Temperature measurement auxiliary device, temperature measurement system and temperature measurement method for vacuum cavity

Abstract

The invention discloses a temperature measurement auxiliary device, a temperature measurement system and a temperature measurement method for a vacuum cavity, and is applied to the field of industrial temperature measurement. The temperature measurement auxiliary device comprises an infrared isolation part surrounding the visual field of the infrared thermometer, the infrared thermometer is located outside the cavity, and the infrared isolation part is used for isolating at least part of infrared light waves radiated by the heating source in the cavity out of the visual field. The temperature measuring system comprises the infrared temperature measuring instrument and the temperature measuring auxiliary device. The temperature measurement method comprises the step of measuring the temperature of the target object in the cavity by using the temperature measurement system. Therefore, an accurate temperature measurement scheme in a vacuum environment is provided.

Description

Technical Field

[0001] The present application relates to the field of industrial temperature measurement, and in particular to a temperature measurement auxiliary device, a temperature measurement system and a temperature measurement method for a vacuum cavity. Background Art

[0002] In some processes, it is necessary to use an infrared thermometer to perform non-contact temperature measurement of the target object in the vacuum chamber. When there is a heating source in the vacuum chamber, infrared interference will be generated, resulting in the inability to accurately measure the temperature of the target object. For example, in the hot wire CVD (chemical vapor deposition) process chamber, the temperature of the coated silicon wafer itself will affect the coating deposition rate. Currently, existing equipment can only roughly measure the temperature of the silicon wafer in the process chamber, with a large error, and it is impossible to accurately control the temperature, and it is impossible to form a stable environment for the coating process. The stability and consistency of the coated products are very poor, and they cannot be stably mass-produced. Therefore, it is crucial to control the temperature of the silicon wafer. The premise of controlling the temperature is to measure the temperature of the silicon wafer, so measuring the temperature of the silicon wafer is crucial. On the one hand, due to the presence of hot wires near the silicon wafer and the mechanical brittleness of the silicon wafer, thermocouples or thermal resistors are difficult to arrange in the vacuum chamber, so contact temperature measurement solutions cannot be used. On the other hand, referring to Figure 1 Because the hot wires in the hot wire CVD chamber are densely arranged and generate great infrared interference, it is impossible to accurately measure the silicon wafer temperature with only an infrared thermometer. Summary of the Invention

[0003] In order to improve the accuracy of infrared temperature measurement in a vacuum environment, the present invention provides a temperature measurement auxiliary device, a temperature measurement system and a temperature measurement method for a vacuum cavity.

[0004] In a first aspect, the present application provides a temperature measurement auxiliary device for a vacuum chamber. The temperature measurement auxiliary device includes an infrared isolation portion surrounding the field of view of an infrared thermometer, the infrared thermometer being located outside the chamber, and the infrared isolation portion is configured to isolate at least a portion of infrared light waves radiated by a heating source within the chamber from the field of view.

[0005] In some embodiments, the infrared isolation portion includes an annular sheet and a connecting tube, and the temperature measurement auxiliary device further includes an infrared transparent portion. The connecting tube is embedded in an opening in the cavity wall, with a first end of the connecting tube outside the cavity connected to the cavity wall and a second end of the connecting tube inside the cavity connected to the annular sheet, with the infrared transparent portion embedded at the second end.

[0006] In some embodiments, the inner wall of the second end is provided with a step, the step being used to support the infrared transparent portion. In some embodiments, the step has a groove opening toward the infrared transparent portion, the groove being used to accommodate a sealing ring between the step and the infrared transparent portion.

[0007] In some embodiments, the central axes of the field of view, the annular base, the annular sheet, and the infrared transparent portion are collinear, the annular sheet is annular, and the infrared transparent portion is cylindrical. Within the allowable error range, the following conditions are simultaneously met:

[0008] L1≥(d-L2)*α

[0009] L3≥L2*α

[0010] L4≥L5*α

[0011] Among them, α represents the field of view of the infrared thermometer; L1 represents the diameter of the annular sheet, L2 represents the distance from the annular sheet to the infrared thermometer along the axial direction, L3 represents the diameter of the infrared transparent part, L4 represents the distance between the two heating sources symmetrically arranged on both sides of the central axis, and L5 represents the distance from the heating source to the infrared thermometer along the axial direction; the axial direction is parallel to the central axis.

[0012] In some embodiments, the annular sheet has an infrared absorption rate of 90% or more, and the connecting tube has an infrared transmittance of 10% or less. In some embodiments, the annular sheet is a nano-carbon coated sheet, and the connecting tube is a metal tube.

[0013] In some embodiments, the temperature measurement auxiliary device further includes an annular base and a fixing ring. The annular plate is connected to the second end via the annular base, and the annular base covers the edge of the infrared-transmissive portion. The outer edge of the annular base is raised, and the fixing ring is connected to the outer edge of the annular base. The annular plate is fixed in the gap between the middle sunken portion of the annular base and the fixing ring.

[0014] In a second aspect, an embodiment of the present application provides a temperature measurement system for a vacuum cavity, comprising: an infrared thermometer located outside the cavity; and a temperature measurement auxiliary device as described in the first aspect.

[0015] In a third aspect, an embodiment of the present application provides a temperature measurement method for a vacuum cavity, comprising: using the temperature measurement system as described in the second aspect to measure the temperature of a target object in the cavity.

[0016] The technical solution provided by the embodiments of the present application has the following advantages compared with the prior art:

[0017] (1) The infrared shielding portion surrounding the infrared thermometer's field of view isolates at least part of the infrared light waves radiated by the heating source in the vacuum chamber from the field of view, which is conducive to accurate temperature measurement in a vacuum environment. Taking the hot wire CVD process as an example, the measured temperature deviation of the silicon wafer in this solution is less than 0.5°C, while the temperature deviation of the existing solution exceeds 20°C and the temperature curve fluctuates;

[0018] (2) Through material selection and size limitation, the interfering infrared light waves entering the field of view of the infrared thermometer can be greatly reduced, thereby greatly improving the accuracy of infrared temperature measurement;

[0019] (3) Benefiting from the precise temperature measurement of this solution, the prerequisites for subsequent temperature control are created to achieve precise temperature control;

[0020] (4) Benefiting from the precise temperature measurement of the present invention, the product stability and consistency of related processes (such as coating processes) are greatly improved, which is conducive to the stable mass production of products;

[0021] (5) The temperature measurement auxiliary device and temperature measurement system provided by this solution have a simple structure and are easy to install. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0023] Figure 1 Schematic diagram of infrared interference generated by the hot wire in hot wire CVD.

[0024] Figure 2 A schematic diagram of the composition of a temperature measurement system for a vacuum chamber provided in an embodiment of the present application.

[0025] Figure 3 A schematic cross-sectional view of a temperature measurement auxiliary device for a vacuum chamber according to a preferred embodiment of the present application.

[0026] Figure 4 for Figure 3 A partially enlarged schematic diagram of the cross-sectional structure shown.

[0027] Figure 5 Schematic diagram of the temperature measurement system.

[0028] Figure 6 This is a schematic diagram of the relative positions of the annular base, infrared isolation part and infrared transmission part. DETAILED DESCRIPTION

[0029] In order to more clearly understand the above-mentioned objects, features and advantages of the present application, the embodiments of the present application will be further described below. It should be noted that the embodiments of the present application and the features therein can be combined with each other in the absence of conflict.

[0030] The following description sets forth many specific details to facilitate a full understanding of the present application, but the present application may also be implemented in other ways than those described herein. Obviously, the embodiments in the specification are only some of the embodiments of the present application, not all of them.

[0031] Figure 2 This is a schematic diagram of the temperature measurement system for a vacuum chamber provided in an embodiment of the present application. Figure 2 As shown, the temperature measurement system includes an infrared thermometer 10 and a temperature measurement auxiliary device 20.

[0032] The infrared thermometer 10 is located outside the vacuum chamber. In this way, there is no need to arrange a measurement circuit in the vacuum chamber, which is more friendly to some processes that require a stable vacuum environment (such as hot wire CVD).

[0033] refer to Figure 2 The temperature measurement auxiliary device 20 includes an infrared isolation portion 220 surrounding the field of view of the infrared thermometer 10. As an example only, the cross section of the infrared isolation portion 220 may be Figure 2 The T-shape shown can also be other shapes (e.g., trapezoidal or rectangular). The infrared isolation portion 220 is used to isolate at least a portion of the infrared light waves radiated by the heating source (e.g., a hot wire) within the vacuum chamber from the field of view of the infrared thermometer 10. The field of view of an infrared thermometer is generally conical, with the sensor position at the apex of the field of view. The target object to be measured is at least partially within the field of view of the infrared thermometer. For example, to measure the local temperature of a silicon wafer, a local area of ​​the silicon wafer is placed within the field of view of the infrared thermometer. Figures 1 to 3 In the figure, the area above the cavity wall is the interior of the cavity, and the area below the cavity wall is the exterior of the cavity.

[0034] In some embodiments, reference Figure 3 The infrared isolation portion 220 includes an annular plate 224 and a connecting tube 221. The temperature measurement auxiliary device 20 also includes an infrared transparent portion 210. For example only, the infrared transparent portion 210 can be made of germanium glass. The connecting tube 221 is embedded in an opening in the cavity wall. The first end of the connecting tube 221, located outside the vacuum cavity, is connected to the cavity wall. The second end of the connecting tube 221, located inside the vacuum cavity, is connected to the annular plate 224. The infrared transparent portion 210 is embedded in the second end of the connecting tube 221.

[0035] In some embodiments, reference Figure 3 The connecting pipe 221 and the cavity wall are connected through the first fastening screw 211 and the connecting flange 214 . The connecting flange 214 and the first end of the connecting pipe 221 have threaded holes that match the first fastening screw 211 .

[0036] In some embodiments, reference Figure 3 The first end of the connecting tube 221 is also connected to the infrared thermometer 10. As an example only, the first end of the connecting tube 221 and the infrared thermometer 10 are connected by a second fastening screw 212.

[0037] In some embodiments, in conjunction with reference Figure 3 and Figure 4The inner wall of the second end of the connecting tube 221 is provided with a step 222 , and the step 222 is used to support the infrared transparent portion 210 .

[0038] A sealing ring may be placed between the step 222 and the infrared transparent portion 210 to ensure the airtightness of the vacuum chamber. Figure 4 The step 222 has a groove 226 opening toward the infrared transparent portion 210 , and the groove 226 is used to accommodate a sealing ring between the step 222 and the infrared transparent portion 210 .

[0039] In some embodiments, the field of view of the infrared thermometer 10, the annular base 223, the annular plate 224, and the central axis of the infrared transparent portion 210 are collinear, the annular plate 224 is annular, and the infrared transparent portion 210 is cylindrical. Based on this, within the allowable error range, the following three conditions are simultaneously met:

[0040] L1≥(d-L2)*α (1)

[0041] L3≥L2*α (2)

[0042] L4≥L5*α (3)

[0043] Among them, reference Figure 5 , α represents the field of view of the infrared thermometer 10; L1 represents the diameter of the annular piece 224, L2 represents the distance from the annular piece 224 to the infrared thermometer 10 along the axial direction, L3 represents the diameter of the infrared transparent portion 210, L4 represents the distance between the two heating sources symmetrically arranged on both sides of the central axis, and L5 represents the distance from the heating source to the infrared thermometer 10 along the axial direction; the axial direction is parallel to the central axis.

[0044] Under the premise that the field of view angle is small enough (for example, α < 0.2 or α < 0.1), the dimensions under some extreme conditions can be obtained by combining optical principles and geometric approximation. To simplify understanding, it is assumed that the infrared isolation effect of the annular plate 224 is ideal. Based on this, if the diameter of the annular plate 224 is less than (d-L2) * α, the annular plate 224 will not be able to block part of the reflected interfering infrared light waves (referred to as reflected light), resulting in interfering infrared light waves passing through the infrared transparent portion 210 and entering the field of view of the infrared thermometer 10. In addition, if the diameter of the infrared transparent portion 210 is less than L2 * α, the infrared light waves radiated by the annular plate 224 will pass through the infrared transparent portion 210 and enter the field of view of the infrared thermometer 10; if the distance between the two heating sources symmetrically arranged on both sides of the central axis is less than L5 * α, the infrared light waves radiated by the heating sources will pass through the infrared transparent portion 210 and enter the field of view of the infrared thermometer 10.

[0045] In some embodiments, the infrared absorptivity of the annular sheet 224 is greater than 90%, and the infrared transmittance of the connecting tube 221 is less than 10%. By way of example only, the annular sheet 224 may be a nano-carbon coating with low infrared reflectivity and an infrared-opaque properties (with an infrared absorptivity of up to 95%), while the connecting tube 221 may be a metal tube (most metals have extremely low infrared transmittance, approximately zero). In this case, the majority of interfering infrared light waves within the vacuum chamber will be absorbed by the annular sheet 224. Combined with structural size restrictions and material parameter restrictions, this significantly reduces the amount of interfering infrared light waves that enter the field of view of the infrared thermometer 10.

[0046] In some embodiments, in conjunction with reference Figure 3 and Figure 4 The temperature measurement auxiliary device 20 also includes an annular base 223 and a fixing ring 225. As an example only, the fixing ring 225 can be a metal ring. The annular sheet 224 is connected to the second end of the connecting tube 221 through the annular base 223. The annular base 223 covers the edge of the infrared transparent portion 210 to press the infrared transparent portion 210. The outer edge of the annular base 223 is raised, and the fixing ring 225 is connected to the outer edge of the annular base 223. The annular sheet 224 is fixed to the gap between the middle sunken part of the annular base 223 and the fixing ring 225.

[0047] Figure 6 The relative positions of the annular base, the annular sheet, and the infrared transparent portion are shown. When the line of sight coincides with the central axis, the outer edge of the annular base, the annular sheet, and the infrared transparent portion can be seen from the outside to the inside.

[0048] In some embodiments, in conjunction with reference Figure 3 and Figure 4 The annular base 223 and the second end of the connecting pipe 221 are connected by a fixing screw 217 (such as a countersunk screw).

[0049] In some embodiments, in conjunction with reference Figure 3 and Figure 4 The annular base 223 and the fixing ring 225 are connected by the second fastening screw 213. Accordingly, the annular base 223 has a screw hole 215 matching the third fastening screw 213, and the fixing ring 225 has a screw through hole 216 matching the third fastening screw 213.

[0050] It should be understood that the annular piece 224 can also be fixed to the annular base 223 in other ways, for example, by a clamping structure. In addition, the annular piece 224 can also be connected to the second end of the connecting tube 221 in other ways, for example, without the annular base 223 and the fixing ring 225, and the annular piece 224 and the second end of the connecting tube 221 are connected by a clamping structure.

[0051] It is worth noting that, considering that the temperature measurement auxiliary device 20 is annular in structure as a whole, at least two of each type of screw (for example, the first / second / third fastening screw or fixing screw) mentioned in the embodiment of the present application can be provided. For example, referring to FIG. Figure 3 and Figure 4 A pair of mutually symmetrical first fastening screws 211 and a pair of mutually symmetrical connecting flanges 214 can be provided, with the axis of symmetry being the central axis.

[0052] The present application also provides a temperature measurement method for a vacuum chamber, which includes using the temperature measurement system provided in the above embodiment to measure the temperature of a target object in the vacuum chamber. Taking hot wire CVD as an example, the target object can be a substrate (such as a silicon wafer) or a carrier.

[0053] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to the process, method, article or device. In the absence of further limitations, an element defined by the sentence "including a..." does not exclude the presence of additional identical elements in the process, method, article or device that includes the element.

[0054] The foregoing is merely an embodiment of the present application, which is intended to enable those skilled in the art to understand and implement the present application. Various modifications to the described embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments described herein, but is intended to conform to the widest scope consistent with the principles and features disclosed herein.

Claims

1. A temperature measurement auxiliary device for a vacuum chamber, characterized in that: It includes an infrared isolation part surrounding the field of view of an infrared thermometer, the infrared thermometer is located outside the cavity, and the infrared isolation part is used to isolate at least part of the infrared light waves radiated by the heating source in the cavity outside the field of view.

2. The temperature measurement auxiliary device according to claim 1, characterized in that: The infrared isolation part includes an annular sheet and a connecting pipe, and the device also includes an infrared transparent part; The connecting tube is embedded in the opening on the cavity wall, the first end of the connecting tube outside the cavity is connected to the cavity wall, the second end of the connecting tube inside the cavity is connected to the annular sheet, and the infrared transparent part is embedded in the second end.

3. The temperature measurement auxiliary device according to claim 2, characterized in that: The inner wall of the second end is provided with a step, and the step is used to support the infrared transparent part.

4. The temperature measurement auxiliary device according to claim 3, characterized in that: The step has a groove opening toward the infrared transparent portion, and the groove is used to accommodate a sealing ring between the step and the infrared transparent portion.

5. The temperature measurement auxiliary device according to claim 2, characterized in that: The central axes of the field of view, the annular base, the annular sheet and the infrared transparent portion are collinear, the annular sheet is annular, and the infrared transparent portion is cylindrical; Within the allowable error range, the following conditions must be met at the same time: L1≥(d-L2)*α L3≥L2*α L4≥L5*α Among them, α represents the field of view of the infrared thermometer; L1 represents the diameter of the annular sheet, L2 represents the distance from the annular sheet to the infrared thermometer along the axial direction, L3 represents the diameter of the infrared transparent part, L4 represents the distance between the two heating sources symmetrically arranged on both sides of the central axis, and L5 represents the distance from the heating source to the infrared thermometer along the axial direction; the axial direction is parallel to the central axis.

6. The temperature measurement auxiliary device according to claim 5, characterized in that: The infrared absorption rate of the annular sheet is greater than 90%, and the infrared transmittance of the connecting pipe is less than 10%.

7. The temperature measurement auxiliary device according to claim 6, characterized in that: The annular sheet is a nano-carbon coating sheet, and the connecting pipe is a metal pipe.

8. The temperature measurement auxiliary device according to claim 2, characterized in that: Also includes a ring base and a fixing ring; The annular sheet is connected to the second end via the annular base, and the annular base covers the edge of the infrared transparent portion; The outer edge of the annular base is raised, the fixing ring is connected to the outer edge of the annular base, and the annular sheet is fixed in the gap between the middle sinking part of the annular base and the fixing ring.

9. A temperature measurement system for a vacuum chamber, characterized in that: include: an infrared thermometer located outside the cavity; And, the temperature measurement auxiliary device according to any one of claims 1 to 8.

10. A temperature measurement method for a vacuum cavity, characterized in that: include: The temperature of the target object in the cavity is measured using the temperature measurement system as claimed in claim 9.

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