13 is washed by the alkali cleaning roller 9. 3 is brought into the chain alkali washing tank 12, wherein a cleaning water knife 14 is also arranged above the chain alkali washing tank 12, and the chain alkali washing tank 12 has the same working principle as the chain roller alkali washing tank 7, and the present invention will not be elaborated on here. After the silicon wafer 13 completes alkali washing in the chain alkali washing tank 12, it is brought into the second water washing tank 11 by the alkali washing roller 9 for further washing. After the washing is completed, it is brought into the drying tank 15 by the alkali washing roller 9 to complete drying. The drying method can be hot air drying, natural drying, nitrogen drying, hot plate drying and rotary drying, etc. The present invention does not carry out the specific drying method here.

[0070] In summary, the present invention is divided into hollow and non-hollow areas by the screen 4, with the aim of realizing PSG (phosphorus silicon glass film) / silicon wafer 13 structure patterning on the surface of the silicon wafer 13, which has the advantages of high-precision and low-damage patterning. The working principle of the overall system is the photolithography patterning principle, that is, negative photoresist is used to protect the patterned area, and other non-exposed pattern areas are removed by alkali washing.

[0071] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as limiting the scope of protection of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0072] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A photovoltaic chain lithography production system, characterized in that: include: A chain roller coating module for coating silicon wafers with photoresist; A laser marking module for forming the silicon wafer marking points; An exposure module, used for grabbing the positioning points of the silicon wafer; a developing module, used for alkaline washing of the silicon wafer; A water washing system, used for cleaning the surface of the silicon wafer; A degumming module, used for degumming the surface of the silicon wafer; A drying module, used for drying the surface of the silicon wafer; A computer controller is used to control the operation of the above modules.

2. A photovoltaic chain lithography production system as claimed in claim 1, characterized in that: The chain roller coating module includes at least twelve gluing stations, and a single silicon wafer is placed in a single gluing station; The upper roller and the lower roller are arranged correspondingly, and are arranged horizontally with the gluing station; The interior of the upper roller is a pipeline structure, the photoresist is transmitted and moved inside the upper roller, and a glue outlet is opened on the surface of the upper roller.

3. A photovoltaic chain lithography production system as claimed in claim 2, characterized in that: The surface of the upper roller is covered with columnar sponge, and the lower roller is made of PP or PVDF material.

4. A photovoltaic chain lithography production system as claimed in claim 1, characterized in that: The laser marking module includes a single laser and a marble platform. The single laser is used to mark 2-4 points on the surface of the silicon wafer. The shape of the points is a cross or a circle. The silicon wafer is transmitted between the marble platform and the glue coating station through a transmission mechanism.

5. A photovoltaic chain lithography production system as claimed in claim 1, characterized in that: The exposure module includes a CCD camera for capturing a cross-shaped or circular point on the surface of the silicon wafer to achieve positioning of the silicon wafer; A screen, the screen comprising quartz glass, borosilicate glass or other optical glass, with an exposure pattern, a hollow area and a non-hollow area on its surface; Rotating platform, used to achieve precise adjustment of silicon wafer position; Light source, the light source is an LED light source, a single wavelength light source with a wavelength range of 100-500nm, and a square light spot with a side length of 182mm-230mm, which is used to irradiate the screen; The exposure platform is used to carry the rotating platform.

6. A photovoltaic chain lithography production system as claimed in claim 1, characterized in that: The developing module comprises a chain roller alkali cleaning tank, a transmission connection is established between the chain roller alkali cleaning tank and the exposure platform via a belt transmission system, and the silicon wafer is corroded in the chain roller alkali cleaning tank via the alkali cleaning roller.

7. A photovoltaic chain lithography production system as claimed in claim 1, characterized in that: The water washing module comprises a No. 1 water washing tank and a No. 2 water washing tank.

8. The photovoltaic chain lithography production system according to claim 1, characterized in that: The degumming module comprises a chain alkali cleaning tank, and a cleaning water jet is arranged above the chain roller alkali cleaning tank and the chain alkali cleaning tank for washing the corroded silicon wafer.

9. A photovoltaic chain lithography production system as claimed in claim 1, characterized in that: The drying module comprises a drying tank, and the chain roller alkali washing tank, the first water washing tank, the chain alkali washing tank, the second water washing tank and the drying tank are all connected through alkali washing rollers, and the surface of the alkali washing rollers is provided with anti-skid patterns.

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