DEVICE AND METHOD FOR SEPARING A LAYER UNDER ATMOSPHERE PRESSURE

Abstract

A method for depositing a layer, comprising: measuring a physical property related to an atmospheric pressure in a reactor chamber (450) of a deposition device (400); introducing, at atmospheric pressure, a main gas mixture (100) comprising a source gas (110) and an auxiliary gas (120) into the reactor chamber (450), wherein the source gas (110) comprises a precursor material (112) and a carrier gas (114); and controlling a gas flow of at least one of the source gas (110) and the auxiliary gas (120) into the reactor chamber (450) in response to a change in the atmospheric pressure in the reactor chamber (450).

Description

TECHNICAL AREA The present disclosure relates to a device for forming a layer and to a method for forming a layer at atmospheric pressure. BACKGROUND CVD (chemical vapor deposition) deposits dielectric layers, metallic layers, amorphous semiconductor layers, polycrystalline semiconductor layers, or single-crystal semiconductor layers onto the front surface of a substrate. For example, gas-phase epitaxy can grow single-crystal layers on a suitable crystalline base. A semiconductor wafer can be placed on a wafer holder (susceptor) in a deposition chamber of a deposition apparatus. The front surface of the semiconductor wafer can be exposed to a cleaning gas and then to a vaporous or gaseous silicon source, such as a silane, at a suitable temperature and pressure to deposit and / or grow a crystalline silicon layer onto the front surface of a substrate.During semiconductor layer deposition, the susceptor can rotate to improve deposition uniformity across the front surface of the semiconductor wafer. There is a need to further improve the deposition of layers, such as semiconductor layers. Document US 2004 / 0166597A1 describes a method and arrangement for improving the etching rate in a plasma etching chamber. Document DE 10345824A1 describes the deposition of aluminum oxide using ALD. In this process, the signal from a pressure measuring device is used to regulate the pressure in a reaction chamber. Document US 2013 / 0092084A1 relates to LPCVD in a vacuum chamber. In document US 2013 / 0052346A1, control units regulate the gas outflow from an LPCVD reactor to a vacuum pump via valves, based on measurement signals from several pressure gauges. The pressure in the deposition zones of the LPCVD reactor is approximately 100 Torr. The publication DE 10 2014 106 339 A1 refers to the deposition of carbon layers by plasma-enhanced chemical vapor deposition (PECVD) at a maximum of 15 hPa. SUMMARY One embodiment of the present disclosure relates to a method for depositing a semiconductor layer. A physical property related to atmospheric pressure in a reactor chamber of a deposition device is measured. A main gas mixture is introduced into the reactor chamber at atmospheric pressure, the main gas mixture containing a source gas and an auxiliary gas. The source gas contains a precursor material and a carrier gas. A gas flow of at least one of the source gas and one of the auxiliary gas into the reactor chamber is controlled in response to a change in atmospheric pressure in the reactor chamber. Another embodiment of the present disclosure relates to a device for forming a semiconductor layer. The device comprises a deposition device, a first main flow controller unit, a second main flow controller unit, and a processor unit. The deposition device is suitable for depositing a semiconductor layer at atmospheric pressure. The first main flow controller unit is configured to control a gas flow of a source gas into a reactor chamber of the deposition device, the source gas containing a precursor material and a carrier gas. The second main flow controller unit is configured to control a gas flow of an auxiliary gas into the reactor chamber. The processor unit is configured to control at least one of the first and second main flow controller units in response to information about a change in the atmospheric pressure in the reactor chamber. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are enclosed to provide a further understanding of the embodiments and are incorporated into and form part of this patent description. The drawings illustrate the embodiments of the present disclosure and, together with the description, serve to explain the principles of the embodiments. Other embodiments and intended advantages are appreciated immediately, as they are better understood with reference to the following detailed description. Fig. 1 is a schematic flow diagram of a layer deposition process according to one embodiment. Fig. 2A is a schematic block diagram of an apparatus containing a processor unit that controls a first main current controller unit and a second main current controller unit in response to a change in atmospheric pressure in a reactor chamber of a deposition apparatus, according to one embodiment.Figure 2B is a schematic diagram illustrating the control of gas flows over time to discuss the effects of the embodiments. Figure 3 is a schematic diagram of a deposition device for gas phase deposition at atmospheric pressure according to one embodiment with an air pressure sensor positioned in an outlet pipe. Figure 4A is a schematic block diagram of a device for film deposition at atmospheric pressure according to one embodiment, relating to the control of a main flow and a cross flow. Figure 4B is a schematic diagram illustrating the control of gas flows to discuss the effects of the embodiments. Figure 5 is a schematic diagram of a device for film deposition at atmospheric pressure according to another embodiment, relating to liquid precursor materials.Figure 6A is a schematic horizontal cross-sectional view of a gas phase deposition device with a cross-flow inlet and an air pressure sensor according to a further embodiment. Figure 6B is a schematic vertical cross-sectional view of the deposition device of Figure 6A. Figure 7 is a schematic horizontal cross-sectional view of a gas phase deposition device with groups of cross-flow inlets according to a further embodiment. DETAILED DESCRIPTION The following detailed description refers to the accompanying drawings, which form part of this document and in which specific embodiments are shown for illustrative purposes, illustrating how the embodiments can be further developed. It is understood that other embodiments may be used and structural or logical modifications may be made without deviating from the scope of this disclosure. For example, features illustrated or described for one embodiment may be used in or in connection with other embodiments to arrive at yet another embodiment. It is intended that this disclosure includes such modifications and changes. The examples are described using specific language, which should not be interpreted as limiting the scope of the appended claims.The drawings are not to scale and are for illustrative purposes only. Relevant elements are labeled with corresponding reference symbols in the various drawings, unless otherwise stated. The term "gas flow," as used below, refers to a mass flow rate of a gaseous substance. "Flow velocity" is a scalar and corresponds to the length of the velocity vector of the mass flow rate. Fig. 1 relates to an embodiment of a method for depositing a layer. A physical property related to the atmospheric pressure in a reactor chamber of a deposition device is measured (902). A main gas mixture containing a source gas and an auxiliary gas is introduced into the reactor chamber, the source gas containing a precursor material and a carrier gas (904). A gas flow of at least one of the source gas and one of the auxiliary gas into the reactor chamber is controlled in response to a change in the atmospheric pressure in the reactor chamber (906). The measured physical property can be any physical quantity from which the atmospheric pressure and / or a change in atmospheric pressure in the reactor chamber can be derived. For example, the atmospheric pressure in the reactor chamber can be measured directly. According to another embodiment, a physical property can be measured in combination with other known parameters and combined with these parameters to obtain the atmospheric pressure in the reactor chamber. For example, the ambient pressure can be measured and combined with parameters that describe the atmospheric pressure in the reactor chamber as a function of the ambient pressure. In the reactor chamber, one or more components of the precursor material are deposited on a front surface of a substrate and form a layer. The substrate can be a semiconductor wafer, e.g., a silicon wafer, a germanium wafer, a germanium-silicon crystal wafer, or a silicon-on-insulator (SOI) wafer with a single-crystal base layer formed on an insulating substrate such as glass. The semiconductor wafer or single-crystal base layer can be intrinsic or may contain dopants. The semiconductor wafer or single-crystal base layer may contain non-doped atoms as process-induced impurities or defects. The layer can be an amorphous, nanocrystalline, microcrystalline, or polycrystalline semiconductor layer. According to one embodiment, the layer can be a single-crystal silicon layer grown by epitaxy on a suitable crystalline base, wherein atoms of the deposited precursor material integrate into the crystallographic orientation of the crystalline base, and the deposited layer grows in accordance with a crystal lattice of the crystalline base. For example, silicon atoms can be deposited on a silicon crystal, a germanium crystal, or a germanium / silicon crystal, forming a silicon semiconductor layer. The semiconductor layer can be intrinsic or may contain dopant atoms. The semiconductor layer may contain non-doping impurities as a result of process defects, such as oxygen, carbon, and / or hydrogen. According to other embodiments, the deposited layer can be a composite semiconductor layer, for example CdTe, a dielectric layer, or a metal-containing layer. The precursor material contains the component(s) of the deposited layer, for example, silicon. The carrier gas and the auxiliary gas can be free of components of the deposited semiconductor layer. The carrier gas and the auxiliary gas can have different or the same composition. The deposition device may include a reactor chamber suitable for gas-phase deposition, e.g., gas-phase epitaxy, at atmospheric pressure. In particular, the deposition device may be free of means to maintain the atmospheric pressure in the chamber at a constant value. For example, the deposition device is an APCVD (atmospheric pressure CVD) deposition device. The atmospheric pressure in the reactor chamber may follow the atmospheric pressure, which deviates from standard atmospheric pressure (101325 Pa) by little more than ±4%, immediately and / or with a certain delay. The auxiliary gas and the source gas may be mixed before being introduced into the reactor chamber, the source gas and auxiliary gas forming a main gas mixture that can be introduced into the reactor chamber through at least one main inlet. The inventors demonstrated that the deposition rate of mesas or mesa structures on a structured substrate surface can change with atmospheric pressure. In semiconductor manufacturing, a mesa structure is an area on the front face of a semiconductor substrate where the semiconductor or a top layer has not been etched away. The mesa structure rises above a surrounding area of ​​the substrate surface and typically has a flat top surface. In particular, deposition at higher atmospheric pressures can result in wider mesa structures than deposition at lower atmospheric pressures. By controlling the flow of at least one of the source gas and the auxiliary gas into the reactor chamber in response to changes in the atmospheric pressure within the reactor chamber, a more uniform deposition rate on mesa structures can be achieved for varying atmospheric pressures. For example, the deposition of an epitaxial silicon layer on mesa structures with a width in the range of 100 nm to 100 µm may result in a slower decrease in width at higher atmospheric pressures than at lower atmospheric pressures. According to one embodiment, the flow rate of at least one of the source gas and the auxiliary gas is increased with increasing air pressure in the reactor chamber, so that at least part of a reduction in the flow velocity of the gas mixture resulting from the increasing air pressure in the reactor chamber is compensated. According to a further embodiment, the gas flow of at least one of the source gas and the auxiliary gas is controlled such that a constant or nearly constant flow velocity of the main gas mixture into the reactor chamber is achieved, even with varying atmospheric pressure in the reactor chamber. By reducing fluctuations in the flow velocity, more reproducible deposition on mesa structure surfaces with a width in the range of 100 nm to 100 µm can be achieved. In particular, coating layers are deposited on mesa structures with higher reproducibility with respect to the width of the coating layers. A more constant flow velocity of the entire gas stream can reduce variations in mesa structure widths among a multitude of substrates after deposition. In other words, after deposition, the width of mesa structures on a multitude of substrates exhibits smaller variations. Changes in atmospheric pressure within the reactor chamber can be compensated for by controlling only one flow of the auxiliary gas. In this case, the flow of source gas into the reactor chamber remains unaffected, thus keeping the amount of precursor material introduced into the reactor chamber per unit of time constant, provided that the concentration of precursor material in the source gas does not change. According to another embodiment, both the gas flow of the source gas and the auxiliary gas into the reactor chamber are controlled in such a way that a change in the flow rate of the main gas mixture is divided between a change in the source gas flow and a change in the auxiliary gas flow. In the source gas, the mass ratio between precursor material and carrier gas can change over time. The flow of source gas into the reactor chamber can be controlled in response to changes in the precursor material concentration in the source gas, such that the amount of precursor material introduced into the reactor chamber per unit time remains constant as the precursor material concentration in the source gas changes. For example, if an initial concentration of the precursor material in the source gas increases from 10% to 11%, the flow of source gas into the reactor chamber can be reduced by approximately 10% to maintain a constant amount of precursor material introduced into the reactor chamber per unit time. A constant feed rate for the precursor material can result in a constant deposition rate over time. In addition to and simultaneously with the source gas, an auxiliary gas is introduced into the reactor chamber, whereby an auxiliary gas flow into the reactor chamber can be controlled in such a way that a total gas flow, consisting of the source gas flow and the auxiliary gas flow into the reactor chamber, is kept constant when the source gas flow changes. Compensating for the reduction of a source gas flow by increasing the auxiliary gas flow in order to keep the total gas flow into the reactor chamber constant can result in the semiconductor layer growing with greater uniformity across the front surface of the semiconductor wafer. According to one embodiment, the flow rate of the source gas can first be controlled as a function of the concentration of the precursor material in the source gas to achieve a desired deposition rate. Subsequently, the auxiliary gas flow is controlled to achieve high uniformity of deposition across the wafer. The auxiliary gas flow can then be adjusted to atmospheric pressure to achieve constant deposition rates on mesa structures. Any potential imbalance or deviation in the flow rate ratio between the auxiliary gas and the source gas can be within a range that hardly affects the uniformity across the wafer. According to an alternative embodiment, the gas flows of the source gas and the auxiliary gas into the reactor chamber are controlled to ensure a constant flow velocity and a constant ratio between the source gas flow and the auxiliary gas flow. Information about the concentration of the precursor material in the source gas can be used to calculate the actual deposition rate and to control the deposition time as a function of the actual deposition rate and a target thickness of the deposited layer. The source gas can be combined with the auxiliary gas to form a crossflow gas mixture in addition to a main gas mixture. The crossflow gas mixture can be introduced into the reactor chamber through at least one crossflow inlet. The flow direction of the crossflow gas mixture at a crossflow inlet opening into the reactor chamber can be inclined to the flow direction of the main gas mixture at a main inlet opening into the reactor chamber. For example, the angle between the flow direction of the crossflow gas mixture at the crossflow inlet opening and the flow direction of the main gas mixture at the main inlet opening can be in a range of 45°C to 135°C, for example, in a range of 85° to 95°. The main inlets and the crossflow inlets can be arranged so that they are oriented towards a horizontal center point on the front surface of the semiconductor wafer. According to one embodiment, the ratio of a gas flow of the main gas mixture to a gas flow of the cross-flow gas mixture can be kept constant when the source gas flow and / or the auxiliary gas flow changes in response to a change in the atmospheric pressure in the reactor chamber. Typically, the mass ratio between the main flow through the main inlets and the cross flow through the cross-flow inlets is not equal to 1, for example, greater than 1. If the auxiliary gas flow in both the main and cross-flows is reduced by an equivalent amount, the mass ratio between the main and cross-flows can change. This change in the mass ratio between the main and cross-flows can adversely affect the uniformity of the deposited semiconductor layer. According to one embodiment, the proportion of the auxiliary gas in the cross-flow gas mixture can be controlled so that the mass ratio of the main flow to the cross-flow is kept constant, allowing semiconductor layers, e.g. epitaxial silicon layers, to be deposited with high uniformity of thickness over the entire wafer surface. According to one embodiment, the precursor material can be a semiconductor material, for example, silicon and / or germanium. The precursor material can be gaseous at 25°C and 1 atm or can contain a gaseous compound. For example, the precursor material can contain dichlorosilane (H₂SiCl₂). Alternatively, the precursor material can be liquid at a temperature of 30°C. According to one embodiment, the precursor material can contain trichlorosilane (HSiCl₃) and / or tetrachlorosilane (SiCl₄). According to one embodiment, the carrier gas and the auxiliary gas can contain hydrogen gas. For example, the carrier gas and the auxiliary gas can contain hydrogen gas as their sole major component, with other components present only as undesirable impurities. According to other embodiments, at least one of the carrier gas and the auxiliary gas can contain at least one noble gas such as helium, argon, and neon, wherein the auxiliary gas and the carrier gas can contain the same major components in the same proportions or in different proportions. According to at least one embodiment, the information about the pressure in the reactor chamber can be obtained from a pressure sensor outside the reactor chamber, for example in the outlet of the separation device, or from a pressure sensor that is remote from the separation device, so that the method can be easily used for different types of separation devices without mechanical modification. According to other embodiments, the atmospheric pressure in the reactor chamber of the separation device is measured, for example, by a pressure sensor mounted in the reactor chamber, so that independent information about the air pressure in the reactor chamber is available without time delay. Fig. 2A shows a device 500 for forming layers, e.g., semiconductor layers. The device 500 can be an APCVD system. The device 500 comprises a deposition device 400, which is suitable for depositing a semiconductor layer by vapor deposition, for example, by vapor-phase epitaxy, at atmospheric pressure. A first main flow controller unit 511 controls a gas flow of source gas 110 into the reactor chamber 450 of the deposition device 400, wherein the source gas 110 contains a precursor material and a carrier gas. A second main flow controller unit 512 controls a gas flow of auxiliary gas 120 into the reactor chamber 450. The first and second main flow controller units 511, 512 can contain MFCs (mass flow controllers) that control the rate of a flow of a gaseous compound or gaseous mixture passing through the MFC according to a selected setpoint or setpoint. The MFC can, for example, contain a mass flow sensor, a control valve, and an internal control unit that can compare a gas flow value obtained from the mass flow sensor to adjust the control valve appropriately to achieve a flow rate according to the selected setpoint. A main mixing unit 513 can combine the source gas 110 and the auxiliary gas 120 after they have passed through the first and second main flow controller units 511 and 512 and before entering the reactor chamber 450. The main mixing unit 513 discharges a main gas mixture 100 containing the source gas 110 and the auxiliary gas 120, which enters the reactor chamber 450 through at least one main inlet 410. A processor unit 600 can control at least one of the first and second main-flow controller units 511, 512 in response to information about a change in the atmospheric pressure p in the reactor chamber 450. For example, the processor unit 600 can control at least one of the first main-flow controller unit 511 and the second main-flow controller unit 512 to reduce the total gas flow Ftotzu when the atmospheric pressure p in the reactor chamber 450 decreases, and the processor unit 600 can control at least one of the first main-flow controller unit 511 and the second main-flow controller unit 512 to increase the total gas flow Ftotzu when the atmospheric pressure p in the reactor chamber 450 increases. For example, the processor unit 600 can control the second main flow controller unit 512 in response to information about the atmospheric pressure p in the reactor chamber 450 to compensate for changes in the flow velocity of the main gas mixture 100 resulting from changes in the atmospheric pressure p in the reactor chamber 450 and to maintain a constant flow velocity of the main gas mixture 100. The processor unit 600 can also control the second main flow controller unit 512 to allow more of the auxiliary gas 120 to pass through when the atmospheric pressure p increases. As a result, the deposition rate on mesa structures formed on a front surface of a semiconductor wafer placed in the reactor chamber 450 can exhibit higher stability and reproducibility. Fig. 2B shows an example of the control of the processor unit 600, which is exerted on at least one of the first and second main flow controller units 511, 512. As long as the atmospheric pressure p in the reactor chamber 450 is constant, the total flow rate Ftot is constant. A linear increase in atmospheric pressure p can result in an increase, e.g., a linear increase, in the total gas flow rate Ftot, and an exponential decrease in atmospheric pressure p can be compensated by a decrease, e.g., an exponential decrease, in the total gas flow rate Ftot. Since the atmospheric pressure p in reactor chamber 450 essentially follows the ambient pressure, and the rate of change of the ambient pressure is slow, it may be sufficient to measure the atmospheric pressure p in reactor chamber 450 and the total mass flow rate Ftot only once at the beginning of a semiconductor wafer deposition process. Once the total mass flow rate Ftot has been selected for a specific deposition process, the partial mass flow rates FSC and Faux can be subjected to further process control. For example, the concentration of the precursor material in the source gas 110 may increase to a certain extent after a specific process time. In response to information indicating this increase, the processor unit 600 can control the first main flow controller unit 511 to reduce the source gas flow FSC into the reactor chamber 450, thus maintaining a constant rate at which the precursor material is introduced into the reactor chamber 450. Furthermore, in response to information indicating a change ΔFSC in the flow of the source gas 110, the processor unit 600 can control the second main flow controller unit 512 to increase the auxiliary gas flow FF, so that the total gas flow Ftot of the source gas 110 and the auxiliary gas 120 into the reactor chamber 450 remains constant.The constant total gas flow Ftotin, combined with the constant rate at which the precursor material is introduced into reactor chamber 450, provides a highly time-independent and uniform deposition rate across a wafer surface. For many applications, the uniformity of deposition and consistent growth on mesa structures can compensate for some thickness variation resulting from a small change in the deposition rate over time. Fig. 3 shows a deposition device 400 suitable for APCVD, e.g., chemical vapor deposition. A wafer holder 472 (susceptor, wafer carrier) in a reactor chamber 450 of the deposition device 400 is suitable for supporting a semiconductor wafer 700, for example, with a thickness of less than 1 mm and a diameter of 100 mm, 150 mm, 200 mm, 300 mm, or 450 mm. In a horizontal plane defined by the support surface of the wafer holder 472, the reactor chamber 450 can have an approximately rectangular cross-section. The deposition device 400 can include heating elements that can heat the wafer holder 472, a chamber wall 451, and / or a semiconductor wafer 700 placed on the wafer holder 472. The separation device 400 can also include a motor drive unit for rotating the susceptor around a vertical axis through the horizontal center point during a separation.According to one embodiment, the deposition device 400 can include a radiation source to apply heat, e.g. a temperature of at least 800°C or at least 900°C, to an exposed front surface of the semiconductor wafer 700. The separation device 400 can include several first main inlets 411 through which a source gas 110 or a mixture of the source gas 110 and an auxiliary gas 120 is introduced into the reactor chamber 450, and can include second main inlets 412 for introducing the auxiliary gas 120 into the reactor chamber 450 without the source gas. The first and second main inlets 411, 412 can be arranged on one side of the reactor chamber 450. The chamber wall 451 can include at least one outlet 490, which can be arranged on a side opposite the first and second main inlets 411, 412. An air pressure sensor 460 can be positioned in an outlet pipe 495, in the reactor chamber 450, or outside the reactor chamber 450, and measures the air pressure in the reactor chamber 450 or in the outlet pipe 495. The air pressure sensor 460 can be connected to the processor unit 600 of Fig. 2A via a data line. In the separation device 400 in Fig. 3, which is used in the device 500 as illustrated in Fig. 2A, the processor unit 600 can control at least one of the first and second main flow controller units 511, 512, so that a flow velocity of a main gas mixture 100, which contains the auxiliary gas 120 and the source gas 110, which is introduced through the first and second main inlets 411, 412, is kept constant when the atmospheric pressure p changes. Figures 4A and 4B relate to a device 500 comprising a separation device 400 with at least one cross-flow inlet 420 for allowing a cross-flow gas mixture 200 to pass through, wherein the flow direction of the cross-flow gas mixture 200 at an opening of the cross-flow inlet 420 into the reactor chamber 450 is inclined to a flow direction of the main gas mixture 100 at an opening of the main inlet into the reactor chamber 450. The angle of inclination between the two flow directions can be in a range of, for example, 45° to 135°, or, for example, 85° to 95°. An air pressure sensor 460 can be positioned in a reactor chamber 450 of the separation device 400. In addition to a first and a second main flow controller unit 511, 512, as described with reference to Fig. 2A and Fig. 2B, the device 500 includes a first cross-flow controller unit 521, which controls a gas flow FSCCrdes of the source gas through the at least one cross-flow inlet 420. A second cross-flow controller unit 522 controls a gas flow FAuxCrdes of the auxiliary gas 120 through the at least one cross-flow inlet 420. The first and second cross-flow controller units 521, 522 can be or can include MFCs. The second cross-flow controller unit 522 can be controlled in response to data containing information about the change ΔFSCCrde of the gas flow FSCCrde of the source gas 110 by the first cross-flow controller unit 521. For example, the second cross-flow controller unit 522 is controlled so that the total gas flow FtotCrde of the auxiliary gas 120 and the source gas 110 through the cross-flow inlet 420 remains constant. Fig. 5 shows another device 500 for forming a semiconductor layer. A bubble generator, or bubbler 310, contains a precursor material 112, which is liquid at a temperature of 30°C. The precursor material 112 can be tetrachlorosilane, trichlorosilane, or a mixture of both. A carrier gas 114 passes through the liquid precursor material 112 and vaporizes a portion of it. A mixture of the carrier gas 114 and vaporized components of the precursor material 112 exits the bubbler 310 through an outlet and forms the source gas 110. The carrier gas 114 can be hydrogen gas and / or one or more noble gases such as helium, argon, and neon. According to one embodiment, the carrier gas 114 contains hydrogen gas as the sole main component and contains other atoms, molecules and / or compounds only as impurities. A concentration measuring unit 320 measures the concentration of the precursor material 112 in the source gas 110. The concentration measuring unit 320 can be connected to a processor unit 600 via a data line and can transmit information about a change ΔCprein concentration Cpredes precursor material 112 in the source gas 110 to the processor unit 600. A first main-flow controller unit 511 controls a gas flow FSC of the source gas 110 through one or more main inlets 410 of a separation device 400. A first cross-flow controller unit 521 controls a gas flow FSCCr of the source gas 110 through one or more cross-flow inlets 420 of the separation device 400. A second main flow controller unit 512 controls a gas flow FAux of auxiliary gas 120 through one or more main inlets 410. A second cross-flow controller unit 522 controls a gas flow FAuxCrde's auxiliary gas 120 through one or more cross-flow inlets 420. A main mixing unit 513 can combine the source gas 110, which passes through the first main flow controller unit 511, and the auxiliary gas 120, which passes through the second main flow controller unit 512, before they are introduced into a reactor chamber 450 of the separation device 400. A cross-flow mixing unit 523 can combine the source gas 110, which passes through the first cross-flow controller unit 521, and the auxiliary gas 120, which passes through the second cross-flow controller unit 522, before they are introduced into the reactor chamber 450. An air pressure sensor 460 can be connected to the processor unit 600 via a data line. The processor unit 600 can control at least one of the first main-stream controller units 511 and the second main-stream controller unit 512 in response to a change Δp in the atmospheric pressure p in the reactor chamber 450. Furthermore, the processor unit 600 can control the first main-stream controller unit 511 in response to a change ΔCpreder concentration of precursor material 112 in the source gas 110 in such a way that the rate at which the precursor material 112 is delivered to the deposition device 400 through the one or more main inlets 410 remains constant, even if the concentration Cpreder changes. For this purpose, the processor unit 600 can manage setting values ​​of the current controller units 511, 512, 521, 522. According to one embodiment, the processor unit 600 can query and / or receive the setpoint values ​​of the first main current controller unit 511 and the first cross-current controller unit 512 to determine the control values ​​for the second main current controller unit 512 and the second cross-current controller unit 522. The processor unit 600 can control at least one of the first cross-flow controller units 521 in response to a change Δp in the atmospheric pressure p. Furthermore, the processor unit 600 can control the first cross-flow controller unit 521 and the second cross-flow controller unit 522 in response to a change ΔCpreder concentration Cpredes of the precursor material 112 in the source gas 110 in such a way that the rate at which the precursor material 112 is delivered to the reactor chamber 450 through the one or more cross-flow inlets 420 remains constant, even if the concentration Cprede changes. The processor unit 600 can control at least one of the first and second main flow controller units 511, 512 such that a flow velocity of a main gas mixture 100, containing the auxiliary gas 120 and source gas 110, which is introduced through the first and second main inlets 411, 412, is kept constant when the atmospheric pressure p changes. Furthermore, if the concentration of Cprede's precursor material 112 in the source gas 110 increases, the processor unit 600 can control the first main flow controller unit 511 and the first cross flow controller unit 521 to reduce the source gas flow into the reactor chamber 450 in such a way that the amount of precursor material introduced into the reactor chamber 450 per unit of time remains constant. The processor unit 600 can further control the second main flow controller unit 512 to increase the auxiliary gas flow FAux so that the total main gas flow Ftot through the one or more main inlets 410 remains constant when the first main flow controller unit 511 reduces the source gas flow FSC. Furthermore, the processor unit 600 can control the second crossflow controller unit 522 to increase the auxiliary gas flow FAuxCr so that a total crossflow FtotCr through the at least one crossflow inlet 420 remains constant when the source gas flow FSCCr through the crossflow inlets changes. The device 500 can maintain a constant flow rate of the main gas stream and the cross gas stream under changing atmospheric pressure. Furthermore, the device 500 can maintain a constant total gas flow into the reactor chamber 450, even when the source gas flow is reduced to compensate for a change in the concentration of the precursor material 112 in the source gas. The device 500 can also maintain a constant ratio of the main stream to the cross stream when the concentration of the precursor material 112 in the source gas 110 changes. The device 500 allows the deposition of epitaxial silicon at a rate of 0 - 20 µm / min on semiconductor wafers, as described above. Figures 6A and 6B show a deposition device 400, which includes a reactor chamber 450 with a nearly circular horizontal cross-section in the plane of a support surface 473 of a wafer holder 472. A semiconductor wafer 700 can be placed on the support surface 473 of a wafer holder 472, which may be centered on a horizontal center of the reactor chamber 450. The deposition device 400 deposits a layer onto an exposed front surface 701 of the semiconductor wafer 700. On a first side, the separating device 400 can include one or a plurality of main inlets 410, which can be arranged such that the partial gas flows through the main inlets 410 are parallel to each other. On a second side opposite the first side, the separating device 400 can include one or more outlets 490. One or more crossflow inlets 420 are arranged such that gas flows passing through the crossflow inlets 420 have a flow direction inclined to the flow direction of the gas flows through the main inlets 410. An air pressure sensor 460 can be positioned in an outlet 490, in the reactor chamber 450, or outside the reactor chamber 450. This sensor measures the air pressure in the reactor chamber 450, in the outlet 490, or the ambient pressure. The air pressure sensor 460 can be connected to a processor unit via a data line, as shown in Fig. 2A. The main flow can be significantly stronger than the cross flow. The main flow can deflect the cross flow in reactor chamber 450 by a certain deflection angle α. Keeping the ratio of the total main flow to the total cross flow constant means that the deflection angle α does not change and the deposition rate across the wafer surface is more uniform. Fig. 7 relates to another embodiment of a separation device 400 with the cross-flow inlets 420 arranged in groups and symmetrically with respect to an axis of symmetry of the main inlets 410. The separation device 400 may include an air pressure sensor 460 as described with reference to one of the preceding figures. A processor unit, as described with reference to Fig. 2A and Fig. 5, can represent a device that controls a deposition device for depositing semiconductor layers at atmospheric pressure. The processor unit can be an integrated part of the deposition device or a control in a stored program that is associated with the deposition device and connected to it via a data line. The processor unit can be a computer, a server, or part of a network of servers and computers that execute software code. The device performs a method for controlling an epitaxial device for depositing layers at atmospheric pressure. The device comprises means for receiving information about the atmospheric pressure in a reactor chamber of a deposition device; means for calculating an updated gas flow of a main gas stream to maintain a constant flow velocity of the main gas into the reactor when the atmospheric pressure in the reactor chamber changes, wherein the main gas stream contains a source gas and an auxiliary gas, and the source gas contains a carrier gas and a precursor material; means for outputting first control data about an updated source gas stream and / or second control data about an updated auxiliary gas stream. The device performs a method for controlling an epitaxial device for depositing layers at atmospheric pressure. The method comprises receiving information about the atmospheric pressure in a reactor chamber of a deposition device; calculating an updated gas flow of a main gas stream to maintain a constant flow velocity of the main gas into the reactor chamber when the atmospheric pressure in the reactor chamber changes, wherein the main gas stream contains a source gas and an auxiliary gas, and the source gas contains a carrier gas and a precursor material; and outputting first control data about an updated source gas stream and / or second control data about an updated auxiliary gas stream. Although specific embodiments have been illustrated and described here, it is obvious to the person skilled in the art that a multitude of alternative and / or equivalent designs can be used for the specific embodiments shown and described without departing from the scope of this disclosure. This application is intended to cover any adaptations or modifications of the specific embodiments discussed herein. Therefore, it is intended that this disclosure is limited only by the claims and their equivalents.

Claims

A method for depositing a layer, comprising: measuring a physical property related to an atmospheric pressure in a reactor chamber (450) of a deposition device (400); introducing, at atmospheric pressure, a main gas mixture (100) comprising a source gas (110) and an auxiliary gas (120) into the reactor chamber (450), wherein the source gas (110) comprises a precursor material (112) and a carrier gas (114); and controlling a gas flow of at least one of the source gas (110) and the auxiliary gas (120) into the reactor chamber (450) in response to a change in the atmospheric pressure in the reactor chamber (450). Method according to claim 1, wherein the gas flow of at least one of the source gas (110) and the auxiliary gas (120) is increased with increasing air pressure in the reactor chamber (450). Method according to one of the preceding claims, wherein the gas flow is controlled by at least one of the source gas (110) and the auxiliary gas (120) in order to obtain a constant flow rate of the main gas mixture (100) into the reactor chamber (450) when the atmospheric pressure in the reactor chamber (450) varies. A method according to any of the preceding claims, wherein a gas flow of the source gas (110) is controlled in response to a change in the concentration of the precursor material (112) in the source gas (110); and a gas flow of the auxiliary gas (120) is controlled such that a total gas flow of the source gas (110) and the auxiliary gas (120) into the reactor chamber (450) is kept constant when the gas flow of the source gas (110) changes. The method of claim 4, wherein the source gas (110) is combined with the auxiliary gas (120) to form a cross-flow gas mixture (200), and the cross-flow gas mixture (200) is introduced into the reactor chamber (450) through at least one cross-flow inlet (420), and wherein a ratio of a gas flow of the main gas mixture (100) to a gas flow of the cross-flow gas mixture (200) is kept constant when the gas flow of at least one of the source gas (110) and the auxiliary gas (120) changes in response to a change in the atmospheric pressure in the reactor chamber (450). Method according to claim 5, wherein a flow direction of the cross-flow gas mixture (200) at an opening of the cross-flow inlet (420) into the reactor chamber (450) is inclined to a flow direction of the main gas mixture (100) at an opening of the main inlet (410) into the reactor chamber (450). Method according to one of the preceding claims, wherein the precursor material (112) contains a semiconductor element. Method according to one of the preceding claims, wherein the precursor material (112) contains at least one of trichlorosilane, tetrachlorosilane and dichlorosilane. Method according to one of the preceding claims, wherein at least one of the carrier gas (114) and the auxiliary gas (120) contains hydrogen gas. Method according to one of the preceding claims, wherein the atmospheric pressure in the reactor chamber (450) is measured. Device for forming a semiconductor layer, comprising: a deposition device (400) suitable for depositing a semiconductor layer at atmospheric pressure; a first main-flow controller unit (511) configured to control a gas flow of a source gas (110) into a reactor chamber (450) of the deposition device (400), wherein the source gas (110) contains a precursor material (112) and a carrier gas (114); a second main-flow controller unit (512) configured to control a gas flow of an auxiliary gas (120) into the reactor chamber (450); and a processor unit (600) configured to control at least one of the first and second main-flow controller units (511, 512) in response to information about a change in the atmospheric pressure in the reactor chamber (450). Device according to claim 11, wherein the gas flow of at least one of the source gas (110) and the auxiliary gas (120) is increased with increasing air pressure in the reactor chamber (450). Device according to one of claims 11 and 12, wherein the gas flow of at least one of the source gas (110) and the auxiliary gas (120) is controlled in order to obtain a constant flow rate of a main gas mixture (100) into the reactor chamber (450) when the atmospheric pressure in the reactor chamber (450) varies, wherein the main gas mixture (100) comprises the source gas (110) and the auxiliary gas (120). Device according to one of claims 11 to 13, wherein the processor unit (600) is configured to control the second main flow controller unit (512) in response to information about a change in the gas flow of the source gas (110) by the first main flow controller unit (511). Device according to claim 14, wherein the processor unit (600) is configured to control the second main flow controller unit (512) to maintain a constant total gas flow of the source gas (110) and the auxiliary gas (120) into the reactor chamber (450) when the gas flow of the source gas (110) changes through the first main flow controller unit (511). Device according to one of claims 11 to 15, wherein the processor unit (600) is configured to control the second main current controller unit (512) in response to information about a change in the concentration of the precursor material (112) in the source gas (110). Device according to claim 16, wherein the reactor chamber (450) has at least one cross-flow inlet (420) configured to allow a cross-flow gas mixture (200) to pass through, wherein a flow direction of the cross-flow gas mixture (200) at an opening of the cross-flow inlet (420) into the reactor chamber (450) is inclined to a flow direction of the main gas mixture (100) at an opening of the main inlet (410) into the reactor chamber (450). Device according to claim 17, further comprising: a first cross-flow controller unit (521) configured to control a gas flow of the source gas (110) through the at least one cross-flow inlet (420); a second cross-flow controller unit (522) configured to control a gas flow of the auxiliary gas (120) through the at least one cross-flow inlet (420); wherein the processor unit (600) is configured to control the second cross-flow controller unit (522) in response to data containing information about a change in the gas flow of the source gas (110) through the first cross-flow controller unit (521). Device according to one of claims 11 to 18, further comprising: an air pressure sensor (460) which is connected to the processor unit (600) via a data line and is arranged in the reactor chamber (450) or in an outlet pipe (495) of the separation device (400). Device according to one of claims 11 to 19, wherein the deposition device (400) is configured to form the semiconductor layer by means of gas-phase epixtaxy and / or gas-phase deposition at atmospheric pressure.

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