FR2935840A1 - Liquid phase semi-conductor material mold for realizing e.g. semi-conductor material plates of photovoltaic cells, has support part covered with superficial layer, where free surface of layer is structured along predetermined motif - Google Patents

Abstract

The mold (1) has a support part (3) covered with a superficial layer (4), where the support part consists of ceramic and/or metallic materials, where the ceramic material is chosen from alumina, zirconia, yttrium-doped zirconia and mullite, and the metallic material is chosen from zirconium . A free surface (2) of the superficial layer is in contact with liquid phase semi-conductor material i.e. silicon, and is structured along a predetermined motif. An independent claim is also included for a method for realizing a mold.

Description

Mold for semiconductor material in liquid phase and method of manufacturing such a mold.

TECHNICAL FIELD OF THE INVENTION The invention relates to a mold for semiconductor material in the liquid phase, formed of a support part coated with a surface layer and advantageously used to make wafers or ribbons of semiconductor material, for photovoltaic cells. The invention also relates to a method for manufacturing a mold for semiconductor material in the liquid phase. State of the art

Currently, photovoltaic cells are mainly made from monocrystalline silicon or polycrystalline silicon. In particular, in recent years, we have witnessed the emergence of so-called liquid processing techniques, that is to say from silicon in the liquid phase. The implementation of these techniques requires the use of a support for the crystallization of silicon when the silicon in the liquid phase is brought into contact with the support. Such techniques make it possible in particular to obtain wafers or ribbons, directly usable for the manufacture of photovoltaic cells. The support must also, according to the technique used, have particular characteristics.

By way of example, silicon wafers may be made by pulling techniques using a moving support contacted with a liquid silicon bath to form on at least one of the faces 2

said support, a silicon ribbon. Such a support, although not necessarily having a hollow impression, can be likened to a mold insofar as the silicon ribbon, in solidifying, takes the form of at least one of the faces of said support.

Among the known drawing techniques, mention may be made, for example, of the horizontal drawing method also known as RGS (Ribbon Growth on Substrate) and mentioned in patent US4670096. In US4670096, a silicon ribbon is obtained by solidification of a liquid semiconductor applied to a horizontal support with a chassis set in motion in a direction parallel to the support. The support may, in particular, be constituted by graphite plates of different densities, possibly covered by suitable coatings, for example silicon nitride or silicon carbide. Other support plates made of silicon carbide and silicon nitride or of ceramic materials containing oxides can also be adapted. The frame may be of silicon carbide, silicon nitride or graphite and may be coated or impregnated with a liquid before being pyrolyzed.

As a pulling technique, the RAD (Ribbon Against Drop) method may also be mentioned. This process, described in the article Growth of silicon ribbons by C. Belouet's RAD process (Journal of Crystal Growth 82 (1987) 110-116), consists of crystallizing a silicon film by vertically pulling a support (also called ribbon ) passing through a bath of molten silicon. Such a support is, for example, a flexible graphite sheet with a thickness of 200 to 300 m, coated with layers of pyrocarbon 2 to 5 m thick. The support, at the exit of the silicon bath, is then coated with silicon on both sides.

With these drawing techniques carried out using a support, the support must have good wettability vis-à-vis the semiconductor material in liquid phase to be crystallized, so that the film made of semi-conductive material

driver obtained is stable morphologically. This is why the support generally comprises coatings, such as pyrolytic layers. For example, in the article Substrate development for the growth of silicon foils by ramp assisted foil casting technique (RAFT) (Journal of Crystal Growth 104 (1990) 113-118), A. Beck et al. In particular, the wettability behavior and the detachment / separation aptitude of several supports that can be used in a so-called RAFT printing process were used to produce silicon wafers that can be used directly in a process for producing photovoltaic cells. The best results are obtained for a graphite support coated with a pyrolitic carbon film. Indeed, according to A. Beck et al., The carbon is converted into silicon carbide when the film is brought into contact with the liquid silicon, which leads to good wettability.

The silicon wafers can also be made by molding techniques, i.e. by filling a silicon mold in the liquid phase. In this case, unlike pulling techniques, the mold does not necessarily need to have a surface having good wettability vis-à-vis silicon in the liquid phase. On the other hand, the solidified platelets must be removed from the mold without adhesion. Thus, the mold may advantageously comprise a non-adherent deposit vis-à-vis the solid phase silicon. I. Hide et al., In the article Mold shaping silicon crystal growth with a molding coating material by the spinning method (Journal of Growth 79 (1986) 583-589), for example, propose a mold formed of graphite covered with a first layer of silicon nitride and a second layer of silicon nitride and silicon oxide.

Furthermore, once the wafers or the ribbons are produced by drawing or molding, the production of the photovoltaic cells generally requires a difficult step to implement and expensive, consisting of texturing one of the surfaces of the wafers or ribbons, in order to that photovoltaic cells capture the maximum incident photons. Such a 4

texturing has, for example, been mentioned in the patent application WO-A-2006/067051, without however being precisely described. This patent application describes the production of a silicon ribbon by the so-called RST (silicon ribbon on temporary carbon substrate) pulling technique, according to which once the silicon ribbon has solidified on the surface of a carbon support, this one is burned. Once the carbon substrate is burned, the front face of the silicon ribbon may optionally be textured so as to increase the efficiency of the cells.

Object of the invention

The invention aims to provide a mold for semiconductor material in the liquid phase having good mechanical and thermal resistance while being cheap. More particularly, the invention aims to provide a mold for simplifying the manufacture of wafers or ribbons of semiconductor material and more generally photovoltaic cells, while being reducing their manufacturing cost.

According to the invention, this object is achieved by a mold for semiconductor material in the liquid phase, formed of a support part coated with a surface layer, characterized in that the support part consists of at least one ceramic material and / or a metallic material and in that the free surface of the surface layer, intended to be brought into contact with the semiconductor material in the liquid phase, is structured in a predetermined pattern.

According to a development of the invention, the ceramic material is chosen from alumina, zirconia, yttria and mullite. According to another development of the invention, the metallic material is chosen from nobium and zirconium. In addition, the surface layer is advantageously constituted by a material that is wettable with respect to the semiconductor material in the liquid phase. or by non-stick material to the solid phase semiconductor material.

Advantageously, the surface of the support piece, in contact with the surface layer, is also structured according to said predetermined pattern and in that the surface layer is of constant thickness. The invention also aims a method for producing a mold for semiconductor material in the liquid phase, easy to implement and low price.

According to the invention, this object is achieved by the fact that the support piece is formed by structuring a main surface of a polymer film according to the predetermined pattern, using a matrix of semiconductor material. provided with a pattern complementary to said predetermined pattern and then debinding and sintering of the polymer film, said polymer film being loaded with at least 50% by volume of particles of ceramic material and / or metal material.

BRIEF DESCRIPTION OF THE DRAWINGS Other advantages and features will become more clearly apparent from the following description of particular embodiments of the invention given by way of nonlimiting example and represented in the accompanying drawings, in which: FIG. 1 represents, schematically and in section, a particular embodiment of a mold according to the invention.

FIGS. 2 to 6 show, schematically and in section, different stages of a manufacturing process of the mold according to FIG. 1. FIGS. 7 to 11 show, schematically and in section, a variant embodiment of a manufacturing process of FIG. a mold according to the invention.

Description of particular embodiments

FIG. 1 represents a particular embodiment of a mold 1 intended to receive silicon in the liquid phase on at least one of its faces 2. The mold 1 is, in particular, intended to be used for producing, by a technique or by a molding technique, silicon wafers or ribbons, themselves intended for use in a method of manufacturing photovoltaic cells. The pulling and molding techniques can be of any known type. By way of example, among the known pulling techniques, mention may be made of RGS, RAFT, RST and RAD type pulling techniques, whereas techniques for making silicon wafers by molding include the technique described by I. Hide et al., in the article Mold shaping silicon crystal growth with a molding coating material by the spinning method (Journal of Growth 79 (1986) 583-589).

The face 2 of the mold 1, intended to receive the liquid silicon, is furthermore structured so as to allow direct obtaining of silicon wafers and ribbons with a textured surface in a pattern suitable for trapping light. Unlike platelets and ribbons obtained with molds according to the prior art, the textured surface of the silicon wafers and ribbons is thus obtained directly by replication in the liquid phase of the face 2 of the mold 1, which facilitates the production textured silicon wafers and ribbons. 7

The mold 1 comprises a support piece 3 ensuring the mechanical and thermal strength of the mold 1 during its subsequent use. In particular, the support piece 3 makes it possible to obtain a mold which is resistant to high temperatures, in particular at a temperature of between 1410 ° C. (silicon melting temperature) and 1550 ° C., having excellent hardness and good scratch resistance. The support piece 3 is thus made of at least one ceramic material and / or a metallic material. It can therefore be formed: by at least one ceramic material, advantageously chosen from alumina, zirconia, yttria and zirconia mullite. by at least one metallic material, advantageously chosen from nobium and zirconium.

The support piece could also consist of a mixture of at least one ceramic material and at least one metallic material.

These materials not only meet the requirements of good mechanical and thermal strength of the mold 1, but they also make it possible to obtain a mold 1 which is inexpensive and may possibly be for single use.

Thus, silicon wafers or ribbons can be made using a cheap mold for each wafer or ribbon. The detachment / detachment of the wafer or ribbon may possibly cause at least partial destruction of the mold. However, the cost caused by the possible loss of the mold is largely offset by the gain in speed and ease to perform the detachment / detachment operation of the wafer or ribbon and by the fact of achieving the texturing of the wafer or ribbon along with his training.

Furthermore, the mold 1 also comprises a surface layer 4 adapted to be brought into contact with the silicon in the liquid phase and covering at least one main surface 3a of the support part 3. Thus, the material 8

forming the surface layer 4 is chosen according to the use of the mold 1 and, in particular, the technique used to make the wafers or the silicon ribbons. Advantageously, the surface layer 4 is constituted: by a wettable material vis-à-vis the silicon in the liquid phase, when the mold is used in a process using a pulling technique - and by a non-stick material vis-à-vis -vis solid phase silicon when the mold is used in a process using a molding technique.

Silicone-wettable materials in the liquid phase include compounds based on carbon or carbon compounds, preferably having a carbon content of greater than 99%, such as, for example, pyrocarbon.

As non-adherent material vis-à-vis the solid phase silicon, there may be mentioned silicon nitride.

Finally, the free surface of the sacrificial layer 4 corresponds to the structured face 2 of the mold 1.

In FIG. 1, the surface 3a of the support piece 3, in contact with the surface layer 4, is structured in a predetermined pattern having a shape complementary to that desired for the pattern texturing the surface of the silicon wafers or ribbons. In addition, the surface layer 4 is of constant thickness. The thickness of the surface layer 4 is advantageously between 10 nm and 2 μm, and preferably between 20 nm and 200 nm, for a surface layer 4 constituted by a wettable material vis-à-vis silicon in the liquid phase. . The thickness of a surface layer 4 made of a non-adherent material with respect to silicon in phase 9

solid is advantageously between 5 m and 500 m and preferably between 20 m and 2001um.

Thus, since the surface layer 4 is of constant thickness, its free surface 5, forming the face 2 of the mold 1 and intended to be brought into contact with the liquid silicon, is also structured in the same pattern as the surface 3a of the support piece 3.

The predetermined pattern is, advantageously, formed of a plurality of zones ~ o in relief having a section that can be square, rectangular, hexagonal, triangular or circular. In Figure 1, the raised areas have a triangular section and they form pyramids.

As represented in FIGS. 2 to 6, the mold 1 represented in FIG. 1 can advantageously be made using a die 5 such as that represented in FIG. 2. The function of the die 5 is to form the structured face 2 of the mold 1.

The die 5, also called the master or master element, has a free surface 5a structured in a particular pattern. Said pattern of the surface 5a corresponds, in particular, to the desired pattern for the surface of the silicon wafers or ribbons. The pattern therefore has a shape complementary to that of the face 2 of the mold 1.

The matrix 5 is generally nickel. It can also be silicon. The surface 5a of the matrix 5 can be obtained by any type of process. It is, for example, obtained by a lithography process conventionally used in the field of microelectronics. In particular, the surface 5a can be obtained by etching through a mask made with a photosensitive resin previously insolated and developed.

As represented in FIGS. 2 to 6, the matrix 5 is, for example, used to structure by co-embossing a bilayer 6. Thus, the matrix 5 is lowered towards the bilayer 6 as represented by the direction of the arrows F1 in FIG. 3, then after allowing structuring of the bilayer 6, the matrix 5 is raised as illustrated by the direction of the arrows F2 in FIG.

The bilayer 6 comprises a polymer film 7 for forming the support member and an additional polymer film 8 for forming the sacrificial layer. The films 7 and 8 present, more particularly, before the co-embossing step, substantially planar surfaces, which the matrix 5 will allow to structure according to the desired pattern for the face 2 of the mold 1. By co-embossing, one means the simultaneous embossing of the film 7 and the film 8.

The polymer film 7 is, in particular, made of a polymer loaded with at least 50% by volume of particles of the ceramic material and / or the metallic material forming the support part 3. The additional polymer film 8 is, for its part composed of a polymer loaded with at least 50% by volume of particles of the material constituting the surface layer 4. Advantageously, the polymer films 7 and 8 each comprise up to 80% by volume of particles. On the other hand, the additional polymer film 8 has, in FIG. 3, a constant thickness.

Polymeric films 7 and 8 are, for example, formed by a band-casting process also known as tape-casting Anglo-Saxon. In addition, the polymers forming films 7 and 8, respectively, may be identical or different. By way of example, they are chosen from: polyolefin-type polymers, such as polyethylene or polypropylene, polymethyl methacrylate or PMMA, polyamide (6,6), polystyrene, and rubber.

The fact of using polymer films 7 and 8 to make the mold 1 makes it possible to shape the support piece and the surface layer easier and at a lower cost.

As shown in FIGS. 3 and 4, the free surface 5a of the matrix 5 is brought into contact with the free surface 8a of the additional polymer film 8, 10 in order to structure said surface 8a in a pattern complementary to that of the surface 5a of the matrix. Similarly, as shown in FIG. 4, the surface 7a of the polymer film 7, in contact with the additional polymer film 8, is also structured during co-embossing, in the same pattern as the surface 8a. The co-embossing step is then followed by a debinding step of the bilayer 6, previously arranged on a support 9. The debinding step thus makes it possible to remove both the polymer from the film 7 as well as that of the additional film 8. In particular, the polymers of the films 7 and 8 are removed by heat treatment at a temperature of between about 300 ° C and about 500 ° C. The removal of the polymers constituting the films 7 and 8 is illustrated by the arrows F3 in FIG.

Thus, as illustrated in FIG. 5, the debinding of the bilayer 6 (arrows F3) makes it possible to eliminate the polymers encapsulating the particles respectively loading the films 7 and 8. The debinding operation thus makes it possible to transform the two films 7 and 8 in two bunk beds of particles 10 and 11, free of polymer. The two beds 10 and 11 have, in addition, a shape substantially identical to that of the films 7 and 8, but their dimensions are, however, slightly reduced compared with those of the initial films 7 and 8. This reduction depends on the rate of particles initially contained in each film. After the debinding step has been performed, the superimposed particle beds 10 and 11 undergo an annealing step to make the support piece as dense as possible. The annealing makes it possible, in fact, to bind the particles of each bed 10 and 11 between them and to sinter the particles of the bed 10 between them. The composite structure thus obtained comprises the support part 3 covered by the surface layer 4. The sintering of the particles of the bed 10 advantageously allows, according to the size of the particles and according to the sintering temperature, to obtain a fusion of a part particles. The annealing is advantageously carried out at a temperature of between about 1500 ° C. and about 2000 ° C. depending on the material and the initial particle size. In addition, the annealing is advantageously carried out in a passage oven. In general, the annealing is carried out in the same furnace as that used during the debinding step, so as not to have to handle the assembly constituted by the particle beds 10 and 11, which is very fragile.

An embodiment such as that embodied in FIGS. 2 to 6 is, in particular, suitable for producing molds intended to be used for producing silicon wafers by the molding technique. By way of example, a mold, which is particularly suitable for producing silicon wafers by a molding technique, is produced using a silicon matrix 5 having a surface 5a structured with pyramidal patterns having a width of 10. m and a height of 10 m. The matrix 5 is used to co-emboss, at ambient temperature, a bilayer 6 comprising: a polymer film 7, made of polypropylene, 1 mm thick and containing 80% by volume of alumina particles having a mean size of the order of 100 nm - and an additional polymer film 8, also polypropylene, 50 m thick and containing 80% by volume of silicon nitride particles having an average size of about 500 nm. The step of co-embossing the bilayer 6 is followed by a debinding step in a resistive furnace, at 400 ° C., for 12 hours in order to evacuate the debinding residue. The co-embossing step is followed by an annealing step at 1700 ° C. under air, for 2 hours in a resistive passage oven.

In the embodiment shown in FIGS. 2 to 6, the surface layer 4 of the mold 1 is formed with the aid of an additional polymer film 8. However, in certain cases, the surface layer 4 can be directly deposited on the 3a surface of the support part 3, once it formed. Thus, in an alternative embodiment shown in FIGS. 7 to 11, the matrix 5 such as that represented in FIG. 2 is used to emboss a single polymer film 7 capable of forming, after debinding and sintering, the support piece 3. The polymer film 7 is loaded with particles of ceramic material and / or metal. Arrows F1 and F2 show the application of the surface 5a to the free surface 7a of the polymer film 7, in order to structure it in a pattern complementary to the pattern of the surface 5a of the matrix 5.

The polymer film 7 is then placed on a support 9 to be delaminated as shown by the arrows F3 in FIG. 9. The bed of particles 10 obtained after debinding is then sintered in order to obtain cohesion between the particles. of ceramic material and / or metal, which allows to form the support part 3 as shown in Figure 10.

The surface layer 4 is then deposited on at least the structured surface 3a of the support part 3, in order to form a mold 12. The deposit 30 is advantageously designed so that the surface layer 4 has a constant thickness. Thus, the free surface of the surface layer, forming the face 2 of the mold 12 intended to be in contact with the silicon in phase 14

liquid, is structured in the same pattern as that of the main surface 3a of the support piece 3, obtained during the embossing operation. In FIG. 11, the surface layer 4 covers not only the main surface 3a of the support piece 3 but also its lateral faces 13.

The deposition of the surface layer 4 can be carried out by any type of method making it possible to obtain a layer of constant thickness. This is, for example, deposited by cracking at 1000 ° C of a mixture comprising 10% by volume of methane and 90% by volume of argon.

Such an embodiment is, in particular, suitable for producing molds intended to be used for producing silicon ribbons by the pulling technique. The surface layer 4 is advantageously constituted by pyrocarbon, which allows, by reaction with the liquid silicon, to form a layer of silicon carbide. Thus, when using the mold, the silicon carbide layer has a very good wettability with respect to the liquid silicon, which allows good replication of the textured patterns of the mold.

Such a method has the advantage of being able to control the thickness of the deposited pyrocarbon surface layer, which makes it possible to determine and thus control the thickness of the layer of silicon carbide formed during the contacting of the face 2 of the mold 12 with silicon in the liquid phase. However, this thickness plays an important role in the phenomena of detachment of the silicon ribbons. It is therefore advantageous to be able to control this thickness upstream and independently of the other parameters of the mold making process. Furthermore, the layer formed of silicon carbide acts as a barrier to the diffusion of impurities from the support part, in particular aluminum when the support part 3 is made of alumina. By way of example, a mold, in particular adapted to produce silicon ribbons by a pulling technique, is produced using a matrix 5

silicon having a surface 5a structured with pyramidal patterns having a width of 10 m and a height of 10 m. The matrix 5 is used to emboss, at ambient temperature, a polypropylene polymer film 7 containing 80% by volume of alumina particles having an average size of the order of 100 nm. The embossing step of the polymer film 7 is followed by a debinding step at 400 ° C., for 12 hours, in air, in a resistive passage oven. Then, the delaminated film undergoes an annealing step at 1700 ° C under air, for 2 hours in the same oven. A pyrolytic or pyrolytic carbon surface layer 4 is then deposited on the support piece 3. This pyrolytic deposit is, for example, carried out by pyrolysis of an organic precursor according to a process used in the metallurgical and glass industries to lubricate the surfaces. of mold.

Processes such as those represented in FIGS. 2 to 6 and 7 to 11 make it possible, in particular, to easily and inexpensively manufacture liquid phase silicon molds, which can be used in processes for manufacturing silicon-textured wafers and wafers for photovoltaic applications. Furthermore, the structuring of the molds is facilitated by the use of at least one polymer film and therefore by the use of techniques from the field of plastics.

Other techniques than embossing can be used for shaping one or more polymer films. Thus, the mixture injection molding technique also known by the Anglo-Saxon name of Powder Injection Molding can also be used. In this case, the polymer film intended to form the support part is produced by injection under pressure in a silicon matrix of a mixture, called master batch, containing the particles intended to form the polymer of said film and the particles of the material constituting the support piece. The matrix then contains an imprint whose shape of the pattern is complementary to that of the

determined pattern for the mold. As in the embodiment shown in FIGS. 2 to 6, the surface layer 4 can also be made using an additional polymer film 8 also formed by injection molding of a mixture. It can also be performed by direct deposition on the support part 3, once it is produced by injection molding mixture.

Such methods make it possible very easily and reproducibly in the mold to produce patterns of great complexity and great fineness. Indeed, the resolution of the patterns in the silicon matrix can go down to 50nm, which makes it possible to replicate many times very fine details to make molds. Thus, as the molds can be manufactured at a very low cost and easily, they can be disposable. Thus, in a method of manufacturing by pulling a silicon ribbon, it will be possible to remove by etching the carbide adhering to the ribbon of the sacrificial layer, which will facilitate the detachment.

In some cases, a mold according to the invention can also be produced according to an alternative manufacturing method, not requiring going through the production of at least one polymer film. In this case, the support piece may be formed by an embossed metal foil on which is formed the pyrocarbon deposit.

Without departing from the scope of the present invention, the mold may be intended to receive, in the place of silicon in the liquid phase, other semiconductor materials in the liquid phase, insofar as these materials can be obtained in the form of platelets. or ribbons by molding or drawing techniques for the purpose of making photovoltaic cells. In addition, the matrix 5 may also be constituted by a metallic material such as nickel. It is, however, advantageously made of the same semiconductor material as that for which the mold is intended.

Claims (16)

Revendications1. Mold (1, 12) for semiconductor material in liquid phase, formed of a support piece (3) coated with a surface layer (4), characterized in that the support piece (3) consists of at least one ceramic material and / or a metallic material and in that the free surface (2) of the surface layer (3), intended to be brought into contact with the semiconductor material in the liquid phase, is structured in a pattern predetermined. 2. Mold (1, 12) according to claim 1, characterized in that the ceramic material is selected from alumina, zirconia, yttria zirconia and mullite. 3. Mold (1, 12) according to one of claims 1 and 2, characterized in that the metallic material is selected from nobium and zirconium 4. Mold (1, 12) according to any one of claims 1 to 3, characterized in that the surface layer (4) is constituted by a material wettable vis-à-vis the semiconductor material in the liquid phase. 5. Mold (1, 12) according to claim 4, characterized in that the wettable material vis-à-vis the semiconductor material in the liquid phase is a carbon compound. 6. Mold (1, 12) according to any one of claims 1 to 3, characterized in that the surface layer (4) is formed by a non-stick material vis-à-vis the semiconductor material in phase 30 solid. 1715 18 7. Mold (1, 12) according to claim 6, characterized in that the non-adherent material vis-à-vis the solid phase semiconductor material is silicon nitride. 8. Mold (1, 12) according to any one of claims 1 to 7, characterized in that the semiconductor material is silicon. 9. Mold (1, 12) according to any one of claims 1 to 8, characterized in that the predetermined pattern is formed of a plurality of ~ o raised areas having a square, rectangular, hexagonal, triangular or circular section . 10. Mold (1, 12) according to any one of claims 1 to 9, characterized in that the surface (3a) of the support piece (3), in contact with the surface layer (4), is structured according to said predetermined pattern and in that the surface layer (4) is of constant thickness. 11. Process for producing a mold (1, 12) according to claim 10, characterized in that the support piece (3) is formed by structuring a main surface (7a) of a polymer film (7) according to the predetermined pattern with the aid of a matrix (5) provided with a pattern complementary to said predetermined pattern and then, by debinding and sintering of the polymer film (7), said polymer film (7) being loaded with at least 50% by volume of particles of ceramic material and / or made of metallic material. 12. Process according to claim 11, characterized in that the structuring of the main surface (7a) of the polymer film (7) is carried out by embossing using the matrix (5). 30 13. Process according to claim 11, characterized in that the structuring of the main surface (7a) of the polymer film (7) is carried out during the formation of said polymer film (7) by injection molding of a mixture comprising the particles of ceramic material and / or metal. 14. Method according to any one of claims 11 to 13, characterized in that the surface layer (4) is made from an additional polymer film (8), loaded with at least 50% by volume of particles of material wettable vis-à-vis the semiconductor material in liquid phase or non-stick material vis-a-vis the semiconductor material in solid phase and deposited on the main surface (7a) of the polymer film (7) before the structuring of the main surface (7a) of said polymer film (7). 15. Method according to any one of claims 11 to 13, characterized in that the surface layer (4) is deposited on the main surface (3a) of the support member (3) after sintering. 16. Use of a mold (1, 12) according to any one of claims 1 to 10, for producing a wafer or a ribbon of semiconductor material having a structured face according to the predetermined pattern.