Chamber temperature measurement device and chemical vapor deposition apparatus

Abstract

The application provides a chamber temperature measuring device and a chemical vapor deposition equipment, the chamber wall of the chemical vapor deposition equipment can transmit infrared radiation, the chamber temperature measuring device is installed outside the chamber wall, comprising: an optical temperature measuring device, which measures the temperature of an object to be measured in the chemical vapor deposition equipment through the infrared radiation; a connecting piece having opposite first and second ends, the optical temperature measuring device is installed on the first end, the second end is connected to the chamber wall, and a light path channel is arranged inside the connecting piece and penetrates through the first and second ends, and the chamber wall connected to the second end is cooled by passing a purge gas in the light path channel. The application can improve the accuracy of temperature measurement without affecting the mechanical strength of the chamber wall.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor equipment, in particular to a chamber temperature measuring device and a chemical vapor deposition equipment. BACKGROUND

[0002] In the CVD (Chemical Vapor Deposition) epitaxial process, the accurate control and measurement of wafer temperature is extremely crucial, because the process temperature required is high (500-1200 degrees Celsius), and the heating of the wafer in the reaction chamber is usually achieved by using infrared lamp heating. Currently, the temperature of the wafer is measured and fed back for temperature control by using the following methods: an infrared non-contact temperature measuring device, a special thermocouple contact temperature measuring device, and a combination of the infrared non-contact temperature measuring device and the thermocouple contact temperature measuring device. However, the above temperature measuring methods have the following problems:

[0003] (1) The infrared non-contact temperature measuring device usually uses a specific temperature zone infrared band pyrometer, which is installed outside the transparent quartz reaction chamber, receives infrared rays emitted from the wafer or wafer tray or preheating ring below the pyrometer, and converts the infrared rays into temperature. However, as the process proceeds, the quartz chamber wall will gradually deposit reaction substances, causing the infrared ray penetration path of the specific wave band of the pyrometer to change, resulting in measurement errors. Even if the chamber wall is cleaned and maintained, it will always be different from the state of the infrared ray penetration path when the pyrometer is initially installed, causing the calibration reference to be different each time, affecting temperature measurement and control, and further affecting the stability of each process, with poor consistency, and even temperature measurement errors may occur.

[0004] (2) The thermocouple contact temperature measuring device usually installs the thermocouple in a rotating component, such as a preheating ring or other components closest to the wafer. At this time, it cannot directly measure the temperature of the wafer, and the control of the wafer temperature can only be obtained through a large number of experimental experiences, greatly reducing the accuracy of temperature measurement. At the same time, the thermocouple is installed in a high-temperature area, which greatly reduces its service life, and the reserved gap for high-temperature thermal deformation of the installation position also reduces the accuracy of temperature measurement. In particular, when the thermocouple is replaced, it is difficult to keep the installation gap position consistent with the previous one, causing the temperature measurement reference to be inconsistent before and after, and further affecting the process consistency.

[0005] (3) In the existing equipment, the infrared temperature measuring instrument is installed outside the chamber through an external clamp, and the temperature measuring lens and light path are exposed to the atmospheric environment. The change of the electric dipole moment caused by the vibration of a small amount of water vapor, carbon dioxide, ozone, methane, nitrogen oxide, carbon monoxide, and other asymmetric molecules in the atmospheric environment produces strong infrared absorption, affecting the infrared light intensity transmitted from the wafer to the infrared temperature measuring instrument lens, and causing measurement errors.

[0006] To solve the above problems, the prior art opens multiple round holes in the upper dome of the chamber, and welds a vertical round pipe made of sapphire or quartz as the light path of the infrared temperature measuring instrument, and sets a flange on the top of the vertical round pipe to form an observation window; the infrared temperature measuring instrument is installed on the flange at the top of the round pipe through a sealing ring, the round pipe is communicated with the inside of the chamber, the side wall of the vertical round pipe is provided with an opening for introducing a purge gas such as N2 gas into the chamber, so as to directly receive the infrared light waves emitted by the wafer surface by the infrared temperature measuring instrument, and the introduced purge gas avoids the deposition of the infrared temperature measuring instrument lens and the wall of the vertical round pipe, which causes the absorption of infrared spectrum and affects the temperature measurement accuracy. Through the above measures, the temperature of the wafer surface can be directly measured by the infrared temperature measuring instrument without passing through the obstacle (quartz chamber wall) affecting the infrared spectrum, and the state of the infrared light path is changed due to the cleaning and maintenance of the chamber each time, and the infrared temperature measuring instrument needs to be recalibrated.

[0007] However, due to the characteristics of infrared radiation heating, the upper and lower tops of the reaction chamber are made of transparent quartz material, and the reaction is carried out at a high temperature of 500 degrees Celsius or above, and at the same time, the inside of the chamber is under negative pressure. At this time, the opening of the chamber on the upper / lower dome will greatly reduce the mechanical strength of the chamber, which will greatly increase the risk of chamber rupture. If the chamber wall is thickened, the heating efficiency of infrared and other heating will be affected. At the same time, multiple sealing points are increased, and are all in the high-temperature working area, which increases the risk of leakage. In addition, the introduced purge gas directly overlaps with the process gas in the chamber, which will affect the uniformity of the process gas flow to a certain extent, and the purge gas will react with other process gases at high temperature to generate other by-products. SUMMARY

[0008] The purpose of the present application is to provide a chamber temperature measuring device and a chemical vapor deposition equipment, which can improve the temperature measurement accuracy without affecting the mechanical strength of the chamber wall.

[0009] In order to achieve the above purpose, the present application realizes the following technical scheme:

[0010] A chamber temperature measuring device applied to a chemical vapor deposition equipment, wherein the chamber wall of the chemical vapor deposition equipment can transmit infrared radiation;

[0011] The chamber temperature measuring device is installed on the outside of the chamber wall and comprises:

[0012] An optical temperature measuring device for measuring the temperature of an object to be measured in the chemical vapor deposition equipment through the infrared radiation;

[0013] A connecting piece has opposite first and second ends, the optical temperature meter is mounted on the first end, and the second end is connected to the cavity wall, and the connecting piece is internally provided with a light path channel passing through the first and second ends, and the cavity wall connected to the second end is cooled by passing a purge gas in the light path channel.

[0014] Further, the connecting piece is provided with a gas inlet and a gas outlet, the purge gas flows into the light path channel through the gas inlet, and flows out of the light path channel through the gas outlet.

[0015] Further, the gas inlet is arranged close to the first end, and the gas outlet is arranged close to the second end.

[0016] Further, the gas inlet and the gas outlet are arranged on both sides of the light path channel.

[0017] Further, the purge gas is a gas with a temperature less than or equal to 70°C.

[0018] Further, the purge gas has an infrared radiation absorption rate less than 0.1.

[0019] Further, the purge gas is hydrogen, nitrogen, argon or oxygen.

[0020] Further, the outer side of the connecting piece is provided with a reflective coating or an infrared absorbing coating.

[0021] Further, the hole wall of the light path channel is provided with a reflective coating or an infrared absorbing coating.

[0022] Further, the light path channel is perpendicular or not perpendicular to the cavity wall.

[0023] Further, the connecting piece is made of transparent quartz material or opaque quartz material.

[0024] Further, the connecting piece is fixedly connected to the cavity wall.

[0025] Further, the connecting piece and the cavity wall are connected by welding.

[0026] Further, the connecting piece and the optical temperature meter are sealed by a sealing ring.

[0027] A chemical vapor deposition device includes a reaction cavity and a susceptor in the reaction cavity, the susceptor is used to carry a substrate, and the cavity wall of the reaction cavity at least includes a partial area that can transmit infrared radiation, and the outer side of the cavity wall is mounted with a cavity temperature measuring device, and the cavity temperature measuring device includes:

[0028] An optical temperature meter measures the temperature of an object to be measured in the reaction cavity through the infrared radiation.

[0029] The connecting piece has opposite first and second ends, the optical temperature measuring device is installed at the first end, and the second end is connected to the cavity wall, and the connecting piece is internally provided with a light path channel passing through the first and second ends, and the cavity wall connected to the second end is cooled by passing the purge gas in the light path channel.

[0030] Further, the object to be measured is the substrate, and the cavity temperature measuring device is installed below the reaction cavity.

[0031] Further, the object to be measured is the substrate, and the cavity temperature measuring device is installed above the reaction cavity.

[0032] Further, the cavity wall outside includes a reinforcing rib, which is integrally arranged with the cavity wall, and the reinforcing rib serves as the connecting piece.

[0033] Further, the cavity wall is transparent quartz material.

[0034] Compared with the prior art, the present application has the following advantages:

[0035] (1) The infrared radiation of the surface of the object to be measured in the reaction cavity is transmitted to the optical temperature measuring device through the light path channel to realize temperature measurement, and the purge gas is also passed in the optical channel to cool the cavity wall connected to the chamber. The temperature of the cavity wall in this area does not reach the pyrolysis temperature of the process reaction, so no deposits are generated, the cavity wall in this area is kept clean, and no temperature measurement error is caused. Even after the reaction cavity is maintained, the situation that the temperature measurement path is inconsistent with the initial state will not occur, the temperature measurement reference can be kept unchanged for a long time, the temperature measurement repeatability is high, and the control is more stable and accurate.

[0036] (2) The light path channel is filled with purge gas to form a sealed space isolated from the atmosphere, which can eliminate the absorption of infrared radiation by water vapor, carbon dioxide and other gases in the atmosphere, so that the infrared radiation of the surface of the object to be measured is transmitted to the optical temperature measuring device without interference, and the temperature measurement is more accurate.

[0037] (3) The purge gas will not be passed into the reaction cavity, so it will not overlap with the process gas in the chamber, will not affect the uniformity of the process gas flow, and will not produce by-products.

[0038] (4) The connecting piece is connected to the outside of the cavity wall and does not need to be opened on the cavity wall, which can ensure the mechanical strength of the cavity wall at high temperature, and does not increase the sealed connection with the cavity wall, and the whole system is reliable in sealing. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the present application, the drawings required to be used in the description will be briefly introduced as follows. Obviously, the drawings in the following description are one embodiment of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0040] Figure 1 A structural diagram of a chemical vapor deposition equipment provided by an embodiment of the present application and installed with the chamber temperature measuring device is shown in the figure;

[0041] Figure 2 Another structural diagram of a chemical vapor deposition equipment provided by an embodiment of the present application and installed with the chamber temperature measuring device is shown in the figure;

[0042] Figure 3 A structural diagram of the chamber temperature measuring device provided by an embodiment of the present application is shown in the figure;

[0043] Figure 4 Another structural diagram of the chamber temperature measuring device provided by an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0044] The technical solutions proposed by the present application will be further described in detail in combination with the drawings and specific embodiments. The advantages and features of the present application will be more apparent according to the following description. It should be noted that the drawings are very simplified and all use non-precise proportions, only to facilitate, clear and assist the purpose of describing the embodiments of the present application. In order to make the purpose, features and advantages of the present application more apparent and easy to understand, please refer to the drawings. It should be noted that the structure, proportion, size, etc. shown in the drawings attached to the present specification are only used to cooperate with the content disclosed in the specification, so as to be understood and read by those skilled in the art, and not to limit the defined conditions for the implementation of the present application, so it does not have the technical meaning in substance, any modification of structure, change of proportion relationship or adjustment of size, without affecting the effect and purpose that can be produced by the present application, should still fall within the scope of the technical content disclosed by the present application.

[0045] Firstly, the structure of the chemical vapor deposition equipment will be introduced in combination with Figure 1 、 2 The chemical vapor deposition equipment includes a reaction chamber 100 and a susceptor 200 located in the reaction chamber, the susceptor 200 is used to carry a substrate (i.e. a wafer W), and the chamber wall of the reaction chamber 100 at least includes a region that can transmit infrared radiation. For example, Figure 1As shown, the side wall 110 of the reaction cavity 100 is made of stainless steel, aluminum, ceramic, and other metal materials suitable for chamber CVD process; the upper wall 120 and the lower wall 130 are made of transparent quartz material, which can transmit infrared radiation. The upper wall 120 and the lower wall 130 of the reaction cavity 100 are provided with a plurality of infrared heating lamp assemblies 300, which are used to emit infrared radiation and heat the wafer W and the susceptor 200 in the reaction cavity 100 through the upper wall 120 and the lower wall 130. The wafer W is further provided with a preheating ring 210. During the reaction, the process gas flow M enters from one side of the reaction cavity 100, reacts on the surface of the wafer W, and is then discharged from the other side by the vacuum system.

[0046] In order to realize temperature measurement of the object to be measured in the reaction cavity 100, the chemical vapor deposition equipment further comprises a chamber temperature measurement device 400. The chamber temperature measurement device 400 adopts an optical temperature measurement method to directly measure the surface temperature of the object to be measured, and then feeds back a temperature detection signal to a control system to control the temperature of the reaction cavity 100. The object to be measured can be the wafer W, the susceptor 200, or other components in the reaction cavity 100. When the object to be measured is the wafer W, the chamber temperature measurement device 400 is installed above the reaction cavity 100; when the object to be measured is the susceptor 200, the chamber temperature measurement device 400 is installed below the reaction cavity 100. Moreover, since the wafer W or the susceptor 200 has a large size, the chamber temperature measurement device 400 can be multiple and uniformly distributed above or below the reaction cavity 100 to measure the temperature of multiple positions on the wafer W or the susceptor 200.

[0047] The following will be described in detail Figures 1 to 4 The chamber temperature measurement device 400 according to the present application will be described in detail.

[0048] The chamber temperature measurement device 400 is applied to a chemical vapor deposition equipment, and the cavity wall of the chemical vapor deposition equipment can transmit infrared radiation. The chamber temperature measurement device 400 is installed on the outside of the cavity wall and comprises an optical temperature meter 410, which measures the temperature of the object to be measured in the chemical vapor deposition equipment through infrared radiation; a connecting piece 420 having opposite first and second ends, the optical temperature meter 410 being installed on the first end, the second end being connected to the cavity wall, and the connecting piece 420 being internally provided with a light path channel 421 penetrating through the first and second ends, and a sweep gas S being introduced into the light path channel 421 to cool the cavity wall connected to the second end.

[0049] The optical temperature meter is an infrared temperature measuring instrument. The infrared radiation of the surface of the object to be measured in the reaction cavity 100 is transmitted to the optical temperature meter 410 through the light path channel 421 after transmitting through the cavity wall, so as to realize temperature measurement. Figure 1The infrared temperature measurement path H is shown. The optical channel 421 also passes through the purge gas S for cooling the cavity wall at the connection with the second end, forming a wall low temperature zone A, so that the cavity wall temperature in this area does not reach the pyrolysis temperature of the process reaction, and no deposits are generated, keeping the cavity wall in this area clean and not causing temperature measurement errors. Even after maintenance of the reaction cavity, the temperature measurement path H will not be inconsistent with the initial state, and the temperature measurement reference can be maintained for a long time, with high repeatability and more stable and accurate control. The optical channel 421 is filled with purge gas S, forming a sealed space isolated from the atmosphere, which can eliminate the absorption of infrared radiation by water vapor and carbon dioxide in the atmosphere, allowing the infrared radiation from the surface of the object being measured to be transmitted to the optical pyrometer 410 without interference, resulting in more accurate temperature measurement. The purge gas S is not introduced into the reaction cavity 100, so it does not overlap with the process gas in the chamber, does not affect the uniformity of the process gas flow, and does not produce by-products. In addition, the connecting piece 420 is connected to the outside of the cavity wall and does not punch holes in the cavity wall, which can ensure the mechanical strength of the cavity wall at high temperatures and does not increase the sealed connection with the cavity wall, ensuring the reliability of the entire system seal.

[0050] In this embodiment, the connecting piece 420 is provided with a gas inlet 422 and a gas outlet 423, and the purge gas S flows into the optical channel 421 through the gas inlet 422 and flows out of the optical channel 421 through the gas outlet 423. By providing the gas inlet 422 and the gas outlet 423, a gas loop can be formed in the optical channel 421 to continuously cool the cavity wall at the connection. Further, the gas inlet 422 is arranged close to the first end, and the gas outlet 423 is arranged close to the second end, i.e. the gas inlet 422 is close to the optical pyrometer 410, and the gas outlet 423 is close to the cavity wall. The purge gas S entering the optical channel 421 at low temperature can first cool the lens of the optical pyrometer 410, which helps to prolong the service life of the optical pyrometer 410. Further, the gas inlet 422 and the gas outlet 423 are arranged on both sides of the optical channel 421, which is conducive to the uniform distribution of the purge gas S in the optical channel 421.

[0051] The purge gas S uses normal temperature or low temperature gas, for example, gas with temperature less than or equal to 70℃. Using normal temperature or low temperature gas can better achieve the effect of cooling the connecting part cavity wall, the connecting part 420 itself and the optical pyrometer 410 lens, and eliminate the influence of the infrared absorption gas molecules in the light path channel 421. In addition, the purge gas S should have low absorption rate of infrared radiation, so as not to affect the temperature measurement accuracy of the optical pyrometer 410, for example, the absorption rate of infrared radiation of the purge gas S is less than 0.1, and the purge gas can be selected from hydrogen, nitrogen, argon or oxygen. Because the molecular formula of nitrogen, oxygen, argon and other gases is symmetrical, their vibration will not cause the change of electric dipole moment, so these gas molecules do not absorb infrared radiation, and therefore do not affect the infrared radiation of the measured object to the optical pyrometer 410.

[0052] As shown in Figure 3 、 4 To avoid the influence of the temperature rise of the connecting part 420 on the temperature measurement accuracy of the optical pyrometer 410, the embodiment further provides a reflective coating or an infrared absorption coating 424 on the outer side of the connecting part 420, or the hole wall of the light path channel 421 of the connecting part 420 is provided with a reflective coating or an infrared absorption coating 424. The reflective coating is, for example, a plated metal layer of gold, aluminum or the like. In this way, the radiant energy F radiated from the infrared heating lamp assembly, the surface of the measured object, the cavity wall and other high temperature parts to the outside of the connecting part 420 can be reflected or absorbed, the temperature of the entire connecting part 420 is reduced, the noise of the infrared radiation is discharged, and the connecting part 420 is cooled by introducing a large amount of low temperature purge gas S into the inside of the light path channel 421, so as to eliminate the influence of the radiant energy of the connecting part 420 itself on the temperature measurement accuracy of the optical pyrometer 410.

[0053] The connecting part 420 and the optical pyrometer 410 are sealed by a sealing ring. The connecting part 420 can be made of transparent quartz material or opaque quartz material. The light path channel 421 and the cavity wall can be perpendicular or not perpendicular, as long as the infrared radiation of the measured object can be transmitted to the optical pyrometer 410 through the light path channel 421.

[0054] The connecting part 420 and the cavity wall are fixedly connected. One connection mode is that the connecting part 420 and the cavity wall are connected by welding, as shown in the left chamber temperature measurement device 400 installed on the upper wall 120 in Figure 2 Another connection mode is that the connecting part and the reinforcing rib outside the cavity wall are integrally provided, as shown in the two chamber temperature measurement devices 400 installed on the upper wall 120 and the lower wall 130 in Figure 1 and as shown in Figure 2The chamber temperature measuring device 400 is installed in the middle of the upper wall 120 and the lower wall 130. The reinforcing rib is made of quartz and is integrated with the chamber wall. The reinforcing rib is used to ensure that the chamber wall has enough mechanical strength under low pressure in the chamber. The reinforcing rib is used as a connecting piece 420. The light path channel 421 is formed in the reinforcing rib. The reinforcing rib is connected with the optical temperature measuring device 410. The gas inlet 422 and the gas outlet 423 are formed in the two sides of the reinforcing rib to form the passage of the purge gas S. Thus, the light path channel, the gas inlet and the gas outlet are formed in the reinforcing rib outside the chamber wall, which does not affect the structure of the chamber wall and does not damage the mechanical strength of the chamber wall.

[0055] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application cover modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

[0056] Although the present application has been described in detail with reference to the preferred embodiments, it should be recognized that the physical arrangements described are not meant to be limiting. Many modifications and variations of the present application will be apparent to those of ordinary skill in the art from the foregoing detailed description. Accordingly, it should be recognized that the scope of the present application is defined by the following claims.

Claims

1. A chemical vapour deposition apparatus comprising a reaction chamber and a susceptor located in the reaction chamber, the susceptor being arranged to carry a substrate, characterised in that, The cavity wall of the reaction cavity comprises at least a partial region that can transmit infrared radiation, and a chamber temperature measuring device is installed on the outside of the cavity wall, which comprises: an optical temperature measuring device that measures the temperature of the object to be measured in the reaction cavity through the infrared radiation; a connecting member having opposite first and second ends, the optical temperature measuring device being installed on the first end, the second end being connected to the outside of the cavity wall, and the cavity wall at the connection with the second end being intact, the connecting member having an optical path channel inside that extends through the first and second ends, the infrared radiation of the object to be measured being transmitted to the optical temperature measuring device through the optical path channel after passing through the cavity wall at the connection with the second end, and the cavity wall at the connection with the second end being cooled by passing a purge gas through the optical path channel, the optical path channel being filled with the purge gas to form a sealed space isolated from the atmosphere.

2. The chemical vapor deposition apparatus of claim 1, wherein The connecting member is provided with a gas inlet and a gas outlet, and the purge gas flows into the optical path channel through the gas inlet and flows out of the optical path channel through the gas outlet.

3. The chemical vapor deposition apparatus of claim 2, wherein The gas inlet is arranged close to the first end, and the gas outlet is arranged close to the second end.

4. The chemical vapor deposition apparatus of claim 2, wherein The gas inlet and the gas outlet are arranged on both sides of the optical path channel.

5. The chemical vapor deposition apparatus of claim 1, wherein The purge gas has a temperature of less than or equal to 70°C.

6. The chemical vapor deposition apparatus of claim 1, wherein The purge gas has an infrared radiation absorption rate of less than 0.

1.

7. The chemical vapor deposition apparatus of claim 6, wherein The purge gas is hydrogen, nitrogen, argon or oxygen.

8. The chemical vapor deposition apparatus of claim 1, wherein, The outside of the connecting member is provided with a reflective coating or an infrared absorbing coating.

9. The chemical vapor deposition apparatus of claim 1, wherein, The hole wall of the optical path channel is provided with a reflective coating or an infrared absorbing coating.

10. The chemical vapor deposition apparatus of claim 1, wherein The optical path channel is perpendicular or not perpendicular to the cavity wall.

11. The chemical vapor deposition apparatus of claim 1, wherein The connecting member is made of transparent quartz or opaque quartz.

12. The chemical vapor deposition apparatus of claim 1, wherein, The connecting member is fixedly connected to the cavity wall.

13. The chemical vapor deposition apparatus of claim 12, wherein The connecting member is connected to the cavity wall by welding.

14. The chemical vapor deposition apparatus of claim 1, wherein, The connecting member and the optical temperature measuring device are sealed by a sealing ring.

15. The chemical vapor deposition apparatus of claim 1, wherein, The object to be measured is the base, and the chamber temperature measuring device is installed below the reaction cavity.

16. The chemical vapor deposition apparatus of claim 1, wherein, The object to be measured is the substrate, and the chamber temperature measuring device is installed above the reaction cavity.

17. The chemical vapor deposition apparatus of claim 1, wherein The outside of the cavity wall comprises a reinforcing rib that is integrally arranged with the cavity wall, and the reinforcing rib serves as the connecting member.

18. The chemical vapor deposition apparatus of claim 1 wherein, The cavity wall is made of transparent quartz.

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