Inorganic compounds

Abstract

The invention relates to a method for producing HGeCl3 from a homogeneous gas phase reaction between GeCl4 and H2 according to (I). # imgabs0 #

Description

DETAILED DESCRIPTION

[0001] For electronic components based on germanium ("germanium stibium telluride" or germanium antimony telluride), Ge x Sb y Te x+1.5y , abbreviated as GST), seeks germanium precursors that release Ge(II) during the deposition process. These compounds are used for vapor phase deposition, which is why the germanium precursor must be highly volatile. One germanium compound considered particularly attractive is HGeCl3 (trichlorogermane or germanochloroform, CAS number: 1184-65-2). It has a boiling point of 75°C and is liquid at room temperature. Furthermore, it has a high germanium content (approximately 40 m%), ensuring a high germanium concentration in the vapor phase. This is essential for achieving high deposition rates.

[0002] The academic literature describes the following reactions:

[0003] 1) Wet chemistry

[0004] i) Reduction of GeCl4 in aqueous solution with phosphite.

[0005] ii) Reduction of GeCl4 in organic solvents using silane.

[0006] 2) Heterogeneous gas-phase reaction (HGR):

[0007] i) Reaction of elemental germanium with anhydrous HCl

[0008] Ge + 3 HCl -> HGeCl3 + H2 (idealized reaction equation)

[0009] ii) GeCl2 reacts with gaseous anhydrous HCl.

[0010] GeCl2 + HCl -> HGeCl3

[0011] iii) Reaction of GeS with gaseous anhydrous HCl.

[0012] GeS + 3 HCl -> HGeCl3 + H2S

[0013] Wet Chemistry:

[0014] Wet chemical syntheses are known, but these generate HGeCl₃ in situ and in solution: isolation of unstable HGeCl₃ from solution has not been reported. Medicinal Chemistry, 2009, 5, 382-384, describes the in situ synthesis of HGeCl₃ in aqueous medium using HCl / NaH₂PO₂ starting from GeCl₄ or GeO₂, but does not describe isolation. The HGeCl₃ obtained is directly further reacted. Furthermore, HGeCl₃ produced by wet chemical methods is not used in the semiconductor industry but is commonly used in wet (metallo)organic chemistry and pharmaceuticals. In the "Encyclopedia of Reagents for Organic Syntheses," CA Roskamp et al. describe the synthesis of HGeCl₃ starting from GeCl₄ and tetramethyldisiloxane. However, the product is not isolated, but the formed HGeCl₃ reacts further at the reaction temperature to yield the dioxane complex GeCl₂(dioxane).

[0015] Therefore, this type of reaction was deemed unsuitable for the intended purpose as described above and was not studied further.

[0016] Regarding heterogeneous gas-phase reactions, reaction 2.i was first described in 1886. C. Winkler, Journal of Practical Chemistry (J. prakt. Chem. 1886, 34, 177-229), showed the synthesis of HGeCl3 starting from Ge + HCl at red heat.

[0017] Georg Brauer's "Handbook of Preparative inorganic Chemistry" describes on page 721 the possibility of synthesizing HGeCl3 starting from Ge + HCl.

[0018] LM Dennis also described the synthesis of HGeCl3 starting from Ge + HCl in the Journal of Physical Chemistry, 1926, 30, 1049-1054.

[0019] Various documents exist, according to which pure HGeCl₃ can be obtained from this mixture by derivatization and subsequent treatment of isolated intermediate derivatives. Since this final step requires distillation under reduced pressure, it is associated with a yield loss of 81% based on the derivative. This procedure involves dissolving the initial mixture in diethyl ether, separating the resulting double-layer system, and cracking the intermediate trichlorogermyl etherate complex with aluminum trichloride.

[0020] L.M. Dennis, Journal of Physical Chemistry, 1926, 30, 1049-1054 and Georg Brauer, Handbook of Preparative Inorganic Chemistry, page 721, report reaction 2.ii as an alternative to reaction 2.i, which utilizes the equilibrium shown below. The problem here is that the GeCl2 used is temperature-sensitive and tends to decompose above room temperature to form so-called germanium subchlorides.

[0021]

[0022] (x < 2), so that in the case of gradual decomposition, only germanium and germanium tetrachloride are retained.

[0023] Georg Brauer's "Handbook of Preparative Inorganic Chemistry" describes on page 721 the possible synthesis of HGeCl3 starting from GeCl2 + HCl.

[0024] L.M. Dennis, Journal of Physical Chemistry, 1926, 30, 1049-1054, also describes the synthesis of HGeCl3 using GeCl2 + HCl as starting materials, and states that both the synthesis of GeCl2 and the subsequent reaction with HCl are carried out at temperatures above room temperature, so that the GeCl2 used is always mixed with low-valent chlorides, which has considerable disadvantages.

[0025] Reaction 2.iii is described as an alternative to reaction 2.ii in Georg Brauer's "Handbook of Preparative Inorganic Chemistry," page 721, and in C.W. Moulton et al., JACS 1956, 78, 2702-2704. A yield of approximately 40% based on GeS was achieved, and it was described as the simplest (stable reactant GeS) and cleanest synthetic route without GeCl4 as a byproduct. However, the presence of H2S during the synthesis could pose a problem, as sulfur is chemically similar to the tellurium in GST. Therefore, sulfur contained in GST could be expected to impair the functionality of electronic components, leading the inventors to conclude that sulfur should not be present in the final product, HGeCl3.

[0026] As mentioned above, compounds that release Ge(II) are particularly desirable. HGeCl3, although formally a Ge(IV) compound, is able to achieve this because it decomposes already at room temperature (and more rapidly at higher temperatures or reduced pressures) according to

[0027]

[0028] This advantage in application is at the same time disadvantageous for larger-scale synthesis: HGeCl3 is a liquid, HCl is a gas, and GeCl2 is a solid (in each case at room temperature and pressure), so HCl is slowly degassed while GeCl2 remains solid.

[0029] The problem is obtaining a product from a stable process that is of consistent quality and high purity, as is required for use in the semiconductor device industry.

[0030] The problem is solved according to the following method by generating HGeCl3 by a homogeneous gas phase reaction between GeCl4 and H2:

[0031]

[0032] In various experiments it was shown that careful reduction, ie the use of nearly equimolar amounts of hydrogen in the reduction of GeCl4 with hydrogen, can indeed selectively produce the desired product HGeCl3.

[0033] It was surprisingly found and completely unexpected that, in view of the fact that in the reaction system Ge / GeCl4 / HGeCl3 / H2 / HCl all components are in equilibrium with one another, this reaction provides a solution to the problem of the present invention.

[0034] Furthermore, the proportion of the starting material GeCl₄ is very small, allowing this previously undescribed synthesis method to produce HGeCl₃ with extremely high purity (with respect to GeCl₄ as a minor component), including 80% of the desired trichlorogermane (HGeCl₃), which is significantly higher than other methods described in the literature. The product obtained directly from the process can be used in applications in the semiconductor device industry without further purification.

[0035] Generally speaking, the above methods employing heterogeneous gas phase synthesis are not well suited to being carried out in a continuous process, or are only difficult to carry out in a continuous process, due to the use of solid starting materials.

[0036] An advantage of the present invention is that both GeCl4 (volatile and liquid) and hydrogen (gaseous) can be easily introduced into the reaction, thereby facilitating a continuous process.

[0037] The inventors of the present invention have found that the gas phase reaction particularly produces the desired product when it is carried out in a furnace (preferably a tubular furnace) and the hydrogen flux through the furnace is not higher than 0.5 L·min -1 cm -2 , preferably not higher than 0.4 L·min -1 cm -2 , and more preferably not higher than 0.3 L·min -1 cm -2In addition, it is preferred that the flux is higher than 0.1 L·min -1 cm -2 .

[0038] Furthermore, it was found that when the gas phase reaction is carried out in a furnace (preferably a tube furnace), hydrogen (H2) and germanium tetrachloride (GeCl4) are preferably provided to the furnace in a molar ratio of hydrogen (H2) to germanium tetrachloride (GeCl4) of between 1:1 and 30:1 (preferably between 2:1 and 25:1).

[0039] Furthermore, it was found that the reaction product containing trichlorogermane obtained from the gas phase reaction is preferably condensed at a temperature below -80°C, more preferably at a temperature between -80°C and -200°C.

[0040] In general, the reaction of germanium tetrachloride (GeCl4) with hydrogen (H2) to produce the desired product trichlorogermane (HGeCl3) has been found to be a very robust reaction that can be carried out at temperatures between 600°C and 1200°C, more specifically between 800°C and 1200°C.

[0041] Suitable pressures can also be applied over an extended range, and the reaction pressure is generally from 100 mbar to 10.000 mbar, more particularly reaction pressures of 800 mbar to 2000 mbar have been found to be suitable, in particular a pressure of about 1000 mbar.

[0042] Generally speaking, the method includes a step in which a gaseous mixture of germanium tetrachloride (GeCl4) and a carrier gas is generated.

[0043] This can be accomplished, for example, by subjecting germanium tetrachloride (GeCl4) to temperature and pressure conditions sufficient to produce gaseous germanium tetrachloride (GeCl4) and passing a carrier gas stream through the gaseous germanium tetrachloride (GeCl4) to generate a carrier gas stream including gaseous germanium tetrachloride.

[0044] In another embodiment, the carrier gas stream is passed through liquid germanium tetrachloride (GeCl4) under conditions sufficient to generate a carrier gas stream comprising gaseous germanium tetrachloride (GeCl4). In this embodiment, it may be advantageous to heat the germanium tetrachloride (GeCl4) to a temperature below its boiling point at ambient pressure. In particular, the germanium tetrachloride (GeCl4) is heated to a temperature of 30°C to 100°C, preferably 40°C to 100°C, more preferably 50°C to 100°C, and particularly 50°C to 80°C at ambient pressure.

[0045] Other means for generating a carrier gas stream comprising gaseous germanium tetrachloride may also be suitable.

[0046] The carrier gas may be an inert gas or hydrogen. More specifically, the carrier gas is selected from nitrogen, hydrogen, helium, neon, argon, hydrogen chloride, xenon, or a combination thereof.

[0047] If the carrier gas comprising germanium tetrachloride (GeCl4) is different from hydrogen, then hydrogen must be added as a reactant, which can be achieved by mixing with hydrogen.

[0048] In another embodiment, the carrier gas is hydrogen. Thus, no effort is required to add hydrogen to the carrier gas stream comprising gaseous germanium tetrachloride.

[0049] The carrier gas stream comprising gaseous germanium tetrachloride is subsequently heated to a temperature of preferably 600°C or higher, in particular 600°C to 1200°C or 800°C to 1000°C, more particularly about 1000°C.

[0050] This can be achieved, for example, by passing a carrier gas stream comprising gaseous germanium tetrachloride through a heat exchanger.In the simple case of this embodiment, a carrier gas stream comprising gaseous germanium tetrachloride is passed through a tube placed in a tube furnace.

[0051] The ratio of hydrogen (H 2 ):germanium tetrachloride (GeCl 4 ) is about 1:1 to about 30:1, more specifically about 2:1 to about 22:1.

[0052] Generally, a tube furnace arrangement has been found to be sufficient, which may comprise, for example, a quartz glass tube with an inner diameter of 1.8 cm and a length of 55 cm, of which 16.5 cm of the tube is externally heated. This heated area is referred to as the reaction zone.

[0053] Generally, the gas flow can be adjusted within the range of about 0.76 L / min to about 1.14 L / min, so that the reaction mixture remains in the reaction zone for 2-3 seconds. Both the flow rate and the time in the reaction zone can be adapted to the length and diameter of the glass tube and the length of the reaction zone within the tube.

[0054] Additionally, it was found that static mixing elements, such as glass wool plugs, could be inserted before or in the reaction zone as they had a positive impact on the purity of the product, most likely due to improved mixing of the reactants.

[0055] Under these conditions, the reaction between (gaseous) germanium tetrachloride and hydrogen begins and will rapidly lead to the production of the desired product trichlorogermane, thereby generating a carrier gas stream comprising gaseous trichlorogermane.

[0056] The carrier gas stream comprising gaseous trichlorogermane is subsequently brought under conditions which allow the trichlorogermane to be collected and separated from gaseous educts and by-products, in particular a suitable temperature and pressure.

[0057] Generally speaking, it is sufficient to operate at ambient pressure and cool to a temperature below 75°C (the boiling point of trichlorogermane). More specifically, the carrier gas stream comprising gaseous trichlorogermane can be cooled to a temperature below 0°C, particularly below -30°C, which can be advantageous because decomposition into germanium chloride and hydrogen chloride can be suppressed at low temperatures. In particular, cooling to a temperature below -71°C (the melting point of trichlorogermane) can be advantageous, with temperatures of -78°C or lower being even more advantageous. Thus, generally speaking, the carrier gas stream comprising gaseous trichlorogermane is cooled to a temperature between -80°C and 75°C, between -80°C and -71°C, or between -80°C and -30°C, particularly between -78°C and 0°C, between -78°C and -30°C, or between -78°C and -71°C. In another embodiment, it has been found that cooling with liquid nitrogen is feasible, so that the carrier gas stream comprising gaseous trichlorogermane can be cooled to a temperature below -80° C., preferably below -120° C., and preferably not below -200° C. Alternatively, the carrier gas stream comprising gaseous trichlorogermane can be cooled to a temperature of -200° C. to 75° C., -196° C. to -71° C., or -196° C. to -30° C.

[0058] In one embodiment, the method comprises the following steps:

[0059] - providing a carrier gas flow comprising hydrogen;

[0060] - contacting the carrier gas stream with a source of germanium tetrachloride (GeCl4) under conditions sufficient to at least partially saturate the carrier gas stream with germanium tetrachloride (GeCl4);

[0061] - The carrier gas flow is subjected to conditions sufficient to effect the reaction of germanium tetrachloride (GeCl4) with hydrogen (H2).

[0062] In this embodiment, the step of contacting the carrier gas stream with the germanium tetrachloride (GeCl4) source may be performed by passing a stream of hydrogen through the germanium tetrachloride at a temperature of 20°C to 100°C, particularly 20°C to 60°C or 23°C to 40°C, before subsequently heating to a reaction temperature of 600°C or higher under inert conditions. It should be noted that throughout this specification, the expression "under inert conditions" is to be understood as conditions in which both oxygen and water are absent or at least minimized, and is not to be broadly understood as being free of any reactive components.

[0063] In another embodiment, the method comprises the following steps:

[0064] - providing a carrier gas flow comprising hydrogen;

[0065] -Providing a flow of germanium tetrachloride (GeCl4);

[0066] - combining the carrier gas flow and the germanium tetrachloride (GeCl4) flow;

[0067] - subjecting the combined carrier gas and germanium tetrachloride (GeCl4) flow to conditions sufficient to effect a reaction of the germanium tetrachloride (GeCl4) with hydrogen (H2).

[0068] In the two embodiments mentioned above, the germanium tetrachloride (GeCl 4 ) flow can be in liquid or gaseous state.

[0069] In both embodiments mentioned above, the step of combining the carrier gas flow and the germanium tetrachloride (GeCl4) flow is performed simultaneously with the step of subjecting the combined carrier gas flow and germanium tetrachloride (GeCl4) flow to conditions sufficient to achieve a reaction between the germanium tetrachloride (GeCl4) and hydrogen (H2). This means that during the combining of the carrier gas flow and the germanium tetrachloride (GeCl4) flow, the temperature is preferably above 600°C and / or the pressure is preferably between 100 mbar and 10,000 mbar.

[0070] The step of combining both the carrier gas flow and the germanium tetrachloride (GeCl 4 ) flow may be performed by injecting the germanium tetrachloride (GeCl 4 ) flow into the carrier gas flow by means of a nozzle.

[0071] As mentioned above, conditions sufficient to achieve the reaction of germanium tetrachloride (GeCl4) with hydrogen (H2) include a reaction temperature above 600°C, in particular, a reaction temperature of 600°C to 1200°C, or a reaction temperature of 1000°C to 1200°C, and / or a reaction pressure of 100 mbar to 10.000 mbar.

[0072] The method according to any of the above technical solutions, wherein the carrier gas flow comprising gaseous germanium tetrachloride (GeCl4) and hydrogen is passed through a static mixing element before or simultaneously under conditions sufficient to achieve a reaction of germanium tetrachloride (GeCl4) with hydrogen (H2).

[0073] In another more specific embodiment, the reaction can be carried out under direct liquid injection conditions, wherein a gas stream (consisting of hydrogen, or a mixture of hydrogen and hydrogen chloride, or a mixture of hydrogen and an inert gas, or a mixture of hydrogen, hydrogen chloride, and an inert gas) is directed through a tube furnace and GeCl4 in pure form is introduced into the gas stream through a nozzle under conditions sufficient to allow reaction of germanium tetrachloride (GeCl4) with the hydrogen.

[0074] The gas stream thus performs the functions of both reactant and carrier gas, allowing it to react hydrogen with GeCl4 to form the product HGeCl3, and driving it through the furnace to a point where it is allowed to cool, allowing the product to condense where it can be collected.

[0075] The conditions for condensation and reaction were essentially the same as mentioned above, wherein the gas stream was bubbled through pure GeCl4 in order to produce a GeCl4-saturated gas stream.

[0076] The present invention also relates to trichlorogermane (HGeCl 3 ) obtained directly by the process of the present invention, in particular a trichlorogermane (HGeCl 3 ) primary product comprising at least 70% trichlorogermane, preferably at least 75% and more preferably at least 80% trichlorogermane (HGeCl 3 ).

[0077] Examples :

[0078] General experimental procedure for the preparation of HGeCl3 from GeCl4 and H2:

[0079] Corresponding parameter T B 、J H2 、T R , t R and the coolant / others used can be obtained from Table 1.

[0080] The tube furnace setup consisted of a 550 mm quartz glass tube (inner diameter: 18 mm). 165 mm of the tube was externally heated, defining the reaction zone. The air flow was adjusted between 0.76 L / min and 1.14 L / min, so that the reaction mixture remained in the reaction zone for approximately 2-3 seconds. Furthermore, a glass wool plug inserted into the reaction zone was found to have a positive impact on product purity, most likely due to better mixing of the reactants. Experiments using glass wool plugs are marked accordingly in Table 1.

[0081] Place GeCl4 in a stainless steel bubbler and preheat the bubbler to a specific temperature T B .

[0082] ● Make pure hydrogen flow at a rate of J H2 Through this bubbler, a flow of H2 saturated with GeCl4 was generated.

[0083] ● This GeCl4 / H2 mixture is placed in a heated R Glass tubes in a tube furnace.

[0084] ●The reaction proceeds for a certain time (t R ).

[0085] ●Use dry ice or liquid nitrogen as a condensing agent to condense the reaction products at the outlet of the tube.

[0086] • In some experiments, a plug of glass wool was introduced into the reaction zone for better mixing of the reactants.

[0087] Table 1: Overview of tests and selected parameters.

[0088]

[0089] a) Reaction in the presence of a glass wool plug.

[0090] b) 1.14 L·min -1 Hydrogen flow J H2 Corresponding to the hydrogen flux Φ H2 0.45 L·min -1 cm -2 ;0.76 L·min -1 Hydrogen flow J H2 Corresponding to the hydrogen flux Φ H2 0.30 L·min -1 cm -2 .

[0091] The test results are summarized in Table 2:

[0092] When selecting parameters or experimental procedures, care was taken to ensure that only one parameter changed from one experiment to the next (Experiments 1-8).

[0093] ●The gas phase concentration of GeCl4 is affected by the bubbler temperature.

[0094] In the first three experiments, it was shown that a high hydrogen to GeCl4 ratio has a positive effect on the HGeCl3 content. The H2:GeCl4 ratio was calculated using the following parameters: Current velocity J H2 × reaction time t R = reaction volume H2, where the reaction volume gives the amount of hydrogen used via the ideal gas equation p×V = n×R×T. The amount of GeCl4 was obtained by weighing the GeCl4 bubbler before and after the reaction.

[0095] This can be explained by the fact that the reaction GeCl4 + H2 <-> HGeCl3 + HCl is an equilibrium reaction, and with increasing hydrogen content, the equilibrium shifts to the right. It is also shown here that as the bubbler temperature increases, the GeCl4 consumption increases, as well as the amount of separated product. This is a direct effect of the increased evaporation rate of GeCl4 (due to the higher vapor pressure / higher bubbler temperature).

[0096] ● Experiments 3 and 4 show that the higher the flow rate of hydrogen gas, the H2 This has a negative impact on product purity: This can be explained by the shorter residence time of the reaction mixture in the reaction zone. Since equilibrium is to the right at higher temperatures, the product side is favored, as equilibrium can be better established by a longer residence time in the hot reaction zone. At the same time, less GeCl₄ is discharged, and less crude product is isolated, which can be explained by the lower stock flow from the bubbler.

[0097] ● Experiments 4 and 5 clearly show that the reaction temperature T R Effect on the HTeCl3 content of the crude product: The lower the reaction temperature, the lower the HGeCl3 content. Since the equilibrium of the reaction GeCl4 + H2 <-> HGeCl3 + HCl is on the right side at high temperatures, the equilibrium shifts toward the reactants GeCl4 and H2 at lower temperatures.

[0098] Experiments 1 and 7 show that with longer reaction times, the GeCl4 output increases (as expected), and the amount of crude product isolated also increases (also expected). Interestingly, the purity also increases, which is likely due to the formation of GeCl2 (a byproduct of the reaction) entering the collection vessel, where it reacts again with HCl (also a byproduct of the reaction) to form HGeCl3.

[0099] Experiments 4 and 8 show that the temperature at which the product is condensed affects the discharge of GeCl4, the amount of crude product isolated, and the purity of the crude product: if the crude product is condensed at -196°C instead of -78°C, the discharge of GeCl4 increases, and the amount of crude product isolated increases; in addition, the HTeCl3 content in the crude product increases. The increased discharge is likely due to the fact that the significantly lower condensation temperature also produces a strong negative pressure, which draws more GeCl4 out of the bubbler. The increased crude yield is directly due to the fact that at -196°C, the vapor pressure of the product is significantly lower than at -78°C, and therefore less material is discharged from the cooling trap with the reaction gas stream from the collection vessel. The increased HGeCl3 content is likely the result of HCl freezing, which occurs at -196°C but not at -78°C. Since GeCl2 is considered one of the main impurities in the crude product, when it enters the collection vessel, it can react with the HCl condensed there to form HGeCl3, which explains the increased HGeCl3 content.

[0100] Experiments 4 and 6 show that the use of glass wool plugs in the reaction zone slightly increases the GeCl4 yield, the amount of crude product isolated, and the HTeCl3 content. While the GeCl4 output (and therefore the increased crude yield) can be explained by statistical fluctuations in adjusting the H2 flow, the increased HTeCl3 content is likely a result of the glass wool plugs, which ensure better mixing of the reactants and better heat transfer from the outer wall of the heated tube to the center of the tube.

[0101] • In the last experiment, it can be seen that the combination of all parameters that showed a positive influence on the response during the first 8 experiments led to a further improvement of the results.

[0102] Table 2: Overview of the tests and the results obtained.

[0103]

Claims

1. A method for producing trichlorogermane (HGeCl3) by a gas phase reaction of germanium tetrachloride (GeCl4) and hydrogen (H2).

2. The method according to claim 1, wherein the gas phase reaction is carried out in a furnace, and wherein the hydrogen flux through the furnace is not higher than 0.5 L·min -1 cm -2 .

3. The method according to claim 1 or 2, wherein the gas phase reaction is carried out in a furnace, and wherein hydrogen (H2) and germanium tetrachloride (GeCl4) are provided to the furnace at a hydrogen (H2) to germanium tetrachloride (GeCl4) molar ratio between 2 and 25.

4. The method according to any one of claims 1 to 3, wherein the reaction product obtained from the gas phase reaction is condensed at a temperature lower than -80°C and not lower than -200°C.

5. The method according to any one of claims 1 to 4, comprising the steps of: - providing a carrier gas flow comprising hydrogen; - contacting the carrier gas stream with a source of germanium tetrachloride (GeCl4) under conditions sufficient to at least partially saturate the carrier gas stream with germanium tetrachloride (GeCl4); - subjecting said carrier gas flow to conditions sufficient to effect said reaction of germanium tetrachloride (GeCl4) with hydrogen (H2).

6. The method according to any one of claims 1 to 5, comprising the steps of: - providing a carrier gas flow comprising hydrogen; -Providing a flow of germanium tetrachloride (GeCl4); - combining the carrier gas flow and the germanium tetrachloride (GeCl4) flow; - subjecting said combined carrier gas flow and germanium tetrachloride (GeCl4) flow to conditions sufficient to effect said reaction of germanium tetrachloride (GeCl4) with hydrogen (H2). 7 . The method according to claim 1 , wherein the germanium tetrachloride (GeCl 4 ) stream is liquid or gaseous.

8. The method of any one of claims 1, 6, and 7, wherein the step of combining the carrier gas flow and the germanium tetrachloride (GeCl4) flow and the step of subjecting the combined carrier gas flow and germanium tetrachloride (GeCl4) flow to conditions sufficient to effect the reaction of germanium tetrachloride (GeCl4) with hydrogen (H2) are both performed simultaneously.

9. The method according to any one of claims 1 and 6 to 8, wherein the step of combining both the carrier gas flow and the germanium tetrachloride (GeCl4) flow is performed by injecting the germanium tetrachloride (GeCl4) flow into the carrier gas flow by means of a nozzle.

10. The method of any one of claims 1 to 9, wherein the conditions sufficient to achieve the reaction of germanium tetrachloride (GeCl4) with hydrogen (H2) include a reaction temperature above 600°C.

11. The process according to any one of the preceding claims, wherein the reaction temperature is from 600°C to 1200°C.

12. The process according to any one of the preceding claims, wherein the reaction temperature is from 1000°C to 1200°C.

13. The method of any one of the preceding claims, wherein the conditions sufficient to effect the reaction of germanium tetrachloride (GeCl4) with hydrogen (H2) comprise a reaction pressure of 100 mbar to 10.000 mbar.

14. The process according to any one of the preceding claims, wherein the reaction pressure is from 800 to 2000 mbar.

15. The method according to any one of the preceding claims, comprising a step in which a gaseous mixture of germanium tetrachloride (GeCl4) and a carrier gas is generated.

16. The method according to any of the preceding claims, in particular according to any of claims 1 or 2, wherein the germanium tetrachloride (GeCl4) is brought to a temperature and pressure sufficient to produce gaseous germanium tetrachloride (GeCl4) and a carrier gas flow is passed through the gaseous germanium tetrachloride (GeCl4).

17. The method according to any of the preceding claims, in particular according to any of claims 1 or 2, wherein the carrier gas flow is passed through liquid germanium tetrachloride (GeCl4) under conditions sufficient to allow generation of a carrier gas flow comprising gaseous germanium tetrachloride (GeCl4).

18. The method according to any one of the preceding claims, wherein the carrier gas is an inert gas or hydrogen.

19. The method according to any one of the preceding claims, wherein the carrier gas is selected from nitrogen, hydrogen, helium, neon, argon, hydrogen chloride, xenon or combinations thereof.

20. The method according to any one of the preceding claims, wherein a carrier gas comprising germanium tetrachloride (GeCl4) is mixed with hydrogen.

21. A method according to any one of the preceding claims, wherein the carrier gas is hydrogen.

22. A process according to any one of the preceding claims, wherein a stream of hydrogen is passed through the germanium tetrachloride at a temperature of 20 to 100°C and then heated to a reaction temperature of 600°C or higher under inert conditions.

23. The process according to any one of the preceding claims, wherein the gas stream is passed through a cold trap at a temperature below -50°C to obtain trichlorogermane (HGeCl3) as a solid product.

24. The method of any one of the preceding claims, wherein the carrier gas stream comprising gaseous germanium tetrachloride (GeCl4) and hydrogen is passed through a static mixing element prior to or while being under conditions sufficient to effect the reaction of germanium tetrachloride (GeCl4) with hydrogen (H2).

25. Trichlorogermane (HGeCl3) directly obtained by the process according to any one of the preceding claims.

26. A trichlorogermane (HGeCl3) primary product, directly obtained by the process according to any one of the preceding claims, the trichlorogermane (HGeCl3) primary product comprising at least 80% trichlorogermane (HGeCl3).

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