SUBSTRATE SUPPORT TRAY FOR DEPOSITTING MATERIAL ON THE EDGES OF ONE SIDE OF THE SUBSTRATE

Abstract

A platform (100) configured to support at least one substrate (106) during the deposition of material (112) onto the substrate, comprising at least: - a solid holding surface (102) on which a principal face of the substrate is intended to be placed during deposition, and whose dimensions are smaller than those of the principal face of the substrate so that edges (105) of the principal face of the substrate are not in contact with the solid holding surface; - connecting elements (104) forming arms mechanically linking the solid holding surface to a frame (108) of the platform. Figure 2 for abbreviations.

Description

Title of the invention: SUBSTRATE SUPPORT TRAY FOR DEPOSITING MATERIAL ON EDGES OF A FACE OF THE SUBSTRATE Technical field

[0001] The invention relates to the field of material deposition, in particular for the production of photovoltaic cells. The invention applies in particular to the production of photovoltaic cells with passivated contacts, and in particular to the deposition of thin layers at the edge of substrates with the aim of maximizing lateral transport and optical confinement of charges. State of the prior art

[0002] A photovoltaic cell is made from a semiconductor substrate, or wafer, on which thin layers are deposited. There are many types of trays used to support the substrates to make these deposits.

[0003] When a deposition must be carried out on both sides (front and rear faces) of the substrate, for example in PVD (physical vapor deposition) equipment, a so-called "open" tray, i.e. forming access to a part of the face of the substrate located on the side of the tray, is used. On such a tray, the substrate is generally held at the edges of the substrate. Such a tray is for example described in document WO 2019 / 219127 AL

[0004] Document DE 10 2020 101 264 A1 also describes an “open” tray comprising, in addition to a portion supporting the edges of the substrate, a central support element masking a separation line between two portions of the substrate. Such a tray is suitable for producing cells intended to be cut at the separation line, to obtain half-cells.

[0005] These “open” trays are however not suitable when a material must be deposited on the edges of one face of the substrate. Statement of the invention

[0006] An aim of the present invention is to propose a support or holding plate for at least one substrate making it possible to deposit material on the edges of one face of the substrate without covering the rest of this face with this material.

[0007] For this, the present invention proposes a tray configured to support at least one substrate during a deposition of material on the substrate, comprising at least:

[0008] - a solid holding surface on which a main face of the substrate is intended to be arranged during deposition, and whose dimensions are smaller than those of the main face of the substrate so that the edges of the main face of the substrate are not in contact with the solid holding surface;

[0009] - connecting elements forming arms mechanically connecting the surface of full support to a frame, or chassis, of the tray.

[0010] When depositing material on the substrate held in such a tray, it is therefore possible to locate the deposited material against the edges of the main face of the substrate which is on the side of the solid holding surface, without covering the rest of this main face of the substrate with material.

[0011] The term “substrate” designates a plate, or wafer, of material, for example of semiconductor such as silicon, on which one or more elements have been possibly deposited (thin layers, metal contacts, etc.).

[0012] Such a plate is advantageously used to deposit an anti-reflective coating, or more generally one or more thin layers of material(s), on the edges of a silicon wafer intended to form a photovoltaic cell.

[0013] The solid holding surface may have a square shape, and the connecting elements may extend from corners of the solid holding surface and / or from sides of the solid holding surface.

[0014] The connecting elements may have a thickness greater than that of the solid holding surface and may form, on the side of the solid holding surface on which the substrate is intended to be arranged, raised portions. Such raised portions make it possible to guide and hold the substrate in a position centered on the solid holding surface.

[0015] The raised parts of the connecting elements can be removable. Thus, it is possible to modify the shape and / or dimensions of these raised parts depending on the dimensions of the substrate held by the plate.

[0016] The tray may be configured to hold a plurality of substrates during deposition of material onto the substrates, and may include a plurality of solid holding surfaces spaced apart from each other and mechanically held to each other and to the frame by the connecting members that join together, and the solid holding surfaces that are adjacent to the frame may be directly held to the frame by a portion of the connecting members.

[0017] The invention also relates to a method for depositing material on edges of one face of at least one substrate, comprising at least:

[0018] - arrangement of the substrate on a tray as described above;

[0019] - placing the tray in a deposition chamber of deposition equipment;

[0020] - deposition of the material on the edges of the main face of the substrate which are not in contact with the solid holding surface.

[0021] The deposition equipment can be of the PVD, PECVD or ALD type.

[0022] The invention also relates to a method for producing at least one cell photovoltaic, comprising the implementation of a deposition process as described above.

[0023] Throughout the document, the term "on" is used without distinction of the orientation in space of the element to which this term relates. For example, in the characteristic "on a face of the substrate", this face of the substrate is not necessarily oriented upwards but can correspond to a face oriented in any direction. Furthermore, the arrangement of a first element on a second element must be understood as being able to correspond to the arrangement of the first element directly against the second element, without any intermediate element between the first and second elements, or as being able to correspond to the arrangement of the first element on the second element with one or more intermediate elements arranged between the first and second elements. Brief description of the drawings

[0024] The present invention will be better understood on reading the description of exemplary embodiments given purely for informational purposes and in no way limiting, with reference to the appended drawings in which:

[0025] [Fig. 1], and

[0026] [Fig.2] represent a tray configured to support at least one substrate during a deposition of material on the substrate, object of the present invention, according to a first embodiment;

[0027] [Fig.3] represents a profile view of a substrate arranged on a solid holding surface of a tray, object of the present invention;

[0028] [Fig.4], and

[0029] [Fig.5] represent a tray configured to support at least one substrate during a deposition of material on the substrate, object of the present invention, according to a second embodiment;

[0030] [Fig.6]

[0031] [Fig.7], and

[0032] [Fig.8] represent different examples of embodiments of connecting elements of a tray, object of the present invention.

[0033] Identical, similar or equivalent parts of the different figures described below bear the same numerical references so as to facilitate the transition from one figure to another.

[0034] The different parts represented in the figures are not necessarily on a uniform scale, in order to make the figures more readable.

[0035] The different possibilities (variants and embodiments) must be understood as not being mutually exclusive and can be combined with each other.

[0036] Detailed description of particular embodiments

[0037] A tray 100, configured to support at least one substrate during a deposition of material on the substrate, according to a first embodiment is described below in connection with Figures 1 and 2. [Fig.l] represents a top view of a solid holding surface 102 and connecting elements 104 of the tray 100 according to the first embodiment. [Fig.2] represents a top view of a part of the tray 100 according to the first embodiment.

[0038] The tray 100 is configured to hold, or support, at least one substrate during a deposition of material on the substrate. In the exemplary embodiment described here, the tray 100 is configured to simultaneously hold several substrates in order to collectively deposit a material on edges 105 of a face of each of these substrates. In [Fig. 2], one of the substrates subjected to the deposition process and arranged on the tray 100 is shown and is designated by the reference 106.

[0039] The plate 100 therefore comprises several solid holding surfaces 102 on each of which a main face of one of the substrates 106 is intended to be arranged during the implementation of the deposition. The dimensions of the surfaces 102 are smaller than those of this main face of the substrate 106 so that edges 105 of said main face of the substrate 106 are not in contact with the surface 102. These edges 105 can form, in a plane parallel to said main face of the substrate 106, a contour of width less than or equal to 500 μm, and advantageously between 100 μm and 500 μm.

[0040] The number of holding surfaces 102 of the plate 100 is a function of the dimensions of the plate 100 and the dimensions of each of the surfaces 102 (and therefore the dimensions of the substrates 106). For example, the number of holding surfaces 102 of the plate 100 may be between 4 and 48.

[0041] The plate 100 is for example made mainly of stainless steel or titanium.

[0042] The plate 100 also comprises connecting elements 104 forming arms mechanically connecting each of the surfaces 102 to a frame 108 of the plate 100, either directly for the holding surfaces 102 which are adjacent to the frame 108, or via other holding surfaces 102 and other connecting elements 104 for the holding surfaces 102 which are not adjacent to the frame 108. In the example shown in [Fig. 2], five of the holding surfaces 102 shown are adjacent to the frame 108 and are mechanically connected to it via connecting elements 104, and one of the holding surfaces 102 (the one on which the substrate 106 is shown) is not adjacent to the frame 108 and is mechanically connected to it via the other holding surfaces 102 and other connecting elements 104. At the intersection of the connecting elements, it is possible to provide more rigid elements in order to limit or eliminate the me- deformations canics linked to the weight of the surfaces 102 and the substrates 106.

[0043] Thus, the plate 100 comprises, in this exemplary embodiment, several solid holding surfaces 102 spaced from each other and mechanically held to each other and to the frame 108 by the connecting elements 104 which join together.

[0044] In the embodiment shown in Figures 1 and 2, each of the holding surfaces 102 has a square shape, and the connecting elements extend from four corners 110 of the holding surface 102.

[0045] In order to minimize the surface area of ​​the substrate(s) 106 which will be masked by the connecting elements 104 during the deposition of material, the width (denoted “a” in [Fig.l]) of the connecting elements 104 is chosen to be as small as possible, while ensuring that this width is sufficient to have sufficient mechanical support for the surface(s) 102 and the substrate(s) 106 arranged thereon.

[0046] The plate 100 is used in particular when implementing a method for depositing material on the edges 105 of one face of at least one substrate 106, the method comprising at least the implementation of the following steps:

[0047] - arrangement of the substrate 106 on the plate 100;

[0048] - placing the tray 100 in a deposition chamber of a deposition equipment for example PVD, PECVD or ALD type;

[0049] - deposition of the material(s) on the edges 105 of the main face of the substrate 106 which are not in contact with the surface 102.

[0050] The plate 100 is advantageously used to deposit one or more materials on substrates 106 intended to form photovoltaic cells, for example of the passivated contact type. The substrate 106 may in particular correspond to a silicon wafer, and the material deposited on the edges 105 of the substrate 106 may in particular correspond to an anti-reflective material, or more generally one or more thin layers of material(s).

[0051] [Fig. 3] represents a profile view of the substrate 106 arranged on the surface 102 during the implementation of the deposition of material on the edges 105 of the substrate 106. The arrows bearing the reference 112 represent the material to be deposited on the edges 105 and sent towards the main face of the substrate 106 arranged against the surface 102 and which includes the edges 105.

[0052] A substrate holding tray 100 according to a second embodiment is described below in connection with Figures 4 and 5. [Fig. 4] represents a top view of a solid holding surface 102 and connecting elements 104 of the tray 100 according to the second embodiment. [Fig. 5] represents a top view of a portion of the tray 100 according to the second embodiment.

[0053] Compared to the first embodiment previously described, the connecting elements 104 extend from sides 114 of the solid holding surface. The others characteristics of the tray 100 according to this second embodiment are similar to those previously described for the first embodiment.

[0054] Whatever the configuration of the plate 100 (first or second embodiment or other), the connecting elements 104 advantageously have a thickness greater than that of the surface 102 and form, on the side of the surface 102 on which the substrate 106 is intended to be arranged, raised parts 116. Thus, the connecting elements 104 allow good centering of the substrate 106 on the surface 102, both by guiding the substrate 106 when the substrate 106 is arranged on the surface 102, and also by maintaining this substrate 106 in its position centered on the surface 102 when the plate 100 is moved.

[0055] [Fig. 6] represents three examples of embodiments of such connecting elements 104 comprising raised parts 116. The profile of these raised parts 116 is for example of pyramidal, truncated pyramidal, rectangular, polygonal shape, or of any other shape.

[0056] The shape of the connecting elements 104, and in particular of the raised parts 116, can in particular be chosen as a function of the size of the substrate(s) 106. [Fig. 7] represents three exemplary embodiments of connecting elements 104 whose raised parts 116 have different shapes and dimensions adapted for substrates 106 of different dimensions. For a space of given dimensions, the dimensions of the raised parts 116 of the connecting elements 104 can thus be larger when the substrates 106 are smaller.

[0057] Whatever the shape and dimensions of the connecting elements 104, the raised portions 116 of the connecting elements 104 may be removable. Thus, it is possible to choose these raised portions 116 as a function of the shape and / or dimensions of the substrate(s) 106 on which the deposition is carried out. By taking the exemplary embodiments shown in [Fig. 7], it is possible to choose, as a function of the dimensions of the substrates 106, the raised portions 116 whose dimensions best match those of the substrates 106.

[0058] [Fig. 8] represents an exemplary embodiment of such a connecting element 104 comprising a removable raised portion 116 which is fixed to a fixed portion 118 of the connecting element 104 by a holding element 120 passing through the fixed portion 118. Other types of fixing of the raised portions 116 to the fixed portions 118 of the connecting elements 104 can be envisaged.

Claims

Claims

1. Tray (100) configured to support at least one substrate (106) during a deposition of material (112) on the substrate (106), comprising at least: - a solid holding surface (102) against which a main face of the substrate (106) is intended to be arranged during the deposition, and the dimensions of which are smaller than those of the main face of the substrate (106) so that edges (105) of the main face of the substrate (106) are not in contact with the solid holding surface (102); - a frame (108); - connecting elements (104) forming arms mechanically connecting the solid holding surface (102) to the frame (108) of the tray (100).

2. A tray (100) according to claim 1, wherein the solid holding surface (102) has a square shape, and wherein the connecting elements (104) extend from corners (110) of the solid holding surface (102) and / or from sides (114) of the solid holding surface (102).

3. Tray (100) according to one of the preceding claims, in which the connecting elements (104) have a thickness greater than that of the solid holding surface (102) and form, on the side of the solid holding surface (102) on which the substrate (106) is intended to be arranged, raised parts (116).

4. Tray (100) according to claim 3, wherein the raised portions (116) of the connecting elements (104) are removable.

5. A tray (100) according to any preceding claim, configured to hold a plurality of substrates (106) during deposition of material (112) onto the substrates (106), comprising a plurality of solid holding surfaces (102) spaced apart from each other and mechanically held to each other and to the frame (108) by the connecting elements (104) which join together, and wherein the solid holding surfaces (102) which are adjacent to the frame (108) are directly held to the frame (108) by a portion of the connecting elements (104).

6. Method for depositing material (112) on edges (105) of a face of at least one substrate (106), comprising at least: - arranging the substrate (106) on a plate (100) according to one of the preceding claims; - placing the tray (100) in a deposition chamber of deposition equipment; - depositing the material (112) on the edges (105) of the main face of the substrate (106) which are not in contact with the solid holding surface (102) of the tray (100).

7. A method according to claim 6, wherein the deposition equipment is of the PVD, PECVD or ALD type.

8. Method for producing at least one photovoltaic cell, comprises the implementation of a deposition method according to one of claims 6 or 7.

Images