Vapor deposition system, thermal expansion measurement method, and method of measuring process gap

Abstract

The application discloses a kind of heater thermal expansion measurement methods, comprising the following steps: at first temperature, gradually reduce the spacing between wafer and heater by height adjusting assembly, keep pumping pipeline pumping and record the air pressure value at the outlet of pumping pipeline in real time in the process, when the air pressure value tends to be stable, obtain the first position of the height adjusting assembly corresponding to when the first air pressure value reaches the first saturation point at first temperature;At second temperature, repeat the above steps, when the air pressure value at the outlet of pumping pipeline tends to be stable, obtain the second position of the height adjusting assembly corresponding to when the second air pressure value reaches the second saturation point at second temperature;Calculate the difference between the first position and the second position, obtain the vertical direction thermal expansion amount of the heater between first temperature and second temperature;The method is simple to operate, and the measurement result is accurate, without changing the internal structure of the reaction cavity, and also will not affect the thermal field distribution in the reaction cavity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor equipment, and in particular to a thin film vapor deposition system, a method for measuring thermal expansion of a heater, and a method for measuring a process gap between a gas showerhead and a heater. BACKGROUND

[0002] Thin film vapor deposition technology is a technology for depositing a thin film on a substrate, such as a semiconductor wafer. For example, a CVD (chemical vapor deposition) process is a process for forming a thin film on a wafer. As shown in FIG. 1, a reaction chamber 100 for a CVD process includes a gas showerhead 101 for introducing a reaction gas containing elements of a thin film into a space above a wafer 200 in the reaction chamber 100. A heater 102 is provided below the wafer 200 to provide heat, so that the reaction gas reacts chemically on the surface of the wafer 200 to form a thin film. Figure 1

[0003] The CVD process and other thin film vapor deposition processes are sensitive to the thermal field and flow field environment in the reaction chamber. The distance between the upper surface of the heater 102 and the lower surface of the gas showerhead 101 (hereinafter referred to as the process gap) has an effect on the thermal field and flow field distribution in the reaction chamber 100. In order to speed up the processing of the wafer during the process, multiple reaction chambers are often used to process batches of wafers, or multiple chambers are used to sequentially process wafers with different processes. Therefore, in order to ensure the accuracy and uniformity of the processed wafers, the process gap needs to be consistent when processing different batches of wafers in the same reaction chamber, and the process gap needs to be consistent between reaction chambers for the same processing process.

[0004] Since the processing of the wafer, such as the CVD process and other thin film vapor deposition technologies, requires high-temperature heating provided by the heater 102, the heater 102 will inevitably expand at high temperatures, which will affect the process gap. In order to ensure the consistency of the process gap in the reaction chamber, the amount of thermal expansion of the heater 102 at high temperatures needs to be determined, and then the process gap is controlled based on the amount of thermal expansion of the heater.

[0005] ​The current method for determining the thermal expansion amount of the heater includes: calculating the thermal expansion amount of the heater at high temperature based on the thermal expansion coefficient of the heater material. However, the heater is not composed of a single material, and the actual raw material components are complex, and the structure is usually not strictly regular. Therefore, the accuracy of this method is poor. The thermal expansion amount of the heater at high temperature obtained by theoretical calculation is often different from the actual thermal expansion amount of the heater at high temperature, thereby affecting the consistency of the process gap of the reaction chamber. In addition, the thermal expansion amount of the heater at high temperature is measured by using an infrared distance measuring method. This method generally opens a hole on the chamber cover of the reaction chamber to set an infrared sensor, and measures the thermal expansion amount of the heater at high temperature by using the principle of optical path difference. However, the infrared sensor is usually not resistant to high temperature, and this method also needs to punch a hole on the gas spraying head. This not only changes the hardware structure of the reaction chamber, but also makes the operation complex and damages the sealing environment of the reaction chamber. Additional sealing of the hole is required, which affects the thermal field distribution in the reaction chamber.

[0006] Therefore, it is necessary to provide a heater thermal expansion amount measurement method which is simple to operate, accurate in measurement and does not need to change the original structure in the reaction chamber. SUMMARY

[0007] The purpose of the present application is to provide a heater thermal expansion amount measurement method which is simple to operate, accurate in measurement and does not need to change the original structure in the reaction chamber.

[0008] To achieve the above-mentioned purpose, the first aspect of the present application provides a thin film vapor deposition system, comprising: a reaction chamber, a gas spraying head arranged in the reaction chamber, a heater arranged opposite to the gas spraying head and used for carrying a wafer; an air extraction pipeline is further arranged in the heater, and a gas pressure detection device is arranged on the air extraction pipeline, the air extraction pipeline is used for extracting gas between the upper surface of the heater and the lower surface of the wafer; a height adjusting assembly is used for adjusting the distance between the wafer and the heater; further comprising: a controller, the controller is used for recording and storing the vertical thermal expansion amount of the heater between a first temperature and a second temperature, and controlling the height adjusting assembly to compensate for the change of the process gap between the lower surface of the gas spraying head and the upper surface of the heater caused by the thermal expansion amount.

[0009] Optionally, the controller is further used for performing the following steps:

[0010] At the first temperature, gradually reduce the distance between the wafer and the heater by the height adjusting assembly, extract air by the air extraction pipeline and record the first gas pressure value of the gas pressure detection device in real time during the process, and obtain the first position of the height adjusting assembly corresponding to the first saturation point of the first gas pressure value at the first temperature.

[0011] at the second temperature, gradually reducing the distance between the wafer and the heater by the height adjusting assembly, in the process, pumping the gas through the gas pumping pipeline and recording the second gas pressure value of the gas pressure detection device in real time, and obtaining the second position of the height adjusting assembly corresponding to the second gas pressure value reaching the second saturation point at the second temperature;

[0012] calculating the difference between the first position and the second position to obtain the vertical thermal expansion amount of the heater between the first temperature and the second temperature.

[0013] Optionally, the surface of the heater is provided with a plurality of bosses, and a sealing ring for sealing the upper surface of the heater and the lower surface of the wafer, the gap between the bosses, the sealing ring and the lower surface of the wafer is communicated with the gas pumping pipeline.

[0014] Optionally, the surface of the heater is provided with a plurality of grooves, and a plurality of the grooves are communicated with the gas pumping pipeline.

[0015] Optionally, the gas pumping pipeline is connected with a vacuum pump, so that the pressure on the back surface of the wafer is less than the pressure on the front surface of the wafer, and a gas flow adjusting device is further arranged on the gas pumping pipeline.

[0016] Optionally, the height adjusting assembly comprises: a driving device for controlling the lifting of the heater; a plurality of pin assemblies arranged through the heater, the pin assemblies being used for supporting the wafer.

[0017] Optionally, the height adjusting assembly comprises: a plurality of pin assemblies arranged through the heater, the pin assemblies being used for supporting the wafer; and a driving device for controlling the lifting of the plurality of pin assemblies.

[0018] Optionally, the driving device is a servo motor, and the stroke position of the servo motor is taken as the first position and the second position of the height adjusting assembly.

[0019] Optionally, the first temperature is a temperature lower than 80℃, and the second temperature is a process temperature.

[0020] Optionally, the measurement method is repeated multiple times, and the average value is taken as the final result.

[0021] The second aspect of the present application provides a method for measuring the thermal expansion amount of a heater, the heater being located in a reaction chamber of a thin film vapor deposition system, the reaction chamber further comprising: a gas pumping pipeline arranged between the heater and a wafer and communicated with the outside of the reaction chamber, a height adjusting assembly for adjusting the distance between the wafer and the heater, comprising the following steps:

[0022] At the first temperature, the distance between the wafer and the heater is gradually reduced by the height adjusting assembly, and the exhaust pipeline is kept pumping and the air pressure value at the outlet of the exhaust pipeline is recorded in real time during the process, when the air pressure value tends to be stable, the first position of the height adjusting assembly corresponding to the first air pressure value reaching the first saturation point at the first temperature is obtained;

[0023] At the second temperature, the above steps are repeated, and when the air pressure value at the outlet of the exhaust pipeline tends to be stable, the second position of the height adjusting assembly corresponding to the second air pressure value reaching the second saturation point at the second temperature is obtained.

[0024] The difference between the first position and the second position is calculated to obtain the vertical thermal expansion amount of the heater between the first temperature and the second temperature.

[0025] Optionally, the exhaust pipeline is connected with a vacuum pump, so that the pressure on the back surface of the wafer is less than the pressure on the front surface of the wafer, and a gas flow adjusting device is further arranged on the exhaust pipeline.

[0026] Optionally, the height adjusting assembly comprises a driving device for controlling the lifting of the heater, and a plurality of pin assemblies arranged through the heater, the pin assemblies being used for supporting the wafer.

[0027] Optionally, the height adjusting assembly comprises a plurality of pin assemblies arranged through the heater, the pin assemblies being used for supporting the wafer, and a driving device for controlling the lifting of the plurality of pin assemblies.

[0028] Optionally, the driving device is a servo motor, and the stroke position of the servo motor is obtained as the first position and the second position of the height adjusting assembly.

[0029] Optionally, the first temperature is a temperature lower than 80℃, and the second temperature is a process temperature.

[0030] The third aspect of the present application provides a method for measuring the process gap between a gas shower head and a heater, comprising the following steps: obtaining the first process gap between the gas shower head and the heater at the first temperature, obtaining the thermal expansion amount between the first temperature and the second temperature by the method for measuring the thermal expansion amount of the heater, and calculating the difference between the first process gap and the thermal expansion amount to obtain the second process gap between the gas shower head and the heater at the second temperature.

[0031] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0032] This scheme uses the existing reaction chamber structure to measure and determine the thermal expansion of the heater. Based on the principle of vacuum chuck adsorption of wafers, by monitoring the gas state between the wafer and the heater, the position of the height adjustment component corresponding to the complete adsorption of the wafer by the heater at different temperatures is determined, and then the thermal expansion of the heater between different temperatures is calculated. This method is simple to operate, does not require changing the internal structure of the reaction chamber, and will not affect the thermal field distribution in the reaction chamber.

[0033] Compared to theoretical calculation methods, this method uses actual measurements of the upper surface height of the heater at different temperatures, resulting in more accurate measurements. Furthermore, by taking the average of multiple measurements, the final result is more reliable, eliminating the randomness of a single measurement.

[0034] This method measures the thermal expansion of the heaters in different reaction chambers and the process gaps to ensure that the process gaps of each reaction chamber are consistent, which helps to ensure the accuracy and compositional uniformity of the processed wafers. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of the reaction chamber according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of a portion of the internal structure of the reaction chamber according to an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram showing the connection between the ejector pin assembly and the heater in one embodiment of the present invention;

[0038] Figure 4 This is a flowchart of a method for measuring the thermal expansion of a heater according to an embodiment of the present invention;

[0039] Figure 5 This is a line graph showing the gas pressure values ​​at low temperature and process temperature in one embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram of the internal structure of the reaction chamber according to another embodiment of the present invention. Detailed Implementation

[0041] The following will be combined with the embodiments of the present invention. Figures 1-6 The technical solutions, structural features, objectives and effects achieved in the embodiments of the present invention will be described in detail.

[0042] It should be noted that the drawings are very simplified and all use non-precise proportions, only to facilitate, clear, auxiliary purpose of the description of the embodiments of the present application, and not to limit the implementation of the present application defined conditions, therefore not have the technical essence, any structure modification, the change of the proportion relationship or the size adjustment, without affecting the effect and the purpose of the present application can be achieved, should still fall within the scope of the disclosed technology can cover.

[0043] It should be noted that in the present application, the term "comprise", "include" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes the explicitly listed elements, but also includes other elements not explicitly listed, or includes the elements inherent to such process, method, article or equipment.

[0044] In the reaction chamber 100 of the thin film vapor deposition system, a deposition process such as CVD is carried out, as shown in Figure 1 The reaction chamber 100 includes a gas shower head 101 arranged inside the reaction chamber 100 above and a heater 102 arranged opposite to the gas shower head 101, when carrying out the vapor deposition process, the reaction gas is introduced into the reaction chamber 100 above the wafer 200 through the gas shower head 101, the heater 102 carries and provides heating for the wafer 200, so that the reaction gas chemically reacts on the surface of the wafer 200 to form a thin film.

[0045] As shown in Figure 2 The height adjustment assembly is arranged below the heater 102 and is used to adjust the distance between the wafer 200 and the heater 102, the height adjustment assembly includes a plurality of needle assemblies 103 arranged through the heater 102, the needle assemblies 103 are used to support the wafer 200, and the height adjustment assembly further includes a driving device 104 for controlling the needle assemblies 103 to rise and fall simultaneously; before carrying out the process, the needle assemblies 103 are controlled by the driving device 104 to rise to a wafer transfer position, so that the top end of the needle assemblies 103 protrudes above the upper surface of the heater 102 to support the wafer 200, the wafer 200 is clamped by a mechanical hand and enters the reaction chamber 100, and is placed on the top end of the needle assemblies 103 so that the needle assemblies 103 support the wafer 200 together, and then the needle assemblies 103 are controlled by the driving device 104 to descend, so as to reduce the distance between the wafer 200 and the heater 102, until the top end of the needle assemblies 103 reaches the upper surface of the heater 102; as Figure 3As shown, the heater 102 has multiple through holes 1021, and the ejector assembly 103 passes through the through holes 1021. When the ejector assembly 103 descends to the process position, the upper surface of the ejector assembly 103 is lower than or level with the upper surface of the heater 102, so that the heater 102 can adsorb the wafer 200 for subsequent processes.

[0046] like Figure 2 As shown, the reaction chamber 100 also includes a suction pipe 105 disposed within the heater 102. The first end of the suction pipe 105 is connected to a vacuum pump 108, used to suction gas between the upper surface of the heater 102 and the lower surface of the wafer 200, ensuring that the pressure on the back side of the wafer 200 is less than the pressure on the front side. This pressure difference causes the wafer 200 to adhere to the upper surface of the heater 102 and prevent it from falling off. The vacuum pump 108 is disposed outside the reaction chamber 100 to provide suction power. The suction pipe 105 is also equipped with an airflow regulating device 106 and a pressure detection device 107, the latter used to acquire the pressure value of the suction pipe 105 in real time.

[0047] The second end of the extraction pipe 105 is connected to the extraction gap between the upper surface of the heater 102 and the lower surface of the wafer 200. Specifically, the surface of the heater 102 is provided with a plurality of bosses and a sealing ring for sealing the upper surface of the heater 102 and the lower surface of the wafer 200. The extraction gap between the bosses, the sealing ring and the lower surface of the wafer 200 is connected to the extraction pipe 105. Alternatively, in other embodiments, a plurality of grooves are provided on the surface of the heater 102, and the plurality of grooves are the extraction gaps connected to the extraction pipe 105.

[0048] The thin film vapor deposition system also includes a controller that controls the lifting and lowering of the pin assembly 103 via the drive device 104, thereby adjusting the spacing between the wafer 200 and the heater 102.

[0049] To accelerate wafer processing, multiple reaction chambers can be used to process batches of wafers simultaneously, or multiple chambers can be used to sequentially process wafers using different processes. To ensure the precision and compositional uniformity of the processed wafers, it is necessary to control the process gap (distance between the upper surface of heater 102 and the lower surface of gas spray head 101) to be consistent when processing different batches of wafers in the same reaction chamber, as well as the process gap between reaction chambers performing the same processing process. Since heater 102 undergoes thermal expansion at high temperatures, affecting the consistency of the process gap, this solution provides a method for measuring the thermal expansion of the heater in the reaction chamber. Based on the thermal expansion of the heater, the process gap of each reaction chamber can be controlled to be consistent.

[0050] The embodiment discloses a method for measuring thermal expansion of a heater, without changing the internal structure of a reaction cavity 100, as shown in the following steps: Figure 4

[0051] Step one, at low temperature, the wafer 200 is transferred into the reaction cavity 100. The controller controls the top pin assembly 103 to lower the wafer 200 through the driving device 104, in the process, the air pumping pipeline 105 pumps air from between the wafer 200 and the heater 102, and the first air pressure value of the air pressure detection device 107 is recorded in real time. When the first air pressure value tends to be stable, the first saturation point of the first air pressure value is recorded, and the first position of the driving device 104 corresponding to the first saturation point of the first air pressure value is obtained.

[0052] Specifically, when the above steps are performed, the reaction cavity 100 is at room temperature, generally below 80℃, at this low temperature, the heater 102 does not produce thermal expansion or the thermal expansion can be ignored. Under the condition of less than 80℃, the test tool can be used to directly test the process gap under low temperature condition, and the process gap is used as the debugging reference. The test tool can be a wafer with a capacitance sensor arranged inside, and the capacitance value between the test gas shower head and the heater is tested to obtain the process gap. The test tool is not limited to the wafer with a capacitance sensor, as long as it can measure the distance between the gas shower head and the heater in the vertical direction under low temperature condition. The controller controls the top pin assembly 103 to rise through the driving device 104, protrudes the upper surface of the heater 102, and then continues to rise until the wafer 200 is transferred into the reaction cavity 100 through the transfer port arranged on the side wall of the reaction cavity 100, and placed on the top end of the plurality of top pin assemblies 103, so that the plurality of top pin assemblies 103 jointly support the wafer 200, at this time, the wafer 200 and the heater 102 have a certain distance.

[0053] In the embodiment, the air flow adjusting device 106 and the air pressure detection device 107 are further arranged on the air pumping pipeline, the air flow adjusting device 106 is used to adjust the air flow between the back surface of the wafer 200 and the upper surface of the heater 102, and the air pressure detection device 107 is used to obtain the air pressure value in the air pumping pipeline 105, and the air pressure detection device 107 is arranged at the outlet of the air pumping pipeline 105.

[0054] Although the air flow adjusting device 106 and the air pressure detection device 107 are independent in the embodiment, this is not a limitation of the present application, in other embodiments, other devices with air flow adjusting and air pressure detection functions can also be arranged on the air pumping pipeline 105.

[0055] ​In the process that the controller drives the pin assembly 103 to descend by the driving device 104 so as to reduce the distance between the wafer 200 and the heater 102, the vacuum pump 108 and the air pumping pipeline 105 continuously pump the air between the wafer 200 and the heater 102, and the controller also records the reading of the air pressure detecting device 107 as a first air pressure value in real time, and records the stroke position of the driving device 104; as the pin assembly 103 descends, the distance between the wafer 200 and the heater 102 is reduced, and the air that can be pumped between the wafer 200 and the heater 102 is less and less, and the reading of the air pressure detecting device 107 is also less and less; when the reading of the air pressure detecting device 107 tends to be stable, it indicates that there is almost no air that can be pumped between the wafer 200 and the heater 102, i.e. the distance between the wafer 200 and the heater 102 is zero, and the wafer 200 is adsorbed and closely attached to the heater 102, at this time, the controller records the first position of the driving device 104 corresponding to the first air pressure value reaching the first saturation point; the first saturation point of the first air pressure value refers to a point when the first air pressure value of the air pressure detecting device 107 tends to be stable and reaches a saturation value at low temperature (<80℃), and generally, the reading of the air pressure detecting device 107 tends to be stable at 0-0.7 torr. As shown in FIG. 8, the air pressure value line graph of the air pressure detecting device 107 at low temperature tends to be stable from the point A, and therefore, the point A is the first saturation point of the first air pressure value at low temperature, and the abscissa corresponding to the point A is the first position of the driving device 104 corresponding to the first saturation point of the first air pressure value. Figure 5

[0056] In this embodiment, the servo motor is used as the driving device 104, and the stroke position of the servo motor is the position of the driving device 104. In other embodiments, any driving component that can record the stroke position can also be used as the driving device 104.

[0057] After the first position of the driving device 104 is obtained according to the step one, the controller controls the pin assembly 103 to ascend by the driving device 104, so that the pin assembly 103 lifts the wafer 200 from the upper surface of the heater 102 until the wafer 200 is transmitted to the wafer transmission position, and the mechanical hand transmits the wafer 200 out of the reaction cavity 100.

[0058] In step two, the process of step one is repeated at the process temperature, specifically, the controller controls the pin assembly 103 to carry the wafer 200 to descend by the driving device 104, and in the descending process, the air pumping pipeline 105 pumps the air between the wafer 200 and the heater 102, and the second air pressure value of the air pressure detecting device 107 is recorded in real time; when the second air pressure value tends to be stable, the controller records the second saturation point of the second air pressure value, and obtains the second position of the driving device 104 corresponding to the second air pressure value reaching the second saturation point.

[0059] ​Similar to step one, before performing step two, the temperature in the reaction chamber 100 is first raised to the process temperature and maintained, which varies according to different processes, and is usually above 250°C, at which the heater 102 will expand. The needle assembly 103 is then raised to the wafer transfer position by the driving device 104, at which the wafer 200 is transferred into the reaction chamber 100 by the robot and placed on the top ends of the needle assemblies 103, so that the wafer 200 is supported by the needle assemblies 103, and a distance is formed between the wafer 200 and the heater 102.

[0060] Similar to step one, during the process of lowering the needle assembly 103 by the driving device 104 to reduce the distance between the wafer 200 and the heater 102, the vacuum pump 108 and the pumping pipe 105 continuously pump the gas between the wafer 200 and the heater 102, and the reading of the pressure detector 107 is recorded as the second pressure value, and the position of the driving device 104. When the reading of the pressure detector 107 tends to be stable, the controller records the second position of the driving device 104 corresponding to the second saturation point of the second pressure value, which refers to the point at which the reading of the pressure detector 107 tends to be stable at the process temperature, and the abscissa corresponding to the second position of the driving device 104 when the second pressure value reaches the second saturation point.

[0061] After obtaining the second position, the needle assembly 103 is raised by the driving device 104, so that the wafer 200 is lifted from the upper surface of the heater 102 until the wafer transfer position, at which the wafer 200 is transferred out of the reaction chamber 100 by the robot.

[0062] It should be noted that, when performing the above thermal expansion measurement method, the wafer 200 used is a test wafer, not a process wafer for process reaction.

[0063] The processes of steps one and two are not in any particular order, and in other embodiments, the second position of the driving device 104 corresponding to the saturation point of the pressure value at the process temperature can be obtained first, and then the first position of the driving device 104 corresponding to the saturation point of the pressure value at the low temperature can be obtained, which only requires the reaction chamber 100 to be controlled at the corresponding temperature.

[0064] Step three, the controller calculates the difference between the first position and the second position of the driving device 104 corresponding to the saturation points of the pressure values at the low temperature and the process temperature, thereby obtaining the vertical thermal expansion amount of the heater 102 between the low temperature and the process temperature.

[0065] Since the first position and the second position record the position of the driving device 104 when the heater 102 fully absorbs the wafer 200 at the low temperature and the process temperature, the controller calculates the difference between the first position of the driving device 104 when the first pressure value reaches the first saturation point and the second position of the driving device 104 when the second pressure value reaches the second saturation point, and the thermal expansion amount of the heater 102 in the vertical direction between the two temperatures is obtained.

[0066] It should be noted that when the above measurement process is performed, the pressure inside the reaction chamber 100 needs to be kept stable, for example, another evacuation pipeline can be arranged on the side wall of the reaction chamber 100 and connected with another vacuum pump outside, so as to stabilize the pressure inside the reaction chamber 100 at a fixed value greater than zero. In the above embodiment, the pressure inside the reaction chamber 100 is stabilized at 5-30 torr.

[0067] In order to obtain more accurate results and eliminate the randomness of the experiment, the above steps 1-3 are repeated multiple times to obtain multiple thermal expansion amounts between the low temperature and the process temperature, and the average value is calculated as the final result.

[0068] The controller is also used to record and store the thermal expansion amount of the heater 102 between the low temperature and the process temperature, which affects the size of the process gap inside the reaction chamber 100. In order to ensure the consistency of the process gap, the controller controls the driving device 104 to compensate for the change of the process gap between the lower surface of the gas shower head 101 and the upper surface of the heater 102 caused by the thermal expansion amount during the process.

[0069] The embodiment also discloses a thin film vapor deposition system, as shown in Figure 1 and Figure 2 The thin film vapor deposition system comprises a reaction chamber 100, a gas shower head 101 arranged in the reaction chamber 100, and a heater 102 arranged opposite to the gas shower head 101 and used for carrying a wafer 200. An evacuation pipeline 105 is arranged in the heater 102 and used for evacuating the space between the wafer 200 and the heater 102 to vacuum. A height adjusting assembly is used for adjusting the distance between the wafer 200 and the heater 102. The evacuation pipeline 105 is used for evacuating the gas between the heater 102 and the lower surface of the wafer 200, and a first end of the evacuation pipeline 105 is connected with the vacuum pump 108 and a second end of the evacuation pipeline 105 is connected with the space between the upper surface of the heater 102 and the lower surface of the wafer 200. A gas flow adjusting device 106 and a gas pressure detecting device 107 are arranged on the evacuation pipeline 105.

[0070] Specifically, the surface of the heater 102 is provided with a plurality of bosses, and a sealing ring for sealing the upper surface of the heater 102 and the lower surface of the wafer 200, and the pumping gap between the bosses, the sealing ring and the lower surface of the wafer 200 is communicated with the pumping pipeline 105; or, in other embodiments, a plurality of grooves are provided on the surface of the heater 102, and the plurality of grooves are communicated with the pumping pipeline 105.

[0071] As shown in Figure 2 The height adjustment assembly includes a plurality of pin assemblies 103 arranged through the heater 102, and the pin assemblies 103 are used to support the wafer 200; and a driving device 104 for controlling the simultaneous lifting and lowering of the plurality of pin assemblies 103.

[0072] The thin film vapor deposition system further comprises a controller for controlling the lifting and lowering of the pin assemblies 103 by the driving device 104, so as to adjust the gap between the wafer 200 and the heater 102 at low temperature and process temperature; the controller is also used to record the reading of the air pressure detection device 107, and when the reading of the air pressure detection device 107 tends to be stable, that is, the air pressure value at the outlet of the pumping pipeline 105 tends to be stable, the controller obtains the first position of the driving device 104 corresponding to the first saturation point of the first air pressure value at low temperature and the second position of the driving device 104 corresponding to the second saturation point of the second air pressure value at process temperature, and calculates the difference between the first position and the second position, so as to obtain the vertical thermal expansion amount of the heater 102 between low temperature and process temperature.

[0073] The controller is also used to record and store the thermal expansion amount of the heater 102 between low temperature and process temperature, and control the driving device 104 to compensate for the change of the process gap caused by the thermal expansion amount.

[0074] The embodiment also provides a method for measuring the process gap between the gas shower head 101 and the heater 102, which comprises the following steps: obtaining the first process gap between the gas shower head 101 and the heater 102 at low temperature, obtaining the thermal expansion amount of the heater 102 between low temperature and process temperature by the above-mentioned method for measuring the thermal expansion amount of the heater, calculating the difference between the first process gap and the thermal expansion amount, so as to obtain the second process gap between the gas shower head 101 and the heater 102 at process temperature.

[0075] Although the embodiment only measures the thermal expansion of the heater 102 between the low temperature and the process temperature and the process gap between the gas shower head 101 and the heater 102 at the process temperature, in other embodiments, when it is necessary to measure the thermal expansion of the heater between other two or more different temperatures and to measure the process gap between the gas shower head 101 and the heater 102 at other temperatures, the above method can still be used, only the different measurement temperatures need to be controlled.

[0076] In another embodiment, other structures can be the same as the above embodiment, only the specific structure of the height adjustment assembly and the controller are different from the above embodiment, as shown in Figure 6 The height adjustment assembly includes a plurality of needle assemblies 103 arranged through the heater 102, which are used to support the wafer 200, and a driving device 109 for controlling the lifting of the heater 102; before the vapor deposition process is performed, the controller controls the heater 102 to lower to a wafer transfer position by the driving device 109, so that the top ends of the needle assemblies 103 protrude above the upper surface of the heater 102 to support the wafer 200, and then the wafer 200 is clamped by a mechanical hand and placed on the top ends of the needle assemblies 103 to be supported by the needle assemblies 103, and then the heater 102 is lifted by the driving device 109 to reduce the distance between the wafer 200 and the heater 102, until the top ends of the needle assemblies 103 are embedded in the upper surface of the heater 102. Figure 3 ).

[0077] In the embodiment, step one of the method for measuring the thermal expansion of the heater is: at a low temperature, the controller controls the heater 102 to lower by the driving device 109, so that the top ends of the needle assemblies 103 protrude above the upper surface of the heater 102, and then the heater 102 is continuously lowered until it reaches a wafer transfer position, at which the wafer 200 is transferred into the reaction chamber and placed on the top ends of the needle assemblies 103, so that the needle assemblies 103 collectively support the wafer 200, and at this time, the wafer 200 and the heater 102 have a certain distance; the controller controls the heater 102 to rise by the driving device 109 to shorten the distance between the wafer 200 and the heater 102, and in the rising process, the pumping pipeline 105 is kept pumping gas from between the wafer 200 and the heater 102, and the first pressure value displayed by the pressure detection device 107 is recorded in real time, and when the first pressure value tends to be stable, the controller records the first saturation point of the first pressure value, and obtains the first position of the driving device 109 corresponding to the time when the first pressure value reaches the first saturation point.

[0078] In step one, as the controller drives the heater 102 to rise by the driving device 109, the distance between the wafer 200 and the heater 102 is reduced, and the gas between the wafer 200 and the heater 102 is lessened, and the reading of the gas pressure detecting device 107 is also reduced. When the reading of the gas pressure detecting device 107 tends to be stable, it indicates that there is almost no gas between the wafer 200 and the heater 102, i.e. the distance between the wafer 200 and the heater 102 is zero, and the wafer 200 is adsorbed on the upper surface of the heater 102. At this time, the controller records the first position of the driving device 109 corresponding to the first saturation point of the first gas pressure value.

[0079] After the first position is obtained, the controller controls the heater 102 to descend by the driving device 109, so that the distance between the heater 102 and the wafer 200 is widened, the pin assembly 103 supports the wafer 200, and the heater 102 reaches the transfer position. The robot clamps the wafer 200 from the top end of the pin assembly 103 and transfers it out of the reaction chamber 100.

[0080] In step two of the method for measuring the thermal expansion amount of the heater in the embodiment, the temperature in the reaction chamber 100 is raised to the process temperature and maintained, the controller controls the heater 102 to descend to the transfer position by the driving device 109. At the transfer position, the robot transfers the wafer 200 into the reaction chamber 100 and places it on the top end of the pin assembly 103, so that the pin assembly 103 supports the wafer 200 together. The controller controls the heater 102 to rise by the driving device 109. In the rising process, the gas suction pipeline 105 is kept to suction the gas between the wafer 200 and the heater 102, and the second gas pressure value shown by the gas pressure detecting device 107 is recorded in real time. When the second gas pressure value tends to be stable, the controller obtains the second saturation point of the second gas pressure value, and records the second position of the driving device 109 corresponding to the second saturation point of the second gas pressure value.

[0081] After the second position is obtained, the controller controls the heater 102 to descend by the driving device 109, so that the pin assembly 103 protrudes from the upper surface of the heater 102 and supports the wafer 200, and the heater 102 descends to the transfer position. The robot transfers the wafer 200 out of the reaction chamber 100.

[0082] It should be noted that when the above method for measuring the thermal expansion amount is performed, the wafer 200 used is a test wafer, not a process wafer for process reaction. The test wafer does not have upward or downward warping deformation, so as to obtain more accurate process gap data.

[0083] In the present embodiment, the third step of the method for measuring the thermal expansion of the heater is that the controller calculates the difference between the first position and the second position of the driving device 109 corresponding to the saturation point of the gas pressure value at low temperature and at process temperature, thereby obtaining the vertical thermal expansion of the heater 102 between low temperature and process temperature.

[0084] Similarly, in order to obtain more accurate results and eliminate the randomness of the experiment, the above steps one to three are repeated multiple times to obtain multiple thermal expansion values between low temperature and process temperature, and the average value is calculated as the final result.

[0085] The controller is also used to record and store the thermal expansion of the heater 102 between low temperature and process temperature, which affects the size of the process gap in the reaction chamber 100. In order to ensure the consistency of the process gap, the controller also controls the driving device 109 to compensate for the change of the process gap caused by the thermal expansion during the process.

[0086] The present embodiment also provides a thin film vapor deposition system, as shown in Figure 1 and Figure 6 The thin film vapor deposition system comprises a reaction chamber 100, and a gas shower head 101 and a heater 102 arranged in the reaction chamber 100, wherein the heater 102 is used to carry a wafer 200, the heater 102 is further provided with a gas suction pipe 105 for sucking the space between the wafer 200 and the heater 102 to vacuum, and a height adjusting assembly is used to adjust the distance between the wafer 200 and the heater 102. The gas suction pipe 105 is used to suck the gas between the heater 102 and the lower surface of the wafer 200, the first end of the gas suction pipe 105 is connected with the vacuum pump 108, and the second end of the gas suction pipe 105 is connected with the space between the heater 102 and the wafer 200 through the back surface of the heater 102. The gas suction pipe 105 is provided with a gas flow adjusting device 106 and a gas pressure detecting device 107.

[0087] The second end of the gas suction pipe 105 is communicated with the gap between the upper surface of the heater 102 and the lower surface of the wafer 200, specifically, the surface of the heater 102 is provided with a plurality of bosses, and a sealing ring is used to seal the upper surface of the heater 102 and the lower surface of the wafer 200, the gap between the bosses, the sealing ring and the lower surface of the wafer 200 is communicated with the gas suction pipe 105; or, in other embodiments, a plurality of grooves are arranged on the surface of the heater 102, and the plurality of grooves are communicated with the gas suction pipe 105.

[0088] As shown in Figure 6As shown, the height adjusting assembly comprises: a plurality of pin assemblies 103 arranged through the heater 102, the pin assemblies 103 being used to support the wafer 200; a driving device 109 used to control the lifting of the heater 102; wherein, as shown, the top ends of the pin assemblies 103 can be engaged and embedded into the upper surface of the heater 102. Figure 3

[0089] The thin film vapor deposition system further comprises a controller, which is used to control the lifting of the heater 102 by the driving device 109, so as to adjust the spacing between the wafer 200 and the heater 102 at the low temperature and the process temperature; the controller is further used to record the readings of the air pressure detecting device 107, and when the readings of the air pressure detecting device 107 tend to be stable, the controller obtains the first position of the driving device 109 corresponding to the first saturated point of the first air pressure value at the low temperature and the second position of the driving device 109 corresponding to the second saturated point of the second air pressure value at the process temperature, and calculates the difference between the first position and the second position, so as to obtain the vertical direction thermal expansion amount of the heater 102 between the low temperature and the process temperature.

[0090] The controller is further used to record and store the thermal expansion amount of the heater 102 between the low temperature and the process temperature, and control the driving device 109 to compensate the change of the process gap between the lower surface of the gas shower head 101 and the upper surface of the heater 102 caused by the thermal expansion amount.

[0091] The embodiment further provides a method for measuring the process gap between the gas shower head 101 and the heater 102, which comprises the following steps: obtaining the first process gap between the gas shower head 101 and the heater 102 at the low temperature, obtaining the thermal expansion amount of the heater 102 between the low temperature and the process temperature by the above-mentioned method for measuring the thermal expansion amount of the heater 102, and calculating the difference between the first process gap and the thermal expansion amount, so as to obtain the second process gap between the gas shower head 101 and the heater 102 at the process temperature.

[0092] Although the content of the present application has been described in detail through the above-mentioned optional embodiments, it should be recognized that the above-mentioned description should not be considered as the limitation of the present application. After the above-mentioned content is read by the person skilled in the art, various modifications and substitutions of the present application will be obvious. Therefore, the protection scope of the present application should be defined by the appended claims.​

Claims

1. A thin film vapor deposition system, comprising: a reaction chamber, a gas showerhead disposed in the reaction chamber, a heater disposed opposite the gas showerhead, and a wafer support; a gas extraction conduit disposed in the heater, the gas extraction conduit having a pressure sensor disposed thereon, the gas extraction conduit configured to extract gas between an upper surface of the heater and a lower surface of the wafer; a height adjustment assembly configured to adjust a spacing between the wafer and the heater; and wherein: Also comprising: a controller for recording and storing the amount of vertical thermal expansion of the heater between the first temperature and the second temperature, and controlling the height adjustment assembly to compensate for the change of the process gap between the lower surface of the gas shower head and the upper surface of the heater caused by the thermal expansion; the controller is further used to perform the following steps: at the first temperature, gradually reduce the distance between the wafer and the heater by the height adjustment assembly, and record the first air pressure value of the air pressure detection device in real time by the air exhaust pipeline during the process, and obtain the first position of the height adjustment assembly corresponding to the first saturation point of the first air pressure value at the first temperature; at the second temperature, gradually reduce the distance between the wafer and the heater by the height adjustment assembly, and record the second air pressure value of the air pressure detection device in real time by the air exhaust pipeline during the process, and obtain the second position of the height adjustment assembly corresponding to the second saturation point of the second air pressure value at the second temperature; calculate the difference between the first position and the second position to obtain the amount of vertical thermal expansion of the heater between the first temperature and the second temperature.

2. The thin film vapor deposition system of claim 1, wherein, The surface of the heater is provided with a plurality of bosses, and a sealing ring for sealing the upper surface of the heater and the lower surface of the wafer, the gap between the bosses, the sealing ring and the lower surface of the wafer is communicated with the air exhaust pipeline.

3. The thin film vapor deposition system of claim 1, wherein, The surface of the heater is provided with a plurality of grooves, and a plurality of the grooves are communicated with the air exhaust pipeline.

4. The thin film vapor deposition system of claim 1, wherein, The air exhaust pipeline is connected with a vacuum pump, so that the pressure on the back surface of the wafer is less than the pressure on the front surface of the wafer, and an air flow adjusting device is further arranged on the air exhaust pipeline.

5. The thin film vapor deposition system of claim 1, wherein, The height adjustment assembly comprises: a driving device for controlling the lifting of the heater; a plurality of pin assemblies arranged through the heater, the pin assemblies are used to support the wafer.

6. The thin film vapor deposition system of claim 1, wherein, The height adjustment assembly comprises: a plurality of pin assemblies arranged through the heater, the pin assemblies are used to support the wafer; a driving device for controlling the lifting of the plurality of pin assemblies.

7. The thin film vapor deposition system of claim 5 or 6, wherein, The driving device is a servo motor, and the stroke position of the servo motor is obtained as the first position and the second position of the height adjustment assembly.

8. The thin film vapor deposition system of claim 1, wherein, The first temperature is a temperature lower than 80℃, and the second temperature is a process temperature.

9. The thin film vapor deposition system of claim 1, wherein, The step is repeated multiple times, and the average value is taken as the final result.

10. A method of measuring thermal expansion of a heater, the heater being located within a reaction chamber of a thin film vapor deposition system, the reaction chamber further comprising: An air exhaust pipeline arranged between the heater and the wafer and communicated with the outside of the reaction chamber, and a height adjustment assembly for adjusting the distance between the wafer and the heater, characterized by comprising the following steps: at the first temperature, gradually reduce the distance between the wafer and the heater by the height adjustment assembly, and keep the air exhaust pipeline during the process and record the air pressure value at the outlet of the air exhaust pipeline in real time, when the air pressure value tends to be stable, obtain the first position of the height adjustment assembly corresponding to the first saturation point of the first air pressure value at the first temperature; at the second temperature, repeat the above steps, when the air pressure value at the outlet of the air exhaust pipeline tends to be stable, obtain the second position of the height adjustment assembly corresponding to the second saturation point of the second air pressure value at the second temperature; A difference between the first position and the second position of the height adjustment assembly is calculated to obtain a vertical thermal expansion amount of the heater between the first temperature and the second temperature.

11. The method of claim 10, wherein the heating rate is 0.1°C / sec or more. The gas extraction pipe is connected to a vacuum pump, so that the pressure on the back surface of the wafer is less than the pressure on the front surface of the wafer, and a gas flow adjusting device is further arranged on the gas extraction pipe.

12. The method of claim 10, wherein the heating rate is 0.1°C / sec or more. The height adjustment assembly comprises: A driving device for controlling the lifting of the heater; A plurality of pin assemblies arranged through the heater, the pin assemblies being used for supporting the wafer.

13. The method of claim 10, wherein the heating rate is 0.1°C / sec or more. The height adjustment assembly comprises: A plurality of pin assemblies arranged through the heater, the pin assemblies being used for supporting the wafer; A driving device for controlling the lifting of the plurality of pin assemblies.

14. The method of measuring thermal expansion of a heater according to claim 12 or 13, wherein The driving device is a servo motor, and the stroke position of the servo motor is obtained as the first position and the second position of the height adjustment assembly.

15. The method of claim 10, wherein the heater is heated to a temperature of 1000 °C or higher. The first temperature is a temperature lower than 80℃, and the second temperature is a process temperature.

16. A method of measuring a process gap between a gas showerhead and a heater, the method comprising: The method comprises the following steps: obtaining a first process gap between the gas shower head and the heater at a first temperature, obtaining a thermal expansion amount between the first temperature and the second temperature according to the thermal expansion amount measurement method of the heater as claimed in any one of claims 10-15, and calculating a difference between the first process gap and the thermal expansion amount to obtain a second process gap between the gas shower head and the heater at the second temperature.

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