METHOD FOR CONTROLLING AN EVAPORATION RATE OF SOURCE MATERIAL, DETECTOR FOR MEASURING ELECTROMAGNETIC RADIATION REFLECTED ON A SOURCE SURFACE AND SYSTEM FOR THERMAL EVAPORATION WITH ELECTROMAGNETIC RADIATION

Abstract

The present invention relates to a method for controlling an evaporation rate of source material (20) in a system (10) for thermal evaporation with electromagnetic radiation (120), wherein the system (10) comprises an electromagnetic radiation source (110) for providing an electromagnetic radiation (120), a vacuum chamber (12) containing a reaction atmosphere (16) and a main detector (40, 100) for measuring electromagnetic radiation (120), wherein a source material (20) and a target material (18) to be coated are arranged in the vacuum chamber (12) and the electromagnetic radiation source (110) is arranged such that its electromagnetic radiation (120) impinges at an angle, preferably at an angle of 45°, on a source surface (22) of the source material (20) for a thermal evaporation and/or sublimation of the source material (20) below the plasma threshold, and wherein the main detector (40, 100) for measuring electromagnetic radiation (120) is arranged such that electromagnetic radiation (120) reflected on the source surface (22) reaches the main detector (40, 100), further wherein the source material (20) is provided by a source element (24), wherein the source surface (22) is located accessible for the electromagnetic radiation (120) at the source element (24), whereby the source element (24) is arranged in a holding structure (28) and movable by the holding structure (28) perpendicular to the source surface (22). Further, the present invention relates to a detector (40) for measuring electromagnetic radiation (120), the detector (40) preferably suitable for a method according to the present invention, and additionally to a system (10) for thermal evaporation with electromagnetic radiation (120) suitable for the method according to the present invention.

Claims

1.-30. (canceled)

31. Method for controlling an evaporation rate of source material in a system for thermal evaporation with electromagnetic radiation, wherein the system comprises an electromagnetic radiation source for providing an electromagnetic radiation, a vacuum chamber containing a reaction atmosphere and a main detector for measuring electromagnetic radiation, wherein a source material and a target material to be coated are arranged in the vacuum chamber and the electromagnetic radiation source is arranged such that its electromagnetic radiation impinges at an angle on a source surface of the source material for a thermal evaporation and/or sublimation of the source material below the plasma threshold, and wherein the main detector for measuring electromagnetic radiation is arranged such that electromagnetic radiation reflected on the source surface reaches the main detector, further wherein the source material is provided by a source element, wherein the source surface is located accessible for the electromagnetic radiation at the source element, whereby the source element is arranged in a holding structure and movable by the holding structure perpendicular to the source surface, the method comprising the following steps: a) Providing the electromagnetic radiation by the electromagnetic radiation source, b) Measuring electromagnetic radiation reflected on the source surface by the main detector, c) Analyzing the measured data obtained in step b), and d) Adjusting the evaporation rate based on the results of the analysis of step c) by Moving the source element with respect to the electromagnetic radiation and/or Adjusting the power of the electromagnetic radiation and/or Adjusting the size and/or shape of a cross section of the electromagnetic radiation.

32. Method according to claim 31, wherein in step d) the source element is moved perpendicular and/or parallel to the source surface.

33. Method according to claim 31, wherein the source element is provided as self-supporting structure, comprising source material with the source surface located at an upper end of the source element.

34. Method according to claim 31, wherein the source element comprises a crucible containing the source material, whereby the crucible is transparent or at least partly transparent for the electromagnetic radiation, with the source surface located within the crucible.

35. Method according to claim 31, wherein as the electromagnetic radiation light, with a wavelength between 100 nm and 1400 nm is used.

36. Method according to claim 31, wherein in step b) a main detector with two or more sensor elements is used, whereby the two or more sensor elements are adjacent to each other and thermally decoupled.

37. Method according to claim 31, wherein in step b) a first additional detector is used for measuring electromagnetic radiation reflected on a side surface of the source element different to the source surface, whereby the data measured by the first additional detector is used in steps c) and d).

38. Method according to claim 31, wherein in step b) a second additional detector is used for measuring electromagnetic radiation missing the source surface of the source element, whereby the data measured by the second additional detector is used in steps c) and d).

39. Detector for measuring electromagnetic radiation reflected on a source surface, comprising a sensor element with an absorption body, the absorption body comprising an absorption surface for at least partly absorbing the electromagnetic radiation, wherein the sensor element further comprises a heat sensing element for measuring a temperature of the absorption body for detecting an absolute temperature and/or a temperature change caused in the absorption body by the absorbed electromagnetic radiation, wherein the absorption body comprises a cooling system for an active cooling of the absorption body, whereby the cooling system comprises at least one cooling duct within the absorption body for a flow of coolant through the absorption body, and wherein the heat sensing element comprises flow sensors to measure the flow of the coolant through the cooling ducts in the absorption body and temperature sensors to measure an absolute temperature of the coolant and/or a temperature change of the coolant induced by flowing through the cooling ducts in the absorption body.

40. Detector according to claim 39, wherein one or more detectors are as main detector and/or as first additional detector and/or as second additional detector in a method for controlling an evaporation rate of source material in a system for thermal evaporation with electromagnetic radiation, wherein the system comprises an electromagnetic radiation source for providing an electromagnetic radiation, a vacuum chamber containing a reaction atmosphere and a main detector for measuring electromagnetic radiation, wherein a source material and a target material to be coated are arranged in the vacuum chamber and the electromagnetic radiation source is arranged such that its electromagnetic radiation impinges at an angle on a source surface of the source material for a thermal evaporation and/or sublimation of the source material below the plasma threshold, and wherein the main detector for measuring electromagnetic radiation is arranged such that electromagnetic radiation reflected on the source surface reaches the main detector, further wherein the source material is provided by a source element, wherein the source surface is located accessible for the electromagnetic radiation at the source element, whereby the source element is arranged in a holding structure and movable by the holding structure perpendicular to the source surface, the method comprising the following steps: e) Providing the electromagnetic radiation by the electromagnetic radiation source, f) Measuring electromagnetic radiation reflected on the source surface by the main detector, g) Analyzing the measured data obtained in step b), and h) Adjusting the evaporation rate based on the results of the analysis of step c) by Moving the source element with respect to the electromagnetic radiation and/or Adjusting the power of the electromagnetic radiation and/or Adjusting the size and/or shape of a cross section of the electromagnetic radiation.

41. Detector according to claim 39, wherein the absorption surface absorbs light, with a wavelength between 100 nm and 1400 nm.

42. Detector according to claim 39, wherein the heat sensing element comprises a temperature sensor arranged in a bore in the absorption body, wherein the bore ends within the absorption body.

43. Detector according to claim 39, wherein the absorption body comprises metal.

44. Detector according to claim 39, wherein the absorption body encloses at one end a hollow absorption volume, whereby the inner sidewalls of the absorption volume form the absorption surface and wherein the absorption volume comprises an absorption orifice, whereby the absorption orifice can be aligned to an assumed and/or determined impinging direction of the electromagnetic radiation to be measured.

45. Detector according to claim 39, wherein the detector comprises an aperture with an aperture opening, wherein the aperture is arranged upstream with respect to the sensor element along the assumed and/or determined impinging direction of the electromagnetic radiation to be measured.

46. Detector according to claim 45, wherein a size of the aperture opening is adapted to the absorption body, such that electromagnetic radiation coming through the aperture opening is impinging on the absorption surface of the absorption body.

47. Detector according to claim 45, wherein the detector comprises a shielding element, wherein the shielding element extends along the assumed impinging direction of the electromagnetic radiation to be measured between the aperture and the absorption body.

48. Detector according to claim 39, wherein the detector comprises two or more sensor elements, whereby the two or more sensor elements are adjacent to each other and thermally decoupled.

49. Detector according to claim 39, wherein the detector comprises arrangement elements for arranging the absorption body at a vacuum feedthrough.

50. System for thermal evaporation with electromagnetic radiation, comprising an electromagnetic radiation source for providing an electromagnetic radiation, a vacuum chamber containing a reaction atmosphere and a main detector for measuring electromagnetic radiation, wherein a source material and a target material to be coated are arranged in the vacuum chamber and the electromagnetic radiation source is arranged such that its electromagnetic radiation impinges at an angle on the source surface of the source material for a thermal evaporation and/or sublimation of the source material below the plasma threshold, wherein the main detector for measuring electromagnetic radiation is arranged such that electromagnetic radiation reflected on the source surface reaches the main detector, wherein the system is adapted to carry out a method according to claim 31.

Description

[0079] The present invention is further described hereinafter with reference to illustrated embodiments shown in the accompanying drawings. There is shown:

[0080] FIG. 1A system according to the present invention,

[0081] FIG. 2A first possible embodiment of the detector according to the present invention,

[0082] FIG. 3 An absorption body with an absorption volume,

[0083] FIG. 4 An embodiment of the detector according to the present invention with two sensor elements,

[0084] FIG. 5 Arrangement patterns of sensor elements,

[0085] FIG. 6A movable source element,

[0086] FIG. 7A cross section of the electromagnetic radiation adapted to the cross section of the source surface,

[0087] FIG. 8A system according to the present invention with a first condition of impinging electromagnetic radiation,

[0088] FIG. 9A system according to the present invention with a second condition of impinging electromagnetic radiation,

[0089] FIG. 10A system according to the present invention with a third condition of impinging electromagnetic radiation,

[0090] FIG. 11A system according to the present invention with a fourth condition of impinging electromagnetic radiation, and

[0091] FIG. 12A source element provided as a rod.

[0092] In FIG. 1, the main components of a system 10 for thermal evaporation of source material 20 with electromagnetic radiation 120 according to the present invention are shown. The source material 20 is arranged within a vacuum chamber 12, whereby the vacuum chamber 12 confines a reaction atmosphere 16. The vacuum chamber 12 itself is only indicated next to a vacuum feedthrough 14. At one of the vacuum feedthroughs 14 an electromagnetic radiation source 110 is arranged, at the other a detector 40 according to the present invention.

[0093] During operation of the system 10, the electromagnetic radiation source 110 provides electromagnetic radiation 120 directed and impinging on the source surface 22 of the source material 20. The source material 20 absorbs a fraction of the electromagnetic radiation 120 and therefore some of the source material 20 evaporates or sublimates, indicated in FIG. 1 by the dashed circular line. Opposite to the source material 20, a target material 18 is arranged. The evaporated source material 20 reaches the target material 18 and forms a coating on the surface of the target material 18.

[0094] The remaining fraction of the electromagnetic radiation 120 is reflected on the source surface 20. As the emitting direction of the electromagnetic radiation source 110 and the position and general orientation of the source surface 22 are known, it is possible to arrange a detector 40 in the assumed and/or determined impinging direction 122 of the reflected electromagnetic radiation 120. As already described for the electromagnetic radiation source 110, also the detector, in particular its absorption body 52, can be arranged at a vacuum feedthrough 14 of the vacuum chamber 12.

[0095] The detector 40 according to the present invention acts as a bolometer. The electromagnetic radiation 120 impinges onto the absorption surface 60 of the absorption body 52 and gets absorbed at least partly. As depicted, the absorption surface 60 faces the source surface 22 and hence also gets coated by evaporated source material 20, indicated in FIG. 1. Hence, after a short build up time, the absorption surface 60 comprises the same or at least similar absorption and reflection properties as the source surface 22.

[0096] The aforementioned energy deposit into the absorption body 52 causes a change in temperature of the absorption body 52 or at least a rise of a demand for cooling. By measuring the temperature or its changing behavior, an evaporation rate and/or a flux distribution of the source material 20 evaporated or sublimated by the impinging electromagnetic radiation 120 can be determined.

[0097] FIG. 2 depicts a cross-section of a possible embodiment of detector 40 according to the present invention. The detector 40 can be used for instance as main detector 100, first additional detector 102 and/or second additional detector 104 in both the method and the system 10 according to the present invention, respectively (see FIGS. 8 to 11).

[0098] The detector 40 comprises a single sensor element 50 with an absorption body 52, preferably consisting of a metal with high thermal conduction like copper or aluminum. An arrangement element 40 allows arranging the absorption body 52 at a vacuum feedthrough 14 of the vacuum chamber 12 of the system 10 according to the present invention. In particular, the arrangement element 42 comprises positioning elements 44 to alter the actual position of the absorption body 52 within reaction atmosphere 16 of the vacuum chamber 12. A movement of other elements of the system 10 arranged in the vacuum chamber 12 as for instance the source material 20, see FIG. 1, can therefore be provided without any hindrance caused by the detector 40.

[0099] The detector 40 according to the present invention is based on the principle of a bolometer. Electromagnetic radiation 120 impinges onto an absorption surface 60 of the absorption body 52 and gets absorbed at least partially. This energy deposit can be measured by measuring the absolute temperature or a change of the temperature of the absorption body 52.

[0100] For this, in the depicted detector 40 according to the present invention two different measurement methods and respective sensing elements 70 are implemented. The respective methods can be used separately to measure the temperature or its change. However, higher accuracy can be provided by combining the two methods described in the following.

[0101] For the first method, the absorption body 52 comprises a cooling system 80 for an active cooling. Coolant 84 flows through a cooling duct 82 through the absorption body 52 and thereby assimilates the energy deposited into the absorption body 80 by the impinging electromagnetic radiation 120. Flow sensors 72 measure the flow rate of the coolant 84, temperature sensors 74 measure the temperature of the coolant 84, as depicted in FIG. 2 both at the inlet port and at the outlet port of the cooling duct 82, respectively. In summary, these measurements combined allow to precisely determine the amount of energy deposited into the absorption body 52.

[0102] For the second method, a temperature sensor 74, preferably a thermocouple element 74, is arranged in a bore 54 of the absorption body 52, in particular in the vicinity of the absorption surface 60. As mentioned above, the energy deposited by the electromagnetic radiation 120 impinging on the absorption surface 60 causes a rise in temperature of the absorption body 52. The thermocouple 76 located within the absorption body 52 near to the absorption surface 60 can measure this as absolute temperature or as a change in temperature. Hence, also this measurement method allows to precisely determine the amount of energy deposited into the absorption body 52.

[0103] FIG. 3 shows a cross-section of a rotationally symmetrical preferred embodiment of the detector 40 according to the present invention, in particular of its absorption surface 60. According to this embodiment, the absorption body 52 of the depicted sensor element 50 comprises at its end, which faces the impinging direction 122 of the electromagnetic radiation 120 to be measured, a hollow absorption volume 56. This absorption volume 56 comprises a single opening, namely an absorption orifice 62, which allows the impinging electromagnetic radiation 120 to enter the absorption volume 56. Inner sidewalls 58 of the absorption volume 56 form the absorption surface 60. In other words, the electromagnetic radiation 120 enters the absorption volume 120 and is reflected many times within the absorption volume 56, indicated in FIG. 3 by arrows, whereby at each reflection a fraction of the energy of the impinging electromagnetic radiation 120 is absorbed. Ideally, the electromagnetic radiation 120 is trapped in the absorption volume 56 and consequently completely absorbed by the absorption surface 60. To enhance a probability for this ideal case, the part of the sidewall which forms a rim 64 surrounding the absorption orifice 62 is tilted inward with respect to the absorption volume 56. This inwardly tilted surface provides the additional advantage that a reflection of electromagnetic radiation impinging on these surfaces back into the impinging direction can be avoided. In addition, the part of the absorption surface 60 arranged opposite of the absorption orifice 62 is conically shaped with the cone tip pointing towards the absorption orifice 62.

[0104] In FIG. 4 a detector 40 with two sensor elements 50 is shown. The sensor elements 50 are arranged adjacent to each other and thermally decoupled. Each sensor element 50 comprises its own absorption body 52 and absorption surface 60. The remaining parts of the sensor elements 50 are not shown. In summary, providing two or more sensor elements 50 can provide a more detailed information about the absorbed electromagnetic radiation 120, for instance for a determination of an evaporation rate and/or of a distribution of a flux of the evaporated source material 20 (not shown).

[0105] In addition, upstream of the each of the respective sensor elements 50, two stacked and aligned apertures 90 are arranged. The aperture openings 92 confine the solid angle of acceptance of the respective sensor element 50. Cross talk between the sensor elements 50, indicated by the dashed arrow, can be avoided. Further, between the apertures 90 and the absorption body 52, and even further along the respective aperture body 52, shielding elements 94 are arranged. These shielding elements 94 on one hand further diminish the aforementioned crosstalk. On the other hand, also electromagnetic radiation 120 impinging on a side surface of the absorption body 52 is stopped and cannot distort the measurement results.

[0106] As mentioned with respect to FIG. 4, the detector 40 according to the present invention can comprise two or more sensor elements 50. A few examples for shapes and arrangement patterns of sensor elements 50 and their absorption surfaces 60 are shown in FIG. 5. Obviously, other arrangements, in one limit a high-resolution pixel array similar to an electronic camera, are possible. In summary, out of the different arrangement patterns the most suitable can be chosen with respect to the purpose of the measurement of the detector 40, for instance a determination of an evaporation rate and/or of a distribution of a flux of the evaporated source material 20.

[0107] The standard geometry with a simple circular active area is shown in the top left panel of FIG. 5.

[0108] A movement of the impinging direction 122 of the electromagnetic radiation 120 can be detected with four quadrants as shown in the top right panel. Here, the sensor elements 50 are shaped as squares and are arranged such that primarily movements in the horizontal and vertical directions along their diagonals can be detected, while keeping the number of sensor elements 50 small.

[0109] The third arrangement with sensor elements 50 forming a rotationally symmetric pattern of circular rings is shown in the lower left panel of FIG. 5. This pattern is most sensitive to focusing or defocusing of the electromagnetic radiation 120 provided by the electromagnetic radiation source 110.

[0110] Both position and defocusing, although in this case only in the vertical direction, may be detected by a stripe arrangement of rectangular shaped sensor elements 50, such as shown in the lower right panel of FIG. 5. This can be favorable, as the electromagnetic radiation 120, being reflected in the impinging direction 122 around 45° on the source surface 22, is more strongly affected in the plane containing the incident and reflected beam, than perpendicular to it.

[0111] FIG. 6 depicts the basic elements of a system 10 according to the present invention, namely an electromagnetic radiation source 110, a source material 20 and a detector 40, in particular a main detector 100. As electromagnetic radiation 120 light, in particular laser light, with a wavelength between 100 nm and 1400 nm is used. In the following, the method according to the present invention will be described.

[0112] In the first step a) of the method according to the present invention, the electromagnetic radiation 120 is provided by the electromagnetic radiation source 110. The electromagnetic radiation 120 impinges on the source surface 22 of the source material 20, preferably at an angle of 45°, and thermally evaporates or sublimates source material 20 below the plasma threshold.

[0113] In the following step b) of the method according to the present invention, electromagnetic radiation 120 reflected on the source surface 22 is measured by the main detector 100 of the system 10. For this purpose, the main detector is suitably positioned within the vacuum chamber 12 (not shown).

[0114] The measurement data obtained in step b) of the method according to the present invention is analyzed in the subsequent step c). As the response function of the detector 40, the properties of the impinging electromagnetic radiation 120 and the desired evaporation rate, and hence the required absorbed electromagnetic radiation 120, are known, the remaining reflected part of the electromagnetic radiation 120 is also determined. By comparing the measurements of the main detector 100 of step b) and the expectation with respect to the reflected electromagnetic radiation 120, it can be deduced whether the desired evaporation rate is met.

[0115] If the actual evaporation rate deduced in step c) differs from the desired evaporation rate, in the last step d) of the method according to the present invention, the evaporation rate can be adjusted to meet the specifications. This adjustment can be provided by different measures.

[0116] As shown in FIG. 6, by moving the source element 20 perpendicular and/or parallel to the source surface 22, the illumination of the source surface 22 by the impinging electromagnetic radiation 120 can be altered, in particular shifted, enlarged and scaled down, respectively. Consequently, also the evaporation rate rises and diminishes, respectively. For this purpose, the source material 20 preferably is provided as self-supporting source element 24, for instance as a rod 30. A holding structure 28 can be used for providing the aforementioned movement of the source surface 22.

[0117] Alternatively or additionally and as shown in FIG. 7, also the size and/or shape of the cross section of the electromagnetic radiation 120 provided by the electromagnetic radiation source 110 can be adjusted. By altering a size and/or shape of the cross section of the electromagnetic radiation 120, the adaptation of the impinging electromagnetic radiation 120 to the size and/or shape of the source surface 22 can be altered, in particular improved. A better, preferably complete, illumination of the source surface 22 by the electromagnetic radiation 120 also leads to an increased evaporation rate. As depicted, the electromagnetic radiation 120 can for instance be provided with an elliptical cross section to match a circular cross section of the source surface 22 provided as melted pool of source material 20 confined in a crucible 32, whereby the crucible 32 is at least partly transparent for the electromagnetic radiation 120.

[0118] Further, also a power, in particular the power density, of the electromagnetic radiation 120 can be adjusted. The power of the electromagnetic radiation 120 directly influences the evaporation rate, as a higher power results in a higher energy deposit.

[0119] In summary, the method according to the present invention described above allows an active adjustment of the evaporation rate during the operation of the respective evaporation system 10 based on actual measurements. Hence, a control of the evaporation rate is possible. Consequently, the coating of target material 18 with source material 20 can also be improved.

[0120] The following FIGS. 8 to 11 show an embodiment of the system 10 according to the present invention, which comprises three detectors 40, the main detector 100, the first additional detector 102 and the second additional detector 104. As described above, the main detector 100 is arranged such that it can measure electromagnetic radiation 120 reflected on the source surface 22 in the impinging direction 122. The first additional detector 104 is arranged such that it can detect electromagnetic radiation 120 reflected on a side surface 26 of the source element 24, and finally the second additional detector 104 detects electromagnetic radiation 120 which misses the source element 24, in particular the source surface 22. In the following, different situations occurring during the operation of the depicted system 10 are described.

[0121] In FIG. 8, an ideal case of the operation of the system 10 is shown. The electromagnetic radiation 120 illuminates the source surface 22 and is partly reflected in the impinging direction 122 to the main detector 100. No electromagnetic radiation 120 reaches the remaining first and second additional detectors 102, 104. No actions are required for the holding structures 28.

[0122] FIG. 9 shows a different condition, as a fraction of the incoming electromagnetic radiation 120 misses the source element 24 and reaches the second additional detector 104. Based on the measurement signal of the second additional detector 104, in combination with the decreased sensor output of the main detector 100, it can be deduced that the source surface 22 is too low or too far left with respect to the incoming electromagnetic radiation 120. Hence, this triggers an activation of the holding structure 28 and the source element 24 is moved upwards or to the right as indicated by the depicted arrows.

[0123] In FIG. 10, the opposite condition is depicted, as a fraction of the incoming electromagnetic radiation 120 is reflected off the side surface 26 of the source element 24 and reaches the first additional detector 102. Analogous, based on the measurement signal of the first additional detector 102, in combination with the decreased sensor output of the main detector 100, it can be deduced that the source surface 22 is too high or too far to the right with respect to the incoming electromagnetic radiation 120. Hence, this triggers an activation of the holding structure 28 and the source element 24 is moved downwards or to the left as indicated by the depicted arrows.

[0124] FIG. 11 depicts another possible static condition during the operation of the system 10 according to the present invention. In this setting, the incoming electromagnetic radiation 120 outshines the source surface 22. In other words, the cross section of the incoming electromagnetic radiation 120 is larger than the cross section of the source surface 22. In this case, electromagnetic radiation 120 reaches all three detectors 40, the main detector 100 and both additional detectors 102, 104. As long as both additional detectors 102, 104 detect a predetermined or at least some electromagnetic radiation 120, a complete illumination of the source surface 22 can be assumed. If one of the additional detectors 102, 104 ceases to detect electromagnetic radiation 120, the position of the source element 24 can be accordingly be altered by triggering the holding structure 28 as described above.

[0125] By relating the relative intensities of the detectors, changes in the incoming electromagnetic radiation can be detected as a proportional change in the signals of pairs of detectors, or all three. This allows the variation and control of the overall electromagnetic radiation magnitude, without triggering a correction movement of the source element 24, and thereby an independent control and optimization of both quantities.

[0126] Likewise, a focusing or defocusing of the electromagnetic radiation leads to an antiproportional intensity variation between the main detector 100 and the additional detectors 102, 104, enabling do distinguish, and thereby to independently control, the focus of the electromagnetic radiation 120 and the position of the source element 24.

[0127] As the first additional detector 102 detects electromagnetic radiation 120 reflected on a side surface 26 of the source element 24, this side surface 26 is preferably provided flat. This is depicted in FIG. 11. The shown source element 24 is provided as self-supporting rod 30 consisting of source material 20. Preferably, the flat side surface 26 is perpendicularly oriented both to the source surface 22 and the incoming electromagnetic radiation 120 provided by the electromagnetic radiation source 110 (not shown).

LIST OF REFERENCES

[0128] 10 System

[0129] 12 Vacuum chamber

[0130] 14 Vacuum feedthrough

[0131] 16 Reaction atmosphere

[0132] 18 Target Material

[0133] 20 Source material

[0134] 22 Source surface

[0135] 24 Source element

[0136] 26 Side surface

[0137] 28 Holding structure

[0138] 30 Rod

[0139] 32 Crucible

[0140] 40 Detector

[0141] 42 Arrangement element

[0142] 44 Positioning element

[0143] 50 Sensor element

[0144] 52 Absorption body

[0145] 54 Bore

[0146] 56 Absorption volume

[0147] 58 Sidewall

[0148] 60 Absorption surface

[0149] 62 Absorption orifice

[0150] 64 Rim

[0151] 70 Heat sensing element

[0152] 72 Flow sensor

[0153] 74 Temperature sensor

[0154] 76 Thermocouple element

[0155] 80 Cooling system

[0156] 82 Cooling duct

[0157] 84 Coolant

[0158] 90 Aperture

[0159] 92 Aperture opening

[0160] 94 Shielding element

[0161] 100 Main detector

[0162] 102 First additional detector

[0163] 104 Second additional detector

[0164] 110 Electromagnetic radiation source

[0165] 120 Electromagnetic radiation

[0166] 122 Impinging direction