TW201504178A - SiO2-based barrier layer for high-temperature diffusion and coating processes - Google Patents

Abstract

The invention relates to a device for modifying semiconductors with corrosive process gases or for coating objects made of silicon, ceramic, glass or graphite, or for manufacturing silicon, comprising components with quartz glass base bodies which are coated with a silicon dioxide layer that has a higher porosity than the quartz glass. Furthermore, the invention relates to a method for doping and coating semiconductors, for coating objects made of glass, silicon, ceramic or graphite, as well as for manufacturing silicon, in which use is made of the device according to the invention. Furthermore, the invention relates to the use of an amorphous silicon dioxide layer on a quartz glass base body in order to reduce the corrosion caused by process gases.

Description

SiO 2 -based barrier layer and coating method for high temperature diffusion

The invention relates to a device for modifying semiconductors, in particular for doping or for coating articles made of enamel, graphite, ceramic or glass or for the manufacture of ultrapure ruthenium. The apparatus comprises an assembly having a quartz glass substrate coated with a ceria layer having a higher porosity than the quartz glass coated therewith. Furthermore, the invention relates to a method of doping a semiconductor, coating an article made of tantalum, graphite, ceramic or glass and manufacturing an ultrapure crucible, wherein the apparatus according to the invention is utilized. Furthermore, the present invention relates to the use of an amorphous ceria layer having a higher porosity than a quartz glass substrate for use on a quartz glass substrate to reduce corrosion caused by a process gas and to be mechanically stable Component.

Quartz glass components, especially those used in the manufacture of semiconductor components, are typically exposed to high heat loads and chemically aggressive media. In these applications, high thermal shock resistance, high chemical resistance and protection from contamination play an important role. The service life and particle-free properties of these quartz glass components must meet increasingly high demands. Regarding the service life of quartz glass components, it is of decisive importance for the chemical resistance of the process gas. Quartz glass assemblies are commonly used in processes that are performed in the gas phase, for example, as part of a processing chamber or as a holding device. When such processing is performed, the substrate to be modified (mainly Si wafer in semiconductor technology) is in contact with the gas chemical etching compound at a high temperature. This not only causes the reaction of the substrate, but also the quartz glass component is also eroded by the partially corrosive processing gas.

One particularly critical process is the doping of semiconductors with boron, where the Si wafer is combined with a source of gaseous boron. This allows the handling of the electrical properties of a particular control metal to play an important role in semiconductor technology. When this treatment is performed, the quartz glass component of the processing chamber is also attacked by a source of gaseous boron, which results in the formation of a binary phase consisting of SiO ₂ and B ₂ O ₃ and containing a liquid phase that is significantly lower than the addressed processing temperature. Line temperature. This can result in melt corrosion of the component, which results in the formation of spots where the component walls become thinner and thinner, which can ultimately lead to component fracture. In addition, a crystalline product deposited as a layer on the assembly is formed. During cooling, these layers of quartz glass that adhere extremely well to the assembly create stresses that begin at a particular thickness of the coating, resulting in the formation of cracks that rupture the assembly by repeatedly forming cracks. In addition, Si wafers may adhere to components and/or components that may adhere to each other, which also causes damage to the components. In order to protect the quartz glass component from such signs of corrosion, it is possible to coat the quartz glass surface with materials and compounds that contain higher tolerances for the erosion of the process gas.

Another area of application for quartz glass components is CVD (" Chemical Vapor Deposition "). In such a coating process, for example, for fabricating microelectronic components and optical cables, a ceramic layer (for example, made of tantalum carbide, tantalum nitride, hafnium oxynitride or aluminum oxide) is applied by depositing a gas component. On the object. This also results in the formation of a layer on the quartz glass component that is in contact with the gas-coated component as a partial processing tube, bell jar, gasket or holder. Due to the different coefficients of expansion of the quartz glass and the layers deposited thereon, temperature changes that occur during processing can cause the layer to flake off, which results in the formation of particles in the process which can damage the surface quality of the article to be coated. . In addition, as long as the quartz glass component is broken, cracks are formed which can cause damage.

A similar problem can be seen in the manufacture of ultrapure ruthenium or in epitaxial processing where ruthenium is deposited on a support in a heat treatment. Among them, gas enthalpy is deposited on the quartz glass component of the processing chamber, which causes the above limitations, such as delamination of the layer and cracking as long as the component is broken.

US 5,540,782 describes the use of quartz glass sheets for applications in heat treated Si wafers as heat shields and radiation shields. These shields are designed as flat sheets made of high purity opaque quartz glass containing at least one layer of transparent quartz glass. Alternatively, the plates may be comprised of high purity opaque quartz glass containing micropores resulting from foaming. Among them, the pore diameter is in the range of 30 μm to 120 μm, and the density of the porous opaque quartz glass is in the range of 1.9 g/cm ³ to 2.1 g/cm ³ . By sealing the processing chamber with the plates, it is intended to obtain sufficient thermal insulation and to ensure a constant temperature distribution during processing.

DE 34 41 056 A1 describes a method for reducing the wear of quartz glass components in chemical vapor deposition crucibles during CVD. Wherein, the quartz glass member is provided with a protective layer which is resistant to the gas-containing cerium compound even at a temperature exceeding 500 ° C, and has a blocking effect against ion diffusion and has a thermal expansion coefficient which does not affect the adhesion to the quartz. Made of materials. This protective layer is made of a non-cerium oxide compound such as tantalum nitride, tantalum carbide or a ceramic material, and is preferably coated by chemical vapor deposition.

DE 197 19 133 C2 describes a quartz glass bell jar for a reactor chamber, which should be used in particular for plasma etching devices. The inner surface of the chamber contains a roughened region having a roughness depth of at least 1 μm, characterized in that a layer of porous bubbles embedded in the non-porous or low-porosity quartz glass is coated on this region. The bell jar is made by glazing the cerium oxide-containing particles, and another component of Si ₃ N ₄ is added to the particles while forming the inner surface, which reacts while releasing the gas during the glazing. This bubble containing inner layer is intended to prevent interference particles from being released during plasma etching.

DE 10 2007 030 698 B4 describes a method for producing a composite (made of a substrate of opaque quartz glass and a sealing layer) and the use of the composite as a heat radiation reflector. This method aims to seal the opaque substrate without any significant modification and deformation. To achieve this, the substrate is made by using a slurry (containing primary amorphous cerium oxide particles) and then coated with another slurry (containing finer amorphous particles and, in addition, 0.2 to 15 weight percent of SiO ₂ nanoparticles) cover. The sealing layer is dried and glazed, wherein the second slurry comprises a lower glaze temperature than the first slurry.

DE 44 29 825 C1 describes a coating assembly made of quartz glass for use in semiconductor technology processing. In order to obtain good temperature resistance and long-term stability of the component (in terms of chemical resistance to hydrofluoric acid and nitric acid and a mixture of two acids), the assembly consists of tantalum carbide and at least one other component. The gradient layer is coated, the other component has a lower hardness and modulus of elasticity than the tantalum carbide, and its concentration decreases from the inside to the outside across the layer thickness. Among them, the second component preferably contains antimony, cerium oxide or cerium nitride.

Doping germanium with impurity atoms such as boron is an important part of semiconductor technology. Due to the corrosion caused by the process gas and the wear of the quartz glass components associated therewith, the latter has only a very limited application time. Similar phenomena can be found in CVD processes, especially in high temperature CVD processes, and in ultrapure germanium fabrication where the components of the process gas can be deposited on quartz glass, which in turn limits the application time of the component, such as by cracking ( Caused by the formation of cracks. According to the prior art, if the component is modified or replaced early enough, only the wear of the component can be offset. In terms of work and cost, since this is related to considerable complexity, it is necessary to prevent, in any case, at least the above-mentioned wear of the quartz glass component.

Accordingly, it is an object of the present invention to provide a quartz glass assembly and apparatus separately that effectively avoids erosion of the process gas (whether due to corrosion or formation of layers) and the resulting wear. Furthermore, it is an object of the present invention to provide a method which promotes gas phase doping or coating with corrosive process gases, reduces wear of the processing chamber and quartz glass based components and increases their useful life.

The present invention solves this problem with respect to the abrasion of the quartz glass surface from corrosion by corrosive process gases, as the assembly (which is provided for use in corrosive areas) The quartz glass-containing component of the treatment of the gas has an additional layer of ruthenium dioxide having a porosity higher than that of the quartz glass itself. This layer acts as a barrier between the quartz glass surface and the corrosive process gas. In this way, it is possible to avoid the process gas damaging the quartz glass surface. In fact, the additional ruthenium dioxide layer should be eroded and, if necessary, replaced by quartz glass before the surface of the quartz glass, and therefore any damage to the assembly. Since the additional ruthenium dioxide layer is very similar in composition to quartz glass, it is possible to avoid the formation of stress-related cracks which can cause the assembly to rupture. However, if cracks are formed in the coating, due to the pores of the ceria layer (having a higher porosity than the quartz glass itself), multiple microcrack branches can cause cracks to disperse, resulting in a plurality of small cracks rather than individual Big cracks. Macroscopically, this increases the mechanical resistance of the component. Furthermore, particle formation caused by spalling can be reduced by coating according to the invention.

Another important treatment, in which quartz glass is used in the form of parts of the processing chamber, is to coat and process ultrapure crucibles, in which a ceramic layer, such as tantalum carbide or tantalum nitride, is applied, for example, to the coating process. On objects made of ceramic, glass, enamel or graphite. In such treatments, gas phase or gas deposition results in the formation of a layer on the surface of the quartz glass facing the process, wherein the layer forms a mechanical bond with the quartz glass. As the layer thickness increases, the mechanical stress due to the different expansion coefficients of the quartz glass and the deposit during the cooling phase also increases. Thereby, the resulting shear stress increases until mechanical debris occurs. Typically, the rupture pattern contains fragments and shell-like dots, where typically the quartz glass is also torn. There may even be cracks that completely pass through the quartz glass component, thus causing damage. Here, an additional ceria layer having a higher porosity than quartz glass helps to increase the mechanical resistance of the assembly due to crack dispersion.

Surprisingly, it has been demonstrated that coating with a layer of ruthenium dioxide (porosity higher than the quartz glass coated therewith) avoids or at least counteracts the formation of cracks. Due to the micropores in the layer, the number and size of the micropores are significantly increased compared to quartz glass, and the cracks being formed are dispersed, resulting in the formation of a plurality of small cracks rather than individual large cracks; macroscopically, the mechanical mechanism of quartz glass resistance.

It is an object of the present invention to provide a device for modifying semiconductors, more particularly for doping, for coating articles made of tantalum, graphite, ceramic or glass, or for making ultrapure crucibles, previously The shortcomings of the technology are avoided. In particular, it is an object of the present invention to provide a device equipped with components that are resistant to aggressive process gases and from deposits such as those occurring in gas phase boron doping, high temperature CVD processes or in the manufacture of ultrapure Damage caused by).

Accordingly, the subject of the invention is a device for doping a semiconductor with a corrosive process gas, or for coating articles made of ruthenium, graphite, ceramic or glass, or for the manufacture of ultrapure ruthenium, the device An assembly comprising one or more substrates comprising wholly or at least partially composed of quartz glass, wherein the quartz glass is coated with a layer of ceria having a higher porosity than the quartz glass of the substrate.

The porosity of the ceria layer according to the invention is determined in accordance with DIN 66133.

Among them, the ruthenium dioxide layer is preferably directly applied to the quartz glass of the module. This means that no additional layers or components are configured between them.

Within the meaning of the invention, an article made of glass, ceramic, graphite or tantalum refers to an article having at least one surface, irrespective of its function, comprising glass or ceramic, graphite or tantalum or consisting of one of the above materials. Preferably, the surface of the article contains only one of the listed components. For example, the item can be a component. Within the meaning of the present invention, for example, articles made of glass, ceramic, graphite or tantalum may be, for example, tantalum wafers used in semiconductor technology. Objects within the meaning of the invention may also be graphite components.

In a preferred embodiment, the coating consists entirely of cerium oxide and contains substantially no additional components. In the coating, the addition of additional components other than cerium oxide is generally less than 5% by weight, preferably less than 2.5% by weight, more preferably less than 1.9 weight percent, most preferably less than 0.1 weight percent, and specifically Less than 0.01 weight percent, each ratio is related to the total weight of the coating material.

Another preferred embodiment of the assembly is one in which there is no other than the cerium oxide coating The outer coating (on the component, especially the coating which is different from the cerium oxide), that is, the cerium oxide layer is preferably the only coating of the component. In another preferred embodiment of the assembly, the coating is configured to contact the corrosive process gas, such as on the inside of the processing chamber or facing an interior region thereof. Preferably, the surface of the coating consists of cerium oxide and forms the outer surface of the quartz glass component which is preferably partially, but more preferably wholly, in contact with the process gas.

The assembly for use in the apparatus according to the invention and exposed to a corrosive process gas preferably and substantially comprises a matrix of quartz glass and a layer of ruthenium dioxide, the ruthenium dioxide layer being disposed directly thereon and having a specific matrix The high porosity of quartz glass. Moreover, the higher porosity of the cerium oxide layer imparts a lower density to the layer than the quartz glass.

In a preferred embodiment of the invention, the coated quartz glass surface of the assembly is in contact with a corrosive process gas. Typically, the device according to the invention comprises one or more components, the matrix of which consists essentially of quartz glass and is coated with cerium oxide. The components (including or consisting of) of the holding device, the gas containing device, the shielding plate, the processing tube, and the processing chamber are intended to be described in detail by way of example (but not by way of limitation).

Wherein the treatment tube may be formed, for example, of a plurality of workpieces, but it is preferably formed of a single workpiece, wherein the treatment tube is sized in the shape of, for example, a cylinder and may have a length of from 1 m to 3 m and an inner diameter of from 150 mm to 600 mm, for example 200mm to 300mm.

Further, the processing tube may have a shape such as a bell jar, wherein the inner diameter may be, for example, 800 mm to 1200 mm.

In a preferred embodiment of the apparatus according to the present invention, the assembly is selected from the group consisting of a holding device, a gas containing device, a shielding plate, a processing tube, and a processing chamber.

Typically such components are directly exposed to corrosive process gases and are therefore particularly prone to signs of wear caused by process gas erosion. The additional ruthenium dioxide layer counteracts these signs and thus extends the application time of the components. The extended application time of the components creates considerable economic advantages because there is no longer a need to replace components frequently, which facilitates continuous flow of processing and The continuous high quality of the product.

A preferred embodiment is characterized in that the ceria layer of the module has a porosity of from 5% to 30%, preferably from 10% to 30%. The non-porous (closed) body has a porosity of 0%. The porosity of the layer can be determined by means of a mercury porosimetry (according to DIN 66133). Wherein, the density of the ceria layer may be from 70% to 95% of the density of the quartz glass of the substrate. In a particularly preferred embodiment of the invention, the ceria layer may have a density from 70% to 85% of the density of the quartz glass of the substrate.

Preferably, the coated cerium oxide is amorphous, which proves to be a fundamental advantage. The amorphous structure ensures that the quartz glass substrate is unaffected by the increase in capacity caused by phase changes and, in addition, has an adverse effect on the resistance of the quartz glass under the processing conditions of the gas phase treatment. Preferably, the quartz glass of the substrate is also amorphous.

According to another preferred aspect of the invention, the apparatus comprises one or more components which can be obtained by a process comprising the steps of: - coating with cerium oxide (preferably coated in a large area) comprising quartz glass A component in which the layer has a higher porosity than quartz glass.

In a preferred embodiment of the apparatus according to the invention, the layers are applied by means of mud treatment and/or thermal spraying.

The cerium oxide layer is preferably applied by means of a mud treatment. To accomplish this, a slurry comprising cerium oxide can be applied to the glazed quartz glass substrate. The slurry is applied by, for example, dipping, spraying, knife coating or screen printing. The consistency of the mud is adjusted for the corresponding coating method.

A typical mud composition suitable for coating a quartz glass substrate contains SiO ₂ particles in a liquid. The liquid selected is preferably a polar liquid, preferably selected from the group consisting of water and an alcohol such as ethanol or methanol, and any mixture thereof. The slurry is applied to a quartz glass substrate and then dried during the formation of the porous layer.

Preferably, the slurry coated quartz glass based system is sintered. Among them, the sintering temperature The degree is preferably between 1000 ° C and 1300 ° C, more preferably between 1100 ° C and 1250 ° C. Preferably, the residence time is from 1 hour to 24 hours, preferably from 3 hours to 12 hours.

Preferably, the SiO ₂ particles in the slurry have an average crystal grain size of from 0.01 μm to 30 μm, preferably from 0.01 μm to 15 μm. Within the meaning of the invention, the average grain size is understood to mean the average size of the SiO ₂ particles in the mud, which is determined in accordance with DIN EN 725.

In another preferred embodiment, the ceria layer is applied by means of a thermal spray process. Among them, the ruthenium dioxide layer can be applied by, for example, vapor deposition of a gas ruthenium dioxide. To accomplish this, a spraying device known in the prior art can be used. Thermal spraying involves a method in which SiO ₂ melts inside or outside the spraying device and strikes the surface of the quartz glass of the substrate. Typical spray methods include plasma spray and flame spray.

The pore size of the layer that can be implemented depends on the coating method. When coated with mud technology, the average longest extension of the micropores is usually 0.1 to 10 μm, while in thermal spraying, the average longest extension of the micropores is usually between 0.1 and 1.0 μm, each determined by microscopic measurement. .

The device according to the invention is suitable for doping, in particular for boron doping semiconductors with corrosive processing gases.

As an alternative, the device according to the invention is suitable for coating articles consisting of or comprising bismuth, graphite, glass or ceramic.

Furthermore, the apparatus according to the invention is preferably suitable for the manufacture of ultrapure oximes starting from gaseous ruthenium containing compounds such as trichloromethane.

The doping of boron in the gas phase is characterized by uniform distribution of boron and high reactivity. In addition, gas phase boron doping allows for a large area doping operation in which a plurality of articles (eg, wafers) to be doped can be simultaneously doped. However, according to the prior art, doping with a gaseous boron source is avoided because the aggressive gas can attack the quartz glass component of the processing chamber and thus considerably limit its application time. Instead, a boron paste is used, but it is disadvantageous because the treatment proceeds very slowly and the doping with boron is only local, ie only at the point of application.

For this reason, another subject of the invention is a doping method comprising the following steps: - contacting the object to be doped with a process gas comprising a dopant, wherein doping in the device, in particular in the processing chamber, and wherein the device comprises one or more components comprising one or more A substrate consisting entirely or at least partially of quartz glass, which is wholly or partially coated with a layer of ceria having a higher porosity than the quartz glass of the substrate.

Therein, the coating is disposed on the assembly to expose it to the process gas during operation.

In a preferred embodiment of the doping method according to the invention, the object to be doped is used in semiconductor technology and/or photovoltaic devices.

In another preferred embodiment of the doping method according to the invention, the article to be doped comprises germanium (especially germanium wafers).

In a preferred embodiment of the doping method according to the invention, the process gas comprises a source of boron. The process gas typically consists of a carrier gas, such as argon or nitrogen, which is mixed with a source of boron. Further, the process gas usually contains oxygen as a reaction gas. Among them, the boron source may be provided, for example, in the form of a boron halide such as boron chloride or boron bromide or in the form of borane. Typically, the actual dopant source B ₂ O _{3 is} subsequently formed in situ from the gaseous boron compound.

Another preferred embodiment of the doping method according to the present invention is characterized in that the temperature of the process gas is in the range of 500 ° C to 1500 ° C, more preferably in the range of 600 ° C to 1200 ° C and most preferably in the range of 750 ° C to 1100 ° C. Inside. These temperatures provide a uniform and efficient doping operation, especially if the process gas comprises a mixture of oxygen, nitrogen, and a boron halide such as boron chloride or boron bromide.

In a preferred embodiment of the doping method according to the present invention, the ceria layer has a porosity of from 5% to 30%, preferably from 10% to 30%.

Among other important treatments in the field of semiconductor technology are, among other things, coating articles made of glass, ceramic, tantalum or graphite and making ultrapure tantalum. Wherein the layer is formed on quartz glass, wherein if the quartz glass is subjected to temperature changes (such as occurs in the cooling phase of the treatment), different coefficients of expansion may result in the formation of cracks.

Therefore, another subject of the invention is a method for coating an article made of glass, ceramic, graphite or tantalum comprising the steps of: - coating a member to be coated with a gas coating agent, An article made of glass, ceramic, graphite or tantalum, which is applied in a device, in particular in a processing chamber, wherein the device comprises one or more components comprising one or more complete or at least Part of a matrix composed of quartz glass, which is wholly or partially coated with a ceria layer having a higher porosity than the quartz glass of the substrate.

Within the meaning of the invention, a gas coating agent is understood to mean a gas or a gas mixture comprising a coating agent, that is to say a substance or a compound which results in the formation of a layer on the article. Preferably, the gas coating agent is selected from the group consisting of SiHCl ₃ , SiCl ₄ , Si(CH ₃ )Cl ₃ , SiH ₂ CH ₂ , trimethylaluminium (TMA), NH ₃ , N ₂ O, tantalum nitride or decane.

In a preferred embodiment, the coating agent is provided as a gas mixture with another gas. The additional gases may be, for example, combustion gases or carrier gases. Preferably, the additional gas system is selected from the group consisting of methane, ethane, propane, butane, CO, CO ₂ , H ₂ , O ₂ , N ₂ , Ar and He.

Preferably, the coating with a gas coating agent is carried out at a temperature above 250 ° C, preferably between 300 ° C and 1500 ° C.

In a preferred embodiment, the article to be coated is a tantalum wafer, and a coating of aluminum oxide or tantalum nitride is applied to one side of the tantalum wafer.

In an alternative preferred embodiment, the article to be coated is a graphite component to which a layer of tantalum carbide is applied.

The ruthenium dioxide layer preferably counteracts mechanical stress because deposits deposited on the quartz glass during processing can cause cracks and damage to the assembly due to different coefficients of expansion.

The manufacture of ultrapure germanium plays an important role in semiconductor technology because of its high purity. It is one of the main components of semiconductors.

Accordingly, another subject of the present invention is a method for making ultrapure germanium comprising the steps of: depositing germanium, wherein the deposit is deposited in a device, in particular, in a processing chamber, wherein the device comprises Or a plurality of components comprising one or more substrates consisting entirely or at least partially of quartz glass, the quartz glass being wholly or partially coated with a ceria layer having a higher porosity than the quartz glass of the substrate.

In a preferred embodiment, the ruthenium is deposited from a gaseous ruthenium containing compound (specifically, trichloromethane).

Preferably, the ruthenium is deposited by introducing a gas-containing ruthenium-containing compound (for example, trichloromethane) into a reactor (for example, a bell-shaped quartz glass reactor), wherein one or more carriers (on which the ruthenium is deposited) are disposed. In the quartz glass reactor. The carrier preferably comprises or consists of. The deposition is preferably effected at a temperature above 800 ° C (eg, between 800 ° C and 1300 ° C, preferably between 1000 ° C and 1200 ° C).

Surprisingly, it has been demonstrated that another coating of quartz glass coated with cerium oxide results in reduced corrosion of the quartz glass, especially in the treatment of gaseous compounds.

Therefore, another subject of the present invention is the use of a cerium oxide layer on a quartz glass substrate, wherein the layer has a higher porosity than the quartz glass of the substrate to reduce or attenuate corrosion of the quartz glass caused by the processing gas or As a barrier layer for high temperature diffusion or coating treatment.

Within the meaning of the present invention, corrosion is the reaction of a material with its environment which causes a measurable change in the material and can result in a functional impairment of the component comprising the material. Within the scope of the invention, the material is preferably quartz glass. Within the meaning of the invention, the environment contains all materials in contact with the quartz glass when processed. Among them, there is no correlation between the state of aggregation of matter. It can be provided as a gas, a liquid or as a solid in pure form or as a mixture.

Preferably, the ruthenium dioxide layer in contact with the process gas should represent a separation layer between the process gas and the quartz glass, which should prevent the process gas from eroding the quartz glass or in place of the quartz glass, and thus serve as a substitute for quartz glass. Sacrifice layer.

In a preferred embodiment of the use according to the invention, the process gas comprises a temperature in the range from 200 ° C to 1600 ° C, especially from 300 ° C to 1500 ° C, but preferably from 400 ° C to 1300 ° C.

Another preferred embodiment is characterized in that the process gas comprises a source of boron. Within the scope of the invention, a boron source is understood to mean boron and boron compounds, especially those which form boron oxide with oxygen under processing conditions, such as boron halides (for example BCl ₃ , BBr ₃ or borane).

In a preferred embodiment of the use according to the invention, the ceria layer having a higher porosity than the quartz glass of the substrate comprises a limited adhesion to the surface of the quartz glass of the substrate which allows removal from the surface of the quartz glass (preferably No residue removal) This layer does not damage the quartz glass surface.

Preferably, the ruthenium dioxide layer is mechanically removed (for example by grinding) or thermally removed (for example by means of a gas burner). Herein, the low porosity of the cerium oxide layer has proven to be advantageous.

In an equally preferred embodiment, the ruthenium dioxide layer is chemically removed, such as by the use of an acid. Suitable acids are, for example, hydrofluoric acid or a mixture of other mineral acids and hydrofluoric acid. It has been found that the larger specific reaction surface of the cerium oxide layer promotes rapid dissolution of the layer and complete capillary penetration of the cerium oxide layer. The layer used in accordance with the present invention and any deposits that may be disposed thereon may thus be rapidly removed and free of residue to the extent that it does not substantially affect the surface of the quartz glass.

At the same time, if the old ruthenium dioxide layer has been used up or its thickness has been reduced to a critical amount (the protective function is no longer fully guaranteed at this critical amount), limited adhesion should allow the quartz glass surface to be cleaned without any damage and rapid And easily coating a new layer of cerium oxide.

In another preferred embodiment of the use according to the invention, the porosity is higher than the matrix The ceria layer of quartz glass is characterized by a layer thickness of between 0.1 mm and 3.0 mm, preferably between 0.5 mm and 2.0 mm.

A further preferred subject of the invention is the use of a device according to the invention for doping semiconductors or for coating articles made of tantalum, ceramic, graphite or glass or for the manufacture of ultrapure tantalum.

Coating agents which are particularly suitable for the use according to the invention are those which comprise one or more compounds selected from the group consisting of SiHCl ₃ , SiCl ₄ , Si(CH ₃ )Cl ₃ , SiH ₂ CH ₂ , trimethyl. Aluminum (TMA), NH ₃ , N ₂ O and decane. Further, the process gas may comprise additional components selected from the group consisting of methane, ethane, propane, butane, CO, CO ₂ , H ₂ , O ₂ , N ₂ , Ar, and He.

The device according to the invention is particularly suitable for use in semiconductor technology, in particular if the subject of the discussion is a modified semiconductor, for example by doping or coating an article with a ceramic layer or fabricating an ultrapure crucible. Thus, the device according to the invention is preferably used for doping semiconductors or for coating articles made of glass, ceramic, graphite or tantalum or for the manufacture of ultrapure crucibles.

The assembly to be used according to the invention is particularly suitable for use in the treatment of corrosive process gases. A further subject of the invention is therefore the use of a component comprising a matrix made of quartz glass coated with cerium oxide, wherein the cerium oxide layer has a higher porosity than the quartz glass matrix, which is used for processing A chamber, preferably a device for doping, uses a corrosive process gas comprising a dopant.

In a preferred embodiment, the component is exposed to a process gas comprising a dopant.

Claims (22)

A device for doping a semiconductor with a corrosive process gas or for coating an article made of tantalum, graphite, ceramic or glass or for manufacturing an ultrapure crucible, the device comprising one or more components comprising Or a substrate consisting at least partially of quartz glass, wherein the quartz glass is coated with a ceria layer having a higher porosity than the quartz glass of the substrate. The device of claim 1, wherein the component is selected from the group consisting of a holding device, a gas containing device, a shielding plate, a processing tube, and a processing chamber. The device of claim 1, wherein the ceria layer of the component has a porosity of from 5% to 30%, preferably from 10% to 30%. The apparatus of any one of claims 1 to 3, wherein the component is obtained by a method comprising the steps of: coating with a cerium oxide (preferably coating in a large area) a matrix comprising quartz glass, wherein This layer has a higher porosity than quartz glass. A device as claimed in claim 4, wherein the layer is applied by means of mud treatment or thermal spraying. A doping method comprising the steps of: contacting an object to be doped with a processing gas comprising a dopant, wherein the doping is implemented in a device, in particular in a processing chamber, and wherein the device comprises The one or more components comprise one or more substrates consisting entirely or at least partially of quartz glass, the quartz glass being wholly or partially coated with a ceria layer having a higher porosity than the quartz glass of the substrate. The doping method of claim 6, wherein the object to be doped is used in a semiconductor technology and/or a photovoltaic device. The doping method of claim 6 or 7, wherein the object to be doped comprises ruthenium. The doping method of any one of claims 6 to 8, wherein the processing gas comprises boron source. The doping method according to any one of claims 6 to 9, wherein the process gas comprises a temperature in the range of from 500 ° C to 1500 ° C, especially from 600 ° C to 1200 ° C, more particularly from 750 ° C to 1100 ° C. The doping method according to any one of claims 6 to 10, wherein the cerium oxide layer has a porosity of from 5% to 30%, preferably from 10% to 30%. A method for coating an article made of glass, ceramic, graphite or tantalum, comprising the steps of: coating a member to be coated with a gas coating agent, preferably of glass, ceramic, graphite or ruthenium a finished article, wherein the coating is carried out in a device, in particular in a processing chamber, wherein the device comprises one or more components comprising one or more substrates wholly or at least partially composed of quartz glass The quartz glass is completely or partially coated with a ceria layer having a higher porosity than the quartz glass of the substrate. A method for making ultrapure germanium comprising the steps of depositing germanium, wherein the depositing is performed in a device, in particular in a processing chamber, wherein the device comprises one or more components comprising one or A plurality of substrates consisting entirely or at least partially of quartz glass, the quartz glass being completely or partially coated with a ceria layer having a higher porosity than the quartz glass of the substrate. The method of claim 13 wherein the ruthenium is deposited from a gaseous ruthenium containing compound, especially trichloromethane. The use of a cerium oxide layer on a quartz glass substrate, wherein the porosity of the layer is higher than that of the quartz glass of the substrate to reduce or attenuate corrosion of the quartz glass caused by the processing gas or as a barrier to high temperature diffusion or coating treatment Floor. The use of the ruthenium dioxide layer of claim 15 wherein the process gas comprises a temperature in the range of from 200 °C to 1600 °C, especially from 300 °C to 1500 °C, more particularly from 400 °C to 1300 °C. The use of the layer of claim 15 or 16, wherein the process gas comprises a source of boron. The use of the layer of any one of claims 15 to 17, wherein the ceria layer having a porosity higher than that of the quartz glass of the substrate comprises limited adhesion to the surface of the quartz glass of the substrate, which allows removal from the surface of the quartz glass This layer (preferably without residue removal) does not damage the surface of the quartz glass. The use of the cerium oxide layer according to any one of claims 15 to 18, wherein the cerium oxide layer having a porosity higher than that of the quartz glass of the substrate comprises between 0.1 mm and 3.0 mm, preferably between 0.5 mm and Layer thickness between 2.0 mm. Use of a device according to any one of claims 1 to 5 for doping a semiconductor or for coating an article made of tantalum, ceramic, graphite or glass or for producing ultrapure germanium. A use comprising a component of a substrate for use in a processing chamber using a corrosive process gas comprising a dopant, preferably for a doping device, the substrate being made of quartz glass coated with cerium oxide, Wherein the cerium oxide layer has a higher porosity than the quartz glass substrate. The use of the component of claim 21, wherein the component is exposed to a process gas comprising the dopant.