WO2015025510A1

WO2015025510A1 - Photoelectric conversion element and method for manufacturing photoelectric conversion element

Info

Publication number: WO2015025510A1
Application number: PCT/JP2014/004208
Authority: WO
Inventors: 訓裕川本; 克也岡部
Original assignee: 三洋電機株式会社
Priority date: 2013-08-21
Filing date: 2014-08-18
Publication date: 2015-02-26

Abstract

　A photoelectric conversion element (10) provided with a substrate (12) and a film formation layer (13) deposited on the surface of the substrate (12), the film formation layer (13) having, on a peripheral edge part, at least one cutout part (14) on which no deposition takes place. The film formation layer (13) is formed using a photoelectric conversion element film formation mask having an opening defining a film formation region and having at least one substrate-holding protrusion protruding from the peripheral edge part of the opening towards the inside of the opening. The cutout part (14) is formed at a position on the photoelectric conversion element film formation mask corresponding to the position of the substrate-holding protrusion.

Description

Photoelectric conversion element and method for producing photoelectric conversion element

The present invention relates to a photoelectric conversion element that forms a film using a mask.

For example, Patent Document 1 relates to the manufacture of an organic EL element, but a vapor deposition method is adopted for forming an organic layer and a metal electrode. In vapor deposition, openings corresponding to predetermined patterns required for each layer are used. It is stated that a vapor deposition mask with a part is used.

JP 2003-157974 A

In the film formation of the photoelectric conversion element, it is necessary to make the photoelectric conversion area as wide as possible while ensuring the overlap between the substrate and the mask for pressing the substrate with the mask.

The photoelectric conversion element according to the present invention includes a substrate and a film-forming layer deposited on the substrate, the film-forming layer having at least one notch that is not deposited on the periphery.

A method for manufacturing a photoelectric conversion element according to the present invention includes a step of preparing a substrate to be formed, and a step of preparing a mask having an opening that defines a film formation region, from the periphery of the opening to the opening. Preparing a mask having at least one substrate pressing projection protruding toward the inside of the substrate, positioning the mask opening portion so as to face the film-forming surface of the substrate, and forming the mask on the substrate through the mask opening portion. A film layer is formed.

According to the present invention, it is possible to widen the photoelectric conversion possible region while ensuring the overlap between the substrate and the mask.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the photoelectric conversion element of embodiment of this invention, (a) is a top view, (b) is sectional drawing, (c) is an enlarged view of (b). It is a top view which shows the positional relationship between the board | substrate and mask in embodiment of this invention. It is an enlarged view of the part of C of FIG. (A) is a top view, (b) is sectional drawing. It is a figure explaining the effect of embodiment of this invention using the relationship between the photoelectric conversion element and mask of embodiment of this invention. In the photoelectric conversion element of embodiment of this invention, it is a figure which shows the example of the arrangement position and number of the notch part of a film-forming layer.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The materials, thicknesses, dimensions, arrangement positions and numbers of notches or protrusions described below are examples for explanation, and can be appropriately changed without departing from the gist of the present invention. In the following, corresponding elements in all drawings are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a diagram showing a photoelectric conversion element 10. The main surface of the photoelectric conversion element 10 includes a light receiving surface and a back surface. (A) is a plan view viewed from the light receiving surface side, and (b) is a light receiving surface side above the paper surface and a back surface side below the paper surface. (C) is an enlarged view of (b).

The photoelectric conversion element 10 generates photogenerated carriers of holes and electrons by receiving light such as sunlight. The photoelectric conversion element 10 includes a substrate 12 and a plurality of film formation layers 13 that are sequentially stacked thereon. The film-forming layer 13 is formed by depositing a predetermined thin film in a film-forming region smaller than the outer shape of the substrate 12, and has a notch 14 on the periphery of which the predetermined thin film is not deposited. In FIG. 1, three

notches

14 _C , 14 _L , and 14 _R are shown. Details of the notch 14 will be described later.

The substrate 12 is crystalline silicon (c-Si). In addition to crystalline silicon, a semiconductor material such as gallium arsenide (GaAs) or indium phosphorus (InP) can be used.

The film forming layer 13 is a thin film layer that has the substrate 12 and the photoelectric conversion element 10 in a broad pn junction structure. As a pn junction structure in a broad sense, a heterojunction of crystalline silicon and amorphous silicon can be used. For example, assuming that the substrate 12 is an n-type single crystal silicon substrate, a p-type film formation layer 13 is formed on the light receiving surface side of the substrate 12, and an n-type film formation layer 15 is formed on the back surface side.

On the light-receiving surface side of the n-type single crystal silicon substrate, which is the substrate 12, the film-forming layer 13 on the light-receiving surface side is a p-type amorphous material doped with i-type amorphous silicon layer 16, boron (B) and the like. It is obtained by sequentially laminating a silicon layer 17 and a transparent conductive film (TCO) 18 composed of a light-transmitting conductive oxide of indium oxide (In ₂ O ₃ ).

The film-forming layer 15 on the back surface side is formed on the back surface side of the n-type single crystal silicon substrate, which is the substrate 12, and on the light-receiving surface side of the n-type single crystal silicon substrate, which is the substrate 12, It is obtained by laminating an n-type amorphous silicon layer 20 doped with phosphorus (P) or the like and a transparent conductive film 21.

The photoelectric conversion element 10 may have a structure other than this as long as it has a function of converting light such as sunlight into electricity. For example, the substrate 12 may be a p-type polycrystalline silicon substrate, an n-type diffusion layer may be formed on the light receiving surface side, and an aluminum metal film may be formed on the back surface side.

Next, the notch 14 will be described in detail with reference to FIG. The notch portion 14 is derived from a substrate pressing projection provided on a mask used for forming the

film forming layers

13 and 15 on the substrate 12, and the substrate 12 is covered with the portion of the substrate pressing projection so that the substrate 12 is a place where a predetermined thin film is not deposited.

FIG. 2 is a diagram showing positioning between the substrate 12 and the mask, and FIG. 3 is an enlarged view thereof. FIG. 4 is a diagram illustrating the operation of the substrate pressing protrusion provided on the mask.

First step of the method for manufacturing the photoelectric conversion element 10 is a step of preparing the substrate 12. Here, an n-type single crystal silicon substrate is prepared as the substrate 12. The prepared substrate 12 is positioned and arranged on the tray 22 of the film forming apparatus. The tray 22 is shown in FIG. An appropriate jig can be used for positioning and fixing the substrate 12 to the tray 22. Hereinafter, a procedure for forming the film formation layer 13 on the light receiving surface side of the substrate 12 will be described unless otherwise specified. However, the film formation layer 15 can be formed on the back surface side of the substrate 12 by the same procedure.

Next, a predetermined metal mask is positioned and arranged on the substrate 12 as the mask 30. This procedure will be described separately for the process of preparing the mask 30 and the process of positioning and arranging the prepared mask 30 on the light receiving surface side of the substrate 12.

The step of preparing the mask 30 is a step of preparing a mask having an opening that defines a film formation region, and has at least one substrate pressing protrusion protruding from the peripheral edge of the opening toward the inside of the opening. This is a step of preparing a mask. The mask 30 is a film forming mask.

As shown in FIG. 2, the mask 30 has an opening 32 surrounded by a frame 31 on four sides. The opening 32 is a window for defining a film forming region on the substrate 12 within this range when a predetermined thin film is deposited in the next film forming process. The four corners of the opening 32 have an oblique shape 33, but this corresponds to the case where the four corners of the substrate 12 have an oblique shape, and is not necessarily required.

The mask 30 has a substrate pressing protrusion 34 that protrudes from the peripheral edge of the opening 32 toward the inside of the opening 32. In the example of FIG. 2, “the peripheral edge of the opening 32” is the inner edge of the frame 31. “Toward the inside of the opening 32” means not in the direction of the recess that cuts out the frame 31, but in the direction in which the inner edge of the frame 31 protrudes. In the example of FIG. 2, the substrate pressing protrusion 34 is provided on the frame 31 on the upper side of the paper toward the lower side of the paper. In this case, the direction toward the lower side of the paper surface is the direction toward the inside of the opening 32. Substrate holding projections 34, along the longitudinal direction of the frame portion 31, the substrate holding protrusion 34 _C is provided at the center thereof, a substrate holding protrusion 34 _L on the left side, the substrate holding projections 34 on the right Each _R is provided. The protrusion amount of the substrate pressing protrusion 34 is shown as D1.

As such a mask 30, a material obtained by processing an appropriate material into a predetermined shape can be used. As a suitable material, a metal material can be used, for example, stainless steel can be used. As the predetermined shape, as shown in FIG. 2, a plurality of substrates 12 may have a shape having a number of openings 32 corresponding to the number of the substrates. Instead of this, the shape having one opening 32 may be used as one mask 30 for one substrate 12.

The step of positioning and arranging the prepared mask 30 on the light receiving surface side of the substrate 12 is performed such that the overlap in the plan view of the substrate 12 and the mask 30 is the same size along the peripheral edge of the substrate 12. Be placed. In FIG. 2, the peripheral edge of the substrate 12 is covered with the mask 30, and this is indicated by a broken line. The overlapping of the substrate 12 and the mask 30 has the same size along the peripheral edge of the substrate 12. The tip of the substrate pressing projection 34 is the innermost edge of the peripheral edge of the mask 30 and the four sides of the frame portion 31 are the same. It means the same. In FIG. 3, the magnitude of this overlap is shown as D2.

As shown in FIG. 3, in the frame portion 31 provided with the substrate pressing projection 34, the peripheral portion of the frame portion 31 recedes outside except for the protruding portion of the substrate pressing projection 34, and only the corresponding region 35 is obtained. The opening area of the opening 32 increases. Since the opening area corresponds to the photoelectric conversion possible area in the photoelectric conversion element 10, the photoelectric conversion possible area is expanded by the area of the expanded area 35. The shape of the substrate pressing projection 34 can be a semicircular shape having a sufficiently small diameter compared to the length L of one side of the opening 32. Therefore, the area of the expanded region 35 is a value close to {(length L of one side of the opening 32) × (projection amount D1 of the substrate pressing projection 34)}.

As described above, by providing the substrate pressing projection 34 having a sufficiently small dimension compared to the length L of one side of the opening 32, the substrate pressing projection 34 spreads while ensuring the overlap between the substrate 12 and the mask 30. The photoelectric conversion possible region can be made wider by the area of the region 35.

After the positioning of the substrate 12 and the mask 30 is completed, a film forming process is performed next. The film forming process is performed using a predetermined film forming apparatus. For example, a CVD (first chamber in which an i-type amorphous silicon layer 16 is deposited, a second chamber in which a p-type amorphous silicon layer 17 is deposited, and a third chamber in which a transparent conductive film 18 is deposited. (Chemical Vapor Deposition) apparatus can be used.

When a CVD apparatus having three chambers is used, a tray 22 on which a set in which the substrate 12 and the mask 30 are combined is mounted on the tray 22 in a predetermined film formation order using the first chamber, the second chamber, and the third chamber. Then, the predetermined film formation layer 13 is formed by sequentially conveying the film. It is preferable to provide a separation chamber between the chambers so that i-type, p-type, etc. are not mixed. As the tray 22, a horizontal tray in which the substrate 12 and the mask 30 are arranged in the horizontal direction can be used. Instead, a vertical tray in which the substrate 12 and the mask 30 are arranged in parallel to the vertical direction may be used.

When the film forming process for the film forming layer 13 on the light receiving surface side of the substrate 12 is completed, the mask 30 is removed from the substrate 12. At this time, in the film forming layer 13 formed on the light receiving surface side of the substrate 12, a notched portion 14 that has not been formed is formed corresponding to the substrate pressing protrusion 34. Although the photoelectric conversion area is narrowed by the area of the notch 14, the shape of the notch 14 is the same as the shape of the substrate pressing protrusion 34, which is sufficiently larger than the length L of one side of the film formation layer 13. Semicircular with a small diameter. Notch amount = projection amount = D1. Therefore, the photoelectric conversion possible area is enlarged by a value close to {(length L of one side of the film formation layer 13) × (notch amount D1 of the notch portion 14)}.

The film forming process is performed on the film forming layer 15 on the back side of the substrate 12 with the same processing contents. The photoelectric conversion element 10 is obtained by completing these film forming processes (S14).

FIG. 5 shows a state where the photoelectric conversion possible area is enlarged without providing the substrate pressing projection 34. Here, it is assumed that the size of the overlap between the substrate 12 and the mask 30 is (D2-D1) without providing the substrate pressing projection 34. When the overlap size is (D2−D1) compared to the case where the overlap size is D2, the enlargement amount of the photoelectric conversion possible area is {(length L of one side of the opening 32) × (substrate presser). The protrusion amount D1)} of the protrusion 34.

FIG. 5A shows an initial state in which the substrate 12 and the mask 30 are positioned. The initial state is room temperature. (B) shows a state in which the film formation process has been performed and the temperature has increased. The mask 30 is made of stainless steel, and the substrate 12 is single crystal silicon. The linear expansion coefficient of stainless steel and the linear expansion coefficient of single crystal silicon are considerably different, and stainless steel has a larger linear expansion coefficient than single crystal silicon.

In FIG. 4A in the room temperature state, the size of the overlap between the substrate 12 and the mask 30 is (D2-D1), so that the substrate 12 is not detached from the mask 30. In the case of FIG. 5A in a high temperature state, the substrate 12 having a small linear expansion coefficient is hardly deformed, but the mask 30 having a large linear expansion coefficient is deformed according to the temperature. For example, when the mask 30 is deformed in a floating direction with respect to the substrate 12, the size of the overlap between the substrate 12 and the mask 30 becomes smaller than (D2-D1). When the size of the overlap becomes zero, the substrate 12 is brought into a free state from the state of being pressed by the mask 30. In particular, when the vertical tray is used, the substrate 12 may be detached from the mask 30. .

Thus, when the peripheral edge of the frame 31 is simply retracted outward in order to increase the photoelectric conversion possible area, the size of the overlap is reduced. For example, the size of the overlap is (D2-D1), and the substrate 12 may be detached from the mask 30 at a high temperature. On the other hand, when the substrate pressing projection 34 is provided, the substrate pressing projection 34 can ensure the overlap between the substrate 12 and the mask 30, and the substrate 12 is prevented from being detached from the mask 30 even at high temperatures. Further, by providing the substrate pressing protrusion 34 having a sufficiently small size compared to the length L of one side of the opening 32, the photoelectric conversion possible region can be further widened.

The notch portion 14 is derived from the substrate pressing projection 34 of the mask 30, but the portion where the substrate 12 and the mask 30 are likely to come off from the mask 30 due to a decrease in temperature due to a rise in temperature is located on the frame portion 31 of the mask 30. It is a central part in the extending direction. Therefore, it is preferable to provide the substrate pressing protrusions 34 _C first, and if necessary, the

substrate pressing protrusions

34 _L and 34 _R on the left and right sides thereof. Even if the substrate pressing projection 34 is provided after providing the substrate pressing projection 34 necessary to prevent the substrate 12 from being removed from the mask 30, the dimension of the substrate pressing projection 34 is the same as that of the opening 32. Since it is sufficiently smaller than the length L of one side, the photoelectric conversion possible region hardly changes.

Therefore, the number of the substrate pressing protrusions 34 or the arrangement position along the peripheral edge is set in accordance with the scheduled film formation history of the film formation layer 13, so that the number of the notches 14 in the film formation layer 13 or The arrangement position along the peripheral edge corresponds to the film formation history of the film formation layer 13. Since the notch 14 formed in the film forming layer 13 is an identifiable mark, it can be used as a tracking mark for the film forming process state.

FIG. 5 is a diagram illustrating an example of the arrangement position and the number of notches in the film formation layer 13. Figure 5 (a) (d) is an example of the upper side of the film formation layer 13 is provided a notch 14, in (a) is provided only notch 14 _C, and the notch portion 14 _C in (b) A notch 14 _R is provided, (c) is provided with a notch 14 _L and a notch 14 _C , and (d) is provided with a notch 14 _L , a notch 14 _C, and a notch 14 _R. Here, if only the notch 14 _C is sufficient to prevent the substrate 12 from being removed from the mask 30, the four types of states can be distinguished by the presence or absence of the notch 14 _{L and} the presence or absence of the notch 14 _R. .

That is, the presence or absence of the cutout portions 14 _L shown in 1 and 0 1bit th, the presence of notch 14 _L 1 of the second bit and when to be indicated by 0, FIG. 6 (a), the state (00) , (B) shows the state of (01), (c) shows the state of (10), and (d) shows the state of (11). By using the distinction between the four states, it is possible to indicate the kind of the film formation layer, the distinction between the film formation apparatuses, the substrate arrangement position in the film formation apparatus, the film formation date and time, and the like.

For example, when there are four types of film forming apparatuses, the four types can be distinguished using the first bit and the second bit. In addition, four types of films, i-type amorphous silicon layers 16 and 19, p-type amorphous silicon layer 17, n-type amorphous silicon layer 20, and transparent

conductive films

18 and 21, are set in the first bit. Can be distinguished using two of the second bit. Alternatively, the first bit can be assigned to distinguish between two types of film forming apparatuses, and the second bit can be assigned to distinguish the substrate arrangement in the film forming apparatus. Also, four types of film formation dates and times can be distinguished by using two of the first bit and the second bit.

FIGS. 5E to 5H are diagrams illustrating an example in which the notch portion 14 is provided on a side other than the upper side of the film formation layer 13. In (e), notches 14 are provided on the upper side and lower side of the film-forming layer 13, and (f) is provided with notches 14 on the upper side and the left side of the film-forming layer 13. Cutouts 14 are provided on the upper left side of the film formation layer 13, and cutouts 14 are provided on the upper side, lower side, left side, and right side of the film formation layer 13 in (h). By providing the notches 14 on the sides other than the upper side of the film formation layer 13 in this way, a much larger number of bits is set as compared with the fact that the four states can be distinguished in FIGS. Is possible.

In the above description, it is assumed that the substrate pressing projection 34 is provided at a position common to a plurality of thin film layers to be stacked, and the notch 14 is formed at a position common to the plurality of thin film layers stacked corresponding thereto. . Instead of this, the arrangement position of the substrate pressing projection 34 may be changed for each thin film, and the cutout portion 14 may be formed at a different position for each thin film correspondingly.

Thus, by appropriately setting the number and arrangement position of the substrate pressing protrusions 34, the overlapping of the substrate 12 and the mask 30 for pressing the substrate 12 with the mask 30 is ensured, the photoelectric conversion possible area is expanded, The film forming history of the film forming process can be traced using the notch 14 of the film forming layer 13 corresponding to the substrate pressing protrusion 34.

DESCRIPTION OF SYMBOLS 10 Photoelectric conversion element, 12 Substrate, 13, 15 Film-forming layer, 14, 14 _C , 14 _L , 14 _R notch, 16, 19 i-type amorphous silicon layer, 17 p-type amorphous silicon layer, 18, 21 transparent conductive film, 20 n-type amorphous silicon layer, 22 tray, 30 mask, 31 frame, 32 opening, 33 oblique shape, 34, 34 _C , 34 _L , 34 _R protrusion, 35 region.

Claims

A substrate,
A film-forming layer deposited on the substrate, the film-forming layer having at least one notch that is not deposited on the periphery;
A photoelectric conversion element comprising:
The photoelectric conversion element according to claim 1,
The number of the cutout portions or the arrangement position along the peripheral portion is a photoelectric conversion element that is set according to the film formation history of the film formation layer.
The photoelectric conversion element according to claim 2,
The number of notches or the arrangement position along the peripheral edge is set based on at least one of the types of film formation layers, the film formation apparatus, the substrate arrangement position in the film formation apparatus, and the film formation date and time. Photoelectric conversion element.
The photoelectric conversion element according to claim 1,
The notch is a photoelectric conversion element provided in the film formation layer on the light receiving surface side.
The photoelectric conversion element according to claim 1,
The photoelectric conversion element, wherein the substrate is a single crystal silicon substrate, and the film formation layer is at least one of an amorphous silicon layer, a transparent conductive film layer, and a passivation layer.
Preparing a substrate to be deposited; and
A step of preparing a mask having an opening that defines a film formation region, the step of preparing a mask having at least one substrate pressing protrusion protruding from the peripheral edge of the opening toward the inside of the opening;
Positioned and positioned with the opening of the mask facing the deposition side surface of the substrate,
A method for manufacturing a photoelectric conversion element, wherein a film formation layer is formed on a substrate through an opening of a mask.
In the manufacturing method of the photoelectric conversion element of Claim 6,
The method for manufacturing a photoelectric conversion element, wherein the mask has at least one pressing projection whose number or arrangement position along the peripheral edge is set according to a deposition schedule history of the deposition layer.