KR101549555B1 - Semiconductor layer doping method Back contact solar cell by using the same method and Manufacturing method thereof - Google Patents

Abstract

The present invention relates to a method of doping a semiconductor layer, a method of manufacturing a back electrode type solar cell including such a process, and a back electrode type solar cell manufactured thereby. Specifically, a process of doping a semiconductor layer includes: Forming an impurity doping channel by etching the surface of the semiconductor substrate on which the etch stopper film is not formed, removing the etch stopper film, and removing the etch stopper film on the impurity doping channel, A method of manufacturing a semiconductor device, the method comprising: attaching a channel shielding film to a semiconductor substrate, the channel shielding film being intercepted from the outside; implanting a semiconductor impurity into the impurity doping channel that is shielded from the outside; and removing the channel shielding film and introducing the impurity into the semiconductor substrate .

Solar cell, doping, impurity, back electrode type, channel, etch, etch resistant film, channel shielding film

Description

[0001] The present invention relates to a doping method of a semiconductor layer, a back electrode type solar cell using the same, and a manufacturing method thereof,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of doping semiconductor impurities and a method of manufacturing a rear electrode type solar cell including an emitter layer and a back surface field (BSF) .

The present invention provides a solar cell that improves a method of doping an impurity into a back electrode type solar cell, simplifies the process of the solar cell, and increases the efficiency of the solar cell.

With the recent depletion of existing energy resources such as oil and coal, interest in alternative energy to replace them is increasing. Among them, solar cells are attracting particular attention because they are rich in energy resources and have no problems with environmental pollution. Solar cells include solar cells that generate the steam needed to rotate the turbine using solar heat, and solar cells that convert sunlight into electrical energy using the properties of semiconductors. Generally, a solar cell is a solar cell.

In the coming decades, the exhaustion of fossil fuels is expected. At the same time, environmental problems such as global warming caused by the emission of carbon dioxide due to the use of large amounts of fossil fuels, A lot of attention and attention is focused on the battery.

Currently, the development of solar cells is being promoted in order to lower the unit cost per watt of electricity. For this purpose, studies are being made to lower the production cost of solar cells or to increase the efficiency of solar cells.

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

These technologies have already been mass-produced and are being produced. Since then, they have been hurrying to introduce new processes and new technologies to further increase the efficiency and lower the production cost. However, the present invention is also applicable to semiconductor doping for producing such high efficiency solar cells at low cost And an improvement of the manufacturing process utilizing the same.

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

It is another object of the present invention to provide a solar cell with a high efficiency by simplifying a manufacturing process of a back electrode type solar cell by using an improved doping method of semiconductor impurities and 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, the rear-electrode type solar cell eliminates the shading loss caused by the front electrode by disposing the cathode and the anode electrode and the wiring on the rear side unlike the conventional solar cell, thereby increasing the light receiving rate and reducing the series resistance In addition, since the emitter and the back surface field (BSF) are formed on the same surface, the manufacturing process is complicated and the manufacturing cost is somewhat high.

In order to solve the above problems, a method of manufacturing a back electrode type solar cell of the present invention, a method of doping an impurity thereof, and a solar cell manufactured by the method have a channel for impurity doping spaced apart from the back surface during texturing of a silicon semiconductor substrate. And simultaneously forming an emitter layer and a BSF layer by diffusing an impurity ink containing p-type and n-type impurities through each channel, thereby simplifying the manufacturing process.

In accordance with another aspect of the present invention, there is provided a method for doping a semiconductor layer with a first impurity doping channel and a second impurity doping channel spaced apart from the first impurity doping channel by a predetermined distance, Doping the first impurity doping channel with an impurity having a first conductivity type and injecting an impurity having a second conductivity type into the second impurity doping channel; And diffusing the impurities into the semiconductor substrate and introducing the impurities into the semiconductor substrate.

According to another embodiment of the present invention, there is provided a method for doping a semiconductor layer, comprising: forming an etching resistive film on a surface of a semiconductor substrate by patterning; etching the surface of the semiconductor substrate on which the etching resistant film is not formed to form an impurity doped channel; Removing the etching resistive film and attaching a detachable channel shielding film to the impurity doped channel by blocking the channel upper surface and the outer surface of the channel; injecting semiconductor impurities into the impurity doped channel blocked from the outside; And removing the shielding film and introducing the impurity into the semiconductor substrate by heat treatment.

According to another aspect of the present invention, there is provided a method of manufacturing a rear electrode type solar cell including an emitter layer and a BSF layer on a rear surface of a semiconductor substrate, Forming a first conductive type semiconductor impurity doping channel and a second conductive type semiconductor impurity doping channel apart from each other on a rear surface of a substrate; forming an impurity doping channel of the first conductive type and an impurity of the second conductive type Implanting a semiconductor impurity of a first conductivity type and a semiconductor impurity of a second conductivity type through a doping channel; and performing a heat treatment of the semiconductor impurity to heat the first conductivity type semiconductor impurity and the second conductivity type semiconductor impurity And diffusing into the semiconductor substrate to form a BSF layer and an emitter layer, respectively.

A method for manufacturing a back electrode type solar cell according to another embodiment of the present invention is a method for manufacturing a back electrode type solar cell including an emitter layer and a BSF layer on the rear surface of a semiconductor substrate, Forming a first conductive impurity doping channel of the first conductivity type and a second conductive impurity doping channel of the second conductive impurity on the doping channel by depositing a channel shielding film on the doping channel, Implanting a first conductive semiconductor impurity and a second conductive semiconductor impurity through the impurity doping channel of the first conductive type and the impurity doping channel of the second conductive type that are shielded from the outside, And the channel shielding film is removed and heat treated to diffuse the first conductive semiconductor impurities and the second conductive semiconductor impurities into the semiconductor substrate And forming a W BSF layer and emitter layer, respectively.

The solar cell manufactured through the method of manufacturing the rear electrode type solar cell includes a first conductive type semiconductor substrate and a second conductive type semiconductor substrate having a conductive type opposite to the first conductive type on the rear surface of the first conductive type semiconductor substrate. A second conductivity type semiconductor layer doped with a second conductivity type semiconductor impurity implanted through a semiconductor impurity doping channel; a second conductivity type semiconductor layer formed on the rear surface of the first conductivity type semiconductor substrate, A first conductivity type semiconductor layer doped with a first conductivity type semiconductor impurity implanted through a first conductivity type semiconductor impurity doping channel having the same conductivity type as the first conductivity type semiconductor layer, And a second electrode electrically connected to the first conductivity type semiconductor layer.

At this time, 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 that simplifies the fabrication process and reduces the manufacturing cost of the solar cell by simplifying the doping process of the semiconductor impurity in forming the emitter layer and the BSF layer on the semiconductor substrate.

INDUSTRIAL APPLICABILITY The present invention provides an improved method of doping an impurity that can be applied to various semiconductor devices other than solar cells, thereby economically reducing the semiconductor device process.

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

According to an aspect of the present invention, there is provided a method of doping a semiconductor layer, the method comprising: forming an etching resistive film on a surface of a semiconductor substrate; etching the surface of the semiconductor substrate, Depositing a channel shielding film on the impurity doping channel; removing impurities from the impurity doping channel; forming a channel shielding film on the impurity doping channel; And introducing the impurity into the semiconductor substrate by desorbing and heat-treating the channel shielding film.

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

That is, according to one embodiment of the present invention, when the semiconductor substrate is a p-type silicon substrate in order to achieve the pn junction structure of the semiconductor layer, the semiconductor layer formed on the surface of the semiconductor substrate must be an n-type semiconductor layer, An n-type impurity dopant selected from a group 5 element consisting of arsenic (As) and antimony (Sb) is used. Conversely, in the case where the semiconductor substrate is an n-type silicon substrate, the semiconductor layer formed on the surface of the substrate in order to achieve the pn junction must be a p-type semiconductor layer, and therefore, boron (B), aluminum (Al), gallium In) is used as the p-type impurity dopant.

In the present invention, after the impurity doping channel is formed, a step of treating the surface of the impurity doping channel with a hydrophilic process may be further added. The method of treating hydrophilicity is not particularly limited, and a technique applicable to a person skilled in the art may be sufficient as a known technique. However, according to one embodiment, a method of immersing in a nitric acid solution or ozone water can be mentioned.

Also, the channel shielding film may be formed of at least one material selected from the group consisting of polydimethylsiloxane (PDMS), silicone rubber, polybutadiene, nitrile rubber, acrylic rubber, butyl rubber, polyisoprene (Polyisoprene), and a polystyrene-butadiene copolymer (Poly (styrene-co-butadiene)). However, the present invention is not limited thereto, and it may block the upper space and the outside of the channel, and may be used as a channel shielding film if a removable material is used.

According to another aspect of the present invention, there is provided a method of manufacturing a rear electrode type solar cell including an emitter layer and a BSF layer on a rear surface of a semiconductor substrate, The method comprising: forming a first conductive semiconductor doping channel and a second conductive semiconductor doping channel apart from each other on a rear surface of a substrate; forming a channel on the doping channel, A method of manufacturing a semiconductor device, comprising the steps of: attaching a shielding film; injecting a semiconductor impurity of the first conductivity type and a semiconductor impurity of the second conductivity type through the impurity doping channel of the first conductivity type and the impurity doping channel of the second conductivity type, And removing and heat-treating the channel shielding film to remove the first conductive semiconductor impurities and the second conductive semiconductor impurities from the semiconductor substrate To form a BSF layer and an emitter layer, respectively. According to the present invention, an emitter layer and a BSF layer can be formed by implanting impurities in a single thermal diffusion process.

The method of forming the first conductive type semiconductor impurity doping channel and the second conductive 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 conductive type semiconductor impurity doping channel and the second conductive type semiconductor impurity doping channel formed in the semiconductor substrate according to an embodiment of the present invention may be formed at the same time or at the time of texturing the front surface of the semiconductor substrate.

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

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

The p-type impurity is a p-type impurity as a mixed liquid of a compound containing any one element selected from the group III elements consisting of boron (B), aluminum (Al), gallium (Ga) to be.

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

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

The forming of the first conductive type semiconductor impurity doping channel and the second conductive type semiconductor impurity doping channel may include forming an etching resistance film on the rear surface of the first conductivity type semiconductor substrate by patterning, Forming a first conductive type semiconductor impurity doping channel and a second conductive type semiconductor impurity doping channel spaced apart by the etching resistant film by etching the rear surface of the semiconductor substrate on which the resistive film is not formed; .

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

In some cases, when the rear surface of the semiconductor substrate on which the etching resistant film is not formed is etched to form a semiconductor impurity channel, the front surface of the semiconductor substrate may be etched together to texture the front surface of the substrate to have a concave / convex shape.

The etching method may be applied by any 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 can be used.

In the present invention, depths and mutual spacing distances of the first conductive type semiconductor impurity doping channel and the second conductive type semiconductor impurity doping channel can be realized in various embodiments.

The semiconductor substrate of the first conductivity type may be an n-type or p-type silicon single crystal or a polycrystalline substrate. The depth of the semiconductor impurity doping channel formed on the rear surface of the substrate may be several to several tens of micrometers, The distance between the semiconductor-impurity-doped channels is preferably at least several micrometers to several millimeters.

Particularly, the depth of the channel is 1 占 퐉 to 100 占 퐉, and the distance between the first conductive semiconductor impurity doping channel and the second conductive semiconductor impurity doping channel may be 1 占 퐉 to 10 mm.

After forming the semiconductor impurity doping channel of the first conductivity type and the semiconductor impurity doping channel of the second conductivity type, the surface of the channel may be treated to be hydrophilic. The hydrophilic surface treatment process may use conventional process technology and is not particularly limited. Particularly, according to one embodiment of the present invention, the surface of the impurity doped channel can be treated with hydrophilic by immersion in nitric acid solution or ozone water.

The channel shielding film used in the method of manufacturing the rear electrode type solar cell according to an embodiment of the present invention may be formed of a material selected from the group consisting of polydimethylsiloxane (PDMS), silicone rubber, polybutadiene, Butadiene copolymer (Poly (styrene-co-butadiene)), which is a polymer film layer selected from the group consisting of acrylic rubber, acrylic rubber, butyl rubber, polyisoprene, and polystyrene- .

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

The impurity diffusion by-product is not particularly limited, and refers to a diffusion by-product produced in the heat treatment process when the impurity dopant ink used in accordance with an embodiment of the present invention is doped and the impurity is doped. Particularly when boron (B) ink is injected, borosilicate glass (BSG) is generated as a byproduct of diffusion and phosphorus silicate glass (PSG) is generated as a byproduct of diffusion when phosphorus (P) ink is injected. Process.

An oxide film such as silicon dioxide (SiO ₂ ) may be deposited on the entire surface of the substrate by plasma chemical vapor deposition (PECVD), chemical vapor deposition (CVD), or the like in order to prevent contamination or impurity diffusion on the entire surface of the semiconductor substrate And then the above method can be performed. The oxide film is removed after the impurity doping process is performed after the emitter layer or the BSF layer is formed.

According to an aspect of the present invention, there is provided a back electrode type solar cell comprising a first conductivity type semiconductor substrate, a second conductivity type semiconductor having a conductivity type opposite to the first conductivity type on the rear surface of the first conductivity type semiconductor substrate, A second conductivity type semiconductor layer doped with a second conductivity type semiconductor impurity implanted through an impurity doping channel; a second conductivity type semiconductor layer formed on the rear surface of the first conductivity type semiconductor substrate, A first conductivity type semiconductor layer doped with a first conductivity type semiconductor impurity implanted through a first conductivity type semiconductor impurity doping channel having the same conductivity type as that of the first conductivity type semiconductor layer and electrically connected to the second conductivity type semiconductor layer And a second electrode electrically connected to the first conductive type semiconductor layer.

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

At this time, 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 conductivity type semiconductor layer and the first conductivity type semiconductor layer is not particularly limited and may have various embodiments, but may be a form arranged alternately in a line shape.

The front surface of the first conductivity type semiconductor substrate may have a textured concavo-convex structure.

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

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

In the drawings, the same reference numerals are used to designate the same or similar components, and the same reference numerals will be used to designate the same or similar components. Detailed descriptions of known functions and configurations are omitted.

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

1 to 9, a method of fabricating a back electrode type solar cell according to an embodiment of the present invention will be described in order of steps. Such a process sequence is only an embodiment of the present invention and is not necessarily limited to this process.

First, a semiconductor substrate 101 is prepared as shown in FIG. According to an embodiment of the present invention, the substrate is an n-type silicon semiconductor substrate, and a wafer is first etched with saw damage caused by cutting a wafer from a silicon ingot. It is needless to say that the p-type silicon semiconductor substrate can be prepared as another embodiment.

2 shows the patterning of the etching resistant film 102 in order to form a doping channel for semiconductor impurity implantation on the n-type silicon semiconductor substrate 101.

In one embodiment, the etching resist film may be formed by patterning an etching resist paste having a width of several micrometers to several millimeters by a screen printing method, a printing method, a photolithography method, or the like.

The distance between the impurity channels which are different from each other by the width of the etching resistant film is formed. The etching resist paste used as the etching resist film may be sufficiently used if it is a known etching prevention material and is not particularly limited.

In one embodiment, the etch resistant layer 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.

FIG. 3 shows etching of the substrate using the etching resistant film 102 as an etching mask. Referring to FIG. 3, it can be seen that a channel or a groove is formed in the remaining portion where the etching resistant film 102 is not formed, that is, the depth of several to several tens of micrometers on the rear surface of the semiconductor substrate 101.

The etching may be carried out by a known method, but a chemical wet etching method may be used, and a silicon non-isotropic method such as sodium hydroxide (NaOH), potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH) It can be etched with an etching solution.

In this case, the front surface of the semiconductor substrate 101 can also be etched, thereby enabling texturing of the front surface.

An n-type impurity semiconductor doping channel 104 having a conductivity type the same as the substrate and a p-type impurity semiconductor doping channel 103 having a conductivity type opposite to the substrate are formed on the rear surface of the n-type semiconductor substrate 101 after etching Two kinds of channels or grooves are formed.

FIG. 4 shows that the oxide film 105 is formed on the front surface of the substrate in order to prevent diffusion of semiconductor impurities and to prevent contamination of the front surface of the substrate before impurity ink is injected into the etched channel.

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

The oxide film 105 may be formed using a known technique, but is preferably deposited using plasma enhanced chemical vapor deposition (PECVD) or the like.

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

Meanwhile, FIG. 4 shows a state in which the lower etching resistant film 102 is removed. After etching resist paste is removed, the substrate is cleaned so that two kinds of channels can be exposed.

Although not shown, according to another embodiment of the present invention, the channel portion of the semiconductor substrate from which the etching resistant film is removed can be surface-treated with hydrophilicity.

Only the channel portion of the substrate or the entire substrate may be immersed in nitric acid solution, ozone water or the like, and then dried and treated to make the surface portion of the channel hydrophilic.

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

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

The channel shielding film 106 can be easily detached and attached to the substrate and can be configured as a non-reactive material with semiconductor impurities.

As one embodiment of the present invention, silicone rubber such as polydimethylsiloxane (PDMS), polybutadiene, nitrile rubber, acrylic rubber, butyl rubber, ), Polyisoprene, and poly (styrene-co-butadiene) (poly (styrene-co-butadiene)).

6 shows that the p-type impurity ink 107 is implanted through the p-type impurity doping channel in accordance with the embodiment.

The p-type impurity ink 107 may be a solution in which a compound containing a Group III element material such as boron (B) is dissolved in water. The p-type impurity ink 107 may be injected through the second conductivity type (p-type impurity doping channel 103 in this embodiment).

Although the implantation method is not particularly limited, it can be implanted into the p-type impurity doping channel in various embodiments. However, since the upper surface of the channel is already blocked by the channel shielding film 106 in the above example, The p-type impurity can be implanted through a part.

When p-type impurity ink is injected through one side portion, ink should be injected while blocking the entrance of the channel side portion on the opposite side.

A method of injecting an impurity ink includes a method in which ink is forcibly forced or the inlet of both sides of a channel is closed and the impurity ink is naturally dipped in the impurity ink liquid to allow the impurity ink to flow naturally.

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

The method of injecting the n-type impurity ink 108 is also the same as described above and therefore will not be described.

It is needless to say that the order of injection of the impurity inks having different conductivity types is not necessarily fixed but may be changed in order.

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

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 belt furnace to perform high temperature heat treatment. When the p-type semiconductor impurity implanted through each channel and the n-type semiconductor impurity 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.

In some cases, diffusion byproducts may be generated by doping the impurities, and the diffusion by-products are removed in the next step.

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

The subsequent process is not different from the conventional rear electrode type solar cell, so a detailed description will be omitted.

As described above, the present invention relates to a method of forming an emitter and a BSF in a process of manufacturing a back electrode type solar cell, wherein two semiconductor impurity doping channels spaced apart from each other are formed during the front texturing process without further processing, By injecting and diffusing the ink, the existing process water is drastically reduced and the manufacturing process is simplified, which is effective in significantly lowering the manufacturing cost.

10 to 17 are rear views of a substrate showing a process of a method of manufacturing a back electrode type solar cell according to an embodiment of the present invention.

FIG. 10 is a rear view showing that the n-type semiconductor silicon substrate 201 corresponding to FIG. 1 is prepared.

Fig. 11 shows the patterned shape of the etching resistant film 202 according to one embodiment, which is a rear view of the semiconductor substrate 201 corresponding to Fig.

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

FIG. 12 shows a state in which two kinds of doping channels 203 and 204 of a semiconductor impurity are etched on the rear surface of a substrate 201 on which an etching resistant film is not formed through the processes of FIGS.

12, after the etching resistant film 202 is removed, a p-type semiconductor impurity doping channel 203 and an n-type semiconductor impurity doping channel 204 are interdigitated with each other on the back surface of the n- .

As described above, the line-shaped finger portions of each impurity doping channel can be formed to be spaced apart from each other by an amount corresponding to the formation thickness of the etching resistant film without overlapping each other.

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

The channel shielding film may be attached in a form capable of blocking the channel top and the outside according to the embodiment. However, in order to simplify the process, the channel shielding film may be collectively attached to the entire substrate in one embodiment.

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

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

The impurity ink may be injected through a comb-shaped channel in which both ends of a channel, which is a central axis to which a finger portion is connected, are connected to the outside.

FIG. 16 illustrates the removal of the channel shielding film 206 in accordance with an embodiment of the present invention, and shows a rear portion of the substrate of FIG. The rear surface of the substrate of FIG. 16 is subjected to a heat treatment process to introduce the respective impurities into the substrate.

17 shows that the p-type impurity ink 207 and the n-type impurity ink 208 diffuse into the substrate through the 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 type solar cell.

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

Referring to FIG. 18, an etching resistant film is formed on the rear surface of a semiconductor silicon substrate by patterning (S01).

Next, the front surface of the substrate is textured by immersing the substrate in an etching solution, and a portion of the rear surface of the substrate where the etching resistant film is not formed is etched as an impurity doping channel of a first conductive type or a second conductive type (S02).

Then, the etching resistant film is removed and the substrate is cleaned (S03).

The entire surface of the substrate is formed with an oxide film such as silicon oxide by a method such as a plasma chemical vapor deposition method or a chemical vapor deposition method (S04).

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

The silicon-based high-temperature portion is attached to the back surface of the substrate on which the channel of the hydrophilic-treated surface is formed (S06).

The silicon-based rubber is not attached, and the first conductive type or the second conductive type semiconductor impurity is injected through the side end portion of the channel connected to the outside (S07).

The semiconductor impurity is an ink-like mixed liquid containing water as a solvent as described above.

Then, the silicone rubber is removed (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 to the rear surface of the semiconductor substrate in the shape of a channel to form an emitter layer and a BSF layer respectively (S10).

Next, BSG, PSG, etc., which are diffusion byproducts that may be generated in the heat treatment diffusion process of impurities, are removed, and the 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 elements.

Although the present invention has been described in connection with the specific embodiments of the present invention, it is to be understood that the present invention is not limited thereto. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. 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 illustrating a process of a method of manufacturing a back electrode type solar cell according to an embodiment of the present invention.

10 to 17 are rear views of a substrate showing a process of a method of manufacturing a back electrode type solar cell according to an embodiment of the present invention.

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

DESCRIPTION OF THE REFERENCE NUMERALS OF THE DRAWINGS FIG.

101, 201: first conductivity type semiconductor substrate 102, 202: etching resistant film

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

104, 204: semiconductor impurity doping channel of the first conductivity type

105: oxide film 106, 206: channel shielding film

107, 207: second conductivity type semiconductor impurity

108, 208: first conductivity type semiconductor impurity

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

Claims (22)

delete A method of manufacturing a rear electrode type solar cell including an emitter layer and a BSF layer on a rear surface of a semiconductor substrate, Forming a first conductivity type semiconductor impurity doping channel and a second conductivity type semiconductor impurity doping channel apart from each other on a rear surface of the first conductivity type semiconductor substrate; Injecting a first conductive semiconductor impurity and a second conductive semiconductor impurity through the impurity doping channel of the first conductive type and the impurity doping channel of the second conductive type, respectively; And Forming a BSF layer and an emitter layer by diffusing the semiconductor impurities of the first conductivity type and the semiconductor impurities of the second conductivity type into the semiconductor substrate by heat treating the semiconductor impurities, A channel shielding film which is detachably attachable to the rear surface of the semiconductor substrate is formed before the step of implanting the semiconductor impurities of the first conductivity type and the semiconductor impurity of the second conductivity type, The method of claim 1, further comprising the step of: 3. The method of claim 2, Wherein the first conductive type semiconductor impurity doping channel and the second conductive type semiconductor impurity doping channel are formed by etching the substrate. 3. The method of claim 2, Wherein the first conductive type semiconductor impurity doping channel and the second conductive type semiconductor impurity doping channel are formed at the same time as texturing the front surface of the substrate. 3. The method of claim 2, And forming an oxide film on the entire surface of the semiconductor substrate after forming the first conductive type semiconductor impurity doping channel and the second conductive type semiconductor impurity doping channel, Way. delete 3. The method of claim 2, Wherein the first conductivity type semiconductor substrate is a p-type silicon substrate, the first conductivity type semiconductor impurity is a p-type impurity, and the second conductivity type semiconductor impurity is an n-type impurity. ≪ / RTI > 3. The method of claim 2, Wherein the first conductivity type semiconductor substrate is an n-type silicon substrate, the first conductivity type semiconductor impurity is an n-type impurity, and the second conductivity type semiconductor impurity is a p-type impurity. ≪ / RTI > 9. The method according to claim 7 or 8, Wherein the p-type impurity is a mixture of a compound containing any one element selected from the group III elements consisting of boron (B), aluminum (Al), gallium (Ga) Type solar cell. 9. The method according to claim 7 or 8, Wherein the n-type impurity is a mixture of a compound including any one element selected from the group 5 elements consisting of phosphorus (P), arsenic (As) and antimony (Sb) and water. Gt; 3. The method of claim 2, Wherein forming the first conductive semiconductor impurity doping channel and the second conductive semiconductor impurity doping channel comprises: Forming an etching resistant film on the rear surface of the first conductivity type semiconductor substrate by patterning; Etching a rear surface of the semiconductor substrate on which the etch stop layer is not formed to form a first conductive type semiconductor impurity doping channel and a second conductive type semiconductor impurity doped channel spaced apart by the etch stop layer; And And removing the etching resistive film. A method of manufacturing a rear electrode type solar cell, 3. The method of claim 2, Further comprising the step of forming a semiconductor impurity doping channel of the first conductivity type and a semiconductor impurity doping channel of the second conductivity type and then treating the surface of the impurity doping channel with a hydrophilic property, A method of manufacturing a solar cell. 3. The method of claim 2, The channel shielding layer may be formed of at least one selected from the group consisting of polydimethylsiloxane (PDMS), silicone rubber, polybutadiene, nitrile rubber, acrylic rubber, butyl rubber, Wherein the polymer layer is at least one polymer film selected from the group consisting of polyisoprene, poly (styrene-co-butadiene), and polystyrene-butadiene copolymer. 3. The method of claim 2, Further comprising the step of removing the impurity diffusion by-products generated on the rear surface of the substrate after the step of forming the BSF layer and the emitter layer, respectively. delete delete delete delete delete delete delete delete

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