Apparatus for deposition by reverse sublimation

Abstract

The invention relates to an apparatus (1) for depositing a layer made of a first material on a substrate (2) by the close-space sublimation technique, comprising: - an enclosure (10); - a first support (11) intended to carry a source sample (3); - a second support (12) intended to carry the substrate (2); and - heating means (13) configured to heat at least the source sample; the first support comprising: - a planar base (11a) comprising at least one opening (20); - a holding structure (11b) which is secured to the base and runs along the perimeter of the base (11a); - a planar cover (11c) intended to engage in the holding structure (11b) so as to encapsulate the source sample (3) in a cavity (11d) delimited by the base (11a), the holding structure (11b) and the cover (11c).

Description

DESCRIPTION Apparatus for reverse sublimation deposition

[0001] The present invention relates to the field of manufacturing electronic and optoelectronic devices for photovoltaic conversion and the detection of radiation such as photons in the visible spectrum, IR, X-rays, gamma rays, alpha and beta charged particles, and neutrons. More particularly, the invention relates to a device for depositing thin films onto a substrate by closed-space sublimation.

[0002] Closed-Space Sublimation (CSS) involves heating a source sample of the material to be deposited under vacuum to a temperature sufficient to induce sublimation, while placing a substrate in front of this source sample, typically at a distance of 0.1 mm to 10 mm. The process takes place in a closed chamber where the pressure is maintained at low values, typically less than or equal to 10 Pa. The deposition temperature is determined by the saturated vapor pressure of the material to be sublimated and remains below the melting temperature of the source sample. In this system, the substrate can also be heated, but to a temperature lower than that of the source sample to allow the sublimated material from the source sample to condense onto the substrate surface and thus form a layer.

[0003] To better understand the technical problem solved by the invention, Figure 1 illustrates a diagram of a D0 sublimation deposition apparatus in the near space according to the state of the art.

[0004] The deposition apparatus D0 comprises: a chamber 10, a first support 11' for receiving the source sample 3, a second support 12' for holding the substrate 2, heating means 13' for heating the first support 11', and a pumping system 40 for reducing the pressure in the chamber to a predetermined pressure P10. The chamber 10 is closed and airtight so as to create, under the action of the pumping system 40, an enclosed space within it having a pressure P10 less than or equal to 10 Pa. The first support 11' and the second support 12' are arranged opposite each other along the Z-direction inside the chamber 10 with a separation distance d1 between 0.1 mm and 10 mm. The apparatus D0 further comprises spacers 31 positioned to maintain the two supports 11', 12' at the separation distance d1.The first support 11' on which the source sample 3 rests is located in the lower compartment of the chamber below the second support 12'. Conversely, the second support 12' to which the substrate 2 is fixed is located in the upper compartment of the chamber above the first support 11'. This arrangement is dictated by the nature of the source sample 3, which is in the form of a bed of powder or a compressed powder capsule. In contrast, substrate 2 is generally a solid disc that can be inverted to be attached to the second support 12'. Sublimation of the source sample allows for its progressive transformation from a solid to a gaseous phase. The particles of the material in gaseous form, indicated by arrows, move from bottom to top until they collide ballistically with the surface of the cooler substrate 2, leading to their condensation and the formation of layer C1.

[0005] When substrate 2 has a large surface area (greater than 10 cm x 10 cm), it flexes at its center under the effect of its own weight and the deposit on it. This flexing of substrate 2 increases the distance between its rear face and the underside of the second support 12', thus reducing the thermal coupling between the two elements. This reduced thermal coupling leads to temperature variations across the substrate surface, resulting in a non-uniform distribution of the deposit on substrate 2. Furthermore, the flexing of substrate 2 can mechanically weaken its structure and damage the components embedded on it.

[0006] A technical problem to be solved in this field is therefore to design a deposition device using the "sublimation in close space" technique without the deflection of the substrate fixed to the second support in order to improve the reliability of the substrate and the homogeneity of the deposition.

[0007] To overcome the limitations of existing solutions, the invention proposes several embodiments of an improved near-space sublimation deposition apparatus in which the substrate support is positioned below the source sample support. The substrate rests on its support, and the risk of deflection due to its own weight is eliminated. The source sample support is adapted to the new configuration according to the invention, allowing the source sample to be encapsulated while guiding the sublimated material gases towards the substrate positioned in the lower compartment of the apparatus. The apparatus according to the invention makes it possible to achieve spatially homogeneous depositions on the substrate plane thanks to the various embodiments of the invention, and more particularly of the source sample support.

[0008] The invention relates to an apparatus for depositing a layer of a first material onto a substrate using the near-space sublimation technique, comprising: - an enclosure; - a first support intended to hold a source sample of the first material and placed inside the enclosure; - a second support intended to carry the substrate and placed inside the enclosure opposite the first support at a predetermined separation distance; - heating means configured to heat at least the source sample to a predetermined temperature to sublimate the first material; the first support comprising: - a planar base extending along a first plane; the base comprising at least one opening having an axis orthogonal to the first plane; - a solid support structure at the base which runs along the perimeter of the base; - a planar hood that extends parallel to the foreground; the hood being intended to engage in the holding structure so as to encapsulate the source sample in a cavity delimited by the base, the holding structure and the hood.

[0009] According to a particular aspect of the invention, the volume of the cavity adjusts with revolution of the volume of the source sample during deposition.

[0010] According to a particular aspect of the invention, the first support is placed below the second support.

[0011] According to a particular aspect of the invention, the base comprises a plurality of identical openings forming a matrix; each opening having an axis orthogonal to the foreground.

[0012] According to a particular aspect of the invention, each opening of the matrix has a diameter that decreases linearly with the depth of the opening.

[0013] According to a particular aspect of the invention, each opening in the matrix is ​​formed by a first hole having a first diameter and a second hole having a second diameter smaller than the first diameter. The first hole opens into the second hole.

[0014] According to a particular aspect of the invention, the hood is made of a thermally conductive material.

[0015] According to a particular aspect of the invention, the support structure is made of a thermally insulating material.

[0016] According to a particular aspect of the invention, the support structure is made of a material that is transparent or reflective to infrared radiation; and in which the hood is made of a material that absorbs infrared radiation; and in which the heating means are made of infrared lamps.

[0017] According to a particular aspect of the invention, the base is made of a thermally conductive and electrically conductive material; the heating means include an electrical circuit configured to inject an electric current through the base.

[0018] According to a particular aspect of the invention, the hood includes a receiving orifice connecting the cavity to a reservoir via a conduit; the reservoir being intended to contain particles of the first material in a solid or liquid form; the heating means are further configured to heat the reservoir to sublime the first material contained in the reservoir; the source sample encapsulated in the cavity being in a gaseous form.

[0019] Other features and advantages of the present invention will become more apparent from the following description in relation to the following attached drawings.

[0020] Figure 1 illustrates a diagram of a deposition apparatus according to the state of the art. This figure has already been described.

[0021] Figure 2a illustrates a diagram of a deposition apparatus according to the first embodiment of the invention.

[0022] Figure 2b illustrates a three-dimensional view of the source sample support of the deposition device according to the first embodiment of the invention.

[0023] Figure 3a illustrates a diagram of a deposition apparatus according to a second embodiment of the invention.

[0024] Figure 3b illustrates a three-dimensional view of the source sample support of the deposition device according to the second embodiment of the invention.

[0025] Figure 4 illustrates a close-up partial view of the substrate support of the deposition device according to a third embodiment of the invention.

[0026] Figure 5 illustrates a close-up partial view of the substrate support of the deposition device according to a fourth embodiment of the invention.

[0027] Figure 6 illustrates a diagram of a deposition apparatus according to the fifth embodiment of the invention.

[0028] In the figures illustrating the invention, the horizontal is represented by the X and Y directions of an orthogonal spatial coordinate system (X,Y,Z). The Z direction of this orthogonal coordinate system represents the vertical direction. Hereafter, terms such as "Upper," "lower," "above," "below," "top," and "bottom" are defined with respect to the Z vector, which is in the opposite direction to the Earth's gravitational force vector, g. More specifically, a first object "above" a second object has a height zi along the Z direction greater than the height Z2 of the second object. The terms "left" and "right" are defined with respect to the X direction. The terms "front" and "back" are defined with respect to the Y direction. Hereafter, the term "thickness" refers to the maximum thickness of an element along the Z direction.

[0029] Figure 2a illustrates a diagram of the deposition apparatus 1 according to a first embodiment of the invention. The deposition apparatus according to the invention is configured to deposit a layer onto a substrate 2 by the near-space sublimation technique from a source sample 3 of a first material which constitutes the layer deposited on the substrate 2.

[0030] The deposition apparatus 1 according to the invention comprises: a chamber 10, a first support 11 for receiving the source sample 3, a second support 12 for carrying the substrate 2, heating means 13 for heating the first support 11, a pumping system 40 for lowering the pressure in the chamber to a predetermined pressure P10.

[0031] The enclosure 10 is closed and airtight so as to create within it, under the action of the pumping system 40, a closed space having a pressure P10 less than or equal to 10 Pa. The enclosure can be a metal casing made of stainless steel or aluminum, for example, or a quartz tube. The first support 11 and the second support 12 are arranged opposite each other along the Z-direction inside the enclosure 10 with a separation distance d1 between 0.1 mm and 10 mm. The device 1 further includes spacers 31 positioned to maintain the two supports 11, 12 at the separation distance d1.

[0032] Unlike the prior art apparatus, the first support 11, which carries the source sample 3, is located in the upper compartment of the chamber, above the second support 12. Conversely, the second support 12, on which the substrate 2 rests, is located in the lower compartment of the chamber 10, below the first support 11. The substrate 2 thus rests on the second support 12, which holds said substrate with a reaction force to the weight of the substrate 2. This arrangement avoids the problem of substrate 2 deflection encountered in prior art CSS deposition apparatus. Conversely, the first support 11 carries the source sample 3 in the form of a compressed powder capsule by encapsulation of said capsule. According to the first embodiment of the invention, the first support 11 comprises three mechanical parts assembled together: a base 11a, a holding structure 11b, and a cover (11c).The base 11a is a planar mechanical part that extends along a plane P1 parallel to the (X,Y) plane when the first support 11 is mounted in the device 1 during a deposition operation. The retaining structure 11b is mechanically fixed to the base 11c. It is a structure that runs along the perimeter of the base 11a and extends along a second plane P2 that is not parallel to the first plane P1, preferably orthogonal to the first plane P1. The retaining structure 11b can be fixed to the base by inset, by mechanical fasteners such as screws, or by chemical fasteners such as adhesive or spot welds. The retaining structure 11b can be mechanically fitted into the base 11a, or conversely, the base 11a can be mechanically fitted into the retaining structure 11b. Alternatively, the support structure 11b and the base 11a are formed from a single machined mechanical part.The hood 11c is a planar structure that extends parallel to the first plane P1 when mounted to the base 11a via the support structure 11b. The hood 11c has smaller geometric dimensions than the base 11a. For example, if the base is a cylinder, its radius is greater than or equal to that of the hood. If the base is rectangular, its length is greater than or equal to that of the hood, and its width is greater than or equal to that of the hood.

[0033] The cap 11c engages with the retaining structure 11b to assemble with the base 11a, which is integral with this structure 11b. The assembly of the cap 11c with the retaining structure 11b is designed to form a cavity 11d for receiving the source sample 3. The cavity 11d is bounded above by the cap 11c, below by the base 11a, and laterally by the retaining structure 11b, and its volume is determined by the volume of the source sample 3. The source sample 3 is encapsulated in the cavity 11d with a lower face resting on the base 11a and an upper face bearing the cap 11c. When the volume of the source sample decreases during deposition, the height of the cap 11c bearing the source sample 3 decreases accordingly. Thus, the volume of the receiving cavity 11d adjusts with revolution of the volume of the source sample 3.

[0034] Advantageously, the hood 11c is inserted into the support structure 11b via lateral slides, thus ensuring its alignment and assembly with the base 11a fixed to this structure 11c without losing the autonomous adjustability of the volume of the cavity 11d according to the decrease in the volume of the source sample 3 during deposition.

[0035] The base 11a includes at least one aperture 20 having an axis A orthogonal to the plane of the base P1. The aperture 20 allows the sublimated and thus transformed source sample material to diffuse into the substrate 2. The diameter of the aperture 20 is chosen to retain the source sample 3 while allowing the vapor emanating from it to pass through. In the case of a solid source sample 3, the aperture 20 has a diameter smaller than the dimensions that define the surface area of ​​the source sample 3 (diameter for a cylindrical capsule, width and length for a parallelepiped-shaped source sample).

[0036] The base 11a allows the vapor from the sublimated source sample 3 to be diffused towards the substrate 2; the hood 3 allows the source sample to be encapsulated and the sublimation vapors to be confined in the cavity 11d so that they only escape in the desired direction; the support structure 11b allows the different parts of the first support 11 to be assembled and the hood 11c to be guided to obtain autonomous adjustment of the volume of the cavity 11d during deposition.

[0037] The heating means 13 are configured to heat the first support 11, in which the source sample 3 to be sublimated is housed, to a temperature that allows the material of the source sample 3 to sublimate at a predetermined rate and quantity. For example, for a cadmium telluride (CdTe) deposition, the heating temperature of the first support is 550°C. For a CsPbBra deposition, the heating temperature of the first support is 475°C. For example, the heating means 13 consist of a thermostat in physical contact with the hood 11c. Alternatively, the heating means 13 consist of heating lamps inside or outside the enclosure 10. Alternatively, the heating means 13 consist of resistors integrated into the first support 11 or an inductive system integrated into the first support 11.The first support 11 must be made of a material having a thermal conductivity greater than or equal to 10 W.nr. 1 .K' 1 and advantageously greater than 100 W.nr 1 .K' 1The material constituting the first support 11 must be chemically inert to the material constituting the source sample 3. For example, the first support 11 is made of copper, steel, or graphite. The temperature of the first support 11 is regulated using a thermocouple (not shown) or any other thermal control system. The thermal conductivity of the first support allows the source sample 3 to be heated to a predetermined temperature corresponding to a desired sublimation rate. This allows for a gradual transformation of the source sample from a solid to a gaseous phase. The particles of the material in gaseous form, indicated by arrows, move from top to bottom until they collide ballistically with the surface of the cooler substrate 2, leading to their condensation and the formation of layer C1.

[0038] According to one particular aspect of the invention, the heating means 13 are provided by infrared lamps that heat the first support 11. In this case, it is advantageous to use a hood 11c made of a thermally conductive material that absorbs the infrared radiation from the lamps, for example, graphite. It is also advantageous to use a base 11a made of a thermally conductive material and a support structure 11c made of a thermally insulating material and / or a material that is transparent or reflective to the infrared radiation from the lamp. This avoids excessive heating at the edges of the base 11a because the edges are well exposed to the radiation from the lamps, whereas the base 11a is obscured by the hood and the source sample.The use of a thermally insulating and / or transparent or infrared-reflective material for the peripheral support structure 11b at the base prevents overheating of the edges, thus resulting in a more homogeneous thermal profile of the base 11a. The edge-center thermal effect is eliminated. Consequently, the source sample 3 is not preferentially heated by the edges but rather uniformly across the plane, resulting in a more homogeneous deposition on the surface of the substrate 2. For example, the hood 11c is made of graphite or copper; the base 11a is made of graphite or copper, and the support structure is made of thermally insulating ceramic.

[0039] According to another particular aspect of the invention, the heating means 13 comprise an electrical circuit configured to inject an electric current through at least the base 11a. The electric current injected through the base 11a heats the latter by Joule heating. Alternatively, the injected current passes through resistive elements fixed on or in the base 11a for resistive heating of the base 11a. Alternatively, the injected current passes through inductive elements fixed on or in the base 11a for induction heating of the base 11a. Advantageously, the electrical circuit is also configured to inject a current through the hood for resistive or inductive heating. This allows for similar heating of the top and bottom of the source sample and thus avoids a vertical thermal gradient that could lead to the formation of cold spots and vapor condensation at the base 11a.

[0040] According to a particular aspect of the invention, the heating means 13 comprise on the one hand an electrical circuit configured to heat the base 11a by resistive or inductive heating and on the other hand infrared lamps which heat the hood 11c by radiation.

[0041] Sample source 3 is for example in a semiconductor material for optoelectronic and / or photovoltaic applications such as cadmium telluride (CdTe), cadmium selenide (CdSe), cadmium sulfide (CdS), cadmium mercury telluride (HgCdTe), zinc selenide (ZnSe), zinc sulfide (ZnS), gallium arsenide (GaAs), indium antimonide (InSb) and lead telluride (PbTe).

[0042] Alternatively, the source sample 3 is, for example, a semiconductor material having a perovskite-type crystal structure, which is in the form of a pressed powder capsule encapsulated in the first support 11. Perovskites represent an emerging solution for the realization of absorption and conversion structures in optoelectronic devices due to their promising optoelectronic properties. For the purposes of this description of the invention, a "perovskite layer" is understood to mean a layer made of a semiconductor material having a perovskite-type or perovskite-like crystal structure.

[0043] Perovskite advantageously has an ABX3 type composition, with: Selected from an initial set of elements: • inorganic cations such as cesium Cs, rubidium Rb, potassium K, sodium Na, or lithium Li; • organic cations such as MA (methylammonium) = CH3-NH3 + FA (formamidinium)=CH5N2 + , GA (guanidinium)=CHEN3 + ; EA (ethylammonium)=CH3CH2NH3 + ; DMA (dimethylammonium)=C2H6NH2 + ; AC (acetamidinium) = C2H3N2H4 + ; AZ (azetidinium)=C3HeNH2 + ; TBA (tetrabutylammonium) = C4HgNH3 + ; PYRI (pyridium) = C5H5NI; PYRO (pyrrolidium) = C4HsNH2 + ; isoP (iso-propylammonium)=C3H7NH3 + ; PIP (piperidium) = CSHIONH2 + • or an alloy of said elements from the first set of elements; B selected from a second group of elements among: • inorganic cations such as lead Pb, tin Sn, germanium Ge, silicon Si, Sr, Ba, Eu, Tm, Yb, Hg; • organic cations such as MDABCO=N-methyl-1,4-diazabicyclo[2.2.2]octane, ODABC=N-hydroxy-N'-diazabicyclo[2.2.2]octonium; • or an alloy of said elements from the second set of elements; X selected from a third set of elements among halogens such as bromine Br, iodine I, chlorine Cl, fluorine F or an alloy of said elements from the third set of elements.

[0044] Alternatively, perovskite has the formula A2C 1+ D 3+ Xe, with: A, X selected respectively from the first set of elements and the third set of elements; C was selected from a fourth group of elements among: • inorganic cations such as gold Au, silver Ag, copper Cu, thallium Tl, lithium Li; cesium Cs, sodium Na, rubidium Rb, potassium K; • or an alloy of said elements from the fourth set of elements; D selected from a fifth group of elements among: • inorganic cations such as gold Au, aluminium Al, gallium Ga, indium In, tin Sn, bismuth Bi, antimony Sb; • or an alloy of said elements from the fourth set of elements.

[0045] Alternatively, perovskite has the formula A2B 4+ Xeou A3B2 3+ Xgavec A, B, X selected respectively from the first set of elements, the second set of elements and the third set of elements.

[0046] Figure 2b illustrates an exploded three-dimensional view of the first support 11 of the source sample 3 of the deposition apparatus according to the first embodiment of the invention. The cover 11c is dimensioned so as to engage with the holding structure 11b and to encapsulate the source sample 3 when placed on the base 11a.

[0047] Figure 3a illustrates a diagram of a deposition apparatus 1 according to a second embodiment of the invention. The second embodiment retains the same technical characteristics and advantages detailed for the first embodiment. According to the second embodiment, the base 11a comprises a plurality of apertures 20 forming a matrix. The apertures 20 are preferably identical and periodic, which allows for a homogeneous spatial distribution of the vapor from the sublimated material to the substrate 2. For example, the apertures 20 have a diameter between 0.1 mm and 4 mm. The spacing between the apertures 20 is between a minimum value equal to the diameter of the aperture plus 0.1 mm and a maximum value equal to the diameter of the aperture plus 5 mm. Figure 3b illustrates an exploded three-dimensional view of the first support 11 of the source sample 3 of the deposition apparatus according to the second embodiment of the invention.

[0048] Figure 4 illustrates a close-up partial view of the sample holder of the deposition apparatus according to a third embodiment of the invention. The other elements of the apparatus 1 are not shown for the sake of simplicity. The third embodiment retains the same technical characteristics and advantages detailed for the preceding embodiments. According to the third embodiment, each opening 20 of the matrix is ​​formed by a first hole 20a and a second hole 20b. The first hole 20a extends from the upper face of the base 11a to the second hole 20b. The second hole 20b extends from the lower face of the base 11a to the first hole 20a. The upper face of the base 11a is the face from which the support structure 11b extends. The first hole 20a has a first diameter D1 greater than the diameter D2 of the second hole 20b.The diameter D1 of the first hole is between 3 mm and 10 mm, while the diameter D2 of the second hole 20b is between 0.1 mm and 3 mm. This particular aspect of the invention makes it possible to maintain a source sample 3 in powder form while allowing the diffusion of sublimated vapor towards the substrate 2. The maximum size of the second hole 11b is determined by the fluidity of the powder that constitutes the source sample 3. For example, for a CsPbBra powder, the diameter of the first holes 20a is 8 mm, the first holes 20a are spaced apart by a spatial period of 10 mm, and the diameter of the second holes 20b is 0.5 mm.

[0049] Alternatively, the base 11b comprises a plurality of first holes 11a that converge to a common second hole 11b. Each of the first holes 20a has a first diameter D1 greater than the diameter D2 of the common second hole 20b. Alternatively, the base 11b comprises a first hole 11a that opens into a plurality of second holes 11b. The first hole 20a has a first diameter D1 greater than the diameter D2 of each common second hole 20b among said plurality of second holes 20b.

[0050] Figure 5 illustrates a close-up partial view of the substrate support of the deposition apparatus according to a fourth embodiment of the invention. The other elements of the apparatus 1 are not shown to simplify the illustration. The fourth embodiment retains the same technical characteristics and advantages detailed for the preceding embodiments. According to the fourth embodiment, each opening 20 of the matrix has a diameter D(z) that varies gradually with the depth of the opening. The opening extends from the upper face of the base 11a to the lower face of said base. The upper face of the base 11a is the face from which the support structure 11b extends. The diameter D(z) is maximum at the upper face of the base 11a and then gradually decreases until it reaches a minimum diameter at the lower face of the base 11a.For example, the maximum diameter is between 4 mm and 10 mm, while the minimum diameter of the opening 20 is between 0.1 mm and 3 mm. This particular aspect of the invention also makes it possible to maintain a source sample 3 in powder form while allowing the diffusion of sublimated vapor towards the substrate 2.

[0051] Figure 6 illustrates a diagram of a deposition apparatus 1 according to the fifth embodiment of the invention. The fifth embodiment retains the same technical characteristics and advantages detailed for the other embodiments of the invention. The fifth embodiment differs from the other embodiments in the following way: The hood 11c includes a receiving orifice 30 connecting the cavity 11d to a reservoir 32 via a conduit 31. The reservoir 32 is filled with the material to be deposited in solid and / or liquid and / or powder and / or gaseous form. The reservoir is located inside or outside the enclosure 10. The heating means 13 include a thermostat 13a in contact with the reservoir to heat its contents until they sublimate. The sublimated gas is guided through the conduit 31 to the cavity 11d of the first support 11.The heating means 13 further include lamps 13b (or other heating means) configured to heat the conduit 31 and the first support 11 to a temperature higher than that of the reservoir 32. This prevents condensation of vapor in the cavity 11d. In this embodiment, the source sample 3 housed in the cavity 11d is thus in gaseous form. This embodiment offers two particular advantages: it can hold more material than required for deposition thanks to the external reservoir, thus eliminating the need for refilling between each deposition operation. Furthermore, it is not necessary to prevent the material from melting in the reservoir. The temperature of the material to be deposited in the reservoir can therefore exceed its melting point, thereby increasing the flow rate and deposition speed.

Claims

DEMANDS 1. Apparatus (1) for depositing a layer of a first material onto a substrate (2) by the near-space sublimation technique comprising: - an enclosure (10); - a first support (11) intended to carry a source sample (3) of the first material and placed inside the enclosure (10); - a second support (12) intended to carry the substrate (2) and placed inside the enclosure (10) opposite the first support (11) at a predetermined separation distance (d1); - heating means (13) configured to heat at least the source sample to a predetermined temperature to sublimate the first material; the first support (11) being placed above the second support (12) and comprising: - a planar base (11a) which extends along a first plane (P1); the base (11a) comprising at least one opening (20) having an axis (A) orthogonal to the first plane (P1); - a support structure (11 b) attached to the base which runs along the perimeter of the base (11a); a planar hood (11c) which extends parallel to the first plane (P1); the hood (11c) being intended to engage in the retaining structure (11b) so as to encapsulate the source sample (3) in a cavity (11d) delimited by the base (11a), the retaining structure (11b) and the hood (11c).

2. Apparatus (1) according to claim 1 in which the cavity (11d) is shaped so that the source sample (3) is encapsulated in the cavity (11d) with a lower face which rests on the base (11a) and an upper face which carries the hood (11c) so that the volume of the cavity (11d) adjusts with the evolution of the volume of the source sample (3) during deposition.

3. Apparatus (1) according to any one of claims 1 or 2 in which the base (11a) comprises a plurality of identical openings (20) forming a matrix; each opening (20) having an axis (A) orthogonal to the foreground (P1).

4. Apparatus (1) according to claim 3 in which each opening (20) of the matrix has a diameter that decreases linearly with the depth of the opening.

5. Apparatus (1) according to claim 3 in which each opening (20) of the matrix is ​​formed by a first hole (20a) having a first diameter (D1) and a second hole (20b) having a second diameter (D2) smaller than the first diameter (D2); the first hole (20a) opening onto the second hole (20b).

6. Apparatus (1) according to any one of claims 1 to 5 in which the hood (11c) is made of a thermally conductive material.

7. Apparatus (1) according to any one of claims 1 to 6 in which the retaining structure (11 b) is made of a thermally insulating material.

8. Apparatus (1) according to any one of claims 1 to 7 in which the retaining structure (11b) is made of a material transparent or reflective to infrared radiation; and in which the hood (11c) is made of a material absorbing to infrared radiation; and in which the heating means (13) are made of infrared lamps.

9. Apparatus (1) according to any one of claims 1 to 7 in which the base (11a) is made of a thermally conductive and electrically conductive material; the heating means (13) comprising an electrical circuit configured to inject an electric current through the base (11a).

10. Apparatus (1) according to any one of claims 1 to 9 in which the hood (11c) includes a receiving orifice (30) connecting the cavity (11d) to a reservoir (32) via a conduit (31); the reservoir being intended to contain particles of the first material in a solid or liquid form; the heating means (13) are further configured to heat the reservoir (32) to sublime the first material contained in the reservoir; the source sample (3) encapsulated in the cavity (11d) being in a gaseous form.

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