CVD reactor and method for regulating the surface temperature of a substrate

Abstract

The invention relates to a CVD reactor and a method for controlling / regulating the surface temperature of a substrate arranged in the CVD reactor, the substrate being arranged on a substrate holder, the substrate holder being supported, for example, by a dynamic air cushion, the actual values ​​of the surface temperature assigned to each substrate holder being measured successively and the surface temperature being regulated to a common value by varying the height of the air cushion. According to the invention, after each measurement of the actual value of the measured surface temperature assigned to a substrate holder, a value is determined using the actual value of the surface temperature of one or more substrate holders measured last, a difference value assigned to the substrate holder is calculated by calculating the difference between the actual value measured during the measurement and the value, and an approximate actual value for at least one other substrate holder is calculated by adding the assigned difference value to the value, which approximate actual value is used for regulation / control.

Description

Technical Field

[0001] The invention relates to a method for controlling / regulating the surface temperature of a substrate, which is arranged in a process chamber of a CVD reactor on a substrate holder assigned to a susceptor, wherein the actual values ​​of the surface temperatures assigned to the substrate holders are measured in sequence and adjusted to a common value by varying a parameter. The parameter may be the height of an air cushion, in particular a dynamic air cushion, which carries a substrate holder forming the substrate holder. The parameter may also be the composition of the gas flow forming the air cushion.

[0002] The present invention also relates to a device in the form of a CVD (chemical vapor deposition) reactor for implementing the method, the device having a plurality of substrate holders assigned to a base, each of which can be composed of a substrate holder supported by a dynamic air cushion, wherein the base is movable so that the substrate holders can be placed in a detection area of ​​a temperature measuring mechanism in sequence, and the surface temperature of the substrate located on the substrate holder can be detected in sequence by the temperature measuring mechanism, wherein the surface temperature is adjusted to a common value by changing the height of the air cushion with the help of a first regulator (21) composed of a control device. Background Art

[0003] Document EP 1 335 997 B1 describes a method for controlling / regulating the surface temperature of a plurality of substrate holders, each of which is located in a recess of an upwardly open susceptor. A gas flow is fed into the bottom of the recess, which lifts the substrate holder located in the recess and rotates it. Below the susceptor is a heater, which can be used to heat the susceptor to the susceptor temperature. A process chamber is located above the susceptor, which is bounded upward by a process chamber cover. An opening is provided in the process chamber cover, through which the optical path of an optical temperature measuring mechanism (e.g., a pyrometer) passes. The susceptor is driven by a rotary drive with a rotation speed of about 5 revolutions per minute. There are five substrate holders on the susceptor, so that only every 12 seconds is the same substrate holder present under the temperature measuring mechanism, by which the surface temperature of the substrate holder or the substrate carried by the substrate holder is measured. An average value is formed from the surface temperatures measured at intervals. In a CVD reactor, a vertical temperature gradient is formed from the heating device via the susceptor to the process chamber cover. Heat is transferred from the susceptor to the substrate holder and to the substrate via an air cushion. The height of the air cushion influences the heat transfer and thus the temperature of the substrate. By varying the height of the air cushion for each substrate holder individually, the substrate temperature can be regulated by a regulator or control device relative to an average value, so that the difference between the substrate temperature and the average value is close to zero. However, in this method, such a regulation of the surface temperature is only possible with a susceptor temperature that is constant over time. In a temperature gradient, the temperature changes rapidly and since only actual values ​​from the past are available for regulation, it is not feasible to use the regulation algorithms of the prior art. Summary of the invention

[0004] The technical problem to be solved by the present invention is to further improve the CVD reactor and method of the above type so that the surface temperature can also be adjusted within the time period when the susceptor temperature changes.

[0005] The object is achieved by the claims of the invention, wherein the dependent claims represent not only advantageous developments of the independent claim of the invention but also independent solutions to the object.

[0006] The present invention firstly and essentially relates to calculating or estimating the approximate actual value of the previously measured substrate holder, using the last measured actual value of the surface temperature of the substrate holder. This is achieved by calculating the difference between the actual value currently measured and another value. The difference value assigned to the substrate holder is calculated by difference calculation. The other value is appropriately estimated. The other value is preferably determined by averaging. In particular, it is provided that only one measured actual value of each substrate holder is used in the averaging, wherein the measured actual value is also understood to be an actual value obtained by averaging a large number of individual measurements, but wherein these measurements are performed one after another for the same substrate holder. According to the present invention, only the following actual values ​​are used for averaging, which are measured at a time less than the rotation time of a disk-shaped base, in which a plurality of substrate holders are arranged on an arc around the center of the arc. Therefore, according to the present invention, only the last measured actual value of each substrate holder is used for averaging. According to the present invention, the difference value is calculated. At each measurement of the actual value, the average value and the difference value are calculated. The difference value is the difference between the actual value measured during the measurement and the calculated average value. According to the present invention, when the substrate holder passes through the detection range of the temperature measuring mechanism, the current temperature of the substrate holder is measured as an actual value, and the average value and the difference value assigned to the substrate holder are calculated based on the aforementioned actual value and the actual values ​​of only the latest (or last) measured multiple other substrate holders. Each time the substrate holder passes through the detection range of the temperature measuring mechanism, the actual value, the average value and the difference value assigned to the substrate holder are updated. Also according to the present invention, each time the substrate holder passes through the detection range of the temperature measuring mechanism, an approximate actual value is calculated based on the average value and the difference value of the latest determined other substrate holders. The currently determined actual value and the approximate actual value are used to control / regulate the surface temperature. The substrate holder can be formed by a storage position of the base, which is designed as a recess, for example. The substrate holder can be a component of the substrate holder or a component of the same material. However, the present invention also preferably includes such an embodiment, wherein the substrate holder is a substrate holder, which is supported by a dynamic air cushion and the substrate can be placed on it. For controlling / regulating the surface temperature, for example, a first regulator can be used, which generates a control value for a mass flow controller, by means of which the mass flow of the gas generating the air cushion is regulated. The height of the air cushion can be varied by varying the mass flow of the gas. For this purpose, each air cushion is individually equipped with a mass flow controller. However, the invention also relates to embodiments in which the parameter is the cooling power or the heating power. If, for the sake of simplicity, the currently measured actual value is also referred to as the approximate actual value, because its distance from the mean value is equal to the current difference, a second mean value can be obtained from all the approximate actual values.In order to obtain the second average value, the current actual value measured on the substrate holder located in the detection area of ​​the temperature measuring mechanism and the latest approximate actual value last measured for other substrate holders are used. If the method is implemented when the susceptor temperature is kept substantially constant, the two average values ​​basically correspond to a processing temperature. Therefore, in order to adjust the susceptor temperature, not only can the temperature of the susceptor directly measured by a separate measuring device be used, but also one of the two average values ​​can be used. When the susceptor temperature changes, the method according to the present invention proves to be particularly advantageous, for example because between two coating steps, for example, a semiconductor material layer is deposited on the substrate at different temperatures. The susceptor temperature increases or decreases in an inclined form. This can be controllable or uncontrollable. Preferably, the heating or cooling of the susceptor is controlled so that the temperature changes at a constant rate of change over time. In the application of the above method, the temperature values ​​measured at different times and thus at different susceptor temperatures are used when obtaining the first average value. With the help of the difference updated in each measurement and the temperature of the substrate holder last measured before, the current temperature of the substrate holder can be estimated as an approximate actual value. This estimated value can be supplied to the regulator as an actual value, so that when the process temperature set by the susceptor temperature changes, the regulation of the surface temperature of the substrate holder does not have to be interrupted or the parameters of the regulator do not have to be changed. The second average value corresponds approximately to the current susceptor temperature, while the first average value lags behind the change in the susceptor temperature in time, i.e. is lower than the susceptor temperature when heating and higher than the susceptor temperature when cooling. In the case of temperature gradient changes, the approximate actual values ​​can also be used as actual values ​​for the control algorithms used so far. They are closer to the actual surface temperature of the substrate holder than the "old" actual values ​​used in the past for the control.

[0007] The CVD reactor according to the invention has a pedestal, which may have a disc shape and may be driven to rotate around an axis of rotation. The pedestal has a substrate holder on its upper side facing the process chamber, such as a recess or other storage position for storing a plurality of substrate holders, which are respectively carried by an air cushion generated by an air flow, which can be preset by a mass flow controller. When the pedestal rotates, the substrate holders move one by one through the detection area of ​​a temperature measuring mechanism, which may be an optical sensor, such as a pyrometer or a photodiode. The control device of the CVD reactor is programmable. The control device may be programmed so that the surface temperature of the substrate holder or the substrate on the substrate holder is adjusted using the above method. The heating device may be an infrared heater or a radio frequency heater.

[0008] The method according to the invention and the device according to the invention are not only suitable for operating conditions in which all substrate holders are occupied by substrates to be coated. The method also includes a part of the total number of substrate holders occupied by substrates. For example, in the test phase, only one or only a few substrate holders can be occupied by substrates. The remaining substrate holders cannot be occupied by any substrate. However, they are preferably covered with dummy substrates, such as old, used substrates. In a variant of the invention, an average value can be obtained from all measured surface temperatures. However, the average value can also be obtained only from the surface temperature of certain substrates, such as substrates for test purposes. In this variant, a second average value can also be calculated. This average value is preferably obtained only from the approximate actual value of the substrate for test purposes. In the simplest case, when only substrates for test purposes are coated in a CVD reactor, the second average value can be the approximate actual value of a single test substrate calculated. The temperature of the substrate can be influenced by changing a parameter, which can be the height of the gas cushion. However, if the gas is, for example, a mixture of a gas with high thermal conductivity and a gas with low thermal conductivity, the parameter can also be the composition of the gas that produces the gas cushion. Furthermore, it can be provided that the temperature of the substrate holder can be individually controlled, for example individually cooled or heated. The parameter can then be the cooling power or the heating power. For example, individual heating can be carried out by means of a laser beam.

[0009] The invention relates in particular to a method for controlling / regulating the surface temperature of a substrate located on a substrate holder associated with a susceptor in a process chamber of a CVD reactor, wherein actual values ​​of the surface temperatures associated with the substrate holders are measured in sequence and the surface temperatures are varied by changing parameters, such as adjusting the height of an air cushion, which carries the substrate holders forming the substrate holders, to a common value, wherein after each measurement of the actual value of the surface temperature associated with the substrate holders, a first average value is calculated using only the last measured actual value of the surface temperature of each substrate holder, a difference value associated with the substrate holder is calculated by subtracting the actual value measured during the measurement from the first average value, and an approximate actual value is calculated for each other substrate holder by adding the associated difference value to the first average value for control / regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The embodiments of the present invention are described below with reference to the accompanying drawings. In the accompanying drawings:

[0011] Figure 1 1 shows a schematic cross-sectional view of a CVD reactor according to the invention, the CVD reactor having a plurality of substrate holders designed as substrate holders 3,

[0012] Figure 2 Shown roughly along Figure 1A schematic top view of a susceptor 2 of a CVD reactor obtained along the section line II-II in FIG. 1 , wherein the susceptor has five storage locations, on which substrate holders 3 carrying substrates 4 are arranged respectively,

[0013] Figure 3 Schematically shown is a mass flow controller 20 for providing a gas flow which is fed into an input line 8 of the susceptor 2 to generate an air cushion 7 on which the substrate holder 3 lies and by which the substrate holder 3 is rotated,

[0014] Figure 4 Schematically showing that when the substrate temperature is kept substantially constant in the first phase A and the substrate temperature increases with a constant slope over time in the second phase B,

[0015] Figure 5 Show according to Figure 4 A zoomed in screenshot to illustrate the differences dT1, dT2, dT3, dT4, dT5,

[0016] Figure 6 A table showing the surface temperatures (measured actual values) T1, T2, T3, T4, T5 measured in time period n when the substrate temperature ST increases, the average values ​​MT and MT' formed thereby, the differences dT1, dT2, dT3, dT4 and dT5 calculated thereby, and the approximate actual values ​​T1', T2', T3', T4', T5' calculated thereby. DETAILED DESCRIPTION

[0017] Figure 1 and Figure 2 The CVD reactor shown has a housing 1 which is gastight to the outside. A disk-shaped susceptor 2, for example made of graphite or coated with graphite, is located in the housing 1. Below the susceptor 2 is a heating device 9, by which the susceptor 2 can be heated to a susceptor temperature ST. The susceptor 2 is carried by a shaft 10 which can rotate about an axis. In the shaft 10, an inlet line 8 extends, which is supplied by a mass flow controller 20. Each of the five inlet lines is supplied by a mass flow controller 20, wherein the mass flow controller 20 is supplied with an inert gas, for example hydrogen or nitrogen or a rare gas, from a gas source 19. In the upper side of the susceptor 2 pointing to the process chamber 14, there are five storage locations for substrates 4, each of which is formed by a substrate holder 3. These substrate holders 3 can be formed of the same material as the susceptor 2, for example in the form of grooves, which respectively accommodate a substrate 4.

[0018] In the embodiment, there are a total of five recesses in the upper side of the susceptor 2 facing the process chamber 14. In each recess there is a disc-shaped substrate holder 3. One of the supply lines 8 is connected to the bottom of each recess 5, so that the gas discharged from the connection opening of the supply line 8 generates a gas cushion, which on the one hand drives the substrate holder 3 to rotate and on the other hand lifts the substrate holder 3. At least one substrate 4 is located on the substrate holder, which substrate can be coated with at least one layer, especially a semiconductor layer, during the deposition process in the process chamber. The process gas required for this is introduced into the process chamber 14 through the gas inlet device 12, wherein the process gas enters the process chamber 14 from the gas outlet area 13. The process chamber 14 is delimited upward by the process chamber cover 11, which has an opening 17, through which the optical path 16 passes. The optical path 16 connects a measuring point 18 located approximately in the center of the substrate holder 3 to an optical temperature measuring device 15, such as a pyrometer, by which the surface temperature of the substrate 4 or the substrate holder 3 can be determined. Additional indicator elements are provided, by means of which the rotational position of the susceptor 2 can be determined. This information is provided to the control device 23. Based on this information, the control device 23 can determine which of the five substrate holders 3 passes through the detection range of the temperature measuring mechanism 15 at a specific moment, so as to measure the current temperature of the substrate holder 3 (measured actual value Tn) in turn.

[0019] The substrate holder 3 floats on an air cushion that forms a heat transfer path to transfer heat from the susceptor 2 to the substrate holder 3. The amount of heat transferred to the substrate holder 3 depends on the height of the air cushion, whereby the surface temperature of the substrate 4 can be changed by changing the height of the air cushion.

[0020] Using actual temperature values ​​T1, T2, T3, T4, T5 measured by temperature measuring device 15, mass flow controller 20 presets the gas flow via first regulator 21 so that actual values ​​T1, T2, T3, T4, T5 approach their average value MT.

[0021] In another embodiment, a nominal value that is the same for all, such as the temperature difference from the susceptor floor or the chamber ceiling, may be used.

[0022] The following reference Figure 4 and 5 Explain the methods used, Figure 4 and 5 The curves shown in show the temperature curves of the surfaces of five substrate holders produced without temperature control. Therefore, the relative distances between the temperature values ​​remain constant over the entire length of the curves. In practice, the relative distances between the curves decrease due to control and are ideally zero. In the first phase A, the susceptor temperature does not change.

[0023] The susceptor 2 rotates around its axis at a constant speed, which can be between 2 and 20 revolutions per minute. Correspondingly, the intervals between individual measurements of the substrate holders 3 that successively pass through the detection area of ​​the temperature measuring mechanism 15 are several seconds long. In the first phase A, the temperatures T1, T2, T3, T4, T5 of the individual substrate holder surfaces do not change while the susceptor temperature is kept constant at approximately 900° C. If an omitted adjustment is now performed for the sake of explanation, the temperatures T1, T2, T3, T4, T5 will approach an average value.

[0024] In a second phase B, the susceptor temperature is increased continuously, for example by increasing the heating power.

[0025] In each of the two phases A, B, the mean value MT is determined as follows

[0026]

[0027] k={6,11,16,21,...}, when S=1, N=5

[0028]

[0029] k={7,12,17,22,...}, when S=1, N=5

[0030]

[0031] k={8,13,18,23,...}, when S=1, N=5

[0032]

[0033] k={9,14,19,24,...}, when S=1, N=5

[0034]

[0035] k={10,15,20,25,...}, when S=1, N=5

[0036] N: Number of substrates

[0037] S: Position of the susceptor when k = 1 (wafer number) | S = {1, 2, 3...N}

[0038] Measuring time:

[0039] ω: rotation frequency of the base.

[0040] The average value is usually calculated as follows

[0041]

[0042] k∈N, k>N, n∈{1,2,3,4,...N}

[0043] Modulo operation: n mod m gives the remainder b when n is divided by m. The sign of b corresponds to the sign of m.

[0044] Here, N is the total number of substrate holders 3 , which is 5 in the exemplary embodiment.

[0045] For each measurement, a mean value is calculated, using the temperature value of the substrate holder 3 currently located in the detection range of the temperature measuring device 15 and the previously measured temperature values ​​of all other substrate holders, but only one measured value is used in each case and only the most recent measured value is always used. During phase B, the mean value is obtained from the temperature measurement values ​​recorded in the past at different substrate temperatures ST. Figure 4 It can be seen that the curve of the mean value MT lies below the measurement curves of the temperature measurement values ​​of the individual substrate holders 3. The sharp bend in the displayed measurement curves leads to a delayed increase in the slope of the mean value curve.

[0046] For each measurement, not only the current actual value but also the difference is calculated as follows

[0047] dT1(k)=T1(k)-MT(k)|k={6,11,16,21,...}, when S=1、N=5

[0048] dT2(k)=T2(k)-MT(k)|k={7,12,17,22,...}, when S=1、N=5

[0049] dT3(k)=T3(k)-MT(k)|k={8,13,18,23,...}, when S=1、N=5

[0050] dT4(k)=T4(k)-MT(k)|k={9,14,19,24,...}, when S=1、N=5

[0051] dT5(k)=T5(k)-MT(k)|k={10,15,20,25,...}, when S=1、N=5

[0052] The difference can usually be calculated as follows

[0053] dT (N -((n-k+NS)mod N)) (k) = T (N -((n-k+NS)mod N)) (k)-MT(k)|n=1

[0054] The difference between t4, t5, t1, t2 and t3 is as follows Figure 4 Shown in. Figure 5 It is shown how to calculate the approximate temperature values ​​T5', T1', T4' and T2' at the time t3 from the mean value MT determined at the time t3 using the previously determined difference values ​​dT1, dT2, dT4, dT5. At the time t3, the temperature T3 of the third substrate holding element is measured. First, the mean value MT is calculated using the actual temperature values ​​T4, T5, T1, T2 measured previously at the times t4, t5, t1, t2. The approximate temperatures T5', T1', T4', T2' are calculated as follows using the difference values ​​dT4, dT5, dT1, dT2 calculated at the times t4, t5, t1, t2.

[0055] T'1(k)=T1(k)|k={6,11,16,21,...}, when S=1、N=5

[0056] T'2(k)=MT(k)+dT2(k-4)

[0057] T'3(k)=MT(k)+dT3(k-3)

[0058] T'4(k)=MT(k)+dT4(k-2)

[0059] T'5(k)=MT(k)+dT5(kl) ...

[0061] Typically, the approximate temperature is calculated as follows

[0062] T' (N-((n-k+N-S)mod N)) =MT(k)+dT (N-((n-k+N-S)mod N)) (k-n+1)

[0063] k∈N>N,n∈{1,2,3,4,...N}

[0064] The second average value can then be calculated from the approximate temperature Tn′ as follows.

[0065]

[0066] Or according to the following calculation

[0067]

[0068] With the aid of the second mean value MT' which can correspond to the current susceptor temperature, if it rises with a constant slope, the mass flow controller 20 is regulated or controlled, wherein the regulation / control is carried out in such a way that the difference between the approximate actual temperature T1' and the second mean value MT' is regulated to zero.

[0069] Figure 6 In table form it is shown how the temperature changes during the temperature ramp.

[0070] The above embodiments are used to illustrate the invention as a whole included in the application, which invention independently expands the prior art at least through the following feature combinations, wherein two, more or all technical feature combinations can also be combined with each other, namely:

[0071] A method, characterized in that after each measurement of an actual value Tn of a measured surface temperature associated with a substrate holder 3, an approximate actual value Tn' is determined using the last measured actual value Tn of the surface temperature of at least one other substrate holder 3, which is used for regulation / control.

[0072] A method, characterized in that a first value MT is calculated using actual values ​​Tn of the surface temperature of a plurality of other substrate holders 3 or each substrate holder 3, and / or that the first value MT is an average value MT of the actual values ​​Tn of the surface temperature measured last, and / or that a difference value dTn assigned to the substrate holder 3 is calculated by calculating the difference between the actual value Tn measured during the measurement and the first value or the average value MT, and / or that an approximate actual value Tn' for each other substrate holder 3 is calculated by adding the associated difference value dTn to the value MT.

[0073] A method, characterized in that the substrate holder is a substrate holder 3 supported by a dynamic air cushion, and the parameter is the height of the air cushion 7 and the composition of the gas generating the air cushion 7, and / or the parameter is the cooling power or heating power applied to the substrate holder 3.

[0074] A method, characterized in that after one or each measurement, a second mean value MT' is calculated using the actual value Tn determined during the measurement and the last calculated approximate actual value Tn' assigned to one, some or all other substrate holders 3, and the difference between the approximate actual value Tn' and the second mean value MT' is used as an input variable for a first regulator 21, which regulates the difference to zero.

[0075] A method, characterized in that the susceptor 2 is heated from a first temperature to a second temperature at a constantly increasing temperature or cooled to a second temperature at a constantly decreasing temperature by means of a heating device 9, and at this time, actual values ​​of a plurality of substrates 4 assigned to the susceptor 2 and respectively arranged on one of the substrate holders 3 are measured intermittently and periodically in sequence.

[0076] A method is characterized in that one of the susceptor temperature, the first mean value, the second mean value or the approximate actual value Tn′ is regulated to a desired value by a second controller 22 .

[0077] A method, characterized in that a disc-shaped susceptor 2 is used and arranged in a process chamber 14 of a CVD reactor, wherein the substrate holders 3 are arranged on an arc around the center of the susceptor 2, and the susceptor 2 rotates around the center, wherein the actual value of the measured surface temperature is determined at a position 18 in the process chamber 14 by means of a temperature measuring device 15.

[0078] A CVD reactor, characterized in that the control device 23 is configured to determine a value MT after each measurement of an actual value Tn of the measured surface temperature assigned to a substrate holder 3, using the actual value Tn of the surface temperature of one or more substrate holders 3 measured last, calculate a difference value dTn assigned to the substrate holder 3 by calculating the difference between the actual value Tn measured during the measurement and the value MT, and calculate an approximate actual value Tn' for at least one other substrate holder 3 by adding the assigned difference value dTn to the value MT, which approximate actual value is used for regulation / control.

[0079] A CVD reactor, characterized in that a first value MT is calculated using actual values ​​Tn of the surface temperature of multiple other substrate holders 3 or each substrate holder 3, and / or the first value MT is the average value MT of the actual values ​​Tn of the surface temperature measured last, and / or a difference dTn assigned to the substrate holder 3 is calculated by calculating the difference between the actual value Tn measured during the measurement and the first value or the average value MT, and / or an approximate actual value Tn' for each other substrate holder 3 is calculated by adding the assigned difference dTn to the value MT.

[0080] A CVD reactor, characterized in that after each measurement, a second mean value MT' is calculated using the actual value Tn determined during the measurement and the last calculated approximate actual value Tn' assigned to one, some or all other substrate holders 3, and the difference between the approximate actual value Tn' and the second mean value MT' is used as an input variable for a first regulator 21, which regulates the difference to zero.

[0081] A CVD reactor, characterized in that the susceptor 2 is heated from a first temperature to a second temperature at a constantly rising temperature or cooled to a second temperature at a constantly falling temperature by means of a heating device 9, and at this time, the actual values ​​of a plurality of substrates 4 supported by the susceptor 2 and respectively arranged on one of the substrate holders 3 are intermittently and periodically measured in sequence.

[0082] A CVD reactor is characterized in that the susceptor temperature or the first average value or the second average value is adjusted to a setpoint value by a second regulator 22.

[0083] All disclosed features (in themselves and in combination with each other) have inventive significance or inventive value. In the disclosure documents of the present application, the disclosure content of the associated / attached priority document (prior application document) is also fully included, and for this purpose, the features in the priority document are also incorporated into the claims of the present application. The features of the dependent claims are all improved designs with independent inventive significance or value for the prior art even without the technical features of the corresponding claims, and in particular, divisional applications can be filed on the basis of these dependent claims. The invention provided in each claim may additionally have one or more technical features provided in the preceding description, in particular with reference numerals and / or in the list of reference numerals. The present invention also relates to some design forms in which individual technical features mentioned in the preceding description cannot be realized, and in particular, it can be identified that they are unnecessary for various application purposes or can be replaced by other devices that can be realized in the same way technically.

[0084] Reference numerals list

[0085] 1 Housing

[0086] 2 Base

[0087] 3 Substrate holder

[0088] 4 substrate

[0089] 5. Concave

[0090] 6 Bottom plate

[0091] 7. Gap, Air Cushion

[0092] 8 Input pipeline

[0093] 9 Heating device

[0094] 10 Axis

[0095] 11. Processing chamber cover

[0096] 12 Intake mechanism

[0097] 13 Exhaust mechanism

[0098] 14. Processing Room

[0099] 15 Temperature measurement mechanism

[0100] 16 Optical Path

[0101] 17 Opening

[0102] 18 measuring points

[0103] 19 Gas source

[0104] 20 Mass Flow Controller

[0105] 21 First Regulator

[0106] 22 Second regulator

[0107] 23 Control Device

[0108] A. Phase I

[0109] B. Second Stage

[0110] dTn difference

[0111] dT1 difference

[0112] dT2 difference

[0113] dT3 difference

[0114] dT4 difference

[0115] dT5 difference

[0116] MT First Average

[0117] MT' Second Average

[0118] n Quantity

[0119] ST base temperature

[0120] Tn Surface actual value

[0121] Tn' approximate actual value

[0122] T1 Surface temperature

[0123] T2 Surface temperature

[0124] T3 Surface temperature

[0125] T4 Surface temperature

[0126] T5 Surface temperature

[0127] T1' Approximate actual value

[0128] T2' Approximate actual value

[0129] T3' Approximate actual value

[0130] T4' Approximate actual value

[0131] T5' Approximate actual value

[0132] Time t1

[0133] Time t2

[0134] Time t3

[0135] t4 time

[0136] Time t5.

Claims

1. A method for individually controlling / regulating the surface temperature of each of a plurality of substrates (4) which are arranged on a plurality of substrate holders (3) on a susceptor (2) in a process chamber (14) of a CVD reactor, wherein: The actual values ​​of the surface temperatures of all substrate holders (3) are measured sequentially over time and the plurality of surface temperatures are adjusted to a common value by varying the amount of heat transferred individually to each substrate holder (3), wherein a first mean value (MT) is calculated using the actual values ​​of the surface temperatures of all substrate holders (3) during each measurement, for which purpose only the last measured actual value of the surface temperature of each substrate holder is used to calculate the first mean value (MT) after each measurement of the actual value of the surface temperature associated with the substrate holder (3), wherein a difference value (dTn) associated with the substrate holder (3) is calculated by calculating the difference between the actual value of the surface temperature last measured during the measurement and the first mean value, and wherein an approximate actual value for each other substrate holder (3) is calculated by adding the associated difference value (dTn) to the first mean value (MT), which approximate actual value is used for regulation / control.

2. The method according to claim 1, characterized in that: The substrate holder is a substrate holder supported by a dynamic air cushion.

3. The method according to claim 1, characterized in that After one or each measurement, a second mean value (MT') is calculated using the actual value determined during the measurement and the last calculated approximate actual value assigned to one, some or all other substrate holders (3), and the difference between the approximate actual value and the second mean value (MT') is used as an input variable for a first controller (21), which regulates the difference to zero.

4. The method according to claim 1, characterized in that The base (2) is heated from a first temperature to a second temperature at a constantly increasing temperature or cooled to a second temperature at a constantly decreasing temperature by means of a heating device (9), and at the same time, actual values ​​of a plurality of substrates (4) assigned to the base (2) and respectively arranged on one of the substrate holders (3) are measured in sequence intermittently and periodically.

5. The method according to claim 3, characterized in that: The susceptor temperature, the first mean value, the second mean value or the approximate actual value is regulated to a setpoint value by a second regulator (22).

6. The method according to claim 1, characterized in that A disc-shaped susceptor (2) is used and arranged in a process chamber (14) of a CVD reactor, wherein the substrate holders (3) are arranged on a circular arc around the center of the susceptor (2) and the susceptor (2) rotates around the center, wherein the actual value of the measured surface temperature is determined at a position (18) in the process chamber (14) by means of a temperature measuring device (15).

7. A CVD reactor having a plurality of substrate holders (3) located on a susceptor (2), wherein: The base (2) is movable so that the substrate holders (3) can be placed in a detection area of ​​a temperature measuring mechanism (15) in sequence, and the surface temperature of the substrate (4) located on each substrate holder (3) can be detected in time in sequence by the temperature measuring mechanism, wherein the surface temperature is adjusted to a common value by changing the amount of heat transferred individually to each substrate holder (3) by means of a first regulator (21) consisting of a control device (23), wherein a first mean value (MT) is calculated using the actual values ​​of the surface temperatures of all substrate holders (3) at each measurement, and for this purpose at each measurement After measuring the actual value of the surface temperature assigned to the substrate holder (3), a first mean value (MT) is calculated using only the last measured actual value of the surface temperature of each substrate holder, wherein a difference value (dTn) assigned to the substrate holder (3) is calculated by calculating the difference between the actual value of the surface temperature last measured during the measurement and the first mean value, and wherein an approximate actual value for each other substrate holder (3) is calculated by adding the assigned difference value (dTn) to the first mean value (MT), which approximate actual value is used for regulation / control.

8. The CVD reactor according to claim 7, characterized in that After each measurement, a second mean value (MT') is calculated using the actual value determined during the measurement and the last calculated approximate actual value assigned to one, some or all other substrate holders (3), and the difference between the approximate actual value and the second mean value (MT') is used as an input variable for a first controller (21), which regulates the difference to zero.

9. The CVD reactor according to claim 7, characterized in that: The base (2) is heated from a first temperature to a second temperature at a constantly increasing temperature or cooled to a second temperature at a constantly decreasing temperature by means of a heating device (9), and at the same time, actual values ​​of a plurality of substrates (4) supported by the base (2) and respectively arranged on one of the substrate holders (3) are measured in sequence intermittently and periodically.

10. The CVD reactor according to claim 7, characterized in that: The susceptor temperature or the first mean value or the second mean value is regulated to a setpoint value by a second regulator (22).

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