Apparatus for manufacturing semiconductor device

Abstract

To provide an apparatus and a method for manufacturing semiconductor devices.SOLUTION: An apparatus for manufacturing semiconductor devices comprising a substrate and a film applied onto the substrate by a chemical-vapor-deposition (CVD) process, comprises: a chamber 2 having a reaction and deposition zone 100 to which at least one substrate 101 is disposed and including at least walls 2D, 2E for partitioning the reaction and deposition zone; a first gas source 20 for supplying a flow of a process gas in a first direction into the reaction and deposition zone; and a second gas source 40 for supplying an inert gas in a second direction into the reaction and deposition zone. At least the wall of the chamber includes a plurality of holes 28 on the reaction and deposition zone which is configured to be in fluid communication with the second gas source and introduce the inert gas into the reaction and deposition zone to form a gas layer for separating at least part of the at least the wall from the contact of the flow of the process gas (F).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an apparatus for manufacturing semiconductor devices of the type comprising a substrate and a film applied thereon by a chemical vapor deposition (CVD) process.

[0002] This type of apparatus comprises a chamber containing reaction and deposition zones in which at least one substrate is placed and in which process gases supplied to the process chamber undergo a CVD process to form a film on the substrate.

[0003] One of the problems to be addressed in this type of apparatus is represented by the deposition on the walls of the chamber of particles that are produced as a result of the reaction of the process gases.

[0004] These particles can then remain attached to the walls of the chamber and grow until they detach from the chamber and deposit on the substrate, thus affecting the quality of the film deposited on the chamber. To avoid the risk of compromising the quality of the film deposited on the substrate, a common solution is to program maintenance interventions at predefined intervals to keep the accumulation of these particles in the chamber below a predefined level.

[0005] However, these outages reduce the productivity of the machine.

[0006] Therefore, a need has been felt to reduce the frequency of equipment maintenance while maintaining the quality of the films achieved on substrates by CVD. Summary of the Invention [Means for solving the problem]

[0007] The present invention proposes a semiconductor device manufacturing apparatus for solving the above technical problems.

[0008] The present invention generally relates to an apparatus as set forth in claim 1.

[0009] The invention also relates to a method according to claim 10.

[0010] The claims form an integral part of the teachings provided herein.

[0011] Further characteristics and advantages of the present invention will become apparent from the following description, given by way of non-limiting example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a preferred embodiment of the apparatus described herein, with the process chamber of the apparatus illustrated in cross-section. [Diagram 2] FIG. 2 is a cross-sectional view of the process chamber of FIG. 1 taken along the plane II-II shown in FIG. [Figure 2A] FIG. 2A is a cross-sectional view of a process chamber of another embodiment of an apparatus described herein. [Diagram 3] FIG. 3 is an enlarged view of a detail of FIG. [Figure 4] FIG. 4 is a schematic diagram of a further embodiment of an apparatus as described herein, in which the process chamber of the apparatus is illustrated according to a cross-sectional view. [Diagram 5] FIG. 5 is a schematic diagram of a second further embodiment of an apparatus as described herein, with the process chamber of the apparatus illustrated according to a cross-sectional view. [Figure 6] FIG. 6 shows a process chamber of a further embodiment of an apparatus described herein. [Figure 7A] FIG. 7A shows a diagram representing curves of operating parameters over time during a process implemented in an apparatus described herein. [Figure 7B] FIG. 7B shows a diagram depicting curves of operating parameters over time during a process implemented in an apparatus described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In the following description, various specific details are illustrated for the purpose of providing a deeper understanding of the embodiments. The embodiments may be realized without one or more of the specific details, or with other methods, components, or materials, etc. In other instances, known structures, materials, or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments.

[0014] References used herein are used merely for convenience and therefore do not define the scope of protection or the scope of the embodiments.

[0015] As mentioned above, the apparatus described herein is for manufacturing a semiconductor device of the type that includes a substrate and a film applied (e.g., deposited) on the substrate by a chemical vapor deposition (CVD) process or a low pressure chemical vapor deposition (LPCVD) process. For example, the deposited film may include or consist of silicon carbide. The CVD process is preferably epitaxial CVD.

[0016] 1 and 2, an apparatus generally designated by reference numeral 10 comprises a chamber 2 including a reaction and deposition zone 100 in which is located at least one substrate 101 that is to undergo a CVD process.

[0017] The apparatus also includes a first gas source 20 for supplying a flow of process gas F into the reaction and deposition zone 100 .

[0018] The process gas (F) may include a silicon precursor gas and a carbon precursor gas.

[0019] For example, the silicon precursor gas may be a chlorinated compound, preferably dichlorosilane, trichlorosilane, or tetrachlorosilane.

[0020] The carbon precursor gas may be a hydrocarbon, in particular propane or ethylene or acetylene or methane. Other types of precursors may also be used.

[0021] The process gas (F) may also contain other precursors such as sources for n-doping and p-doping. For example, the n-source may be nitrogen, acetonitrile, pyrrole, ammonia, hydrazine, hydrogen cyanide, methylamine.

[0022] The chamber 2 has an inlet 2A for receiving process gas from a first gas source 20 and an outlet 2B through which process exhaust gas exits the chamber 2 .

[0023] The chamber 2 extends along a reference axis Y from an inlet 2A to an outlet 2B, fluidly connects the inlet 2A to the outlet 2B, defines an inner flow passage 2C, and includes a reaction and deposition zone 100.

[0024] In one or more preferred embodiments, such as the one illustrated, the inner channel 2C has a cross-section that is substantially constant and uniform along the reference axis Y, i.e., from the inlet to the outlet, and across the reaction and deposition zone 100.

[0025] In one or more preferred embodiments, such as the one illustrated (see FIG. 2), the inner flow passage 2C has a rectangular or square cross-section and is bounded by several walls of the chamber 2, namely an upper wall 2D, a lower wall 2E, a left side wall 2F, and a right side wall 2G.

[0026] In one or more preferred embodiments, such as the one illustrated, the lower wall 2E is provided with a receiving area 2H configured to receive a substrate 101 therein.

[0027] In one or more preferred embodiments, such as the illustrated embodiment, the receiving area 2H may comprise a support element 102 configured to receive a substrate 101 and capable of rotating about a vertical axis of rotation I, in operation.

[0028] The substrate 101 received in a receiving area 2H, possibly supported by a support element 102, is presented such that its upper surface 101A lies in a given lying plane L.

[0029] In one or more preferred embodiments, such as the one shown, the lying plane L is above the lower wall 2E.

[0030] Chamber 2 is preferably made of a material that is thermally conductive and resistant to high temperatures. Note that "high temperatures" refers to temperatures above 1000° C. and up to 1700° C., which represents the range of temperatures typically required in a process chamber during a CVD process. Chamber 2 is preferably made of graphite.

[0031] In one or more preferred embodiments, such as the one illustrated, the apparatus 10 includes a heating system for heating the reaction and deposition zone 100 to a predetermined temperature, typically within the range of 1000° C. to 1700° C. mentioned above.

[0032] In one or more preferred embodiments, such as the one shown, the heating system is an induction heating system comprising at least one inductor 30, for example in the form of an electrical winding surrounding the chamber 2 and extending along the reference axis Y. Preferably, different insulating and / or protective layers are interposed between the inductor 30 and the chamber 2, which are not shown in Figures 1 and 2 for simplicity of representation.

[0033] In one or more preferred embodiments, such as the one illustrated, the chamber 2 comprises a number of susceptors 21, 22, 23 and 24 assembled together and in contact with one another to form the chamber 2 itself.

[0034] With particular reference to FIG. 2, susceptors 21, 22, 23, and 24 each include walls 2D, 2E, 2F, and 2G that bound an inner flow passage 2C.

[0035] In one or more preferred embodiments, such as the one illustrated, susceptors 21 and 22 each have a hollow cylindrical configuration extending parallel to a reference axis Y.

[0036] In particular, in one or more preferred embodiments such as the one illustrated, the susceptor 21 includes a curved wall 21A and a top wall 21D that connects opposing lateral side ends of the curved wall 21A to form a hollow cylinder having a half-moon shape.

[0037] Similarly, susceptor 22 comprises a curved wall 22A and a lower wall 2E connecting opposite side edges of curved wall 22A to form a half-moon shaped hollow cylinder similar to that of susceptor 21, but disposed upside down relative to the latter.

[0038] As is known, when an alternating current is supplied to the inductor 30, a current is induced in the susceptors 21, 22, 23 and 24, determining the heating of the chamber 2 so as to heat the reaction and deposition zone 100 to a predetermined temperature.

[0039] Those skilled in the art will understand that the hollow cylindrical configuration of the two susceptors 21, 22 has the primary purpose of making the induced currents follow the same closed shape of the susceptor.

[0040] However, it should be noted that the other susceptors 23 and 24 may instead ultimately be replaced by electrical insulators.

[0041] In one or more preferred embodiments, the chamber 2 is constructed to provide a predetermined temperature profile within the chamber in accordance with the teachings of European Patent no. EP3880863B1.

[0042] The alternative embodiment shown in Figure 2A differs from that of Figures 1 and 2 in that the two susceptors 21, 22 have opposite open ends and that two disks 25A, 25B made of an electrically insulating material are bonded to these open ends to close from opposite sides the inner cavities 21C, 22C of each of the two susceptors 21, 22. Made on the two disks 25A, 25B respectively are an inlet 2A and an outlet 2B, both of which communicate with an inner flow passage 2C.

[0043] 6, the chamber 2 comprises an outer susceptor 27 and an inner casing 29 comprising an inner flow passage 2C and arranged in heat exchange with the outer susceptor 27. The outer susceptor 27 extends circumferentially around the reference axis I and completely surrounds the inner casing 29.

[0044] During operation, the outer susceptor 27 is inductively heated by the inductor 30, while the inner casing 29 is indirectly heated through the outer susceptor 27, and preferably the chamber 2 is configured such that heat transfer from the outer susceptor 27 to the inner casing 29 is achieved via thermal radiation.

[0045] In one or more preferred embodiments, such as the one illustrated, the inner casing 29 can be extracted from the outer susceptor 27 following a translational movement along a direction parallel to the reference axis I in order to perform preventive maintenance on the inner casing 29.

[0046] In this regard, it should be noted that in the prior art, preventive maintenance typically involves disassembling the process chamber to allow an operator to access the inner flow passage 2C, as well as the reaction and deposition zone 100, which naturally involves extensive downtime of the equipment.

[0047] Conversely, in this embodiment of the apparatus, the inner casing 29 can simply be unscrewed from the outer susceptor 27 whenever preventive maintenance is due, such that disassembly of the chamber 2 is not performed.

[0048] Preferably, the inner casing 29 is slidably mounted inside the outer susceptor 27 by longitudinal guides 27A, 27B which are mounted inside the susceptor 29 and extend along the reference axis I, and in the illustrated embodiment, the susceptor 27 is provided with a pair of upper guides 27A which engage with the upper side of the inner casing 29 and a pair of lower guides 27B which engage with the lower side of the inner casing 29.

[0049] A robotic arm equipped with an end effector may be used to move the inner casing 29 along the guides 27A, 27B and extract it from the susceptor 27.

[0050] In one or more preferred embodiments such as the one illustrated, the inner casing 29 preferably comprises a base 29A containing the receiving area 2H and preferably in the form of a general drawer (i.e. a container having a bottom and side walls surrounding the bottom) and a cover 29B removably attached to the base 29A so as to be separable from the base 29A during preventive maintenance, thus facilitating cleaning of the inner surface of the inner casing 29. In their mutually assembled state, the base 29A and the cover 29B together delimit an inner flow path 2C.

[0051] According to an important feature, the apparatus 10 comprises a gas source 40 for supplying an inert gas. Furthermore, at least a wall of the chamber 2 delimiting the reaction and deposition zone 100 comprises a plurality of openings 28 in fluid communication with the gas source 40 and configured to introduce the inert gas into the reaction and deposition zone 100 to form a gas layer 200 separating at least a portion of the wall of the chamber from contact by the flow of process gas F (see FIG. 3 ).

[0052] The inert gas may be, for example, a noble gas, such as helium (He), neon (Ne), argon (Ar), krypton (Kr), or xenon (Xe). Preferably, the noble gas may be argon gas. In general, the inert gas may be any gas that does not react during the CVD process or interfere with the CVD process in any possible way, in particular, the inert gas does not contain silicon and carbon. The inert gas may be provided in a pressurized tank of the supply unit 40.

[0053] Preferably, the plurality of openings 28 is in the form of a two-dimensional array of openings 28 covering a predetermined area of ​​the wall.

[0054] The openings 28 may have various cross-sections, such as circular, oval, slit-shaped, etc., depending on the needs and / or circumstances of a particular application.

[0055] Additionally, the opening 28 may have a longitudinal axis Z1 that is perpendicular to or inclined relative to the wall of the chamber 2. In this second example, the longitudinal axis of the opening 28 is preferably inclined (with respect to an observation point outside the chamber) towards the outlet 2B of the chamber 2, such that the velocity of the flow of inert gas exiting the opening 28 has a component that is directed towards the outlet 2B itself.

[0056] In one or more preferred embodiments, such as the one shown, the opening 28 is made in the upper wall 2D and preferably covers an area A1 of the same wall that extends across the receiving area 2H and also upstream of the receiving area relative to the direction of flow of the process gas F.

[0057] In one or more preferred embodiments such as the one shown, an opening 28 is also made in the lower wall 2E, preferably covering an area A2 of the same wall upstream of the receiving area 2H relative to the direction of flow of the process gas F.

[0058] In another embodiment (not shown), at least the wall of the chamber 2 instead comprises a single elongated opening which is itself configured to introduce the inert gas into the reaction and deposition zone 100 to form the gas layer 200.

[0059] Preferably, the elongated opening is in the form of a slit, extends along a direction transverse to the direction of flow of process gas F and is configured to introduce into the reaction and deposition zone 100 a gas veil representing the protective gas layer 200 described above, immediately adjacent to the wall of the chamber and shielding the latter from the flow of process gas F.

[0060] Preferably, the areas A1 and / or A2 have a width W, measured along a direction transverse to the reference axis Y, that is at least equal to the width of the receiving area 2H.

[0061] Referring to said elongated opening, it preferably has a length, transverse to the direction of gas flow F, equal to at least 50% of the dimension of the receiving area 2H.

[0062] Now, taking into account the technical problem of parasitic deposition of particles discussed at the beginning, the gas layer 200 constitutes an isolating layer which prevents particles produced by CVD and contained in the flow of process gas F, or at least a relevant portion of these particles, from adhering to at least the walls of the chamber 2, e.g. the upper wall 2D and / or the lower wall 2E.

[0063] In this manner, particle buildup within the chamber is eliminated, or at least the respective rate of buildup thereof is substantially reduced.

[0064] The gas layer 200 is thus formed and maintained by an inert gas constantly introduced into the chamber 2 through the opening 28. This gas flows over the walls and is eventually exhausted through the outlet 2B together with the process exhaust gases.

[0065] Those skilled in the art will understand that the size, shape, mutual distance, orientation, total number, etc. of the openings 28 may be selected based on the characteristics of the gas layer to be formed (area, thickness, density, etc.). These data may be obtained experimentally for any particular application of the apparatus described herein. The same applies to operating parameters such as the pressure and flow rate of the inert gas.

[0066] In one or more preferred embodiments, such as the one illustrated, the gas layer 200 formed on the lower wall 2E has a thickness d1 that is smaller than the distance from the underlying plane L to the wall, such that the upper surface 101A of the substrate 101, which is in the same plane L, is located completely above the gas layer 200, thereby eliminating the risk of the gas layer 200 affecting film deposition on the substrate 101.

[0067] Preferably, the opening 28 is the result of machining the wall by removing material or by manufacturing the wall by a forming process.

[0068] For example, the opening 28 can be made by a drill.

[0069] In another embodiment, the wall (and the chamber components of which it is a part) is realized by casting, with the casting mold having an inner formation configured to realize a plurality of openings 28 directly in the casting material, e.g., graphite.

[0070] In one or more preferred embodiments, such as the one illustrated, the susceptor 21 is configured to fluidly connect each opening 28 to a gas source 40 via the inner cavity 21C, such that the latter constitutes a flow path for delivering an inert gas to the openings 28. For example, in one or more preferred embodiments, such as the one illustrated in Figure 2, the susceptor 21 has an inlet 21D opening into the inner cavity 21C and connected to the gas source 40, whereas in the embodiment of Figure 2A, similar openings 21D', 21C' are made in the disk 25A in reverse.

[0071] Similarly, in one or more preferred embodiments such as the one illustrated, the susceptor 22 is configured to fluidly connect the opening 28 to the gas source 40 through the inner cavity 22C; for example, in one or more preferred embodiments such as the one illustrated, the susceptor 22 has an inlet 22D that opens into the inner cavity 22C and is connected to the gas source 40.

[0072] In view of the above, it will be appreciated that the preferred embodiment described above makes it possible to utilise the internal cavities typically present in susceptors such as susceptors 21 and 22 to connect the openings 28 of the susceptor to a gas source 40 and thus solve the problem of delivering gas to these openings in a very simple and reliable manner.

[0073] Referring now to the alternative embodiment of FIG. 6, an opening 28 is made in a cover 29B of an inner casing 29. As shown in FIG.

[0074] Further, similar to that described above with reference to susceptors 21, 22, the outer susceptor 27 is in fluid communication with a gas source 40 and is configured to deliver inert gas through its inner cavity 27C, particularly that portion defined between the inside of the outer susceptor 27 and the cover 29B of the inner casing 29B, to an opening 28 created in the cover 29B.

[0075] In a further embodiment, the opening 28 may also be made in the bottom wall of the base 29A that defines the receiving area 2H.

[0076] 4 and 5 show further embodiments of the devices described herein.

[0077] In the following, the same reference numbers as in the previous embodiment are used to refer to the same or similar parts.

[0078] FIG. 4 shows a process chamber 2 comprising an inner casing 210 ′ for delimiting a reaction and deposition zone 100 .

[0079] Process gases are supplied to the case 210' through an inlet (not shown) located at one end of the case or in the same region of the case where the reaction and deposition zone 100 is also located.

[0080] In either case, the flow of process gas F across the case 210' is parallel to the plane L in which the substrate 101 lies.

[0081] The case 210' includes an upper wall 2D of the flow passage 2C with the opening 28, but does not have an internal cavity defining the wall 2D for delivering the inert gas to the opening 28. Instead, according to this embodiment, delivery of the inert gas to the opening 28 is accomplished via an internal passage 214' made directly in the wall 2D.

[0082] The realization of the internal passageway 214' in the wall is subject to the same teachings provided above with respect to the realization of the opening 28.

[0083] 5 on the other hand shows a chamber 2 having a wall 220' which extends cylindrically around an axis Z and which delimits the reaction and deposition zone 100 such that the lying plane L of the substrate 101 is perpendicular to the axis Z of the same wall. Correspondingly, the flow of the process gas F is perpendicular to the lying plane L.

[0084] The wall 220 ′ includes a plurality of openings 28 , which are preferably disposed to cover the entire cylindrical portion 220 ′A of the wall 220 ′ that surrounds the support element 102 .

[0085] The gas layer 200 formed by the inert gas introduced through the array of such openings 28 has a corresponding ring configuration.

[0086] As with the previous embodiment, delivery of the inert gas to the opening 28 is accomplished via an internal passageway 214' (or multiple internal passageways) made directly in the wall 220' itself. The internal passageway 214' can be made according to the same teachings provided above with respect to the realization of the opening 28.

[0087] As in the preferred embodiment, in both the further embodiment of FIG. 4 and the further embodiment of FIG. 5, the inert gas introduced into the reaction and deposition zone 100 through openings 28 formed in the upper wall 2D of the case 210' in the embodiment of FIG. 4 and in the wall 220' in the embodiment of FIG. 5 forms a gas layer 200 that separates the walls of the chamber from contact with the flow of process gas F.

[0088] In one or more preferred embodiments, the apparatus described herein may also include a third gas source (not shown) for supplying a cleaning gas.

[0089] The cleaning gas may be any gas suitable for removing particles from at least one opening 28 and from at least the wall 2D of the chamber 2, such as Cl2, ClF3, NF3, O2, HCl, and / or combinations thereof, such as Cl2+O2.

[0090] The above embodiment is particularly suitable for etching silicon carbide deposits at temperatures above 500°C, preferably above 800°C.

[0091] A cleaning gas can be selectively set in fluid communication with the at least one opening 28 to introduce the cleaning gas into the reaction and deposition zone 100 and remove particles from the at least one opening 28 and from at least the wall 2D of the chamber 2. In this way, particles that may eventually deposit on at least the wall 2D of the chamber 2 despite the separation provided by the gas layer 200 can be removed, thus postponing any intervention of maintenance on the chamber.

[0092] In one or more preferred embodiments, the apparatus described herein may also include a fourth gas source (not shown) for supplying an etching gas, such as hydrogen, to perform etching of a parasitic SiC film produced in chamber 2 as a by-product of the CVD epitaxial reaction.

[0093] In view of the above, the apparatus described herein can prevent parasitic particles generated as a by-product of a CVD epitaxial reaction from adhering to one or more walls of a reaction chamber.

[0094] Preferably, in order to prevent the adhesion of such parasitic particles to at least one wall of the device comprising at least one opening 28, (i) increasing the process temperature of the chamber 2 to 1000° C. to 1700° C., preferably 1500° C. to 1650° C.; (ii) maintaining the process temperature of chamber 2 constant; and (iii) flowing a process gas F through flow path 2C into reaction and deposition zone 100; (iv) flowing an inert gas through at least one opening 28 into the reaction and deposition zone 100, thereby forming a gas layer 200 separating at least a portion of at least one wall (2D, 2E; 220') from contact with the flow of process gas F; (v) cooling the chamber 2 to a temperature of ≦900° C. A process can be carried out in the described apparatus, in which steps (iii) and (iv) are carried out simultaneously during step (ii) and the process gas F comprises at least a first gas selected from chlorinated compounds, preferably dichlorosilane, trichlorosilane, or tetrachlorosilane, and at least a second gas selected from hydrocarbons, preferably propane or ethylene or acetylene or methane.

[0095] Preferably, the process set forth above further comprises step (i') of flowing a cleaning gas into the reaction and deposition zone 100 through at least one opening 28, the cleaning gas comprising Cl2, ClF3, NF3, O2, and / or HCl, step (i') being performed before step (iii) or after step (iv), and preferably step (i') being performed when the chamber 2 is at a temperature above 500°C, even more preferably at a temperature above 800°C.

[0096] Preferably, the process set out above further comprises step (ii') of flowing hydrogen through flow path (2C) into the reaction and deposition zone (100), step (ii') being carried out during step (ii) and before steps (iii) and (iv), step (ii') may be carried out simultaneously with step (i') as long as the cleaning gas is not oxygen.

[0097] 7A and 7B, each shows a diagram representing the temperature of the chamber over time and the flow rates of the inert gas and cleaning gas through opening 28 during the above-mentioned process, showing steps i), i'), ii), ii'), iv), and v) of the same process along a timeline.

[0098] It should be noted that the diagram in Figure 7A refers to an embodiment of the process where the time interval of step i') coincides with the time interval of step i), and similarly the time interval of step iv) coincides with the time interval of step ii), meaning that cleaning is performed while heating the chamber 2 to the process temperature, and then the CVD process is immediately started with inert gas flowing into the reaction and deposition zone 100 to protect the chamber walls from the process gases.

[0099] Conversely, the diagram in FIG. 7B shows a process in which cleaning is still performed for some time when the chamber reaches the process temperature, and then, before the CVD process begins, etching of the SiC parasitic film is performed by flowing hydrogen into the reaction and deposition zone 100 according to step ii′, always with a flow of inert gas.

[0100] The apparatus described herein may be purposefully configured to carry out the above-mentioned processes, for example the apparatus may include a control unit configured to control the heating system and gas sources of the apparatus to carry out the processes.

[0101] Obviously, provided that the principles of the invention are maintained, the details of construction and aspects of the embodiments may be varied to a considerable extent from those illustrated herein, merely as non-limiting examples, without departing from the scope of the invention as defined in the appended claims. [Explanation of symbols]

[0102] 2 Chamber 2D, 2E, 220' wall 10 equipment 20 First Gas Source 21, 22, 23, 24 Susceptor 28 Opening 30 Inductor 40 Gas source, second gas source 100 Reaction and deposition zones 101 Substrate 200 Gas Layer F Process gas

Claims

1. An apparatus for manufacturing semiconductor devices of the type comprising a substrate (101) and a film applied thereon by a chemical vapor deposition (CVD) process, comprising: a chamber (2) comprising a reaction and deposition zone (100) in which at least one substrate (101) is placed, and comprising at least walls (2D, 2E; 220′) delimiting said reaction and deposition zone (100); a first gas source (20) for supplying a flow of a process gas (F) into said reaction and deposition zone (100) in a first direction; a second gas source (40) for supplying an inert gas into said reaction and deposition zone (100) in a second direction, 1. An apparatus for manufacturing a semiconductor device, wherein at least the walls (2D, 2E; 220') of the chamber (2) comprise at least one opening (28) on the reaction and deposition zone (100), the opening being in fluid communication with the second gas source (40) and configured to introduce the inert gas into the reaction and deposition zone (100) to form a gas layer (200) separating at least a portion of the at least walls (2D, 2E; 220') from contact with the flow of the process gas (F).

2. 2. The apparatus according to claim 1, wherein at least the wall (2D, 2E; 220') of the chamber (2) comprises a plurality of openings (28) configured to introduce the inert gas into the reaction and deposition zone (100) to form the gas layer (200), the plurality of openings being preferably arranged according to a two-dimensional array of openings (28) covering a given area (A1, A2; 220'A) of the wall.

3. 3. The apparatus according to claim 1 or 2, wherein the reaction and deposition zone (100) comprises a receiving area (2H) configured to receive the substrate (101) according to a predetermined lying plane (L), and wherein at least the wall (2D) of the chamber comprising the at least one opening (28) faces the receiving area (2H) and is substantially parallel to the lying plane (L).

4. 4. The apparatus according to claim 3, wherein the chamber (2) comprises a second wall (2E) in which the receiving area (2H) for receiving the substrate (101) is provided, the second wall (2E) comprising at least one opening (28) on an inner zone of the chamber (2) upstream of the reaction and deposition zone (100) with respect to a flow direction of the flow of the process gas (F), the at least one opening (28) being in fluid communication with the second gas source (40) and configured to introduce the inert gas into the upstream zone to form a gas layer (200) separating at least a portion of the second wall (2E) from the flow of the process gas.

5. 5. The apparatus according to claim 4, wherein the at least wall (2D) and / or the second wall (2E) comprises at least one opening (28) on an inner zone of the chamber (2) downstream of the reaction and deposition zone (100) with respect to the flow direction of the flow of the process gas (F), the at least one opening (28) being in fluid communication with the second gas source (40) and configured to introduce the inert gas into the downstream zone to form a gas layer (200) separating at least a portion of the at least wall (2D) or the second wall (2E) from a flow of process exhaust gas leaving the chamber (2).

6. the chamber (2) comprises at least one susceptor electromagnetically coupled to an inductor and configured to heat the reaction and deposition zone (100) to a predetermined temperature; 3. The apparatus of claim 1, wherein the susceptor has an inner cavity (21C, 22C) configured to be in fluid communication with the second gas source (40) and to deliver the inert gas to the at least one opening (28).

7. the chamber (2) comprises a plurality of susceptors (21, 22; 21, 22, 23, 24) assembled together to define a flow path (2C) containing the reaction and deposition zone (100) and to be in fluid communication with the first gas source (20); 7. The apparatus of claim 6, wherein at least one of the susceptors (21, 22) has an inner cavity (21C, 22C) set in fluid communication with the second gas source (40), and wherein the at least one wall (2D, 2E) is interposed between the flow path (2C) and the inner cavity (21C, 22C) of the susceptor (21, 22), and the opening (28) in the at least one wall sets the inner cavity (21C, 22C) and the flow path (2C) in reciprocating fluid communication.

8. 8. The apparatus of claim 7, wherein the chamber (2) comprises a pair of susceptors (21, 22) and a pair of electrical insulators assembled together and in contact with each other to delimit the flow path (2C) and form the chamber (2).

9. 4. The apparatus of claim 3, wherein the at least one opening (28) is an elongated opening configured to introduce the inert gas into the reaction and deposition zone (100) to form the gas layer (200), the elongated opening being a slit on the wall (2D) of the chamber (2) extending along a direction transverse to the direction of gas flow in the reaction and deposition zone and having a length equal to at least 50% of a dimension of the receiving area in the same transverse direction.

10. 3. The apparatus of claim 1 or 2, wherein at least the wall (2D, 220') with the at least one opening (28) has an internal passage (214') fluidly connecting the at least one opening (28) to the second gas source (40).

11. 3. The apparatus according to claim 1 or 2, wherein the reaction and deposition zone (100) comprises a receiving area (2H) configured to receive the substrate (100) according to a given lying plane (L), and wherein at least the wall (220') of the chamber extends according to a cylindrical shape around an axis (Z) perpendicular to the lying plane (L).

12. 3. The apparatus of claim 1, further comprising a third gas source for supplying a cleaning gas, selectively configured in fluid communication with the at least one opening (28) to introduce the cleaning gas into the reaction and deposition zone (100) to remove particles from the at least one opening (28) and from at least the wall (2D) of the chamber (2).

13. A method for manufacturing a semiconductor device of the type comprising a substrate (101) and a film applied thereon by a chemical vapor deposition (CVD) process, comprising the steps of: - placing at least one substrate (101) in a reaction and deposition zone (100) contained in a chamber (2) and bounded by at least walls (2D, 2E; 220') of said chamber (2); - supplying a flow of process gas to said reaction and deposition zone (100) of said chamber (2); - introducing an inert gas into the reaction and deposition zone (100) through at least one opening (28) provided in at least the wall of the chamber to form a gas layer (200) separating at least a portion of the at least the wall from the process gas flow.

14. The method of claim 13, comprising introducing a cleaning gas through said at least one opening (28) into said reaction and deposition zone (100) to remove particles from said at least one opening (28) and from said at least one wall (2D) of said chamber (2).

15. 3. A process for preventing SiC parasitic particles produced as a by-product of a CVD epitaxial reaction from adhering to at least the walls of the chamber of the apparatus of claim 1, comprising: (i) raising the chamber (2) to a process temperature of 1000°C to 1700°C, preferably 1500°C to 1650°C; (ii) maintaining the process temperature of the chamber (2) constant; and (iii) flowing said process gas (F) through a flow path (2C) into said reaction and deposition zone (100); (iv) flowing an inert gas through said at least one opening (28) into said reaction and deposition zone (100) thereby forming a gas layer (200) separating at least a portion of said at least walls (2D, 2E; 220') from contact with the flow of said process gas (F); (v) cooling the chamber to a temperature of ≦900° C.; A process, wherein steps (iii) and (iv) are carried out simultaneously during step (ii), and said process gas (F) comprises at least a first gas selected from chlorinated compounds, preferably dichlorosilane, trichlorosilane, or tetrachlorosilane, and at least a second gas selected from hydrocarbons, preferably propane or ethylene or acetylene or methane.

16. The method further comprises the step (i') of flowing a cleaning gas through the at least one opening (28) into the reaction and deposition zone (100), the cleaning gas being Cl ２ , ClF ３ , N.F. ３ , O ２ and / or HCl, and step (i') is carried out before step (iii) or after step (iv), preferably at a temperature above 500°C, even more preferably at a temperature above 800°C.

17. 17. The process of claim 16, further comprising the step (ii') of flowing hydrogen through said flow passage (2C) into said reaction and deposition zone (100), wherein step (ii') is performed during step (ii) and before steps (iii) and (iv), and wherein step (ii') is finally performed simultaneously with step (i') if said cleaning gas is not oxygen.

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