DE102006009460A1 - Process device used in production of integrated circuits comprises process chamber, holder within chamber for holding substrate, radiation source, radiation detector and control and evaluation unit - Google Patents

Abstract

A process device (1a) comprises a process chamber (10) with outer walls (30), a holder within the chamber for holding a substrate (18) during the process, a radiation source (36) for producing a light beam (50) emitting in the infrared wavelength region, a radiation detector (38) for detecting light from the radiation source reflected onto a surface (25) of the substrate and a control and evaluation unit (43) connected to the detector and/or radiation source to determine the wavelength of an absorption edge which characteristic for the material on the surface of the substrate and to calculate a temperature of the substrate from the determined wavelength. An independent claim is also included for determining a temperature of a substrate during use of the process device.

Description

The The invention relates to a process device and a method for determining the temperature of a substrate in the process device. The invention particularly relates such process devices, with which physically reinforced chemical deposition (PECVD), dry etching or sputtering processes (Cathode) carried out can be where plasma sources are used. The invention relates also the processing of substrates in low-temperature processes.

integrated Circuits are generally based on a layered structure of material layers of different electrical properties as well a respective subsequent lithographic patterning process produced.

A such material layer is, for example, in a deposition process applied to a substrate, which is a semiconductor wafer or a photomask can act before the actual lithographic Structuring takes place. Depending on the desired homogeneity of the profile the layer applied to an existing topography different deposition methods available.

Subsequently, will For example, a photosensitive resist applied, exposed and designed so that the desired pattern of the circuit corresponding etching mask remains. In an etching process can the structures exposed in the previous development from the etch mask transferred to an underlying layer become.

With progressive reduction of the structural widths in the products to be produced Integrated circuits also do not meet the quality requirements only the lithographic step itself, but on the respective Nachprozessierung. This also applies to the etching to transfer the pattern into the underlying layer or the subsequent structure of other layers by deposition of material layers.

Especially during etching are no longer used purely chemical etching processes, it will be rather, dry etching processes prefers. With these can the structures formed in the resist or a hard mask anisotropic transferred to the underlying material become. The dimensional accuracy is significantly improved.

Such etch or Separation processes usually become by generating a plasma in which reactive species or at least high-energy ions are formed, due to their Charge to be accelerated with respect to an electrode on the the substrate to be processed is stored, for example. By the ion bombardment becomes a chemical etching reaction in the case of etching fires where the ions may also participate themselves.

in the Case of plasma-enhanced chemical vapor deposition (PECVD, plasma enhanced chemical vapor deposition) in plasma, for example, from appropriate gases Generates ions that serve as reactants for the layer to be formed. These become the substrate surface accelerates, where they react accordingly and to the formation of the Layer are deposited.

At the Sputtering uses the ions generated in the plasma to be used at the Counter electrode to knock out the material to be applied to the substrate, from where the material is deposited in the direction of the electrode Substrate moves. Depending on what energy the particles are on attached to the substrate, can also be attached here Particles are knocked out and elsewhere on the substrate again be attached so that influence is taken on the layer profile can be.

The above-described processes, which a processing of the substrate surface by means of generation effect of a plasma are closely related and can be related combined, such as HDP deposition (High density plasma) elements of the PECVD and the sputtering method has. Such plasma processes are usually via a Number of process parameters controlled. These include, for example, the setting the frequency and power of the high frequency generator for generating of the plasma, the control of the gas flow rates for the reactive gases as well the density within the process chambers of the respective process devices.

To The state of the art modern process devices can be two different Have high frequency generators, one of which the generation the plasma controls while the other for accelerating the ions towards the substrate. examples are process equipment for etching with inductively coupled plasma source (ICP, inductively coupled plasma).

A Process or quality control can be carried out with the aid of test substrates, which are processed in advance and subsequently be supplied to a measurement in a metrology meter. It is also known to observe the plasma itself, for example by recording a spectrum of the light emitted by the plasma.

It is an object of the present invention tion to improve process equipment for the implementation of the above-described processes in so far as the quality of these processes is increased.

• – Eine Prozesskammer mit Außenwänden;
• – eine Halterung innerhalb der Prozesskammer zur Aufnahme des Substrat während der Anwendung des Prozessschrittes;
• – eine Strahlungsquelle zur Erzeugung eines im infraroten Wellenlängenbereich emittierten Lichtstrahls;
• – einen Strahlungsdetektor, welcher eingerichtet ist, den Lichtstrahl, welcher von der Strahlungsquelle auf einer Oberfläche des auf der Halterung in der Prozesskammer abgelegten Substrats eingestrahlt und von diesem reflektiert wird, zu detektieren;
• – eine mit dem Strahlungsdetektor und/oder der Strahlungsquelle verbundene Steuer- und Auswerteeinheit, anhand welcher (a) aus dem detektierten Lichtstrahl die Wellenlänge einer für das Material an der Oberfläche des Substrats charakteristischen Absorptionskante bestimmt werden kann, und (b) aus der bestimmten Wellenlänge eine Temperatur des Substrats berechnet werden kann.

The object is achieved by a process device for applying a process step to a substrate for the production of integrated circuits, comprising:

• - A process chamber with outer walls;
• A holder within the process chamber for receiving the substrate during the application of the process step;
• A radiation source for generating a light beam emitted in the infrared wavelength range;
• A radiation detector arranged to detect the light beam radiated from and reflected from the radiation source on a surface of the substrate deposited on the support in the process chamber;
• A control and evaluation unit connected to the radiation detector and / or the radiation source, by means of which (a) the wavelength of an absorption edge characteristic of the material at the surface of the substrate can be determined from the detected light beam, and (b) from the determined wavelength a temperature of the substrate can be calculated.

• – Bereitstellen des Substrats auf einer Halterung in dem Prozessgerät;
• – Beginnen der Anwendung des Prozesses auf das Substrat und dessen Oberfläche, wobei das Substrat eine Temperatur annimmt;
• – Emittieren eines Lichtstrahls im infraroten Wellenlängenbereich auf die Oberfläche des Substrats mittels einer Strahlungsquelle;
• – Detektieren des von der Oberfläche reflektierten Strahls durch einen Strahlungsdetektor;
• – aus dem detektierten Lichtstrahl bestimmen einer Wellenlänge einer für das Material an der Oberfläche des Substrats charakteristischen Absorptionskante;
• – aus der bestimmten Wellenlänge berechnen der vom Substrat angenommenen Temperatur.

The object is further achieved by a method for determining a substrate temperature during the application of a process step in a process device to the substrate, wherein the process step is used to produce integrated circuits, comprising:

• - Providing the substrate on a holder in the process device;
• - beginning the application of the process to the substrate and its surface, the substrate assuming a temperature;
• - emitting a light beam in the infrared wavelength range on the surface of the substrate by means of a radiation source;
• Detecting the surface-reflected beam by a radiation detector;
• From the detected light beam, determine a wavelength of an absorption edge characteristic of the material on the surface of the substrate;
• From the determined wavelength calculate the temperature assumed by the substrate.

It is provided while the implementation a process for the manufacture of integrated circuits the temperature of the substrate to determine. This is an in-situ temperature measurement. The process device, with which the process performed is equipped accordingly with a temperature measuring device. The proposal goes, the temperature by means of infrared spectroscopy to investigate. The temperature measuring device therefore comprises an im infrared wavelength range emitting radiation source and a radiation detector, the is suitable for detecting the radiation of these wavelengths. The radiation passes by irradiation of the surface of the substrate by means the radiation source as well as the direct reflection of the radiation from this surface away to the radiation detector.

In from the surface The radiation reflected by the substrate is information about the contain current temperature of the substrate or the substrate surface. From the radiated infrared radiation is at one for the material on the surface characteristic wavelength a proportion of the radiation intensity due to the excitation of lattice shrinkages absorbed in the crystal lattice of the substrate. The transmitted by photons Energy can stimulate phonons. Due to an increased density close together lying energy levels in the crystal lattice can be found in the absorption spectrum significant band or absorption edges.

The Positions of such absorption edges within the spectrum are temperature dependent. For example, the wavelength of such an absorption edge is provided and based on a previously performed calibration (table, predetermined Relation) to derive a temperature from it.

a According to the aspect, in the outer walls of the Process chamber of the process device window provided by which the in the infrared wavelength range emitted light beam is directed into the process chamber on the substrate can be. In the same way, the light beam by reflection be led out of the process chamber from the substrate to the radiation detector. It can be the same or another window. It is important that the window in the outer wall of the process chamber is transparent across from the light beam in the infrared wavelength range, and that in the region of interest of the wavelength range through the window glass no signature is added to the spectrum, in particular more Absorption lines, which complicate the evaluation of the spectrum.

According to advantageous aspects, it is provided to set up the temperature measuring device in process devices with a plasma source. Thus, the invention can be used in PECVD, sputtering, HDP, dry etching and many similar devices. The advantage is to see that the temperature of the substrates during the implementation of the corre sponding may be assumed to be below 400 ° C.

The Substrate temperatures can doing so to a considerable extent from the temperatures of the plasma or other gases in the process chamber differ. It has been found here that one about the previous estimate In addition, accurate determination of the temperature of the substrate itself from elevated Meaning can be.

It can, for example, the experienced in the course of the previous processing Be aware of the temperature budget of the substrate. So can the Difference be substantial, whether a substrate with 350 ° C or with 400 ° C in a process chamber was processed with plasma source. The temperature development For example, diffusion profiles of already formed in the substrate influence active areas.

It is basically also a temperature determination by means of pyrometers into consideration but it has been found that these are actually only for solutions at substrate temperatures above 400 ° C are suitable. Because with pyrometers the Temperature of the examined object from the radiation intensity as such is determined (black body radiation), can be generated in the space between observer / detector and substrate Plasma radiation exercise a falsifying the measurement result influence.

A Particularly advantageous embodiment provides, the temperature measuring device except for Set up the process chamber of a parallel plate reactor as a plasma source. In this case, the holder of the substrate constitutes a first electrode (Cathode) while the second electrode (anode) lies opposite this first electrode. The second electrode can be identical to the lid of the process chamber be. The window through which the infrared radiation in the Process chamber can be introduced, and through which the reflected Radiation also led out again is in this case enclosed in the lid designed as an electrode.

The Radiation therefore becomes perpendicular through the electrode (anode) on the surface of the Substrate irradiated. The reflected beam therefore substantially decreases the same way back to the window, so that only one window to be provided needs. Because conventional process equipment with parallel plate reactor often anyway have a window at this point, but so far only for the observation of the plasma was this aspect according to only minor structural changes on the process devices required.

One Another aspect of the invention relates to those in the infrared wavelength range emitting radiation source. For this purpose, a laser can be provided, the narrowband emits a focused beam of light, wherein This laser tunable in wavelength is. It is possible the interest here section of the wavelength range with the absorption edge using the laser to tune. It therefore becomes a spectrum recorded. The radiation detector has in this case one over the Wavelength cut is substantially homogeneous sensitivity, so is sufficient broadband.

Vice versa can also be tuned to the radiation detector or a Variety of channels each having different wavelength ranges of the reflected light can be examined. Then the Strahlunsgquelle be formed sufficiently broadband.

The Radiation source and the radiation detector are advantageously coupled to a control and evaluation unit, so that the radiation from the detector measured intensity with the wavelength currently tuned by the radiation source can be brought. The recorded spectrum consists in one Assignment of measured intensity values to wavelengths.

The Position of the absorption edge can be determined, for example, by a pattern recognition for the absorption edge is performed in the recorded spectrum. The pattern of the absorption edge to be examined can be deposited here be. Alternatively, it is also possible in the relevant wavelength section that wavelength to determine, for the measured intensity just takes a minimum. The invention is in none of the above Examples limited.

a Another aspect is that the control and evaluation unit with a cooling mechanism for the Mounted on which the substrate is deposited during the process becomes. In plasma source-based process devices, cooling usually takes place by simple heat conduction of the substrate is held on the holder, whereby by electrostatic Attraction of contact between substrate and holder improved can be.

An alternative embodiment provides to effect a feedback of the temperature determination on the cooling or heating of the substrate (by the process) in that the control and evaluation unit is connected to the control of the high-frequency generators of the process device. Thus, depending on the measured temperature, the ion flux density and / or the ions energy to be adjusted. As a result, for example, the maintenance of a constant target temperature is achieved, and / or a temperature change is effected when a threshold value is exceeded.

The Invention will now be based on embodiments with the help a drawing closer explained become. Show:

1 a first embodiment of a process apparatus with a parallel plate reactor, which has a temperature measuring device;

2 an exemplary, with the temperature measuring device according to 1 recorded infrared spectrum with a band edge characteristic of the material on the surface of the processed substrate;

3 a modified embodiment according to 1 in which the temperature measuring device is attached to a lid of the process device;

4 a further embodiment of a process device with inductively coupled plasma source and temperature measuring device.

1 shows a reference to the representation of a dry etching process device 1a with parallel plate reactor, a first embodiment. With the device, a RIE process can be performed (RIE: reactive ion etching). The process device 1a includes a process chamber 10 in which two electrodes 12 . 14 are arranged. The lower electrode 14 serves as a holder for a substrate 18 , which may be a semiconductor wafer or a photomask, wherein the term photomask also includes EUV masks.

The substrate 18 has a carrier material 20 such as monocrystalline silicon in the case of semiconductor wafers or EUV masks, or quartz or glass in the case of transmissive photomasks. On the carrier material 20 there is a layer 22 , in the present a pattern with structures 24 is to be transferred from a resist mask formed in lithographic process. The layer 22 may be formed of any material, such as an oxide, a metal layer such as tungsten, aluminum or copper, chromium or molybdenum silicide in the case of masks, a nitride, poly-silicon, etc. It may also be the substrate itself etched, so for example silicon ,

About the lower electrode 14 is powered by a high frequency generator 28 an alternating voltage coupled, which is an alternating electric field between the electrodes 12 . 14 generated. In the process chamber 10 is located a process gas. The alternating field becomes a plasma 16 , generated.

The upper, grounded electrode 12 is with the exterior walls 30 the process chamber 10 connected (reference numeral 32 ) so that the effective grounded area as a whole is larger than that of the lower electrode 14 , The asymmetric effective area ratio causes a corresponding inversely proportional adjustment of the plasma boundary layer stresses. The ions from the plasma bulk are directed through these plasma edge layer voltages onto the lower electrode 14 and the grounded electrode 12 accelerated. The positively charged ions 48 become due to the lower electrode 14 accelerated. Together with a reactive gas in the process chamber, the ions cause 48 an etching of the surface 25 the layer 26 on the substrate 18 , where the structures 24 serve as an etching mask.

It should be noted that an etching process can in principle be carried out by, inter alia, energy input and sputtering effect of argon ions, by energy input and sputtering effect various ions of the process gas, by chemical reactions of the ions of the process gas and, above all, by chemical reactions of activated neutral particles. The ions 48 are therefore shown here only as an example.

Due to the ion bombardment and the etching reactions, the surface heats up 25 and thus the substrate. For example, a temperature of 200 ° C is reached. Due to the low pressure in the process chamber, cooling takes place practically only by means of heat conduction over the holder, such as, for example, an electrostatic chuck with He backside cooling and the lower electrode 14 instead of.

The features of an exemplary process device described so far 1a are well known to those skilled in the art. The invention is by no means limited to the detailed form of the parallel plate reactor.

As in further 1 is shown in, is located in one of the outer walls 30 of the process device 1a a window 42 , behind which a temperature measuring device 34 is appropriate. The temperature measuring device 34 has a radiation source 36 and a radiation detector 38 on. At the radiation source 36 it is a laser, which is a light beam 50 through the window 40 or an opening 42 in the upper electrode 12 emitted through. The light beam 50 has a wavelength in the infrared region (IR) between 700 nm and 1 mm. He falls sharply bundled / focused in a narrow section 26 almost perpendicular to the surface 25 of the substrate 18 ,

From the surface 25 the light beam is directly reflected (light beam 52 ), so he's the process chamber 10 in substantially the same way through the opening 42 and the window 40 leaves again. When passing through the process chamber 10 pierce the light rays 50 . 52 also the plasma 16 , The reflected light beam hits outside the process chamber 10 on the radiation detector 38 ,

The radiation source 36 , ie the IR laser, is tunable in wavelength. For this purpose, the IR laser with a control and evaluation unit 43 connected. From this he receives a signal, so that he gets the beam of light 50 emitted at a first wavelength. In the further course passes through a wavelength range until it finally reaches a second wavelength.

Through the radiation detector 38 becomes progressively the intensity of the light beam reflected from the surface 52 measured. Also the radiation detector 38 is with the control and evaluation unit 43 connected. This includes a first unit 44 with which the wavelength of the emitted light is assigned a measured intensity. It will record an IR spectrum.

Such an IR spectrum is exemplary in 2 shown. Plotted is the measured intensity of the reflected light beam 52 against the wavelength of the emitted light beam 50 for two different temperatures T1, T2 of the substrate 18 or from its surface 25 , Clearly visible are band or absorption _edges at the wavelengths λ _abs1 , λ _abs2 corresponding to the temperatures T1, T2. The band edges are formed by absorption of light quanta in the region of the (close to each other) excitation levels of the crystal lattice of the material from which the layer 22 is designed. For silicon, the band edge is at 200 ° C in a wavelength range of 1100 nm.

The control and evaluation unit 43 further includes a second unit 46 , The second unit 46 evaluates the recorded spectrum and derives a temperature that corresponds to the currently determined band edge position in the spectrum. For this purpose, a calibration of temperatures T_x against band edge positions λ _{abs_x may} have been carried out in advance, for example by a more complex, alternative and sometimes destructive method of measuring the temperature.

At the control and evaluation unit 43 It can be a computer, a workstation or a PC. It can also be part of the device control of the process device 1a be.

3 shows a further embodiment of the aforementioned embodiment. Here has the process chamber 10 a chamber lid 31 in which the window 40 is arranged. The lid 31 can be opened (reference number 31 ) to the substrate 18 in the chamber 10 to insert or remove from there, or to maintain the process chamber. The upper electrode 12 and the lid 31 are identical. The window 40 and the opening 42 In this particular case, they also agree, so that the structure becomes particularly simple.

The temperature measuring device 34 with radiation source 36 and radiation detector 38 is in this embodiment on the lid 31 appropriate. Since the window also serves for visual observation of the plasma process, the temperature measuring device can also be easily removed and reassembled.

4 shows a second embodiment. The process device shown there 1b is a dry-etch device with inductively coupled plasma source (ICP). A coil 54 is powered by its own, first high-frequency generator 27 supplied with an AC voltage to a plasma 17 to create. The acceleration of the ions from the plasma 17 is caused by another alternating field, that of a second high frequency generator 29 via the substrate holder or electrode 15 is coupled.

The process chamber 10 also has an inlet 56 for the reactive etching gas and an outlet 58 for the etching products. The process is controlled by a central control unit 62 controlled with the first and second high frequency generators 27 . 29 as well as with the gas inlet 56 and the gas outlet 58 is connected (the latter for the sake of clarity not shown).

The process chamber has outer walls 30 in which opposite windows 40a . 40b are arranged. Through the window 40a becomes an infrared light beam 50 through a radiation source 36 (eg IR laser) introduced. At an inclined angle, the beam hits the surface of the substrate 18 on the holder or electrode 15 and is from there as a ray of light 52 reflects and thus leaves the process chamber 10 through the second window 40b , After that, the light beam 52 through the radiation detector 38 receive. The mode of operation of the temperature determination is analogous to the first exemplary embodiment.

Of particular note in this example is the connection between the central control unit 62 of the process device 1b and the control and evaluation unit 43 for temperature determination.

This connection makes it possible, for example, to carry out a feedback from the determined temperature to the process flow. Thus, the gas flow, the density, the pressure, the ion flux density, the ion acceleration, etc. depending on the temperature can be influenced. Also can connect to the mechanism 60 the ESC (electrostatic chucking) be provided to the cooling of the substrate 18 influenced by heat conduction.

Last A warning signal may also be generated indicating that a temperature threshold has been exceeded has been. About that In addition, an end point detection can take place, namely if the band edges in the recorded spectrum disappear because one currently too corrosive Layer was removed and the further underlying layer the corresponding band edge not as a feature at least in the examined Has wavelength range.

1a, 1b

process unit

10

process chamber

12 14

electrodes

16 17

plasma

18

substratum

20

support material

22

layer

24

structure in the resist

25

reflective surface of the substrate

26

close Impact area of the light beam

27-29

High Frequency Generators

30

Exterior walls of the process chamber

31

chamber cover (opening Exterior wall)

32

connection

34

Temperature measuring device (Source and detector)

36

radiation source (IR laser)

38

radiation detector

40 40a, 40b

window in outer wall

42

Opening in electrode

43

evaluation and control unit for temperature determination

44 46

subunits

48

ions

50

incident IR light beam

52

reflected IR light beam

54

Kitchen sink for inductive coupled alternating field (ICP)

56

inlet

58

outlet

60

cooling mechanism

62

central Control unit for process unit

Claims (20)

Process device ( 1a . 1b ) for applying a process step to a substrate ( 18 ) for the manufacture of integrated circuits, comprising: - a process chamber ( 10 ) with outer walls ( 30 ); A holder within the process chamber ( 10 ) for receiving the substrate ( 18 ) during the application of the process step; A radiation source ( 36 ) for generating a light beam emitted in the infrared wavelength range (US Pat. 50 ); A radiation detector ( 38 ), which is set up, the light beam ( 52 ), which from the radiation source to a surface ( 25 ) of the holder in the process chamber ( 10 ) stored substrate ( 18 ) and reflected by it, to detect, - one with the radiation detector ( 38 ) and / or the radiation source ( 36 ) connected control and evaluation unit ( 43 ), based on which (a) from the detected light beam ( 52 ) the wavelength (λ _abs1 ) one for the material at the surface ( 25 ) of the substrate ( 26 ) characteristic absorption edge can be determined, and (b) from the determined wavelength (λ _abs1 ) a temperature (T ₁ ) of the substrate can be calculated. Process device ( 1a . 1b ) according to claim 1, wherein the radiation source ( 36 ) is a laser and emits light in the infrared wavelength range at a discrete wavelength, the laser being tunable to vary the discrete wavelength. Process device ( 1a . 1b ) according to claim 1 or 2, which further comprises a relative to the infrared light beam ( 50 ) transparent window ( 40 . 40a ) in one of the outer walls ( 30 ), wherein the radiation source ( 36 ) outside the process chamber ( 10 ) and the light beam ( 50 ) through the window ( 40 . 40a ) through to the in the process chamber ( 10 ) deposited substrate ( 18 ). Process device ( 1a . 1b ) according to one of claims 1 to 3, in which the radiation detector ( 38 ) outside the process chamber ( 10 ) and that of the surface ( 25 ) of the substrate ( 18 ) reflected light beam ( 52 ) through the window ( 40 ) or another window ( 40b ) detected in one of the outer walls. Process device ( 1a . 1b ) according to one of claims 1 to 4, which is a device for generating a plasma 16 . 17 ), from which reactive particles and / or ions () are used to carry out an etching process, a chemical-physical deposition process or a sputtering process ( 48 ) in the direction of the surface ( 25 ) of the substrate deposited on the holder ( 18 ) who accelerates you can. Process device ( 1a . 1b ) according to claim 5, in which the device for generating a plasma is a parallel plate reactor which comprises two electrodes ( 12 . 14 ), of which one with a high-frequency voltage ( 28 ) for the formation of the plasma ( 16 ) between the electrodes ( 12 . 14 ) is supplied. Process device ( 1a . 1b ) according to claim 6, wherein the support for the substrate ( 18 ) a first ( 14 ) of the two electrodes. Process device ( 1a . 1b ) according to one of claims 6 or 7, in which the second electrode ( 12 ) by an openable lid ( 31 ) of the process chamber ( 10 ) formed outer wall ( 30 ), in the case of the window (s) ( 40 . 40a . 40b ) these in the as openable lid ( 31 ) formed outer wall ( 309 the process chamber ( 10 ) are arranged. Process device ( 1a . 1b ) according to claim 8, wherein the radiation source ( 36 ), the radiation detector ( 38 ) and the window or windows ( 40 . 40a . 40b ) are arranged such that the light beam ( 50 . 52 ) substantially perpendicular to the surface ( 25 ) of the substrate ( 18 ) and is reflected by this. Process device ( 1a . 1b ) according to claim 9, wherein the control and evaluation unit ( 43 ) with the radiation source ( 36 ) and with the radiation detector ( 38 ) and is arranged to (a) detect one of the radiation detectors ( 38 ) measured intensity as a function of the varied wavelength of the radiation source ( 38 ) to form a spectrum, and (b) to determine from the spectrum the absorption edge and its wavelength (λ _abs1 ). Process device ( 1a . 1b ) according to one of the preceding claims, in which in the control and evaluation unit ( 43 ) a relation or a table created by calibration is stored, which assigns a wavelength (λ _{abs_x} ) of an absorption edge a temperature (T _x ). Process device ( 1a . 1b ) according to one of the preceding claims, in which the holder is connected via a cooling mechanism ( 60 ), which can be controlled as a function of the determined temperature (T ₁ ), to the substrate ( 18 ) with its surface ( 25 ) at a desired temperature. Process device ( 1a . 1b ) according to claim 12, wherein the holder for effecting the cooling mechanism ( 60 ) has an electrostatic coupling with which the substrate ( 18 ) is fixed to the support so that it is cooled by conduction through the support by means of electrostatic attraction or by exposing the substrate back to cooled helium. Method for determining a temperature of a substrate ( 18 ) during the application of a process step in a process device ( 1a . 1b ), the process step of manufacturing integrated circuits, comprising: - providing the substrate ( 18 ) on a holder in the process device ( 1a . 1b ); - Begin the application of the process to the substrate ( 18 ) and its surface ( 25 ), the substrate ( 18 ) assumes a temperature (T ₁ ); - emitting a light beam ( 50 ) in the infrared wavelength range on the surface ( 25 ) of the substrate ( 18 ) by means of a radiation source ( 36 ); - Detecting from the surface ( 25 ) reflected light beam ( 52 ) by a radiation detector ( 38 ); - from the detected light beam ( 38 ) Determining a wavelength (λ _abs1 ) of one for the material on the surface ( 25 ) of the substrate ( 18 ) characteristic absorption edge; From the determined wavelength (λ _abs1 ) calculating a temperature (T ₁ ) of the surface ( 25 ) of the substrate ( 18 ). A method according to claim 14, wherein the process comprises a dry etching process for removing a layer ( 22 ) is applied. A method according to claim 14, wherein as a process a chemical physical deposition to form a layer ( 22 ) is performed on the substrate. Method according to Claim 14, in which a sputtering process for depositing and / or reshaping the surface ( 25 ) of the substrate ( 18 ) is carried out. Method according to Claim 14, in which the light beam ( 50 ) from a laser as a radiation source ( 36 ) and thereby tuned in wavelength over a spectral range, and wherein the radiation detector ( 38 ) as a function of the wavelength of the emitted light beam ( 50 ) the intensity of the detected light beam ( 52 ) to form an infrared spectrum. Method according to Claim 18, in which the absorption edge is detected in the infrared spectrum and determined on the basis of the position of the absorption edge in the infrared spectrum whose wavelength (λ _abs1 ). The method of claim 19, _wherein the wavelength (λ _{from s1} ) is a relation or table which wavelength (λ _{abs_x} ) is related to temperatures (T _x ), so that from the wavelength (λ _abs1 ) of the absorption edge the temperature (T ₁ ) at the surface ( 25 ) of the substrate ( 18 ) can be determined.