Disclosure of Invention
The invention aims to provide a manufacturing method, a device and equipment of a laser SE structure on the surface of a silicon wafer and a computer readable storage medium, which solve the problem of uneven sheet resistance of the position where a thin grid line is arranged on the surface of the silicon wafer.
In order to solve the technical problem, the invention provides a method for manufacturing a laser SE structure on the surface of a silicon wafer, which comprises the following steps:
presetting a laser moving track for manufacturing a laser SE structure pattern on the surface of a silicon wafer; the surface of the silicon wafer is subjected to phosphorus source diffusion doping by adopting a tubular diffusion technology; the laser SE structure pattern is a position pattern on the silicon wafer, wherein a thin grid line needs to be arranged;
and controlling the laser irradiated on the surface of the silicon wafer to move according to the laser moving track, forming a laser SE structure at the laser irradiation position, and controlling the power of the laser to increase along with the decrease of the distance between the laser irradiation position and the center of the silicon wafer and decrease along with the increase of the distance between the laser irradiation position and the center of the silicon wafer.
Wherein the controlling of the power of the laser light increases as the distance between the laser irradiation position and the center of the silicon wafer decreases, and the decreasing as the distance between the laser irradiation position and the center of the silicon wafer increases comprises:
dividing the surface of the silicon wafer into a plurality of processing areas which are arranged from the center of the silicon wafer to the edge of the silicon wafer in a surrounding way one by one, wherein the center of each processing area is the center of the silicon wafer;
controlling the power of a processing area close to the center of the silicon wafer irradiated by the laser to be larger than the power of a processing area far away from the center of the silicon wafer; and when the laser irradiation position is located in the same processing area, the power of the laser is unchanged.
Each processing area is an area with gradually increased width from the center of the silicon wafer to the radial direction of the edge of the silicon wafer.
Wherein the controlling of the power of the laser light increases as the distance between the laser irradiation position and the center of the silicon wafer decreases, and the decreasing as the distance between the laser irradiation position and the center of the silicon wafer increases comprises:
dividing the surface of the silicon wafer into a first processing area, a second processing area and a third processing area in advance, wherein the first processing area is a circular area taking the center of the silicon wafer as the center of a circle, the second processing area is a circular ring area surrounding the first processing area, and the third processing area is an area surrounding the second processing area;
controlling the power of the laser for irradiating the first processing area to be larger than the power for irradiating the second processing area; the power of the laser for irradiating the second processing area is greater than that of the third processing area; and when the laser irradiation position is located in the same processing area, the power of the laser is unchanged.
The difference between the radius of the first processing area, the width of the second processing area and the distance between the outer ring connection line of the second processing area and the edge line of the silicon wafer is not more than a preset distance;
the power of the laser for irradiating the first processing area is controlled to be larger than the power of the laser for irradiating the second processing area; the laser irradiates the second processing area with a power larger than that of the third processing area, and the laser irradiates the second processing area with a power larger than that of the third processing area, the:
controlling the power of the laser to irradiate the first processing area to be 37W-41W, controlling the power of the laser to irradiate the second processing area to be 34W-37W, and controlling the power of the laser to irradiate the third processing area to be 31W-34W.
The application also provides a device for manufacturing the laser SE structure on the surface of the silicon wafer, which comprises:
the track setting module is used for presetting a laser moving track for manufacturing a laser SE structure pattern on the surface of the silicon wafer; the surface of the silicon wafer is subjected to phosphorus source diffusion doping by adopting a tubular diffusion technology; the laser SE structure pattern is a position pattern on the silicon wafer, wherein a thin grid line needs to be arranged;
and the pattern preparation module is used for controlling the laser irradiated on the surface of the silicon wafer to move according to the laser moving track, forming a laser SE structure at the laser irradiation position, and controlling the power of the laser to increase along with the decrease of the distance between the laser irradiation position and the center of the silicon wafer and decrease along with the increase of the distance between the laser irradiation position and the center of the silicon wafer.
Wherein the preparing the pattern module includes:
the processing device comprises an area dividing unit, a processing unit and a processing unit, wherein the area dividing unit is used for dividing the surface of the silicon wafer into a first processing area, a second processing area and a third processing area in advance, the first processing area is a circular area taking the center of the silicon wafer as the center of a circle, the second processing area is a circular ring area surrounding the first processing area, and the third processing area is an area surrounding the second processing area;
the laser control unit is used for controlling the power of the laser for irradiating the first processing area to be larger than the power for irradiating the second processing area; the power of the laser for irradiating the second processing area is greater than that of the third processing area; and when the laser irradiation position is located in the same processing area, the power of the laser is unchanged.
The area dividing unit is specifically configured to divide the surface of the silicon wafer into a first processing area, a second processing area and a third processing area in advance, where the first processing area is a circular area with the center of the silicon wafer as a center of a circle, the second processing area is a circular ring area surrounding the first processing area, and the third processing area is an area surrounding the second processing area;
the laser control unit is specifically configured to control the power of the laser for irradiating the first processing area to be greater than the power of the laser for irradiating the second processing area; the power of the laser for irradiating the second processing area is greater than that of the third processing area; and when the laser irradiation position is located in the same processing area, the power of the laser is unchanged.
The application also provides a manufacturing device of the laser SE structure on the surface of the silicon wafer, which comprises:
a memory for storing a computer program;
and the processor is used for realizing the steps of the manufacturing method of the laser SE structure on the surface of the silicon wafer when the computer program is executed.
The application also provides a computer readable storage medium, on which a computer program is stored, which when executed by a processor implements the steps of the method for manufacturing the laser SE structure on the surface of the silicon wafer.
The invention provides a method for manufacturing a laser SE structure on the surface of a silicon wafer, which comprises the following steps: presetting a laser moving track for manufacturing a laser SE structure pattern on the surface of a silicon wafer; the surface of the silicon wafer is subjected to phosphorus source diffusion doping by adopting a tubular diffusion technology; the laser SE structure pattern is a position pattern on the silicon wafer, wherein a thin grid line needs to be arranged; and controlling the laser irradiated on the surface of the silicon wafer to move according to the laser moving track, forming a laser SE structure at the laser irradiation position, and controlling the power of the laser to increase along with the decrease of the distance between the laser irradiation position and the center of the silicon wafer and decrease along with the increase of the distance between the laser irradiation position and the center of the silicon wafer.
When forming the SE structure to solar energy silicon chip surface in this application, consider to the P type doping layer on silicon chip surface, because there is inhomogeneous problem in the doping degree, can lead to the doping layer of the SE structure that same thin grid line corresponds also inhomogeneous, influence the electric conductive property of follow-up thin grid line, for this reason, when forming thin grid line, to the SE structure of different positions on the silicon chip, adopt the laser irradiation of not equidimension of power, in order to realize the homogeneity reinforcing of the doping layer of the SE structure that same thin grid line corresponds, and then improve the electric conductive property of thin grid line, thereby further improve the working property of silicon chip.
The application also provides a device and equipment for manufacturing the laser SE structure on the surface of the silicon wafer and a computer readable storage medium.
Detailed Description
In the process of manufacturing a solar cell, a P-type doping layer is formed on the surface of a silicon wafer in a tubular diffusion mode, then laser beams are sequentially irradiated on the surface of the silicon wafer at positions where fine grid lines need to be printed, the P source at the positions is subjected to secondary diffusion to form an SE structure, and finally silver paste is printed on the SE structure to form the fine grid lines. And the SE structure formed by laser is also the position where the surface of the silicon chip is contacted with the fine grid line.
However, the doping layer formed on the surface of the silicon wafer by adopting tubular diffusion at present has the distribution of low middle doping concentration and high edge doping concentration, so that the sheet resistance of the surface of the silicon wafer from the center to the edge is gradually reduced; the thin grid lines are arranged in parallel with the edge of the silicon chip, so that the sheet resistance is different at different positions where the same thin grid line is contacted with the silicon chip; in a laser SE structure formed at the position where the thin grid line needs to be printed on the surface of the silicon wafer, the square resistance of the laser SE structure corresponding to the same thin grid line can be different, so that the conductivity between the thin grid line on the front surface of the battery piece and the surface of the battery piece is uneven, the conductivity of the thin grid line is reduced, and the working performance of the battery piece is influenced.
However, the current technical scheme for forming the P-type doping layer on the surface of the silicon wafer by diffusion has high improvement difficulty and high cost, and the problem of uneven sheet resistance caused by uneven distribution of the doping layer on the surface of the whole silicon wafer cannot be fundamentally solved.
The applicant thinks that when the laser beam irradiates the surface of the silicon wafer, the purpose of the laser beam is to change the doping concentration of the position of the silicon wafer surface where the fine grid line needs to be arranged, and the power of the laser beam directly influences the doping concentration of the laser irradiation position, so that the sheet resistance of the laser SE structure is influenced. In the laser beam irradiation process, the higher the laser power is, the higher the laser energy is, the smaller the sheet resistance value of the doped part irradiated by the laser is, otherwise, the smaller the laser power is, the larger the sheet resistance is. Therefore, when different positions of the surface of the silicon wafer are irradiated by controlling the laser beam, the laser power is controlled and adjusted based on the distance between the irradiation position and the central point of the surface of the silicon wafer, so that the influence of laser irradiation on the doping layer and the influence of diffusion on the doping layer to form the doping layer have a complementary effect, the sheet resistance area of the silicon wafer doping layer printed with the fine grid line position is uniform, the conductivity of the fine grid line is improved, and the working performance of the battery piece is further improved.
The technical solution of the present application will be described in detail with specific examples.
In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1, fig. 1 is a schematic flow chart of a method for manufacturing a laser SE structure on a silicon wafer surface according to an embodiment of the present invention, where the method may include:
step S11: presetting a laser moving track for manufacturing a laser SE structure pattern on the surface of a silicon wafer;
the surface of the silicon wafer is subjected to phosphorus source diffusion doping by adopting a tubular diffusion technology; the laser SE structure pattern is a position pattern on the silicon wafer where the thin grid line needs to be arranged.
Step S12: and controlling the laser irradiated on the surface of the silicon wafer to move according to the laser moving track, forming a laser SE structure at the laser irradiation position, and controlling the power of the laser to increase along with the decrease of the distance between the laser irradiation position and the center of the silicon wafer and decrease along with the increase of the distance between the laser irradiation position and the center of the silicon wafer.
Specifically, when the laser beam irradiates the surface of the silicon wafer, the higher the laser power is, the more beneficial to increase the doping of the phosphorus element is, and the closer the surface of the silicon wafer is to the central position, the lower the diffusion density of the phosphorus element of the diffusion layer obtained by tubular diffusion is, the lower the concentration of the phosphorus element in the region is, and accordingly, the power when the laser beam irradiates the region can be relatively increased; conversely, the power of the laser is relatively small at a position far away from the center of the silicon wafer.
Further, as shown in fig. 2, fig. 2 is a schematic view of the distribution of the thin gate lines on the surface of the silicon wafer according to the embodiment of the present invention, each thin gate line 2 is disposed in parallel on the surface of the silicon wafer 1, and when the laser beam irradiates the surface of the silicon wafer 1, the laser beam also irradiates the position where each thin gate line 2 is disposed in sequence, therefore, when the laser irradiates the printing position of the same thin gate line 2, the distance from the laser irradiating position to the center of the silicon wafer 1 is decreased first and then increased, and accordingly, when the laser irradiates the printing position of each thin gate line 2, the power of the laser substantially shows a trend of increasing first and then decreasing, so as to obtain a laser SE structure with more uniform sheet resistance, thereby ensuring that the sheet resistance of the contact portion between each thin gate line and the silicon wafer is substantially uniform.
When forming the SE structure on the surface of the irradiation battery through controlling laser in the application, the power of the laser is variable along with the central position of the irradiation position away from the silicon wafer, the promotion effect of the laser on the doping concentration of the surface of the silicon wafer and the promotion effect of tubular diffusion on the doping concentration are complementary, the doping layer of the SE structure at the fine grid line position is made to be substantially uniform, the conductivity of the fine grid line is improved, and the working performance of the silicon wafer is improved.
Based on the foregoing embodiment, in view of the fact that as the laser irradiation position moves on the surface of the silicon wafer, the temporal change of the nonlinearity of the laser irradiation position and the silicon wafer center position, and if the temporal change of the laser beam is correspondingly required, the requirement on the laser device is obviously higher, and the stability of the generated laser beam is relatively poor, the present application further proposes another technical solution, specifically, as shown in fig. 3, fig. 3 is a schematic flow diagram of a method for manufacturing a laser SE structure on the surface of the silicon wafer according to another embodiment of the present invention, where the method may include:
step S21: presetting a laser moving track for manufacturing a laser SE structure pattern on the surface of a silicon wafer.
Similarly, the silicon wafer is doped with phosphorus source diffusion by adopting a tubular diffusion technology on the surface.
Step S22: the method comprises the following steps of dividing the surface of a silicon wafer into a plurality of processing areas which are arranged from the center of the silicon wafer to the edge of the silicon wafer in a surrounding mode one by one, wherein the center of each processing area is the center of the silicon wafer.
Specifically, referring to fig. 4, fig. 4 is a schematic distribution diagram of the processing regions divided on the surface of the silicon wafer according to the embodiment of the present invention. In fig. 4, the silicon wafer is divided into three processing regions, the first processing region is a circular region 3, the center of the circular region 3 is the center of the silicon wafer, the second processing region is a circular ring region 4 surrounding the circular region, and the third processing region is an annular region 5 surrounding the circular region to the edge of the silicon wafer.
Certainly, fig. 4 is only a specific dividing manner for the silicon wafer surface in the present application, and in practical application, the silicon wafer may be further divided into more processing areas, but the distribution of each processing area is similar to that in fig. 4, and is an area that is looped around, even in the corner area near the silicon wafer, only four corners of the silicon wafer that are not communicated with each other may be used as the same area.
In addition, for the size of each processing area, the difference between the radius of the central circular area and the width of each annular area can be determined according to the radial variation gradient of the doping density on the surface of the silicon wafer.
For example, if the doping concentration of the doping element after the tubular diffusion of the silicon wafer is linearly changed in the radial direction from the center to the edge of the silicon wafer, the radius of the circular region at the center can be approximately equal to the width of each annular region; if the gradient of the change of the doping density in the radial direction is gradually reduced, the width of each annular processing area from the center to the edge of the silicon wafer is gradually increased.
Step S23: and controlling the power of the processing area with the laser irradiation distance close to the center of the silicon wafer, wherein the power of the processing area with the laser irradiation is constant.
Specifically, for example, in the division manner of the processing area shown in fig. 4, the radius of the circular area 3 is 25mm, the outer diameter of the circular area 4 may be 52mm, the circular area is an adjacent central area, and the rest is the annular area 5. Accordingly, the power of the laser irradiation to the circular region 3 may be 37W to 41W, the power of the laser irradiation to the annular region 4 may be 34W to 37W, and the power of the laser irradiation to the annular region 5 may be 31W to 34W.
As shown in fig. 5, fig. 5 is a coordinate diagram illustrating a power change when the laser irradiates the position of the fine gate line AB in fig. 4. The thin grid line AB in fig. 4 spans three different regions, so that in fig. 5, when the laser irradiates C, D, E, F on the thin grid line AB, the power of the laser makes one jump respectively, so that the power of the laser generally tends to increase first and then decrease when the laser irradiates the position of the thin grid line AB. Of course, for a thin grating line that does not span several regions, but only one region, the laser power can be kept constant while processing the corresponding laser SE structure.
The following describes a device for manufacturing a laser SE structure on a silicon wafer surface according to an embodiment of the present invention, and the device for manufacturing a laser SE structure on a silicon wafer surface described below and the method for manufacturing a laser SE structure on a silicon wafer surface described above may be referred to in correspondence with each other.
Fig. 6 is a block diagram of a device for manufacturing a laser SE structure on a silicon wafer surface according to an embodiment of the present invention, where the device for manufacturing a laser SE structure on a silicon wafer surface in fig. 6 may include:
the track setting module 100 is used for presetting a laser moving track for manufacturing a laser SE structure pattern on the surface of the silicon wafer; the surface of the silicon wafer is subjected to phosphorus source diffusion doping by adopting a tubular diffusion technology; the laser SE structure pattern is a position pattern on the silicon wafer where the thin grid line needs to be arranged.
And a pattern preparation module 200 for controlling the laser irradiated on the surface of the silicon wafer to move according to the laser moving track, forming a laser SE structure at the laser irradiation position, and controlling the power of the laser to increase with the decrease of the distance between the laser irradiation position and the center of the silicon wafer and decrease with the increase of the distance between the laser irradiation position and the center of the silicon wafer.
Alternatively, in another specific embodiment of the present application, the pattern preparation module 200 includes:
the processing device comprises an area dividing unit, a processing unit and a processing unit, wherein the area dividing unit is used for dividing the surface of the silicon wafer into a first processing area, a second processing area and a third processing area in advance, the first processing area is a circular area taking the center of the silicon wafer as the center of a circle, the second processing area is a circular ring area surrounding the first processing area, and the third processing area is an area surrounding the second processing area;
the laser control unit is used for controlling the power of the laser for irradiating the first processing area to be larger than the power for irradiating the second processing area; the power of the laser for irradiating the second processing area is greater than that of the third processing area; and when the laser irradiation position is located in the same processing area, the power of the laser is unchanged.
Optionally, in another specific embodiment of the present application, the region dividing unit is specifically configured to divide each processing region into regions with gradually increasing widths in a radial direction from the center of the silicon wafer to the edge of the silicon wafer.
Optionally, in another specific embodiment of the present application, the area dividing unit is specifically configured to divide the surface of the silicon wafer into a first processing area, a second processing area, and a third processing area in advance, where the first processing area is a circular area using the center of the silicon wafer as a center of a circle, the second processing area is a circular area surrounding the first processing area, and the third processing area is an area surrounding the second processing area.
The laser control unit is specifically used for controlling the power of the laser for irradiating the first processing area to be greater than the power for irradiating the second processing area; the power of the laser for irradiating the second processing area is greater than that of the third processing area; and when the laser irradiation position is located in the same processing area, the power of the laser is unchanged.
Optionally, in another specific embodiment of the present application, the region dividing unit is specifically configured to divide the surface of the silicon wafer into a region where a difference between a radius of the first processing region, a width of the second processing region, and a distance between an outer ring connection line of the second processing region and an edge line of the silicon wafer is not greater than a preset distance in pairs;
the laser control unit is specifically configured to control power of the laser to irradiate the first processing area to be 37W-41W, power of the laser to irradiate the second processing area to be 34W-37W, and power of the laser to irradiate the third processing area to be 31W-34W.
The manufacturing apparatus of the laser SE structure on the surface of the silicon wafer in this embodiment is used to implement the aforementioned manufacturing method of the laser SE structure on the surface of the silicon wafer, and therefore, the specific implementation manner in the manufacturing apparatus of the laser SE structure on the surface of the silicon wafer can be found in the foregoing embodiment sections of the manufacturing method of the laser SE structure on the surface of the silicon wafer, for example, the track setting module 100 and the pattern preparation module 200, which are respectively used to implement steps S11 and S12 in the manufacturing method of the laser SE structure on the surface of the silicon wafer, so that the specific implementation manner thereof may refer to the description of the corresponding embodiments of each section, and will not be described herein again.
The application also provides an embodiment of a device for manufacturing the laser SE structure on the surface of the silicon wafer, which specifically includes:
a memory for storing a computer program;
and the processor is used for realizing the steps of the manufacturing method of the laser SE structure on the surface of the silicon wafer according to any embodiment when the computer program is executed.
The memory may particularly be a Random Access Memory (RAM), a memory, a Read Only Memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
The present application also provides a computer-readable storage medium comprising:
the computer readable storage medium stores a computer program, and the computer program is used for realizing the steps of the method for manufacturing the laser SE structure on the surface of the silicon wafer.
The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.