KR20100088398A - Semiconductor layer doping method, back contact solar cell by using the same method, and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A doping method, a back side electrode type solar cell thereof, and a manufacturing method thereof are provided to simplify a manufacturing process by diffusing an ink containing p-type and n-type impurity in two semiconductor impurity doping channels which are separated with each other. CONSTITUTION: A first impurity doping channel and a second impurity doping channel are formed in one side surface of a semiconductor substrate(101), respectively. The second impurity doping channel is separated from the first impurity doping channel with a uniform interval. An impurity having a first conductivity type is injected into the first impurity doping channel. The impurity having the second conductive type is injected into the second impurity doping channel. The impurity is diffused into the inside the substrate by heat-treating the injected impurity.

Description

Doping method of semiconductor layer, back electrode type solar cell using same and manufacturing method thereof {Semiconductor layer doping method, Back contact solar cell by using the same method, and Manufacturing method}

The present invention relates to a method of doping semiconductor impurities and a method of manufacturing a back-electrode solar cell including an emitter layer and a back surface field (BSF) on a back surface of a semiconductor substrate using the same. .

The present invention provides a solar cell that simplifies the process of the solar cell and increases the efficiency of the solar cell by improving a method of doping impurities into the back electrode solar cell.

Recently, as the prediction of depletion of existing energy sources such as oil and coal is increasing, interest in alternative energy to replace them is increasing. Among them, solar cells are particularly attracting attention because they are rich in energy resources and have no problems with environmental pollution. Solar cells include solar cells that generate steam required to rotate turbines using solar heat, and solar cells that convert sunlight into electrical energy using properties of semiconductors. In general, a solar cell refers to a solar cell.

In the coming decades, the depletion of fossil fuels is anticipated, and at the same time, environmental issues such as global warming due to carbon dioxide emissions due to the use of large amounts of fossil fuels are emerging. Much attention and attention is focused on batteries.

Currently, the development of solar cells is being promoted in order to lower the unit cost per W of power production. To this end, research is being conducted toward lowering the production cost of solar cells or increasing the efficiency of solar cells.

In the case of bulk silicon solar cells, which account for more than 90% of the global market, many alternatives have been proposed for the purpose of high efficiency. For example, buried contact solar cells, HIT solar cells, interdigitated back contact solar cells, IBC Cell).

These technologies have already been mass-produced and are being produced. Since then, new processes and new technologies have been rushed to increase efficiency and lower production costs. The present invention also provides semiconductor doping to produce such high-efficiency solar cells at low cost. It relates to a method and an improvement of a manufacturing process using the same.

It is an object of the present invention to provide an improved method of doping semiconductor impurities in a semiconductor device.

It is also an object of the present invention to simplify the manufacturing process of a back electrode solar cell using an improved doping method for semiconductor impurities and to provide a high efficiency solar cell at a low production cost.

The technical objects to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical subjects which are not mentioned can be clearly understood by those skilled in the art from the description of the present invention .

In general, unlike the conventional solar cell, the rear electrode type solar cell has a negative electrode, a positive electrode, and a wiring disposed at the rear to eliminate shading loss caused by the front electrode, thereby increasing the light receiving rate and reducing the series resistance. In addition, there is an advantage that the module is easy to manufacture, since the emitter and the back surface field (BSF) are formed on the same surface, the manufacturing process is complicated and thus the manufacturing cost is rather high.

Therefore, a method of manufacturing the back-electrode solar cell of the present invention, an impurity doping method thereof, and a solar cell manufactured by the same according to the present invention provide impurity doping channels spaced apart from the back surface of the silicon semiconductor substrate during texturing. The manufacturing process can be simplified by forming at the same time, impurity ink containing p-type and n-type impurities through each channel, and forming an emitter layer and a BSF layer through diffusion.

Specifically, the impurity doping method of the semiconductor layer of the present invention for solving the above problems is to form a first impurity doping channel and a second impurity doping channel spaced apart from the first impurity doping channel at a predetermined interval on one surface of the semiconductor substrate Forming each, implanting impurities having a first conductivity type into the first impurity doping channel, implanting impurities having a second conductivity type into the second impurity doping channel, and heat-treating the implanted impurities Thereby diffusing the impurities into the semiconductor substrate and introducing the impurities.

In another embodiment, an impurity doping method of a semiconductor layer of the present invention may include forming an etch resistive film on a surface of a semiconductor substrate, forming an impurity doped channel by etching the surface of the semiconductor substrate on which the etch resistive film is not formed, Removing the etch resistant film, attaching a channel shielding film that blocks the upper and upper portions of the channel and the outside on the impurity doped channel, and injects semiconductor impurities into the impurity doped channel blocked from the outside; and Desorbing and thermally treating the shielding film to introduce the impurities into the semiconductor substrate.

Method of manufacturing a back-electrode solar cell of the present invention for achieving the above object, in the method of manufacturing a back-electrode solar cell comprising an emitter layer and a BSF layer on the back of the semiconductor substrate, the first conductivity type semiconductor Forming a first conductivity type semiconductor impurity doping channel and a second conductivity type semiconductor impurity doping channel on a rear surface of the substrate, the impurity doping channel of the first conductivity type and the impurity of the second conductivity type Implanting semiconductor impurity of a first conductivity type and semiconductor impurity of a second conductivity type through a doping channel, and heat treating the semiconductor impurity to remove the semiconductor impurity of the first conductivity type and semiconductor impurity of the second conductivity type Diffusing into the semiconductor substrate to form a BSF layer and an emitter layer, respectively.

According to another aspect of the present invention, there is provided a method of manufacturing a back electrode type solar cell, wherein the back electrode type solar cell includes an emitter layer and a BSF layer on a back surface of a semiconductor substrate. Forming a first conductivity type semiconductor impurity doping channel and a second conductivity type semiconductor impurity doping channel spaced apart from each other, and attaching a channel shielding film that blocks an upper surface portion and an outside of the channel and is detachable on the doping channel And injecting semiconductor impurities of the first conductivity type and semiconductor impurities of the second conductivity type through the impurity doping channel of the first conductivity type and the second conductivity type impurity doping channel that are blocked from the outside. Desorption and heat treatment of the channel shielding film to diffuse the first conductive semiconductor impurity and the second conductive semiconductor impurity into the semiconductor substrate. And forming a W BSF layer and emitter layer, respectively.

The solar cell manufactured by the method of manufacturing the back electrode type solar cell has a second conductivity type having a first conductivity type semiconductor substrate and a conductivity type opposite to the first conductivity type on a rear surface of the first conductivity type semiconductor substrate. A second conductive semiconductor layer doped by a second conductive semiconductor impurity implanted through a semiconductor impurity doping channel, and a second conductive semiconductor layer formed on a rear surface of the first conductive semiconductor substrate and spaced apart from the second conductive semiconductor layer A first conductivity type semiconductor layer doped by a first conductivity type semiconductor impurity injected through a first conductivity type semiconductor impurity doping channel having the same conductivity type as that of the first conductivity type, and the second conductivity type semiconductor layer And a second electrode electrically connected to the first conductivity-type semiconductor layer.

In this case, the second conductivity type semiconductor layer is an emitter layer and the first conductivity type semiconductor layer is a BSF layer.

The present invention can provide an economical method of manufacturing a solar cell to reduce the manufacturing cost of the solar cell by simplifying the manufacturing process by simplifying the doping process of semiconductor impurities in forming the emitter layer and the BSF layer on the semiconductor substrate.

The present invention has an effect of economically reducing the semiconductor device processing process by providing an improved impurity doping method that can be applied to various semiconductor devices other than solar cells.

In addition, through the improved method of the impurity doping process, the back-electrode solar cell can be produced at a low production cost, thereby contributing to the popularization of high-efficiency solar cells.

The semiconductor layer doping method according to an embodiment of the present invention for achieving the above object is formed by patterning an etching resistance film on the surface of the semiconductor substrate, by etching the surface of the semiconductor substrate is not formed the etching resistance film is doped with impurities Forming a channel, removing the etch resistant film, and attaching a channel shielding film that blocks the upper and outer portions of the channel and the external portion on the impurity doped channel, and attaches a detachable channel shielding film to the impurity doped channel. And injecting the impurity into the semiconductor substrate by desorption and heat treatment of the channel shielding film.

In the present invention, the semiconductor substrate may be a p-type silicon substrate or an n-type silicon substrate, the semiconductor impurity is a Group III element consisting of boron (B), aluminum (Al), gallium (Ga), indium (In) And a compound including any one element selected from Group 5 elements composed of phosphorus (P), arsenic (As), and antimony (Sb).

That is, according to an embodiment of the present invention, in order to form a pn junction structure of the semiconductor layer, when the semiconductor substrate is a p-type silicon substrate, the semiconductor layer formed on the surface thereof should be an n-type semiconductor layer. An n-type impurity dopant selected from Group 5 elements consisting of arsenic (As) and antimony (Sb) is used. Conversely, when the semiconductor substrate is an n-type silicon substrate, the semiconductor layer formed on the surface of the substrate must be a p-type semiconductor layer in order to achieve pn junctions. Thus, boron (B), aluminum (Al), gallium (Ga), and indium ( A p-type impurity dopant selected from Group 3 elements consisting of In) is used.

After the impurity doped channel is formed in the present invention, a step of treating the surface of the impurity doped channel with hydrophilicity may be further added. The method of treating hydrophilicity is not particularly limited, and any known technique may be sufficient as a technique applicable to those skilled in the art, but the method of dipping in nitric acid solution or ozone water may be exemplified.

In addition, the channel shielding film may be made of polydimethylsiloxane (PDMS), silicone rubber, polybutadiene, polybutadiene, nitrile rubber, acrylic rubber, butyl rubber, polyisoprene (Polyisoprene), and polystyrene-butadiene copolymer (Poly (Styrene-co-Butadiene)) may be any one or more polymer film layer selected from the group consisting of. However, the present invention is not limited thereto, and the upper space and the outside of the channel may be blocked, and any removable material may be used as the channel shield.

Method of manufacturing a back-electrode solar cell of the present invention for achieving the above object, in the method of manufacturing a back-electrode solar cell comprising an emitter layer and a BSF layer on the back of the semiconductor substrate, the first conductivity type semiconductor Forming a first conductive semiconductor impurity doping channel of a first conductivity type and a second conductive semiconductor impurity doping channel on a rear surface of the substrate, and separating and removing an upper surface of the channel and an outside of the channel on the doping channel. Attaching a shielding film and implanting a first conductive semiconductor impurity and a second conductive semiconductor impurity through the first conductive impurity doping channel and the second conductive impurity doping channel that are blocked from the outside And desorption and heat treatment of the channel shielding film to remove the first conductive semiconductor impurity and the second conductive semiconductor impurity into the semiconductor substrate. Diffusion to form a BSF layer and an emitter layer, respectively. According to the present invention, there is an advantage in that an emitter layer and a BSF layer can be formed by injecting impurities in one thermal diffusion process.

The method of forming the first conductivity type semiconductor impurity doping channel and the second conductivity type semiconductor impurity doping channel according to an embodiment of the present invention may be a method of etching the back surface of the semiconductor substrate.

The first conductivity type semiconductor impurity doping channel and the second conductivity type semiconductor impurity doping channel formed in the semiconductor substrate according to the exemplary embodiment of the present invention may be formed simultaneously or at the same time as texturing the entire surface of the semiconductor substrate.

In the embodiment of the present invention, the first conductive semiconductor substrate may be a p-type silicon substrate, the first conductive semiconductor impurity may be a p-type impurity, and the second conductive semiconductor impurity may be an n-type impurity. .

The first conductive semiconductor substrate may be an n-type silicon substrate, the first conductive semiconductor impurity may be an n-type impurity, and the second conductive semiconductor impurity may be a p-type impurity.

The p-type impurity ink may be a p-type impurity ink as a mixture of water and a compound containing any one element selected from Group III elements consisting of boron (B), aluminum (Al), gallium (Ga), and indium (In). to be.

The n-type impurity is an n-type impurity ink as a mixture of water and a compound containing any one element selected from Group 5 elements composed of phosphorus (P), arsenic (As), and antimony (Sb).

Therefore, it is possible to control the doping concentration level of the semiconductor layer by adjusting the absolute content of dopant elements in these impurity inks.

In the present invention, the forming of the first conductivity type semiconductor impurity doping channel and the second conductivity type semiconductor impurity doping channel may include forming an etching resistance film on a rear surface of the first conductivity type semiconductor substrate, and etching Etching the back surface of the semiconductor substrate on which the resist film is not formed to form a first conductive semiconductor impurity doping channel and a second conductive semiconductor impurity doping channel spaced apart by the etching resistance film, and removing the etching resist film. It includes a step.

The arrangement of the first conductive semiconductor impurity doping channel and the second conductive semiconductor impurity doping channel may be implemented in various embodiments, and in particular, may be formed such that the fingers of the line shape are alternately arranged. Fingers of each of the semiconductor impurity doping channels may be connected to one main center line to form a comb shape and spaced apart from each other so that the fingers are engaged with each other.

In some cases, when the back surface of the semiconductor substrate on which the etch resistance layer is not formed is etched to form a semiconductor impurity channel, the front surface of the semiconductor substrate may be etched together and the front surface of the substrate may be textured to have an uneven shape.

The etching method may be applicable to a known technique, and a mechanical etching method such as a laser method, a dry chemical etching method, a wet chemical etching method, or the like may be used.

In the present invention, the depth and the distance between the first conductive semiconductor impurity doping channel and the second conductive semiconductor impurity doping channel may be implemented in various embodiments.

The first conductive semiconductor substrate may be an n-type or p-type silicon single crystal or polycrystalline substrate, and the depth of the semiconductor impurity doping channel formed on the rear surface of the substrate may be several to several tens of micrometers, and may be different from each other. The distance between the semiconductor impurity doping channels is preferably formed to be separated by at least several micrometers to several mm.

In particular, the depth of the channel may be 1 μm to 100 μm, and the distance between the first conductive semiconductor impurity doped channel and the second conductive semiconductor impurity doped channel may be 1 μm to 10 mm.

After forming the first conductive semiconductor impurity doped channel and the second conductive semiconductor impurity doped channel, the surface of the channel may be hydrophilically treated. The hydrophilic surface treatment may be carried out using conventional process technology and is not particularly limited. In particular, according to an embodiment of the present invention, the surface of the impurity doping channel may be hydrophilic by immersion in nitric acid solution or ozone water.

The channel shielding film used in the method of manufacturing a back-electrode solar cell according to an embodiment of the present invention may be polydimethylsiloxane (PDMS), silicon rubber, polybutadiene, or nitrile rubber. At least one polymer film layer selected from the group consisting of rubber, acrylic rubber, butyl rubber, polyisoprene, and polystyrene-butadiene copolymer (Poly (Styrene-co-Butadiene)) Can be.

The method may further include removing impurity diffusion by-products generated on the rear surface of the substrate after forming the BSF layer and the emitter layer in the method of manufacturing the back-electrode solar cell.

The impurity diffusion by-products are not particularly limited and refer to the diffusion by-products produced during the heat treatment process when the impurity dopant ink used in accordance with an embodiment of the present invention is injected and doped with impurities. In particular, when boron (B) ink is injected, BSG (Boro silicate glass) is produced as a diffusion by-product, and when phosphorus (P) ink is injected, PSG (Phosphorous silicate glass) is produced as a diffusion by-product. The process proceeds.

In some embodiments of the present invention, in order to prevent contamination or diffusion of impurities on the entire surface of the semiconductor substrate, an oxide film such as silicon dioxide (SiO ₂ ) or the like may be applied to the entire surface of the substrate, such as plasma chemical vapor deposition (PECVD) or chemical vapor deposition (CVD). After deposition, the method may be performed. The oxide film is removed after the emitter layer or the BSF layer is formed after the impurity doping process.

In order to achieve the above object, a back electrode type solar cell of the present invention has a first conductivity type semiconductor substrate and a second conductivity type semiconductor having a conductivity type opposite to the first conductivity type on a rear surface of the first conductivity type semiconductor substrate. A second conductive semiconductor layer doped by a second conductive semiconductor impurity implanted through an impurity doping channel, and a second conductive semiconductor layer formed on a rear surface of the first conductive semiconductor substrate and spaced apart from the second conductive semiconductor layer, A first conductivity type semiconductor layer doped by a first conductivity type semiconductor impurity injected through a first conductivity type semiconductor impurity doping channel having the same conductivity type as the conductivity type, and electrically connected to the second conductivity type semiconductor layer And a second electrode electrically connected to the first conductive semiconductor layer.

In the solar cell, the first conductive semiconductor substrate may be a p-type silicon substrate, the second conductive semiconductor layer may be an n + type semiconductor layer, and the first conductive semiconductor layer may be a p + type semiconductor layer.

The first conductivity type semiconductor substrate may be an n-type silicon substrate, the second conductivity type semiconductor layer may be a p + type semiconductor layer, and the first conductivity type semiconductor layer may be an n + type semiconductor layer.

In this case, the second conductivity type semiconductor layer is an emitter layer and the first conductivity type semiconductor layer is a BSF layer.

The arrangement form of the second conductive semiconductor layer and the first conductive semiconductor layer is not particularly limited and may have various embodiments, but may be arranged alternately in a line shape.

The front surface of the first conductive semiconductor substrate may have a textured concave-convex structure.

The first electrode and the second electrode may be formed of any one conductive metal selected from the group consisting of aluminum, titanium, palladium, nickel, copper, and silver, but is not particularly limited thereto.

Hereinafter, various exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

In adding reference numerals to components of the following drawings, it is determined that the same components have the same reference numerals as much as possible even if displayed on different drawings, and it is determined that they may unnecessarily obscure the subject matter of the present invention. Detailed descriptions of well-known functions and configurations will be omitted.

1 to 9 are cross-sectional views showing the process of the manufacturing method of the back-electrode solar cell according to an embodiment of the present invention.

A method of manufacturing a back electrode solar cell according to an exemplary embodiment of the present invention will be described with reference to FIGS. This process sequence is only one embodiment of the present invention and is not necessarily limited to this process.

First, as shown in FIG. 1, the semiconductor substrate 101 is prepared. According to an embodiment, the substrate is an n-type silicon semiconductor substrate, which prepares a wafer which is first etched from saw damage caused by cutting the wafer from a silicon ingot. As another example, the p-type silicon semiconductor substrate may be prepared.

FIG. 2 illustrates that an etch resistance layer 102 is formed in a pattern to form a doping channel for implanting semiconductor impurities spaced apart from the n-type silicon semiconductor substrate 101.

In some embodiments, the etching resist layer may be formed by patterning an etching resist paste having a width of several μm to several mm using screen printing, printing, photolithography, or the like.

The separation distance between the impurity channels different from each other by the width of the etch resistive film is formed. An etching resist paste used as an etching resist film may be used as long as it is a known anti-etching material, and is not particularly limited.

Also, as an example, the etch resistant film may be formed of one etch resistant material selected from a dry film, a wet film, an ink, a plastic film, and a solder mask ink.

3 illustrates that the substrate is etched using the etch resistant film 102 as an etch mask. Referring to FIG. 3, it can be seen that channels or grooves are formed at a depth of several to several tens of micrometers on the remaining portion where the etch resistant film 102 is not formed, that is, the back surface of the semiconductor substrate 101.

The etching method may be a known method, but in particular, chemical wet etching may be used, and silicon anisotropy such as sodium hydroxide (NaOH), potassium hydroxide (KOH), tetramethyl ammonium hydroxide (TMAH), and the like can be used. Etchable solution can be etched.

In this case, the front surface of the semiconductor substrate 101 can also be etched to allow texturing of the entire surface.

After etching, the back portion of the n-type semiconductor substrate 101 corresponds to the n-type impurity semiconductor doping channel 104 having the same conductivity type as the substrate and the p-type impurity semiconductor doping channel 103 having the conductivity type opposite to the substrate. Two kinds of channels or grooves are formed.

4 shows that the oxide film 105 is treated on the front surface of the substrate to prevent diffusion of semiconductor impurities and to prevent contamination of the front surface of the substrate before injecting the impurity ink into the etched channel.

The oxide film according to an embodiment of the present invention may be silicon dioxide (silicon oxide) SiO ₂ , but is not necessarily limited thereto and may form various oxide films.

The formation method of the oxide film 105 may be sufficient using a known technique, but in particular, deposition is performed using a plasma chemical vapor deposition (PECVD) or the like.

The deposition thickness of the oxide film is not particularly limited, but may be deposited at 500 nm or more.

Meanwhile, in FIG. 4, the lower etching resistive film 102 is removed. After removing the etching resist paste, the substrate is cleaned to expose two kinds of channels.

Although not shown, according to another embodiment of the present invention, the channel portion of the semiconductor substrate from which the etch resistance film is removed may be hydrophilically surface treated.

If only the channel portion of the substrate or the entire substrate is immersed in a nitric acid solution or ozone water and dried, the surface portion of the channel can be made hydrophilic.

The hydrophilic treatment of the channel surface is such that the solvent of the impurity dopant ink is water so that the dopant is effectively introduced into the substrate through the channel when doping.

Next, referring to FIG. 5, a channel shielding film 106 is formed on the rear surface of the semiconductor substrate to block the channel and the outside.

The channel shielding layer 106 may be easily attached or detached to a substrate and may be configured as a non-reactive material with semiconductor impurities.

One embodiment of the present invention, including silicone rubber such as polydimethylsiloxane (PDMS), polybutadiene (Polybutadiene), nitrile rubber (Nitrile rubber), acrylic rubber (butyl rubber), butyl rubber (Butyl Rubber) ), Polyisoprene, and a polymer film layer such as polystyrene-butadiene copolymer (Poly (Styrene-co-Butadiene)) can be used.

6 shows that the p-type impurity ink 107 is injected through the p-type impurity doping channel according to the embodiment.

The p-type impurity ink 107 may be a solution obtained by dissolving a compound containing a Group 3 elemental material such as boron (B) in water. The p-type impurity ink 107 may be injected through the second conductive type (p type in this embodiment) impurity doping channel 103.

The injection method is not particularly limited and may be injected into the p-type impurity doped channel in various embodiments. However, in the above example, since the upper surface of the channel has already been blocked by the channel shielding film 106, P-type impurities can be implanted through some.

In the case of injecting the p-type impurity ink through one side portion, the ink must be injected while blocking the opening of the opposite channel side portion.

The impurity ink injection method is a method of forcibly flowing ink or blocking one of both side openings of the channel and immersing it in the impurity ink liquid so that impurity ink flows naturally.

7 shows that after the p-type impurity ink is injected and dried, the n-type impurity ink 108 such as phosphorus (P), arsenic (As), or the like is injected and dried through the n-type impurity doping channel 104.

Since the method of injecting the n-type impurity ink 108 is also the same as described above, it is omitted.

The order of injection of the impurity inks of different conductivity types is not necessarily fixed, and may be changed in a different order.

FIG. 8 illustrates a form in which a channel shielding film of a silicon-based rubber such as PDMS attached to the rear surface of the semiconductor substrate 101 is detached.

Referring to FIG. 8, a p-type semiconductor ink injected through a p-type semiconductor doping channel and an n-type semiconductor ink injected through an n-type semiconductor doping channel are disclosed. In this state, a diffusion furnace or a belt furnace ( Heat treatment is carried out at high temperature in a furnace such as a belt furnace. When the p-type semiconductor impurity and the n-type semiconductor impurity injected through each channel are simultaneously diffused into the channel of the semiconductor substrate, the emitter layer 109 and the BSF layer 110 are formed as shown in FIG. 9.

In some cases, diffusion by-products may be generated according to doping of impurities, and the diffusion by-products are removed by the following process.

In addition, a process of removing the oxide film 105 deposited on the front surface of the substrate is performed.

Since the subsequent process is not different from the conventional back-electrode type solar cell, a detailed description thereof will be omitted.

As described above, the present invention relates to a method of forming an emitter and a BSF during a back-electrode solar cell manufacturing process, and makes two semiconductor impurity doping channels spaced apart from each other during full-texturing without an additional process, and each has p-type and n-type impurities. By injecting and diffusing the contained ink, it is effective in drastically reducing the number of existing processes and simplifying the manufacturing process, thereby greatly reducing the manufacturing cost.

10 to 17 is a rear view of the substrate showing the process of the manufacturing method of the back-electrode solar cell according to an embodiment of the present invention.

FIG. 10 illustrates an example of preparing an n-type semiconductor silicon substrate 201 corresponding to FIG. 1 from the rear surface thereof.

FIG. 11 is a view of the back surface of the semiconductor substrate 201 corresponding to FIG. 2, and shows a patterned shape of the etch resistive film 202 according to one embodiment.

The portion where the etch resistant film is not formed is a portion to be etched as an impurity doped channel in the present invention.

FIG. 12 illustrates a form in which two doping channels 203 and 204 of semiconductor impurities are etched on the rear surface of the substrate 201 where the etch resistive film is not formed through the processes of FIGS. 3 to 4.

Referring to FIG. 12, after the etch resistive film 202 is removed, the p-type semiconductor impurity doping channel 203 and the n-type semiconductor impurity doping channel 204 are interdigitated with each other in the form of a comb. Is formed.

As described above, the line-shaped finger portions of each of the impurity doping channels may be formed to be spaced apart by an interval equal to the thickness of the etch resistive layer without overlapping each other.

FIG. 13 corresponds to the step of FIG. 5 and illustrates that a channel shielding film 206 is attached to a rear surface of the semiconductor substrate on which the channel is formed.

In some embodiments, the channel shielding film may be attached in such a manner that the upper portion and the outside of the channel may be blocked. However, in one embodiment, the channel shielding film may be collectively attached to the entire substrate.

FIG. 14 illustrates a form in which the p-type impurity ink 207 is injected through the p-type impurity doping channel 203 by the process of FIG. 6.

FIG. 15 illustrates a form in which n-type impurity ink 208 is injected through the n-type impurity doping channel 204 by the process of FIG. 7.

The impurity ink may be injected through a comb-shaped channel through both side ends of the channel, which are the central axes to which the finger parts are connected, and the outside of the channel.

FIG. 16 illustrates the backside of the substrate on which the channel shielding layer 206 is removed in one embodiment of the present invention. The impurity is introduced into the substrate by performing a heat treatment process on the rear surface of the substrate of FIG. 16.

FIG. 17 shows that the p-type impurity ink 207 and the n-type impurity ink 208 are respectively diffused into the substrate through a heat treatment process to form the emitter layer 209 and the BSF layer 210, respectively.

The subsequent process also follows the general process of the back-electrode solar cell.

18 is a flowchart illustrating some processes of a method of manufacturing a back electrode solar cell according to an embodiment of the present invention.

Referring to FIG. 18, first, an etching resistance film is patterned on a rear surface of a semiconductor silicon substrate (S01).

Next, the substrate is immersed in an etching solution to texture the front surface of the substrate, and at the same time, a portion of the substrate backside in which the etch resistance film is not formed is etched as an impurity doping channel of the first conductivity type or the second conductivity type (S02).

Subsequently, the etch resistant film is removed and the substrate is cleaned (S03).

The front surface of the substrate forms an oxide film such as silicon oxide by a method such as plasma chemical vapor deposition or chemical vapor deposition (S04).

The entire substrate or the rear surface of the substrate on which the channel is formed is surface treated with hydrophilicity (S05).

The silicon-based recess is attached to the rear surface of the substrate on which the channel of the hydrophilic surface is formed (S06).

Since the silicon rubber is not attached, semiconductor impurities of the first conductivity type or the second conductivity type are injected through the side ends of the channels connected to the outside (S07).

As described above, the semiconductor impurity is a mixed liquid in the form of an ink using water as a solvent.

Subsequently, the silicon rubber is desorbed (S08), and the semiconductor substrate is heat treated at a high temperature (S09). Impurity ions implanted into the channel by the heat treatment process are diffused on the rear surface of the semiconductor substrate in the shape of the channel to form an emitter layer and a BSF layer, respectively (S10).

Next, BSG and PSG, which are diffusion byproducts that may be generated in the heat treatment diffusion process of impurities, are removed, and an oxide film deposited on the front surface of the substrate is removed (S11).

The impurity doping method of the present invention can be applied not only to impurity doping for forming a pn junction layer of a solar cell, but also to impurity doping of various semiconductor devices.

The present invention has been described above in connection with specific embodiments of the present invention, but this is only an example and the present invention is not limited thereto. Those skilled in the art can change or modify the described embodiments without departing from the scope of the present invention, and such changes or modifications are within the scope of the present invention. In addition, the materials of each component described herein can be readily selected and substituted for various materials known to those skilled in the art. Those skilled in the art will also appreciate that some of the components described herein can be omitted without degrading performance or adding components to improve performance. In addition, those skilled in the art may change the order of the method steps described herein depending on the process environment or equipment. Therefore, the scope of the present invention should be determined by the appended claims and equivalents thereof, not by the embodiments described.

1 to 9 are cross-sectional views showing the process of the manufacturing method of the back-electrode solar cell according to an embodiment of the present invention.

10 to 17 is a rear view of the substrate showing the process of the manufacturing method of the back-electrode solar cell according to an embodiment of the present invention.

18 is a flowchart illustrating some processes of a method of manufacturing a back electrode solar cell according to an embodiment of the present invention.

{Description of symbols for main parts of the drawing}

101, 201: first conductive semiconductor substrate 102, 202: etch resistive film

103 and 203: semiconductor impurity doping channel of the second conductivity type

104, 204: Semiconductor impurity doping channel of a first conductivity type

105: oxide film 106, 206: channel shielding film

107 and 207: second conductivity type semiconductor impurity

108, 208: first conductivity type semiconductor impurity

109, 209: emitter layer 110, 210: BSF layer

Claims (22)

Forming a first impurity doping channel and a second impurity doping channel spaced apart from the first impurity doping channel at predetermined intervals on either surface of the semiconductor substrate; Injecting impurities having a first conductivity type into the first impurity doping channel and implanting impurities having a second conductivity type into the second impurity doping channel; And Heat-treating the implanted impurities to diffuse and introduce the impurities into the semiconductor substrate, respectively. In the method of manufacturing a back-electrode solar cell comprising an emitter layer and a BSF layer on the back of the semiconductor substrate, Forming a first conductive semiconductor impurity doped channel and a second conductive semiconductor impurity doped channel on a rear surface of the first conductive semiconductor substrate, spaced apart from each other; Implanting a first conductive semiconductor impurity and a second conductive semiconductor impurity through the impurity doping channel of the first conductivity type and the impurity doping channel of the second conductivity type, respectively; And Heat treating the semiconductor impurities to diffuse the first conductive semiconductor impurities and the second conductive semiconductor impurities into a semiconductor substrate to form a BSF layer and an emitter layer, respectively. Manufacturing method. 3. The method of claim 2, And the first conductive semiconductor impurity doping channel and the second conductive semiconductor impurity doping channel are formed by etching a substrate. 3. The method of claim 2, And the first conductive semiconductor impurity doping channel and the second conductive semiconductor impurity doping channel are formed simultaneously with texturing the entire surface of the substrate. 3. The method of claim 2, After forming the first conductivity type semiconductor impurity doping channel and the second conductivity type semiconductor impurity doping channel, further comprising the step of forming an oxide film on the front surface of the semiconductor substrate manufacturing of a back-electrode type solar cell Way. 3. The method of claim 2, Before the step of implanting each of the first conductivity type semiconductor impurity and the second conductivity type semiconductor impurity, a removable channel shielding film is formed on the rear surface of the semiconductor substrate, and the channel shielding film is removed after the implantation of the semiconductor impurity Method of manufacturing a back-electrode solar cell, characterized in that it further comprises the step. 3. The method of claim 2, Wherein the first conductive semiconductor substrate is a p-type silicon substrate, the first conductive semiconductor impurity is a p-type impurity, and the second conductive semiconductor impurity is an n-type impurity Manufacturing method. 3. The method of claim 2, The first conductive semiconductor substrate is an n-type silicon substrate, the first conductive semiconductor impurity is an n-type impurity, and the second conductive semiconductor impurity is a p-type impurity Manufacturing method. The method according to claim 7 or 8, The p-type impurity is a rear electrode, characterized in that a mixture of water and a compound containing any one element selected from Group III elements consisting of boron (B), aluminum (Al), gallium (Ga), indium (In). Method of manufacturing a type solar cell. The method according to claim 7 or 8, The n-type impurity is a mixture of water and a compound containing any one element selected from Group 5 elements consisting of phosphorus (P), arsenic (As), antimony (Sb) of the back-electrode type solar cell Manufacturing method. 3. The method of claim 2, Forming the first conductivity type semiconductor impurity doped channel and the second conductivity type semiconductor impurity doped channel, Patterning and forming an etch resistant film on a rear surface of the first conductive semiconductor substrate; Etching a rear surface of the semiconductor substrate on which the etch resistant film is not formed to form a first conductive semiconductor impurity doped channel spaced by the etch resistant film and a second conductive semiconductor impurity doped channel; And Method of manufacturing a back-electrode solar cell comprising the step of removing the etching resist film. 3. The method of claim 2, And forming the first conductive semiconductor impurity doping channel and the second conductive semiconductor impurity doping channel, and then treating the surface of the impurity doping channel with hydrophilicity. Manufacturing method of solar cell. 3. The method of claim 2, The channel shielding film may be polydimethylsiloxane (PDMS), silicone rubber, polybutadiene, polynitrile rubber, nitrile rubber, acrylic rubber, butyl rubber, polyisoprene (Polyisoprene), and polystyrene-butadiene copolymer (Poly (Styrene-co-Butadiene)) A method for manufacturing a back-electrode solar cell, characterized in that at least one polymer film layer selected from the group consisting of. 3. The method of claim 2, After the step of forming the BSF layer and the emitter layer, respectively, further comprising the step of removing the impurity diffusion by-products generated on the back of the substrate. A first conductivity type semiconductor substrate; An emitter layer doped with a second conductive semiconductor impurity through a predetermined semiconductor impurity doping channel formed on a rear surface of the first conductive semiconductor substrate; A BSF layer doped with a first conductive semiconductor impurity through a semiconductor impurity doping channel formed on a rear surface of the first conductive semiconductor substrate to be spaced apart from the emitter layer; A first electrode electrically connected to the emitter layer; And A back electrode type solar cell comprising a second electrode electrically connected to the BSF layer. The method of claim 15, And the first conductive semiconductor substrate is a p-type silicon substrate, the emitter layer is an n + type semiconductor layer, and the BSF layer is a p + type semiconductor layer. The method of claim 15, And the first conductive semiconductor substrate is an n-type silicon substrate, the emitter layer is a p + type semiconductor layer, and the BSF layer is an n + type semiconductor layer. The method of claim 15, The emitter layer and the BSF layer is a back-electrode solar cell, characterized in that the shape is arranged alternately in a line shape. The method of claim 15, The depth of the semiconductor impurity doping channel is a back electrode type solar cell, characterized in that 1 ㎛ to 100 ㎛. The method of claim 15, A back electrode type solar cell, wherein a distance between the semiconductor impurity doping channel formed to be spaced apart from the emitter layer and the emitter layer is 1 μm to 10 mm. The method of claim 15, The front surface of the first conductive semiconductor substrate is a back electrode type solar cell, characterized in that the textured concave-convex structure. The method of claim 15, The first electrode and the second electrode, A back-electrode type solar cell, which is formed of any one conductive metal selected from the group consisting of aluminum, titanium, palladium, nickel, copper, and silver.

Images