Method and apparatus for deposition of a main group V element-containing layer in a process chamber and subsequent cleaning of the process chamber - Patents.com

Abstract

The present invention relates to a method for depositing a layer comprising a main group V element on a substrate in a CVD reactor, in which a process gas is fed into a process chamber (2) through a central gas inlet element (11) and flows radially through the process chamber (2). After deposition of the layer, the process chamber (2) is cleaned and the process chamber (2) is heated to a first cleaning temperature (T 1 ) to the first cleaning temperature (T 2 After the first cleaning step (21), a halogen or a halogen compound is supplied into the process chamber (2), and after the first cleaning step (21), the process chamber (2) is heated to a second cleaning temperature (T 2 ) and the second washing temperature (T 2 ), then in the second washing step (22) O 2 is supplied into the process chamber (2), and after the second cleaning step (22), the process chamber (2) is heated to a third cleaning temperature (T 3 ) and the third washing temperature (T 2 ), then in the third washing step (23), essentially H 2 Only the aqueous solution is provided in the process chamber (2) and after a third cleaning step (23), the process chamber (2) is cooled (24).

Description

[Technical field]

[0001] The invention relates to a method for depositing a layer comprising an element of the main group V on a substrate in a CVD reactor. The CVD reactor has a reactor housing in which a graphite part is arranged. The graphite part may be coated with SiC. It may be coated for Cl2 resistance. The graphite part may be covered with a parasitic coating consisting of decomposition products of the process gases during the execution of the deposition method. The method also relates to a cleaning method subsequent to the method of depositing a layer on a substrate, which consists of several cleaning steps performed in succession to remove the parasitic coating from at least one graphite part.

[0002] The apparatus according to the invention comprises a control device containing a control program which executes control commands, by means of which the valves and mass flow controllers of the gas supply device are switched and / or controlled so that the method is carried out in the apparatus. [Background technology]

[0003] US Pat. No. 5,399,633 discloses a method carried out after deposition of a layer in a CVD reactor, in which Cl2 is used to remove parasitic coatings from the walls of components in the process chamber.

[0004] US Pat. No. 5,399,633 discloses a CVD reactor and a method carried out therein for removing wall coatings by injecting chlorine.

[0005] In the method according to the invention, the process gas may also be a gas containing carbon. For example, the process gas may contain an organometallic compound of an element of main group III. This is particularly the case when a III-V layer is deposited on a substrate. Carbon may be formed when this component of the process gas is decomposed. It is deposited on the surface of the graphite part in the form of pure carbon or as a component of a carbon compound. Carbon residues may be formed, especially if the process gas contains NH3. US Pat. No. 5,399,433 discloses a method in which such carbon residues may be removed by an etching gas.

[0006] US Pat. No. 5,399,633 discloses a method for removing carbon residues from a process chamber using plasma and chlorine.

[0007] A cleaning method using chlorine is also disclosed in Patent Document 5. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] US Patent Application Publication No. 2020 / 385861 [Patent Document 2] DE 10 2017100 725 A1 [Patent Document 3] DE 102013 104 105 A1 [Patent Document 4] U.S. Pat. No. 4,816,113 [Patent Document 5] US Patent Application Publication No. 2013 / 005118 Summary of the Invention [Problem to be solved by the invention]

[0009] The invention is based on the object of improving the cleaning step in a general method in a manner that is advantageous to use. The invention is in particular based on the object of improving a method for depositing a layer in a manner that is advantageous to use. The invention is also based on the object of making the cleaning step more efficient. The invention is further based on the object of improving a method for depositing a layer comprising elements of main groups II to IV, followed by a process comprising several steps of cleaning the process chamber, and in particular the object of improving the cleaning process in deposition processes in which process gases and / or cleaning gases are supplied to the center of the process chamber and flow radially through the process chamber. In that case, a susceptor carrying a substrate holder rotates around the center of the process chamber.

[0010] However, the method can also be carried out in an apparatus in which the gas inlet part is configured as a showerhead. [Means for solving the problem]

[0011] This object is achieved by the invention as specified in the claims, the dependent claims not only representing advantageous developments of the main claim but also representing independent solutions to the object.

[0012] The method of the present invention contemplates the use of a CVD reactor having a reactor housing in which a further surface is located, which may be a graphite part disposed therein. There may be a plurality of graphite parts in the reactor housing. At least one of the preferred plurality of graphite parts is preferably coated. It may preferably be coated with silicon carbide. However, it may also be coated with another coating that provides the graphite part with resistance to exposure to Cl2, O2 or HCl. The graphite part may be a part of the process chamber or a part constituting the boundary of the process chamber. In particular, it is envisaged that a susceptor forming the floor of the process chamber is made of graphite and coated with silicon carbide. The susceptor may have a rear side facing away from the process chamber and adjacent to a heating area. A heating device may be arranged in the heating area. The heating device may be an IR heater or an RF heater. However, the graphite part may also be the process chamber ceiling constituting the upper boundary of the process chamber. The process chamber can be heated to high temperatures by thermal radiation emitted by the susceptor, which can be heated to temperatures of 1000° C. or more during the deposition of a layer. The gas inlet part may be located in the center of the process chamber. It may be essentially made of quartz or metal. However, the gas inlet part or parts of the gas inlet part may also be made of graphite. These parts may also be coated with silicon carbide. A number of pockets may be located within the susceptor. The pockets may be arranged with an equal angular distribution around the center of the process chamber. They are therefore equidistant from the gas inlet fitting so that process gases exiting the gas inlet fitting flow radially through the process chamber and past the pockets. Within each pocket is at least one substrate holder that supports a substrate such that process gases flow over the substrate. Gas supply lines can be open into the floor of the pocket through which an inert gas can be supplied into the pocket. A gas cushion is formed. The directed gas flow can be used to rotate the substrate holder about its axis by the gas cushion. The process chamber is surrounded by a gas outlet part which may be made of ceramic material or metal, but also partly or entirely of graphite, in particular of graphite coated with SiC. The gas inlet part may have multiple gas discharge areas arranged above one another, through which different components of the process gas can be fed into the process chamber. The graphite part may be only partially coated with SiC.

[0013] However, a showerhead can also be used as the gas inlet component, in particular a plate with multiple nozzles arranged above the substrate, so that the gas flows vertically into the process chamber towards the substrate, although the process gas can then be removed radially from the process chamber. The flow can also be horizontal through the process chamber, radially from the center outwards, or linearly from one side of the process chamber to the other side of the process chamber. Thus, the process chamber can be a horizontal reactor chamber, through which the flow is guided horizontally in a linear manner.

[0014] This is preferably achieved by supplying a process gas into the process chamber, which preferably comprises one or more reactive gases. One of the reactive gases may consist of molecules comprising elements of main groups II-VI, III-V, and in particular elements of main group V. The process gas preferably comprises a plurality of reactive gases, for example a gas of main group III and a gas of main group V, or a gas of main group II and a gas of main group VI, or one or more gases of main group IV. Thus, the process gas can be a mixture of hydrides of elements of main group V and organometallic compounds of elements of main group III. For example, the process gas can contain AsH3, PH3 (or also NH3). The process gas can also contain organometallic gases, which in particular contain elements of main group III, for example TMGa, TMIn, or TMAl, or TEGa. The latter reactive gases are supplied into the process chamber together with an inert gas, for example H2. It is also possible to use silicon-containing gases, for example silane, and carbon-containing gases, for example methane. In other embodiments, the process gas may include alkaline earth compounds, such as compounds of magnesium or calcium. The process gas may also contain elements of main group VI, for example oxides. The reactive gases of the process gas decompose in the process chamber due to the high temperature, in particular due to the high temperature of the substrate, whereby a layer of elements of main groups II-VI, and in particular of main groups III and V, is deposited on the substrate surface. At the same time, reaction products of the reactive gases, i.e. parasitic compounds of reaction products of the reactive gases, are formed and condensed on the surfaces of the process chamber, in particular on the surfaces of graphite parts that are at least partially coated, in particular coated with a Cl2 / O2 resistant coating such as SiC. After the first step is completed, for example after one or more layers are deposited on the substrate, at least one substrate is removed from the process chamber. During this intermediate step of removing the substrate from the process chamber, no reactive gas is supplied to the process chamber, or at most only a reactive gas of main group V is supplied to the process chamber. Otherwise, only an inert gas, for example hydrogen, is supplied to the process chamber. During the intermediate step of removing the at least one substrate, the process chamber can be cooled to a low temperature.

[0015] In a further process following the first step, the process chamber is cleaned. The parasitic coating on the walls of the process chamber, and especially on the walls of the graphite parts, is removed. This is achieved by injecting a cleaning gas, which in turn forms various volatile compounds with the molecules of the coating, and these compounds are carried away through the gas outlet parts. According to the invention it is envisaged that after removal of the at least one substrate the process chamber is heated to a first cleaning temperature, which may be in the range of 500° C. to 1000° C. or in the range of 800° C. to 900° C. At the first cleaning temperature a first cleaning step is performed in which a halogen or a halogen compound is supplied into the process chamber.

[0016] In one embodiment of the present invention, HCl or Cl2 is preferably provided in the process chamber. The halogen or Cl2 is provided in the process chamber together with nitrogen. The total pressure in the process chamber may range from 50 mbar to 200 mbar. It is envisaged that about 10 slm of N2 is provided in the process chamber during the first cleaning step.

[0017] However, it is also possible to supply another flow of this inert gas, for example nitrogen, at a flow rate of 110 slm. The first cleaning gas used for cleaning, and the other cleaning gases mentioned below, are each provided in the form of a gas source. The halogen, for example Cl2, can be provided in any desired mixture ratio with nitrogen. A 5% mixture is preferred. This cleaning gas is supplied into the process chamber at a mass flow rate of 2-40 slm when the temperature of the process chamber reaches the first cleaning temperature. In the first cleaning step, substantial metallic components and components belonging to the main group V of the parasitic coating are converted into volatile compounds, which are then removed from the process chamber together with the inert gas. In particular with Cl2, an etching rate of 80±20 μm / h is achieved.

[0018] The intermediate step of heating the process chamber from, for example, 300° C. to the first cleaning temperature, for example, 900° C., takes about 10 minutes. During this intermediate step, the inert gas can be switched from hydrogen to nitrogen. During the intermediate step, the total pressure in the process chamber can be changed, particularly lowered, from the pressures mentioned above.

[0019] The first cleaning step is carried out for about 20-30 minutes at a constant temperature, for example 900 ° C. Afterwards, the supply of the first cleaning gas is switched off. In a subsequent intermediate step, the temperature of the process chamber is changed and in particular increased to the second cleaning temperature. During this intermediate step, the total pressure in the process chamber can also be changed.

[0020] Once the second cleaning temperature is reached, the intermediate step is terminated. The second cleaning temperature can be between 500°C and 1100°C. It can be, for example, between 950°C and 1000°C. As soon as the second cleaning temperature is reached, a second cleaning gas is fed into the process chamber. This cleaning gas can take the form of "dry air", O3, O2 or NH3. The cleaning gas can be provided as a mixture in nitrogen. Preferably, 9 slm of this mixture is fed into the process chamber. Together with this second cleaning gas, N2 is fed into the process chamber, preferably with a mass flow rate of 11 slm. The total pressure during the second cleaning step is between 100 mbar and 800 mbar, in particular between 600 mbar and 800 mbar. During the second cleaning step, the carbon-containing components of the parasitic coating are substantially removed. For this purpose, the oxygen fed reacts with carbon or with carbon-containing compounds to form oxides of carbon. The second cleaning step may be carried out with a duration of 7 to 15 minutes. The duration of the second cleaning step is preferably shorter than the duration of the first cleaning step. However, its duration may also depend on the thickness of the layer to be removed. Removal of a thicker layer requires a longer time than removal of a shorter layer.

[0021] In a further intermediate step after the second cleaning step, no cleaning gas is fed into the process chamber but only an inert gas, and the temperature of the process chamber is changed, in particular lowered to a third cleaning temperature, which may be between 500°C and 1100°C. However, it can also be between 800°C and 1000°C. At the same time, the total pressure in the process chamber can also be changed. The total pressure is preferably lowered to a pressure between 50 mbar and 200 mbar. A third cleaning step is then carried out at this total pressure. During the intermediate step, the inert gas can also be changed and after the intermediate step hydrogen is fed into the process chamber.

[0022] The third cleaning step is an "H2 bake" or "N2 bake" in which the process chamber is heated in the presence of substantially only H2. This occurs for a period of 15 to 30 minutes at the third cleaning temperature described above. The third cleaning step can be longer than the first cleaning step. During the third cleaning step, only hydrogen is supplied to the process chamber, preferably at a mass flow rate of 26 slm.

[0023] The third cleaning step can be followed by an optional step in which the process chamber is alternately filled with an inert gas, which can be hydrogen or nitrogen, and evacuated, which is achieved by means of a vacuum pump connected to a gas outlet fitting. [Brief description of the drawings]

[0024] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. [Figure 1] FIG. 1 is a schematic cross-section of a CVD reactor, a gas supply system including a gas source, and a schematic diagram of an electronic controller. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is a flow diagram of the process steps of depositing a layer on a substrate followed by a cleaning step. [Figure 4] FIG. 4 is a graph showing the relationship between time and temperature for the cleaning method shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The method of the invention is carried out in an apparatus as shown in Figure 1. The CVD reactor has an airtight housing 1, for example made of stainless steel, in which a process chamber 2 is located. The floor of the process chamber 2 is formed by a susceptor 3, which may be made of graphite and is coated with SiC. The susceptor 3 has a disk shape and has a rear surface facing downwards towards a heating device 31. The heating device 31 may be in the form of a coil and generates an RF field which induces eddy currents in the susceptor 3 so as to heat it to a process temperature.

[0026] The susceptor 3 is rotatable about an axis of rotation 8 by means of a shaft 9 and a rotary drive (not shown). A supply line, also not shown, passes through the shaft 9 to supply an inert gas to gas channels (not shown) of the susceptor 3. These gas channels open into the floor of pockets 4 arranged on the upwardly facing surface of the susceptor 3. A graphite substrate holder 5 is inserted into each of these pockets 3. The substrate holder 5 may also be coated with SiC. A substrate 6 may be placed on the substrate holder 5. This may be a substrate made of Si, GaAs or a substrate made of sapphire or other suitable material.

[0027] The central area of ​​the susceptor 3 has a recess 18 into which the lower part of the gas inlet part 11 can be inserted. The gas inlet part 11 is fixed to the housing 1 and has three gas discharge areas 13, 15, 17 arranged vertically above one another. Gas supply lines 12, 14, 16 lead to each of the three gas discharge areas 13, 15, 17. Reactive and inert gases can be supplied through the gas supply lines 12, 14, 16 into the process chamber 2 extending between the process chamber ceiling 10 and the susceptor 3. The process gases entering the process chamber 2 through the gas discharge areas 13, 15, 17 flow radially through the process chamber 2 and thereby over the substrate 6.

[0028] 1 shows just one example of a process chamber in a CVD reactor. In further exemplary embodiments (not shown), the central gas inlet piece 11 may have another configuration. In a further exemplary embodiment, it is proposed that the gas inlet piece is formed by the process chamber ceiling and is in the form of a showerhead having a large number of substantially uniformly distributed gas outlet holes.

[0029] The process chamber ceiling 2 may be made of graphite and coated with SiC.

[0030] The process chamber 2 is surrounded by an annular gas outlet fitting 19 having gas outlet holes (not shown) to which a suction line of a vacuum pump (not shown) can be connected to evacuate the process chamber 2 or to set a predetermined total pressure within the process chamber 2.

[0031] Fig. 1 further shows a schematic gas supply arrangement with a number of gas sources 25. The gas supply arrangement can provide, for example, the following gases: AsH3, PH3 as reactive gas components of the process gas, and TMGa, TMIn as reactive gas components of the process gas for depositing III-V layers on a substrate 6 arranged annularly around the gas inlet piece 11 shown in Fig. 2. The gas supply arrangement can also provide inert gases, for example H2 and N2. Furthermore, the gas supply arrangement can provide cleaning gases Cl2 and O2. The two cleaning gases are preferably provided mixed at 5% in N2.

[0032] A programmable electronic controller 32 can control valves 27 and mass flow controllers 26 to supply predetermined mass flow rates of the above-mentioned gases through supply lines 12 , 14 , 16 to process chamber 2 25 .

[0033] One of the above-mentioned devices is used to deposit layers of elements from main groups III and V on the above-mentioned substrate 6. These may take the form of GaInAsP layers or layers containing at least two of the above-mentioned elements. For this, first the substrate is transferred into the process chamber 2, which is then heated to the process temperature and the above-mentioned reactive gases are then fed into the process chamber 2. After one or more layers have been deposited, the process chamber 2 is cooled, for example to 200°C-300°C, 300°C-400°C or 300°C, and the substrate is removed. During the above-mentioned deposition process, a coating is formed on some SiC surfaces, consisting of solid chemical compounds formed during the reaction of the reactive gases.

[0034] After the substrate is removed, the temperature in the process chamber 2 is heated to a first cleaning temperature T1 in a heating step 20 from time t1 to time t2, which may be 800° C. to 1000° C., and may be 900° C. The process chamber is set to a total pressure of 50 mbar to 100 mbar.

[0035] After reaching the first cleaning temperature T1, Cl2 is supplied to the process chamber together with N2 in a first cleaning step 21 from time t2 to time t3. In the process chamber 2, a reaction occurs between the chemical compounds deposited on the SiC surface and O2. Volatile reaction products are formed and are removed from the process chamber 2 together with N2.

[0036] In an intermediate step following the first cleaning step 21, the temperature of the process chamber 2 is heated from time t3 to time t4 in an N2 atmosphere to a second cleaning temperature T2, which can be between 900 ° C and 1000 ° C, or between 1000 ° C and 1100 ° C, but it can also be between 1100 ° C and 1200 ° C, or even 1050 ° C. The total pressure in the process chamber is changed. In particular, it changes to a pressure between 600 mbar and 800 mbar. After reaching the second cleaning temperature T2, O2 is supplied to the process chamber together with N2 during the period from time t4 to time t5. During this second cleaning step 22, the carbon compounds are removed from the SiC surface by chemical reaction of the carbon compounds with oxygen. Volatile oxides are formed and are removed from the process chamber 2 together with N2.

[0037] After reaching the time t5, the temperature of the process chamber is changed to a third cleaning temperature T3. In particular, the temperature is lowered to a temperature which may be between 800° C. and 1000° C., or may be 900° C. At the same time, the total pressure can be set to a value between 50 mbar and 100 mbar. After reaching the third cleaning temperature T3, only H2 is supplied into the process chamber during the period from t6 to t7. During this third cleaning step 23, all remaining oxides are removed from the surface. Adjustments of the CVD reactor can also be performed.

[0038] After reaching time t7, in a cooling step 24, the temperature of the process chamber 2 is reduced, for example, to 200° C. to 400° C., or to 300° C. At time t8, the process temperature 2 reaches a value of 300° C., for example, about 70 minutes having passed since the start of the cleaning process at time t1.

[0039] 3 shows an exemplary embodiment in which a heating step 20 is followed by a Cl2 etch step 21, and a rinsing step 21' is performed before a subsequent O2 etch step 22. The O2 etch step 22 is followed by a heating step 23, which is then followed by a cooling step 24.

[0040] During the rinsing step 21', the etching gases used in the Cl2 etching step 21, and in particular Cl2, can be completely removed from the reactor housing, so that in the subsequent O2 etching step 22, no Cl2 is present in the process chamber anymore.

[0041] An exemplary embodiment of the method can be carried out by the following steps: Heating the process chamber to a first cleaning temperature T2 (800°C to 900°C) Inject Cl2 into the nitrogen atmosphere (12 slm of 5% Cl2, 11 slm of N2, 50 mbar to 100 mbar total pressure) A step of terminating the injection of Cl2 and heating to a second cleaning temperature T2 (950°C to 1000°C). Inject O2 into the nitrogen atmosphere (5% O2 at 9 slm, N2 at 11 slm, total pressure between 600 mbar and 800 mbar) Stop the injection of O2 and change the temperature to the third cleaning temperature T3 (800°C to 1000°C). Heating in a hydrogen atmosphere (26 slm, 50 mbar to 100 mbar total pressure)

[0042] The foregoing is intended to generally describe the inventions encompassed by this application, which may also advance the prior art by at least one combination of the following features, and independently, any two, more or all of these features in combination:

[0043] A method for depositing a layer comprising an element of main group V on a substrate (6) in a CVD reactor, the CVD reactor having a reactor housing (1) in which at least one graphite part (3, 5, 10, 11, 19) coated with SiC is arranged, the graphite part being in contact with a process gas supplied in a process chamber (2) of the CVD reactor during deposition, whereby decomposition products of the process gas are deposited on a surface of the graphite part (3, 5, 10, 11, 19) forming a parasitic coating, A process gas is provided having molecules including elements of main group V; At least one substrate (6) is transferred into the process chamber (2); A process gas is supplied into the process chamber (2); A process gas is decomposed in a process chamber (2) heated to a process temperature, and a main group V element is deposited on the substrate (6) as a component of a layer on the substrate, The substrate (6) is removed from the process chamber (2); The process chamber (2) is heated to a first cleaning temperature (T1); After reaching the first cleaning temperature (T2), a halogen or a halogen compound is supplied into the process chamber (2) in a first cleaning step (21), After the first cleaning step (21), the process chamber (2) is brought to a second cleaning temperature (T2), After reaching the second cleaning temperature (T2), O2 is supplied into the process chamber (2) in a second cleaning step (22); After the second cleaning step (22), the process chamber (2) is brought to a third cleaning temperature (T3); After the third cleaning temperature (T2) is reached, substantially only H2 is supplied into the process chamber (2) in the third cleaning step (23); and After the third cleaning step (23), the process chamber (2) is cooled (24).

[0044] A method characterized in that the process gas comprises AsH3, PH3, or NH3, and / or the process gas further comprises a gas of molecules comprising an element of main group III, and / or the process gas further comprises TMGa, TMIn, or TMAl.

[0045] A method characterized in that during the heating step (20), an inert gas and / or a noble gas and / or N2 or H2 is supplied into the process chamber (2) and / or only an inert gas is supplied into the process chamber (2).

[0046] 1. A method according to claim 1, characterized in that during the first cleaning step (21), only a halogen or a halogen compound and N2 are supplied into the process chamber (2) and / or only Cl2 is supplied into the process chamber (2) together with N2.

[0047] A method according to claim 1, characterized in that during the second cleaning step (22), only O2 is supplied into the process chamber (2) together with N2.

[0048] A method according to claim 1, characterized in that during the cooling step (23), only H2 is supplied into the process chamber (2).

[0049] a graphite part being a susceptor (3) constituting the boundary of a process chamber (2) and / or a graphite part being a process chamber ceiling (10) constituting the boundary of the process chamber (2) and / or a graphite part being a gas inlet part (2) and / or a graphite part being a gas outlet part (19) and / or a substrate holder (5) which is inserted into a pocket (4) of the susceptor (3), wherein an inert gas can be supplied into the pocket (4) through a supply line, so that a gas cushion is formed therein causing the substrate holder (5) to rotate about an axis (7).

[0050] The method according to claim 1, characterized in that the susceptor (3) is driven in rotation about the axis of rotation (8) at least during the deposition of the layer and / or the susceptor is heated by a heating device (31) during the deposition of the layer and during the heating step (20) and / or during the three cleaning steps (21, 22, 23).

[0051] 10. An apparatus for performing a method using a CVD reactor having a reactor housing (1) in which at least one graphite component (3, 5, 10, 11, 19) is arranged, a gas supply device having a gas source (25) by means of which process gases of elements of main group III, halogens or halogen compounds, molecules comprising O2, H2, and N2 are provided, and a control device (32) for controlling valves (27) and mass flow controllers (26) such that the method according to any one of claims 1 to 8 is performed in a process chamber (2) of the reactor housing (1).

[0052] All disclosed features are essential to the invention (both by themselves and in combination with one another). The disclosure of the present application includes in its entirety the disclosure content of the relevant / added priority documents (copies of the earlier application), also with a view to incorporating the features of these documents in the claims of the present application. The dependent claims are characterized by an independent, inventive further development of the prior art, even without the features of the cited claims, in particular in order to file a divisional application on the basis of these claims. The invention specified in each claim may additionally have one or more features specified in the preceding description, in particular those given reference signs and / or specified in the explanation of the signs. The present invention also relates in particular to design forms in which individual ones of the features mentioned in the preceding description are not implemented, insofar as they are obviously unnecessary for the respective intended use or can be replaced by other means having the same technical effect. [Explanation of symbols]

[0053] 1 Reactor housing 2. Process chamber 3 Susceptor 4 Pockets 5 PCB holder 6 Substrate 7 Rotation axis of the substrate holder 8 Rotation axis of the susceptor 9 Shaft 10 Process chamber ceiling 11 Gas inlet parts 12 Supply Line 13 Gas release area 14 Supply Line 15 Gas release area 16 Supply Line 17 Gas release area 18 Recess 19 Gas outlet member 20 heating 21 Chlorine Cleaning 21' Rinse 22 Oxygen Cleaning 23 Hydrogen heating 24 Cooling 25 Gas Source 26 Mass Flow Controller 27 Valve 28 Supply Line 29 Supply Line 30 Supply Line 31 Heating device 32 Control device

Claims

1. A method for depositing a layer on a substrate (6) in a process chamber (2) disposed in a reactor housing (1) of a CVD reactor, comprising the steps of: The process chamber (2) is heated to a process temperature; The substrate (6) is transferred into the process chamber (2); A process gas (2) is supplied into the process chamber; at the process temperature, the process gas decomposes into decomposition products; At least a portion of the decomposition products is deposited as a layer on the substrate (6); Another part of the decomposition products is deposited on other surfaces within the reactor housing (1) as a parasitic coating; The substrate (6) is removed from the process chamber (2); The process temperature (2) is the first washing temperature (T １ ) is heated to The first washing temperature (T ２ ), a halogen or a halogen compound is supplied into the process chamber (2) in a first cleaning step (21), After the first cleaning step (21), the process chamber (2) is heated to a second cleaning temperature (T ２ ) and The second washing temperature (T ２ ), in a second washing step (22) ２ is provided into the process chamber (2), After the second cleaning step (22), the process chamber (2) is heated to a third cleaning temperature (T ３ ) and The third washing temperature (T ２ ), then in a third washing step (23) substantially H ２ is fed into the process chamber (2), and After said third cleaning step (23), said process chamber (2) is cooled (24).

2. the process gas comprises at least one reactive gas; said reactive gas containing at least one element of main groups II-IV, said layer containing an element of main groups II-IV; the reactive gas comprises at least one element of main groups III-V and the layer comprises an element of main groups III-V, or 2. The method of claim 1, wherein the reactive gas comprises at least one element of main group V, and the layer comprises an element of main group V.

3. The at least one reactive gas is AsH ３ , P.H. ３ , N.H. ３ , silane, carbon compounds, magnesium compounds, organometallic compounds, TMGa, TMIn, TMAl, and / or oxides.

4. 10. The method according to any one of the preceding claims, characterized in that the other surface is a surface of a graphite part (3, 5, 10, 11, 19) arranged in the reactor housing (1).

5. 10. The method according to any one of the previous claims, characterized in that the parasitic coating is deposited on a coating on the surface of the graphite component (3, 5, 10, 11, 19), the coating being an etching gas resistant coating, a carbide coating, a TaC coating or a SiC coating.

6. During the heating step (20), an inert gas and / or a noble gas and / or N ２ Or H ２ 10. The method according to claim 9, characterized in that a gas containing an inert gas is supplied into the process chamber (2) and / or that only an inert gas is supplied into the process chamber (2).

7. During the first washing step (21), the halogen or halogen compound and N ２ Only O is supplied into the process chamber (2) and / or ２ Only N ２ 4. The method according to claim 1, characterized in that the process chamber (2) is supplied with

8. During the second washing step (22), O ２ Only N ２ 4. The method according to claim 1, characterized in that the process chamber (2) is supplied with

9. During the cooling step (23), H ２ 10. The method according to claim 9, wherein only 100% water is supplied into the process chamber (2).

10. 10. The method according to claim 9, characterized in that the graphite part is a susceptor (3) constituting the boundary of the process chamber (2) and / or the graphite part is a process chamber ceiling (10) constituting the boundary of the process chamber (2) and / or the graphite part is a gas inlet part (11) and / or the graphite part is a substrate holder (5) which is inserted into a pocket (4) of the susceptor (3), and inert gas can be supplied into the pocket (4) through a supply line, so that a gas cushion is formed therein causing the substrate holder (5) to rotate about an axis (7).

11. 10. The method according to claim 9, characterized in that the susceptor (3) is driven in rotation about an axis of rotation (8) at least during deposition of the layer and / or the susceptor (3) is heated by a heating device (31) during deposition of the layer and during the heating step (20) and / or during the three cleaning steps (21, 22, 23).

12. An apparatus for carrying out the method, comprising: a CVD reactor having a reactor housing (1) with at least one graphite part (3, 5, 10, 11, 19) disposed therein; a gas supply system having a gas source (25) for providing a process gas; and a control device (32) for controlling the valves (27) and the mass flow controllers (26) so that the method according to any one of claims 1 to 11 is performed in the process chamber (2) of the reactor housing (1).

13. 13. Apparatus according to claim 12, characterized in that the gas supply device comprises a gas source (25) for supplying at least one reactive gas comprising at least one element of main groups II-IV, comprising at least one element of main groups III-V, or comprising at least one element of main group V.

14. The gas supply device comprises at least AsH ３ , P.H. ３ , N.H. ３ 14. The apparatus of claim 13, further comprising a gas source (25) for providing silane, a carbon compound, a magnesium compound, an organometallic compound, TMGa, TMIn, TMAl, or an oxide.

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