CN118064872B

CN118064872B - Vapor deposition device

Info

Publication number: CN118064872B
Application number: CN202410479388.1A
Authority: CN
Inventors: 王兆祥; 张朋兵; 梁洁; 涂乐义; 邱勇
Original assignee: Shanghai Nippon Semiconductor Equipment Co ltd
Current assignee: Shanghai Nippon Semiconductor Equipment Co ltd
Priority date: 2024-04-22
Filing date: 2024-04-22
Publication date: 2024-06-25
Anticipated expiration: 2044-04-22
Also published as: CN118064872A

Abstract

The embodiment of the application relates to the technical field of semiconductor processing, in particular to a vapor deposition device. The vapor deposition device comprises a cavity and a bearing mechanism. The cavity is provided with an inner wall surface and an outer wall surface which are oppositely arranged, and the inner wall surface is surrounded to form a reaction cavity; the bearing mechanism is partially positioned in the reaction chamber and is used for bearing the wafer, and the bearing mechanism is provided with a heating unit; the bearing mechanism is provided with a first channel for fluid flow, a second channel for fluid flow is arranged between the inner wall surface and the outer wall surface, an outlet of the first channel is communicated with an inlet of the second channel, and the inlet of the first channel and the outlet of the second channel are respectively connected to a cooling source for providing cooling liquid. The vapor deposition device provided by the embodiment of the application can ensure the effect of heating the cavity and simultaneously effectively reduce the energy consumption and the cost in the CVD process.

Description

Vapor deposition device

Technical Field

The invention relates to the technical field of semiconductor processing, in particular to a vapor deposition device.

Background

Chemical Vapor Deposition (CVD) is a technique for synthesizing coatings or nanomaterials on the surface of a substrate by chemical gas or vapor reactions. In the semiconductor industry, CVD techniques are widely used to deposit a variety of materials, including insulating materials, metallic materials, and metallic alloy materials. However, by-products such as particulates are often produced in the process, and these particulates may adhere to equipment surfaces and affect equipment performance. During metal CVD, the chamber needs to be heated to reduce by-product adhesion, thereby avoiding the formation of a source of particulate contamination.

In the operation process of the conventional CVD equipment, a temperature controller is generally used to heat the cavity. However, as a special device, the temperature control machine is high in cost and huge in energy consumption. Therefore, how to effectively reduce the energy consumption and cost in the CVD process while ensuring the effect of heating the cavity remains an important issue.

Disclosure of Invention

The embodiment of the application aims to provide a vapor deposition device which can ensure the effect of heating a cavity and simultaneously effectively reduce the energy consumption and the cost in the CVD process.

In order to solve the technical problems, an embodiment of the application provides a vapor deposition device, which comprises a cavity and a bearing mechanism. The cavity is provided with an inner wall surface and an outer wall surface which are oppositely arranged, and the inner wall surface is surrounded to form a reaction cavity; the bearing mechanism is partially positioned in the reaction chamber and is used for bearing the wafer, and the bearing mechanism is provided with a heating unit; the bearing mechanism is provided with a first channel for fluid to flow, a second channel for fluid to flow is arranged between the inner wall surface and the outer wall surface, the outlet of the first channel is communicated with the inlet of the second channel, the inlet of the first channel and the outlet of the second channel are respectively connected to a cooling source for providing cooling liquid, the cooling liquid enters the first channel through the inlet of the first channel and cools the bearing mechanism, and after flowing out of the first channel, the cooling liquid enters the second channel through the inlet of the second channel and heats the cavity until flowing back to the cooling source.

In some embodiments, the load bearing mechanism includes a base and a heat block mounted on the base, the heating unit is disposed within the heat block, the base is coupled to the cavity, and the first channel is disposed within the base.

In some embodiments, the first channel includes a first section and a second section disposed in parallel, and a third section connecting one end of the first section with one end of the second section, the other end of the first section being connected to the cooling source, the other end of the second section being connected to an inlet of the second channel, the third section being disposed adjacent to the heat block.

In some embodiments, the thermal platform includes a carrier portion and a connecting portion connected to each other, the surface of the carrier portion is used for carrying the wafer, the connecting portion is connected to the base, and the connecting portion is in a strip shape.

In some embodiments, the load bearing mechanism further comprises a telescoping tubular body, the base being connected to the cavity via the tubular body.

In some embodiments, the wall thickness of the tubular body is greater than or equal to 0.1mm and less than or equal to 0.2mm.

In some embodiments, the second channel extends around a portion of the carrying mechanism in the cavity, and an inlet and an outlet of the second channel are disposed on two sides of the carrying mechanism.

In some embodiments, a buffer cavity is arranged between the outlet of the first channel and the inlet of the second channel, the inlet of the buffer cavity is communicated with the outlet of the first channel, the outlet of the buffer cavity is communicated with the inlet of the second channel, and a heating element is arranged in the buffer cavity.

In some embodiments, a temperature measuring element is further disposed within the buffer cavity, the temperature measuring element being disposed adjacent to an outlet of the buffer cavity.

In some embodiments, the buffer chamber is further provided with a liquid level detector that detects the level of the liquid.

According to the vapor deposition device provided by the embodiment of the application, the design of cooling liquid circulation is adopted, so that the effective cooling of the bearing mechanism and the uniform heating of the cavity are realized. The cooling liquid starts from the cooling source, cools the bearing mechanism through the first channel, and enters the second channel to heat the cavity after absorbing the heat of the bearing mechanism, and then returns to the cooling source to cool again, so that continuous temperature control circulation is realized. Therefore, the energy consumption and the cost in the CVD process can be effectively reduced while the heating cavity effect is ensured.

Drawings

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which the figures of the drawings are not to be taken in a limiting sense, unless otherwise indicated.

FIG. 1 is a schematic illustration of the fluid circulation of a prior art vapor deposition apparatus;

FIG. 2 is a schematic view of a vapor deposition apparatus according to some embodiments of the present application;

FIG. 3 is a schematic view of another vapor deposition apparatus according to some embodiments of the present application;

FIG. 4 is a schematic diagram of a buffer chamber in a vapor deposition apparatus according to some embodiments of the present application;

Fig. 5 is a schematic fluid circulation diagram of a vapor deposition apparatus according to some embodiments of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the following detailed description of the embodiments of the present application will be given with reference to the accompanying drawings. However, those of ordinary skill in the art will understand that in various embodiments of the present application, numerous technical details have been set forth in order to provide a better understanding of the present application. The claimed application may be practiced without these specific details and with various changes and modifications based on the following embodiments. The following embodiments are divided for convenience of description, and should not be construed as limiting the specific implementation of the present application, and the embodiments can be mutually combined and referred to without contradiction.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion.

In the description of embodiments of the present application, the technical terms "first," "second," and the like are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In Chemical Vapor Deposition (CVD) processes, heating of the chamber is critical to reduce the adhesion of byproducts to the inner walls. During this process, the chamber needs to be maintained at a temperature to prevent the gaseous precursor species from condensing on the inner walls to form particulates, thereby contaminating the chamber and affecting the quality of the deposited film. Typical operating temperatures are generally around 45 c, which allows the gaseous precursor species to remain gaseous and effectively react at the substrate surface.

For example, for metal chemical vapor deposition (MOCVD) processes, tungsten compound WF6 is used as a precursor material, which has a boiling point of about 17.5 ℃. If the cavity temperature is low, gaseous WF6 readily liquefies and adheres to the interior walls of the cavity, forming particulates. These particulates can not only contaminate the deposited film, but can also lead to instability and performance degradation of the system. Therefore, by maintaining a proper chamber temperature, the adhesion of byproducts can be effectively reduced, and the stability and film quality of the system can be maintained, thereby improving the efficiency and reliability of the CVD process.

As shown in fig. 1, in the conventional vapor deposition apparatus, a temperature controller is generally used to heat the liquid and thus the cavity, and a cooling tower is responsible for cooling the heat stage by passing a cooling liquid. The temperature control machine is used as an independent closed-loop system and is provided with a circulation and temperature control mechanism, and liquid with specified temperature can be accurately provided. However, such a high-precision temperature control apparatus has a problem of insufficient utilization of resources in practice for the CVD process, and has disadvantages of excessive power consumption and excessive cost. Therefore, how to effectively reduce the energy consumption and cost in the CVD process while ensuring the effect of heating the cavity remains an important issue.

For this reason, some embodiments of the present application provide a vapor deposition apparatus, which adopts a design of cooling liquid circulation, so as to achieve effective cooling of the carrying mechanism and uniform heating of the cavity. The cooling liquid starts from the cooling source, cools the bearing mechanism through the first channel, and enters the second channel to heat the cavity after absorbing the heat of the bearing mechanism, and then returns to the cooling source to cool again, so that continuous temperature control circulation is realized. Therefore, the energy consumption and the cost in the CVD process can be effectively reduced while the heating cavity effect is ensured.

The following describes the structure of a vapor deposition apparatus according to some embodiments of the present application with reference to fig. 2 to 5.

As shown in fig. 2, some embodiments of the present application provide a vapor deposition apparatus including a chamber 10 and a carrying mechanism. The cavity 10 is provided with an inner wall surface and an outer wall surface which are oppositely arranged, and the inner wall surface is surrounded to form a reaction chamber; the bearing mechanism is partially positioned in the reaction chamber and is used for bearing the wafer 11 and is provided with a heating unit; the bearing mechanism is provided with a first channel 12 for fluid flow, a second channel 13 for fluid flow is arranged between the inner wall surface and the outer wall surface, the outlet of the first channel 12 is communicated with the inlet of the second channel 13, the inlet of the first channel 12 and the outlet of the second channel 13 are respectively connected to a cooling source 20 for providing cooling liquid, the cooling liquid enters the first channel 12 through the inlet of the first channel 12 and then cools the bearing mechanism, and after flowing out of the first channel 12, enters the second channel 13 through the inlet of the second channel 13 and heats the cavity 10 until flowing back to the cooling source 20.

The chamber 10 has an inner wall surface and an outer wall surface disposed opposite to each other, and the inner wall surface encloses a reaction chamber for performing a vapor deposition process of the wafer 11. The process gas enters from above the chamber 10 and passes through the gas homogenizing device 17 to ensure that the gas is uniformly dispersed on the upper surface of the wafer 11. The carrier mechanism is partially located in the reaction chamber and has the main function of carrying the wafer 11 and ensuring the stability of the wafer 11 during processing. In addition, a heating unit is provided in the carrier to provide a desired high temperature environment for the wafer 11 during processing.

The support means is internally provided with a first channel 12 for the flow of cooling liquid. Meanwhile, a second passage 13 is provided between the inner wall surface and the outer wall surface of the chamber 10, also for the flow of the cooling liquid. The cooling fluid may enter the first passage 12 in the direction of arrow a in fig. 2 and exit the first passage 12 in the direction of arrow B. The cooling liquid can enter the inlet of the second channel 13 through the outlet of the first channel 12 along the arrow C direction, so as to heat the cavity 10, and raise the temperature inside the cavity 10 to maintain the reaction environment required by vapor deposition. Finally, the cooling liquid flows back from the outlet of the second passage 13 to the cooling source 20 in the direction of arrow D, completing one cycle.

As shown in fig. 3, the cooling source 20 may provide cooling fluid to the entire device. The inlet of the first channel 12 and the outlet of the second channel 13 are connected to a cooling source 20, respectively, forming a closed cooling cycle. In operation, coolant fluid is directed from the cooling source 20 through the inlet of the first passage 12 into the first passage 12. According to the heat conduction principle, the temperature difference between the cooling liquid and the surface of the bearing mechanism causes heat to flow from the high-temperature bearing mechanism to the low-temperature cooling liquid. That is, the cooling liquid effectively absorbs and takes away the heat accumulated on the bearing mechanism, realizes the cooling effect on the bearing mechanism, and prevents the bearing mechanism from being damaged due to high temperature or affecting the processing precision. After flowing through the first channel 12, the cooling liquid enters the inlet of the second channel 13 through the outlet of the first channel 12, so as to heat the cavity 10, and raise the temperature inside the cavity 10, so as to maintain the reaction environment required by vapor deposition. Finally, the cooling liquid flows back from the outlet of the second passage 13 to the cooling source 20, completing one cycle.

The vapor deposition apparatus provided in some embodiments of the present application adopts a design of cooling liquid circulation, so as to realize effective cooling of the carrying mechanism and uniform heating of the cavity 10. The cooling liquid starts from the cooling source 20 to cool the bearing mechanism through the first channel 12, and after the cooling liquid absorbs the heat of the bearing mechanism, the cooling liquid enters the second channel 13 to heat the cavity 10, and then returns to the cooling source 20 to cool again, so that the continuous temperature control cycle is realized. So that the energy consumption and cost in the CVD process can be effectively reduced while ensuring the effect of heating the chamber 10.

In some embodiments, the carrying mechanism comprises a base 15 and a heat stage 16 mounted on the base 15, the heating unit is arranged in the heat stage 16, the base 15 is connected with the cavity 10, and the first channel 12 is arranged in the base 15.

The carrying mechanism comprises a base 15 and a heat table 16, and the heat table 16 is installed on the base 15 and is used for carrying the wafer 11. The heating unit is provided inside the heat stage 16, and the heating unit is started to heat the heat stage 16 to 400 ℃ or higher when the wafer 11 is processed. This high temperature environment is necessary for the deposition of certain materials, particularly metals and their oxides, and can effectively promote the performance of the relevant chemical or physical reactions, improving the processing efficiency and quality.

In addition, the base 15 is connected to the chamber 10, ensuring stability and sealability of the entire system. Meanwhile, a first passage 12 is provided inside the base 15 for transferring a cooling liquid to effect cooling of the base 15.

In some embodiments, the first channel 12 includes a first section and a second section disposed in parallel, and a third section connecting one end of the first section with one end of the second section, the other end of the first section being connected to the cooling source 20, the other end of the second section being connected to the inlet of the second channel 13, the third section being disposed adjacent to the heat block 16.

The first channel 12 comprises a first section and a second section arranged in parallel, which are connected together by a third section, so that the path of the second channel in the base 15 increases. The cooling liquid has more time to contact the base 15 as it passes through a longer path, thereby achieving a more sufficient heat exchange and a more pronounced cooling effect. The third section is disposed adjacent to the heat stage 16, and can cool the heat stage 16 more directly, improving cooling efficiency. Meanwhile, the design is convenient for connection among all devices, and the difficulty of installation and maintenance is reduced.

In some embodiments, the heat stage 16 includes a carrier 161 and a connecting portion 162 connected to each other, the surface of the carrier 161 is used to carry the wafer 11, the connecting portion 162 is connected to the base 15, and the connecting portion 162 has an elongated shape.

The heat stage 16 includes a carrier 161 and a connecting portion 162 connected to each other, and a surface of the carrier 161 is used for carrying the wafer 11. The heat table 16 is not in direct contact with the cavity 10, so that large-area heat exchange between the heat table 16 and the cavity 10 is avoided, and the heat table 16 can be independently and efficiently heated. If the heat block 16 is in direct large area contact with the chamber 10, heat is rapidly introduced into the chamber 10, resulting in the heat block 16 not reaching the desired heating temperature. By avoiding such direct contact, it is ensured that the thermal block 16 can be independently and efficiently heated, thereby improving the working efficiency and processing quality of the entire vapor deposition apparatus.

In practice, the connection 162 of the heat block 16 may be elongated, which may help to increase the temperature gradient between the cold and hot ends. By increasing the temperature gradient, the heating process of the heat block 16 can be more effectively controlled, ensuring that the heat block 16 can be stably heated to 400 ℃ without affecting the heating effect by the heat being transferred to the chamber 10 too quickly.

In some embodiments, the carrying mechanism further comprises a telescopic tubular body 14, the base 15 being connected to the cavity 10 via the tubular body 14.

The load bearing mechanism may also include a telescoping tubular body 14, and the telescoping tubular body 14 may be a telescoping bellows. The base 15 is not directly connected with the cavity 10, but is indirectly connected with the cavity 10 through the tubular body 14, and the indirect connection mode effectively reduces a heat transfer path between the base 15 and the cavity 10, so that the temperature between the base 15 and the cavity 10 can be relatively independent.

In some embodiments, the wall thickness of the tubular body 14 is greater than or equal to 0.1mm and less than or equal to 0.2mm.

The tubular body 14 may hermetically vacuum the reaction chamber. The wall thickness of the tubular body 14 is controlled to be greater than or equal to 0.1mm and less than or equal to 0.2mm, and the wall thickness of the tubular body 14 may be 0.1mm,0.13mm,0.15mm,0.14mm,0.2mm. Specifically, the wall thickness of the tubular body 14 is greater than or equal to 0.1mm, ensuring that the tubular body 14 is able to withstand various stresses and pressures during operation, maintaining a stable morphology and function. At the same time, the wall thickness of the tubular body 14 is smaller than or equal to 0.2mm, and the thin wall reduces the heat conduction efficiency, ensures that the heat can be effectively controlled and managed, and realizes the heat isolation between the base 15 and the cavity 10.

In some embodiments, the second channel 13 extends around a portion of the carrying mechanism in the cavity 10, and the inlet and the outlet of the second channel 13 are disposed on two sides of the carrying mechanism.

The second channel 13 extends in the part of the chamber 10 surrounding the carrier, with its inlet and outlet arranged opposite sides of the carrier. This arrangement enables the heated coolant to flow evenly through the outer walls of the cavity 10, thereby achieving even heating of the entire cavity 10. The heated coolant enters the second channel 13 through the inlet and then flows along the second channel 13, and the heated coolant transfers heat to the chamber 10 to raise its temperature. Finally, the heated coolant flows out through the outlet of the second passage 13. In this way, the second channel 13 is able to heat the cavity 10 effectively to meet the temperature requirements during the process.

In some embodiments, a buffer chamber 30 is disposed between the outlet of the first channel 12 and the inlet of the second channel 13, the inlet of the buffer chamber 30 is in communication with the outlet of the first channel 12, the outlet of the buffer chamber 30 is in communication with the inlet of the second channel 13, and a heating element 31 is disposed within the buffer chamber 30.

As shown in fig. 2, the first channel 12 is used for cooling the base 15, the second channel 13 is used for heating the cavity 10, and a buffer cavity 30 may be provided between the two channels. The cooling liquid cools the base 15 first through the first passage 12. During this process, the cooling fluid absorbs heat generated by the base 15, thereby lowering the temperature of the base 15. The temperature of the cooling fluid cooled through the first passage 12, although it rises, may not be sufficient for directly heating the chamber 10. Thus, these cooling fluids then enter the buffer chamber 30. In the buffer chamber 30, the cooling liquid is further heated by providing a heating element 31. In this way, the temperature of the cooling liquid can be raised to a level sufficient to heat the cavity 10.

From the point of view of the heat transfer and exchange process, when the temperature of the heat stage 16 remains stable and the pressure inside the chamber 10 is low, the heat will be preferentially and mostly carried away by the cooling liquid. In this case, the heat generated by the heat stage 16 is mainly absorbed by the cooling liquid flowing over the surface thereof, resulting in a corresponding increase in the temperature of the cooling liquid. It will be appreciated by those skilled in the art that when the thermal power of the thermal block 16 is constant, the magnitude of the increase in the temperature of the cooling fluid per unit time will be inversely proportional to the flow rate of the cooling fluid, i.e., the smaller the flow rate of the cooling fluid, the greater the magnitude of the increase in the temperature, and the smaller the magnitude of the increase in the temperature. Meanwhile, the temperature rise of the cooling liquid is also influenced by factors such as the convection heat exchange coefficient, heat exchange area, logarithmic average temperature difference and the like of the fluid in the channel and the wall of the channel. These factors together determine the efficiency and speed of heat transfer. Those skilled in the art may further design or select related structures and parameters according to the corresponding relation of related technical coefficients (including thermal power) within the technical scope of the disclosure of the present invention, so as to achieve the technical effects and purposes of the present invention, i.e. to achieve the (first stage) temperature rise of the cooling liquid through the heat stage 16.

For example, the cooling fluid provided by the cooling source 20 is water, the temperature of which is 25 ℃, and the temperature of which rises to a first temperature T1 (e.g., 40 ℃) after passing through the heat stage 16. This water will then enter the buffer chamber 30 and be further heated within the buffer chamber 30 to a second temperature T2 (e.g. 45 c) by the heating element 31. Finally, this heated water will flow through the second channel 13 for heating the cavity 10.

In some embodiments, a temperature sensing element 32 may also be disposed within the buffer chamber 30, and the temperature sensing element 32 may be disposed adjacent to an outlet of the buffer chamber 30.

A temperature measuring element 32 is arranged near the outlet of the buffer chamber 30 to ensure that the temperature of the liquid that is about to enter the second channel 13 can be accurately measured.

In some embodiments, the buffer chamber 30 may also be provided with a liquid level detector 33 that detects the liquid level.

The liquid height detector 33 can be used for detecting the height of liquid, and can timely give an alarm when the liquid height in the buffer cavity 30 is insufficient, so that the heating element 31 is prevented from being heated empty, the normal operation of the device is ensured, and a safer and more reliable operation environment is provided for processing the wafer 11.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples of carrying out the application and that various changes in form and details may be made therein without departing from the spirit and scope of the application.

Claims

1. A vapor deposition apparatus, comprising:

the cavity is provided with an inner wall surface and an outer wall surface which are oppositely arranged, and the inner wall surface is surrounded to form a reaction cavity;

the bearing mechanism is partially positioned in the reaction chamber and is used for bearing a wafer, and the bearing mechanism is provided with a heating unit;

The bearing mechanism is provided with a first channel for fluid to flow, a second channel for fluid to flow is arranged between the inner wall surface and the outer wall surface, an outlet of the first channel is communicated with an inlet of the second channel, the inlet of the first channel and the outlet of the second channel are respectively connected to a cooling source for providing cooling liquid, the cooling liquid enters the first channel through the inlet of the first channel and cools the bearing mechanism, and enters the second channel through the inlet of the second channel after flowing out of the first channel and heats the cavity until flowing back to the cooling source;

a buffer cavity is arranged between the outlet of the first channel and the inlet of the second channel, the inlet of the buffer cavity is communicated with the outlet of the first channel, the outlet of the buffer cavity is communicated with the inlet of the second channel, and a heating element is arranged in the buffer cavity.

2. The vapor deposition apparatus according to claim 1, wherein the carrying mechanism comprises a base and a heat stage mounted on the base, the heating unit is disposed in the heat stage, the base is connected to the chamber, and the first passage is disposed in the base.

3. The vapor deposition apparatus of claim 2, wherein the first passage comprises a first section and a second section arranged in parallel, and a third section connecting one end of the first section with one end of the second section, the other end of the first section being connected to the cooling source, the other end of the second section being connected to an inlet of the second passage, the third section being disposed adjacent to the heat stage.

4. The vapor deposition apparatus according to claim 2, wherein the thermal stage comprises a carrying portion and a connecting portion, the carrying portion is configured to carry a wafer, the connecting portion is connected to the base, and the connecting portion is elongated.

5. The vapor deposition apparatus of claim 2, wherein the carrier further comprises a telescoping tubular body, the base being connected to the chamber via the tubular body.

6. The vapor deposition apparatus according to claim 5, wherein the wall thickness of the tubular body is greater than or equal to 0.1mm and less than or equal to 0.2mm.

7. The vapor deposition apparatus of claim 1, wherein the second channel extends around a portion of the carrier in the chamber, and an inlet and an outlet of the second channel are disposed opposite sides of the carrier.

8. The vapor deposition apparatus according to claim 1, wherein a temperature measuring element is further provided in the buffer chamber, and the temperature measuring element is disposed adjacent to an outlet of the buffer chamber.

9. A vapor deposition apparatus according to claim 1, wherein the buffer chamber is further provided with a liquid level detector for detecting the level of the liquid.