Pressure controller, semiconductor processing equipment and pneumatic control method

Abstract

This invention provides a pressure controller, a semiconductor processing device, and a pneumatic pressure control method. The pressure controller includes: a housing covering a fluid pipeline, with branch pipelines of the fluid pipeline extending toward the housing, and a maximum delivery pressure in the fluid pipeline being a first pressure; a pressure gauge disposed within the housing and mounted at the end of a branch pipeline via a mounting base, the branch pipeline being at least partially located within a first region of the mounting base; the pressure gauge having a maximum range pressure of a second pressure, which is at least 5 times the first pressure; a temperature sensor at least partially disposed within the first region, its end facing the sidewall of the branch pipeline and its side facing the bottom surface of the pressure gauge; a calculation unit for calculating a calibration pressure value; and a control valve for adjusting the opening of the control valve based on the calibration pressure value to maintain the calibration pressure value constant for a certain period of time.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a pressure controller, semiconductor processing equipment, and air pressure control method. Prior Technology

[0002] In the field of semiconductor manufacturing technology, plasma processing of wafers is frequently required within semiconductor processing equipment. This equipment has a vacuum reaction chamber that includes an electrostatic chuck (ESC) for electrostatically holding the wafers during the process.

[0003] In semiconductor processing, controlling the surface temperature of the wafer is crucial to ensuring the quality of the wafer processing. This can be achieved by improving the heat dissipation of the back side of the wafer to ensure that the surface temperature meets the process requirements.

[0004] One method involves using an electrostatic chuck to conduct heat to the wafer. The metal base of the electrostatic chuck has cooling fluid channels connected to an external cooling system. Cooling liquid flowing through these channels removes heat conducted from the wafer to the base, controlling the base temperature and consequently, the wafer temperature. Another method involves incorporating multiple cooling gas channels within the electrostatic chuck. Cooling gas is then introduced through these channels to the back of the wafer to control its temperature. These two methods can also be used in combination.

[0005] When cooling gas is introduced into the back of a wafer, it is necessary to monitor the gas pressure in the cooling gas channel. This pressure measurement requires low pressure and high accuracy. However, currently, high-precision pressure gauges generally use capacitive pressure gauges, which have the characteristics of high accuracy in a small range, but are more expensive and larger in size, requiring more installation space. This makes the overall pressure controller occupy a large space, which is not conducive to modular and miniaturized design.

[0006] In contrast, large-range pressure gauges are characterized by low cost and small size, which allows for a more compact and integrated pressure controller, facilitating the design of small modular pressure controllers, such as silicon resistance pressure gauges. However, compared to capacitive pressure gauges, these pressure gauges have a larger range, and the cost and accuracy of pressure gauge products are inversely proportional to their range but directly proportional to their size. The measurement accuracy is relatively low in the low-pressure measurement range (less than 1 / 3 of the range).

[0007] On the other hand, the measurement results of a pressure gauge within its short measurement range are more susceptible to the influence of the ambient temperature. When there is a large temperature gradient in the temperature field where the pressure gauge is located, temperature compensation for the measurement results is also quite complex and difficult to achieve the required measurement accuracy.

[0008] How to provide a low-cost and miniaturized pressure gauge to accurately control the air pressure in the cooling fluid channel and ensure the safety of wafer processing is an urgent problem to be solved. Summary of the Invention

[0009] The purpose of this invention is to provide a pressure controller, a semiconductor processing device, and a gas pressure control method. This invention can overcome the influence of the ambient temperature field (with a large temperature gradient) on the measurement results of a large-range pressure gauge, improve the measurement accuracy of the large-range pressure gauge in its low-pressure measurement range, and improve the accuracy of the gas pressure in the control fluid pipeline (used to provide cooling gas to the gas channel inside the electrostatic chuck).

[0010] To achieve the above objectives, the present invention provides a pressure controller, disposed on a fluid pipeline for conveying a process fluid, wherein the maximum conveying pressure of the process fluid is a first pressure, and the pressure controller comprises: A housing, which covers the fluid pipeline to form an installation space for the pressure controller, the fluid pipeline having branch lines extending toward the housing; A pressure gauge is disposed within the housing and mounted at the end of the branch pipe via a mounting base. The mounting base has a first region, which is the projection area of ​​the pressure gauge onto the mounting base. The branch pipe is at least partially located within the first region. The maximum range pressure of the pressure gauge is a second pressure, which is at least five times the first pressure. A temperature sensor is provided, with a temperature measuring hole provided on the side wall of the mounting base. The temperature sensor is located in the temperature measuring hole and is at least partially disposed in the first region. The end of the temperature sensor is opposite to the branch pipe, and the side of the temperature sensor is opposite to the bottom surface of the pressure gauge. A calculation unit, electrically connected to the pressure gauge and the temperature sensor, compensates for the measurement results of the pressure gauge based on the measurement results of the temperature sensor to obtain a calibrated pressure value; A control valve is installed on the fluid pipeline and located upstream of the branch pipeline; The control unit adjusts the opening of the control valve based on the calibration pressure value so that the calibration pressure value remains constant for a certain period of time.

[0011] Optionally, the end of the temperature sensor has a first distance from the side wall of the branch pipe, and the side of the temperature sensor has a second distance from the bottom surface of the pressure gauge, wherein the first distance is greater than the second distance.

[0012] Optionally, an installation groove is provided on the wall of the fluid pipeline, and the mounting seat is installed in the installation groove and submerged in the wall of the fluid pipeline.

[0013] Optionally, the mounting base and the mounting groove have a spacer cavity.

[0014] Optionally, the upper end face of the spacer cavity is sealed, and the spacer cavity is in a vacuum environment.

[0015] Optionally, it may also include a heating unit, which is at least partially located within the spacer cavity.

[0016] Optionally, the heating unit does not contact the mounting slot.

[0017] Optionally, the heating unit is wrapped with a heat insulation layer.

[0018] Optionally, the heat insulation layer does not contact the mounting groove.

[0019] Optionally, the pressure controller further includes a drive device disposed within the mounting base, the drive device driving the temperature sensor to move in a direction approaching or away from the branch pipeline based on the command signal from the control unit.

[0020] Optionally, the pressure gauge includes: a pressure-sensitive diaphragm layer and four pressure-sensitive resistors; the pressure-sensitive diaphragm layer deforms accordingly based on the air pressure in the branch pipeline; the four pressure-sensitive resistors are disposed on the pressure-sensitive diaphragm layer and form a Wheatstone bridge, the Wheatstone bridge outputting a voltage signal corresponding to the deformation.

[0021] Optionally, two of the four piezoresistors are disposed in the positive strain region of the pressure-sensitive film layer, and the other two piezoresistors are disposed in the negative strain region of the pressure-sensitive film layer.

[0022] Optionally, the pressure-sensitive diaphragm layer is further provided with a conformal insulating layer; the four varistors are disposed on the insulating layer.

[0023] Optionally, the pressure gauge further includes a rigid substrate; the pressure-sensitive diaphragm is arranged in an arch shape on the substrate.

[0024] Optionally, a vacuum arched cavity is formed between the pressure-sensitive membrane layer and the substrate.

[0025] Optionally, the distance between any two points on the pressure-sensitive membrane layer is no greater than 2 cm.

[0026] Optionally, the outer surface of the housing is coated with thermal insulation material.

[0027] Optionally, the pressure controller further includes a heating unit that surrounds the pressure gauge.

[0028] Optionally, a heat insulation layer is provided on the outside of the heating unit.

[0029] Optionally, the portion of the insulation layer near the fluid conduit has a first thickness, and the portion of the insulation layer away from the fluid conduit has a second thickness, wherein the first thickness is greater than the second thickness.

[0030] Optionally, the temperature sensor includes a first temperature probe and a second temperature probe; the first temperature probe is opposite to the branch pipe, and the second temperature probe is opposite to the pressure gauge; the calculation unit calculates a calibration temperature value based on the temperature value measured by the first temperature probe and the temperature value measured by the second temperature probe; the calculation unit calculates a calibration pressure value based on the calibration temperature value.

[0031] Optionally, the control unit controls the heating power of the heating unit based on the temperature value measured by the temperature sensor, so that the absolute value of the difference between the measured temperature value and the preset temperature value is less than a set temperature difference threshold.

[0032] Optionally, the control unit includes: The signal processing module amplifies and filters the voltage signal; The A / D conversion module converts the amplified and filtered voltage signal into a corresponding digital signal; the calculation unit calculates and generates a pressure value corresponding to the digital signal, and compensates the pressure value based on the temperature value measured by the temperature sensor to obtain the calibration pressure value.

[0033] Optionally, the pressure controller further includes a flow sensor for measuring the gas flow rate in the fluid line and providing the measurement result to the control unit.

[0034] Optionally, the pressure controller further includes a communication module, whose signal connection is set between the control unit and the host computer to realize data transmission between the control unit and the host computer.

[0035] The present invention also provides a semiconductor processing apparatus, comprising: The reaction chamber is equipped with an electrostatic chuck to support and fix the wafer to be processed. The electrostatic chuck has multiple gas channels inside, and cooling gas is supplied to these channels through fluid pipes connected to an external cooling gas source. These gas channels are connected in parallel with branch pipes. The pressure controller described in this invention is used to control the gas pressure value of the gas channel.

[0036] Optionally, when the wafer is fixed to the electrostatic chuck, the pressure controller controls the gas pressure in the gas channel to remain constant.

[0037] Optionally, when the wafer is fixed to the electrostatic chuck, the flow sensor is used to detect the quality of the electrostatic chuck's fixation of the wafer.

[0038] The present invention also provides a pneumatic pressure control method for a semiconductor processing apparatus as described herein, comprising the steps of: Based on the process within the reaction chamber, the temperature sensor is driven to reach a designated position in the temperature measuring orifice; The calculation unit generates the corresponding air pressure value based on the measurement results of the pressure gauge, and compensates the air pressure value based on the measurement results of the temperature sensor to obtain the calibrated pressure value; The controller adjusts the opening of the control valve based on the calibrated pressure value.

[0039] Optionally, the process of generating the pressure value further includes: The controller controls the heating power of the heating unit based on the measurement results of the temperature sensor, so that the absolute value of the difference between the temperature value measured by the temperature sensor and the preset temperature value is less than the set temperature difference threshold.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1) The pressure controller, semiconductor processing equipment, and pneumatic control method of this invention can overcome the influence of complex ambient temperature on the measurement results of large-range pressure gauges. By compensating for the pressure gauge measurement results through the measurement results of a temperature sensor, the measurement accuracy of large-range pressure gauges in their low-pressure measurement range (less than 1 / 5 of the maximum range) is significantly improved. This meets the practical needs of pneumatic control of fluid pipelines during wafer processing, effectively ensuring the stability and consistency of wafer processing. Furthermore, this invention can maintain the wafer at a set temperature during the process, improving the wafer processing yield.

[0042] 2) The pressure gauge of the present invention uses a small pressure-sensitive diaphragm layer, which greatly reduces the volume of the pressure gauge while ensuring measurement accuracy, thereby realizing the miniaturization design of the pressure gauge.

[0043] 3) The pressure gauge of this invention operates within a temperature field with a large temperature gradient. If the voltage output of the pressure gauge is compensated solely based on a single temperature value measured at a single location, the calculated fluid pipeline pressure value will still deviate significantly from the actual fluid pipeline pressure value, making it difficult to fit the functional relationship between the single temperature value and the actual fluid pipeline pressure value. The temperature sensor of this invention simultaneously acquires the temperature of the pressure gauge's outer surface (the outer surface of the pressure gauge closest to the Wheatstone bridge) and the temperature of the contact area between the mounting base and the pressure gauge, forming a comprehensive temperature measurement result to compensate for the pressure gauge's measurement result, greatly improving the accuracy of fluid pipeline pressure measurement.

[0044] 4) This invention obtains the temperature of the contact area between the mounting base and the pressure gauge by collecting the temperature of the first temperature measuring area of ​​the branch pipeline (which is on the same temperature contour line as the contact area mentioned above), thus solving the problem that the temperature of this contact area is inconvenient to collect. Through the layout of the temperature sensor, pressure gauge, and branch pipeline, the internal structure of the mounting base is made compact, greatly reducing the volume of the mounting base, thereby realizing the miniaturization design of the mounting base.

[0045] 5) This invention, based on the strength of the correlation between the temperature of the outer surface of the pressure gauge, the temperature of the first temperature measuring area, and the output voltage of the pressure gauge, controls the distance between the end of the temperature sensor and the first temperature measuring area (i.e., the first distance), and the distance between the side of the temperature sensor and the outer surface of the pressure gauge (i.e., the second distance), thereby obtaining a more accurate comprehensive temperature measurement result. This invention can also dynamically adjust the size of the first distance through a driving device, further improving the accuracy of air pressure measurement in fluid pipelines.

[0046] 6) The temperature sensor of the present invention may also have a first temperature probe and a second temperature probe. The first temperature probe measures the temperature of the first temperature measurement area, and the second temperature probe measures the temperature of the outer surface of the pressure gauge. A more accurate calibration temperature value is obtained by weighted calculation of the temperature values ​​collected by the first temperature probe and the second temperature probe. The voltage value output by the pressure gauge is compensated based on the calibration temperature value, thereby further improving the air pressure measurement accuracy of the fluid pipeline.

[0047] 7) By wrapping the pressure gauge with a heating unit, the present invention maintains the temperature value measured by the temperature sensor at a constant preset temperature value, thereby simplifying the temperature compensation calculation of the pressure gauge measurement results.

[0048] 8) In this invention, the heat insulation layer outside the heating unit has a varying thickness, which can reduce the temperature gradient of the pressure gauge and improve the accuracy of temperature compensation for the pressure gauge measurement results. Simple Explanation of the Diagram

[0049] Figure 1 is a schematic diagram of a semiconductor processing device; Figure 2 is a schematic diagram of the pressure controller in one embodiment of the present invention; Figure 3 is a schematic diagram of a pressure controller and a temperature sensor installed in a fluid pipeline in one embodiment of the present invention; Figure 4 is a schematic diagram showing the connection relationship of the components of the pressure controller in one embodiment of the present invention; Figure 5 shows the state of the pressure-sensitive film and the piezoresistor in one embodiment of the present invention when no external force is applied. Figure 6 shows the state of the pressure-sensitive film and the varistor when an external force is applied in one embodiment of the present invention. Figure 7 is a top view of a varistor in one embodiment of the present invention; Figure 8 is a schematic diagram of a Wheatstone bridge in one embodiment of the present invention; Figure 9 is a schematic diagram of another embodiment of the present invention, in which the temperature sensor has two temperature probes; Figure 10 is a schematic diagram of the structure in another embodiment of the present invention, showing the pressure gauge surrounded by the heating unit; Figure 11 is a schematic diagram showing the connection relationship between the driving device and the temperature sensor in another embodiment of the present invention; Figure 12 is a schematic diagram of another embodiment of the present invention, in which there is a spaced cavity between the mounting base and the mounting groove of the fluid pipeline; Figure 13 is a flowchart of the air pressure control method of the present invention; Figure 14 is a flowchart of a pressure control method in one embodiment of the present invention. Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] It should be understood that, when used in this specification and the claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0052] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0053] It should also be further understood that the term “and / or” as used in this application specification and the claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0054] As used in this specification and the claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0055] Furthermore, in the description of this application, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0056] Figure 1 shows a semiconductor processing device 1, which includes a vacuum reaction chamber 10. The reaction chamber 10 includes a generally cylindrical reaction chamber sidewall 101 made of a metallic material, and an opening 102 is provided on the reaction chamber sidewall 101 for accommodating the entry and exit of a wafer W.

[0057] A gas spray head 110 and an electrostatic chuck 120 are disposed opposite each other within the reaction chamber 10. The gas spray head 110 is connected to a gas supply device 111 for supplying process gas into the reaction chamber 10 and also serves as the upper electrode of the reaction chamber 10. The electrostatic chuck 120 includes a base 121 and a dielectric layer 122. After applying a DC voltage to the electrode 123 (connected to an external DC power supply 126) inside the dielectric layer 122, the dielectric layer 122 generates electrostatic attraction to fix the wafer W placed thereon. The base 121 also serves as the lower electrode of the reaction chamber 10, forming a reaction region between the upper and lower electrodes. At least one radio frequency power supply 140 is applied to one of the upper or lower electrodes, generating a radio frequency electric field between the upper and lower electrodes to dissociate the process gas into plasma. Plasma contains a large number of active particles such as electrons, ions, excited-state atoms, molecules, and free radicals. These active particles can undergo various physical and chemical reactions with the surface of the wafer W to be processed, thereby changing the morphology of the wafer surface and completing the etching process. An exhaust pump 150 is also provided below the reaction chamber 10 to discharge reaction byproducts from the reaction chamber 10 and maintain the vacuum environment of the reaction chamber 10.

[0058] The etching and deposition rates of different material layers are sensitive to temperature. Different process technologies often require different wafer temperatures, making wafer temperature one of the key parameters affecting process performance. Taking etching as an example, the wafer W is often kept at a set temperature during the process. The temperature sensitivity of the material layers is used to adjust the etch selectivity of the current material layer for the next material layer, thereby increasing the process window for etching the interface and controlling process parameters (such as critical dimension, CD). For some complex wafer W structures, different interfaces will appear, and the temperature requirements for each processing stage will also be different. For example, in the photoresist mask etching stage, a relatively low temperature is required to prevent the opening from being too large; while in the overetch stage, a high temperature is needed to increase the selectivity for the landing layer while controlling the bottom critical dimension.

[0059] Therefore, controlling the wafer surface temperature is crucial to ensuring the quality of wafer fabrication. This can be achieved by improving the heat dissipation of the back side of the wafer, thus ensuring the wafer surface temperature meets process requirements. One method is to incorporate a cooling fluid channel 124 within the substrate 121. The cooling liquid flowing within the channel 124 removes heat conducted from the wafer W to the substrate 121, thereby controlling the substrate 121 temperature and consequently the wafer W temperature. Another method involves using gas channels 125 that penetrate the substrate 121 and the dielectric layer 122 to deliver cooling gas (such as helium) between the upper surface of the dielectric layer 122 and the bottom surface of the wafer W. This utilizes convective heat transfer to regulate the wafer surface temperature. In this way, the cooling gas within the gas channels 125 acts as a heat exchange medium, and multiple gas channels 125 function as a heat pipe structure for external heat exchange.

[0060] Liquid helium is stored in a high-pressure tank 160, vaporized by a vaporizer 170 (serving as a cooling gas source), and then sent to a fluid pipe 180. From there, it is transported to the gas channel 125 inside the electrostatic chuck 120. When helium is introduced to the back side of the wafer, the pressure in the fluid pipe 180 needs to be monitored by a first pressure gauge 190 to prevent excessive pressure from the helium flowing out of the gas channel 125 from damaging the wafer W. Furthermore, since the heat transfer rate of the equivalent heat pipe is directly related to the pressure inside the gas channel 125, precise temperature control requires high accuracy in controlling the pressure within the gas channel 125.

[0061] The first type of pressure gauge 190 generally includes capacitive pressure gauges and strain gauges. While capacitive pressure gauges offer high measurement accuracy, they are expensive. Furthermore, to ensure sufficient measurement accuracy and sensitivity, small-range capacitive pressure gauges require a large pressure-sensing diaphragm (typically larger than 100 cm²), increasing their size and affecting the layout of other components in semiconductor processing equipment. Generally, strain gauges have a larger range, smaller size, and lower cost than capacitive pressure gauges. Their cost and accuracy are inversely proportional to their range and directly proportional to their size. This offers advantages for low-cost, miniaturized pressure control units, but large-range strain gauges have lower measurement accuracy in their low-pressure measurement range.

[0062] A strain gauge pressure gauge consists of a measuring circuit formed by multiple piezoresistors. The corresponding air pressure value is obtained based on the output voltage of the measuring circuit. Changes in ambient temperature will cause fluctuations in the resistance of the piezoresistors, thus affecting the accuracy of the pressure gauge measurement results. Therefore, temperature compensation is required for the measurement results.

[0063] However, when a strain gauge is in a temperature field with a large temperature gradient, it is difficult to accurately compensate for the temperature of its measurement results, especially when one end of the gauge is near a low-temperature cooling pipe and the other end is heated by circuit components. How to use the simplest measurement method, reduce costs, avoid disassembling and modifying the gauge itself to avoid reducing the stability and consistency of the gauge, and still obtain accurate compensation temperature is a problem that urgently needs to be solved.

[0064] The pressure controller of the present invention employs a large-range strain gauge, particularly a silicon resistance gauge, which significantly reduces the size and cost of the gauge. At the same time, by setting a temperature sensor 293 at a specific location, the temperature sensor 293 can obtain the temperature measurement results of different temperature contour lines of the temperature field (with a large temperature gradient) where the gauge is located, thereby significantly improving the temperature compensation accuracy and improving the measurement accuracy of the large-range strain gauge in its low-pressure measurement range with a large temperature gradient.

[0065] The pressure controller of the present invention can adjust the valve opening of the control valve upstream of the fluid pipeline 180 based on the calibration pressure value output by the computing unit and the air pressure value of the fluid pipeline required by the process, thereby adjusting the air pressure of the fluid pipeline 180, providing a safety guarantee for wafer processing, and keeping the wafer W at the set temperature during the process, thus improving the yield of wafer processing.

[0066] According to one aspect of the present invention, a pressure controller is provided, disposed on a fluid line 280 for conveying a process fluid, wherein the maximum conveying pressure of the process fluid is a first pressure. The pressure controller includes: a housing 291, a pressure gauge 290, a temperature sensor 293, a computing unit 294, a control valve 298, and a control unit 295.

[0067] The housing 291 covers the fluid pipeline 280, forming an installation space for the pressure controller. The fluid pipeline 280 has branch pipelines 281 extending toward the housing 291. The housing 291 is used to modularly encapsulate the pressure controller, thereby sealing the heat generated by the internal electrical components within the housing 291, preventing direct heat transfer to the outside of the housing 291.

[0068] The pressure gauge 290 is disposed inside the housing 291 and disposed at the end of the branch pipe 281 via the mounting base 296. The mounting base 296 has a first region 2961, which is the projection area of ​​the pressure gauge 290 on the mounting base 296. The branch pipe 281 is at least partially located within the first region 2961. The maximum range pressure of the pressure gauge 290 is a second pressure, which is at least 5 times the first pressure.

[0069] The mounting base 296 has a temperature measuring hole on its side wall, and the temperature sensor 293 is located in the temperature measuring hole and is at least partially disposed in the first region 2961. The end of the temperature sensor 293 is opposite to the branch pipe 281, and the side wall of the temperature sensor 293 is opposite to the bottom surface of the pressure gauge 290.

[0070] The calculation unit 294 is electrically connected to the pressure gauge 290 and the temperature sensor 293. The calculation unit 294 compensates for the measurement results of the pressure gauge 290 based on the measurement results of the temperature sensor 293 and outputs the calibration pressure value.

[0071] The control valve 298 is installed on the fluid line 280 and located upstream of the branch line 281.

[0072] The control unit 295 adjusts the opening of the control valve 298 based on the calibration pressure value so that the calibration pressure value remains constant for a certain period of time.

[0073] When considering that the fluid in fluid line 280 is at a low temperature, branch line 281 is in contact with the lower end of pressure gauge 290, and pressure gauge 290 is mounted on mounting base 296, which is often made of metal and has good thermal conductivity, and branch line 281 runs through mounting base 296, the low-temperature fluid in branch line 281 will cool mounting base 296, and a temperature gradient will be formed within mounting base 296 by the diffusion of fluid from branch line 281 outwards. Meanwhile, the upper end of pressure gauge 290 is located in an area with dense electrical components, and when heated, pressure gauge 290 is in a high temperature gradient environment with the upper part hot and the lower part cold. This presents a problem for temperature compensation: how to accurately reflect the true temperature that pressure gauge 290 should compensate for.

[0074] On the one hand, the contact area A between the mounting base 296 and the pressure gauge 290 has a significant impact on the temperature of the pressure gauge 290, and therefore also significantly affects the temperature of the environment surrounding the pressure-sensitive resistor inside the pressure gauge 290. On the other hand, the pressure-sensitive resistor is located inside the pressure gauge 290 on the side close to the fluid pipeline 280. We denote the outer surface of the pressure gauge 290 closest to the pressure-sensitive resistor as the pressure gauge temperature-measuring outer surface 2901. The temperature of the pressure gauge temperature-measuring outer surface 2901 also has a significant impact on the temperature of the environment surrounding the pressure-sensitive resistor. Therefore, we compensate the pressure value measured by the pressure gauge 290 based on the temperature measurement results of the contact area A and the pressure gauge temperature-measuring outer surface 2901 (calculated based on the output voltage U0 of the Wheatstone bridge, which is existing technology and will not be elaborated here).

[0075] However, it is inconvenient to arrange the temperature sensing element between the mounting base 296 and the pressure gauge 290, so the temperature of the contact area A cannot be directly measured. On the branch pipe 281 in the first area 2961, we found a first temperature sensing area B (opposite to the end of the temperature sensor 293) that is at the same temperature contour as the contact area A. Therefore, the temperature of the contact area A can be obtained by measuring the temperature of the first temperature sensing area B.

[0076] The study found that temperature changes in the first temperature measurement area B cause small fluctuations in the output voltage U0, while temperature changes in the outer surface 2901 of the pressure gauge cause larger fluctuations in the output voltage U0. To improve measurement accuracy, the temperature sensor 293 is at least partially located within the first area 2961, with the end of the temperature sensor 293 facing the branch pipe 281 and the sidewall of the temperature sensor 293 facing the bottom surface of the pressure gauge 290. This allows the sensor to collect not only the temperature of the outer surface 2901 of the pressure gauge but also the temperature of the first temperature measurement area B, forming a comprehensive temperature measurement result Tc.

[0077] In one embodiment, it was found that the temperature of the pressure gauge's outer surface 2901 correlated more strongly with the output voltage U0. Therefore, the end of the temperature sensor 293 and the branch pipe 281 are at a first distance, and the temperature sensor 293 and the pressure gauge 290 are at a second distance, making the first distance greater than the second distance. This results in a more accurate overall temperature measurement result Tc, further improving the accuracy of the gas pressure measurement in the fluid pipe 280 and ensuring the safety of wafer processing.

[0078] Specifically, in one embodiment, as shown in Figures 2 and 3, the pressure controller of the present invention is disposed on a fluid line 280 (having a relatively thick wall). In this embodiment, the fluid line 280 is used to deliver a process fluid (e.g., helium gas at a low temperature) to the gas channel within the electrostatic chuck, and the maximum delivery pressure of this process fluid is a first pressure. As shown in Figures 2, 3, and 4, the pressure controller of the present invention includes: a housing 291, a pressure gauge 290, a temperature sensor 293, a computing unit 294, a control valve 298, a control unit 295, a flow sensor 299, and a communication module 220.

[0079] As shown in Figures 2 and 3, the housing 291 covers the fluid pipeline 280, and the fluid pipeline 280 has branch pipelines 281 extending toward the housing 291. In this invention, the housing 291, fluid pipeline 280, and branch pipelines 281 are all made of metal and have good thermal conductivity. In a preferred embodiment, the outer surface of the housing 291 is also coated with a thermal insulation material.

[0080] As shown in Figures 2 and 3, a mounting groove is formed on the surface of the fluid pipeline 280, and a mounting base 296 is fixedly installed in the mounting groove. The pressure gauge 290 is disposed within the housing 291 and is mounted at the end of the branch pipeline 281 via the mounting base 296. The mounting base 296 is recessed into the wall of the fluid pipeline 280. Since the mounting base 296 is less exposed to the environment above the fluid pipeline 280, this helps to reduce the temperature gradient of the mounting base 296. Simultaneously, because the mounting base 296 is recessed into the wall of the fluid pipeline 280, the pressure gauge 290 is closer to the fluid pipeline 280, making the branch pipeline 281 shorter, reducing pressure loss in the branch pipeline 281, and making the pressure gauge reading closer to the actual pressure value of the portion of the fluid pipeline 280 connected in parallel with the branch pipeline 281.

[0081] The maximum range pressure of pressure gauge 290 is the second pressure, which is at least 5 times the first pressure. For example, if the first pressure is less than 50 torr, the second pressure is greater than 250 torr; or if the first pressure is less than 30 torr, the second pressure is greater than 150 torr, etc. Obviously, the first pressure falls within the low-pressure measurement range of pressure gauge 290, which allows for the use of smaller and lower-cost pressure gauges, but also presents challenges in terms of measurement accuracy.

[0082] Because the fluid pipeline 280, the mounting seat 296, and the housing 291 are all made of metal materials with good thermal conductivity, there is heat transfer between the fluid pipeline 280 and the mounting seat 296 and the housing 291. Let T1, T2, and T3 represent the temperatures of the fluid pipeline 280, the mounting seat 296, and the housing 291 respectively, where T1 < T2 < T3. It is easy to understand that the pressure gauge 290 is in a temperature field with a large temperature gradient.

[0083] As shown in Figure 3, in this embodiment, a stepped hole is provided on one side of the mounting seat 296 facing the housing 291. The outer surface of the pressure gauge 290 is provided with a protruding flange 2902. The pressure gauge 290 is partially embedded in the stepped hole, and the stepped hole provides support for the flange 2902. To further fix the pressure gauge 290 and prevent it from loosening, the hole wall of the stepped hole fits the pressure gauge 290 (it can also be understood that the mounting seat 296 surrounds the part of the pressure gauge 290 located in the stepped hole). Heat transfer occurs between the pressure gauge 290 and the mounting seat 296, causing heat loss of the pressure gauge 290 and further making the temperature of the pressure gauge 290 uneven.

[0084] As shown in Figure 3, a temperature measuring hole is provided on the side wall of the mounting seat 296, and the temperature sensor 293 is located in the temperature measuring hole. By arranging the temperature sensor 293 at least partially in the first region 2961, the end of the temperature sensor 293 has a first distance from the branch pipeline 281, and the temperature sensor 293 has a second distance from the pressure gauge 290, and the first distance is greater than the second distance. It is possible to measure the temperature at the bottom of the pressure gauge 290 while relatively obtaining the temperature at the end of the branch pipeline 281. That is, the measured value of the temperature sensor 293 is obtained by the combined action of the bottom of the pressure gauge 290 and the end of the branch pipeline 281. Thus, compared with measuring the temperature of the pressure gauge 290 alone, the temperature compensation of the cold end, that is, the end of the branch pipeline 281, is increased, and the obtained temperature is closer to the compensation temperature corresponding to the pressure gauge 290. The accuracy of the compensated pressure value of the pressure gauge 290 is improved. Thus, to a certain extent, the problem of serious temperature drift in the low range caused by using a pressure gauge with a large range more than 5 times the working pressure for the pressure gauge 290 can be overcome, and thus the compensated pressure gauge 290 can be applicable to the precise measurement and control of fluid pressure with a small working pressure.

[0085] In one embodiment, as shown in Figures 5, 6, and 7, the interior of the pressure gauge 290 is provided with: four piezoresistors (denoted as R1, R2, R3, and R4 respectively, only piezoresistors R2 and R4 are shown in Figures 4 and 5), an insulating layer 2903, a pressure-sensing film layer 2904, and a rigid substrate 2905.

[0086] The pressure-sensitive membrane layer 2904 is arched and disposed on the substrate 2905. Figure 5 shows the state of the pressure-sensitive membrane layer 2904 when no external force is applied. The helium gas flowing out from the branch pipe 281 has a certain pressure. Under the action of this pressure, as shown in Figure 6, the pressure-sensitive membrane layer 2904 undergoes corresponding deformation. In this embodiment, to improve the sensitivity of the deformation of the pressure-sensitive membrane layer 2904, a vacuum arched cavity 2906 is formed between the pressure-sensitive membrane layer 2904 and the substrate 2905.

[0087] In this invention, the distance between any two points on the pressure-sensitive diaphragm 2904 is no greater than 2cm. Therefore, the area of ​​the pressure-sensitive diaphragm 2904 used in the pressure gauge 290 of this invention is small, which greatly reduces the volume of the pressure gauge 290 and thus realizes the miniaturization design of the pressure gauge 290.

[0088] As shown in Figures 5 and 6, the insulating layer 2903 is disposed on the pressure-sensitive film layer 2904 and conforms to the shape of the pressure-sensitive film layer 2904. As shown in Figures 7 and 8, four varistors are disposed on the insulating layer 2903 and form a Wheatstone bridge, which is powered by a constant current power supply.

[0089] As shown in Figure 7, piezoresistors R2 and R4 are located in the positive strain region of the pressure-sensitive membrane layer 2904, while piezoresistors R1 and R3 are located in the negative strain region. When the pressure-sensitive membrane layer 2904 is subjected to force and deforms, piezoresistors R2 and R4 experience outward tensile force and thus positive strain, increasing their resistance; piezoresistors R1 and R3 experience inward compressive force and thus negative strain, decreasing their resistance. Therefore, the greater the pressure on the pressure-sensitive membrane layer 2904, the greater its deformation, and the greater the output voltage U0 of the Wheatstone bridge. Theoretically, the gas pressure in the fluid pipeline 280 can be calculated based on this output voltage U0 (this is existing technology and will not be elaborated here).

[0090] However, the resistance of the varistor changes with the ambient temperature, causing a mismatch between the output voltage U0 of the Wheatstone bridge and the pressure applied to the pressure-sensitive diaphragm 2904. Since the varistor is sealed within the pressure gauge 290, it is inconvenient to place the temperature sensor 293 inside the pressure gauge 290 to directly measure the temperature of the varistor. Otherwise, if the temperature sensor 293 needs to be replaced, the entire pressure gauge 290 must be replaced, which is too costly. We hope to obtain the temperature of the environment surrounding the varistor (located inside the pressure gauge 290) by measuring the temperature of the pressure gauge surface or the external environment, and then perform temperature compensation on the output of the pressure gauge 290.

[0091] Because heat transfer occurs between the pressure gauge 290 and the mounting base 296, the contact area A between the mounting base 296 and the pressure gauge 290 significantly affects the temperature of the pressure gauge 290, and consequently, the temperature of the environment surrounding the varistor inside the pressure gauge 290. On the other hand, the varistor is located inside the pressure gauge 290 on the side closest to the fluid conduit 280. We denote the outer surface of the pressure gauge 290 closest to the varistor as the pressure gauge temperature-sensing outer surface 2901. The temperature of the pressure gauge temperature-sensing outer surface 2901 also significantly affects the temperature of the environment surrounding the varistor. Therefore, we aim to obtain a comprehensive temperature measurement result Tc by simultaneously measuring the temperature of this contact area A and the temperature of the pressure gauge temperature-sensing outer surface 2901, and use Tc to compensate for the output of the pressure gauge 290.

[0092] Since the first temperature measuring area B on the branch pipe 281 and the contact area A are on the same temperature contour line (as shown by the dashed arc in Figure 3), this invention obtains the temperature of the contact area A by measuring the temperature of the first temperature measuring area B at the end of the temperature sensor 293, thus solving the problem that the temperature of the contact area A is inconvenient to collect. It also facilitates the layout of the temperature sensor 293, pressure gauge 290, and branch pipe 281, making the internal structure of the mounting base 296 compact and greatly reducing its volume, thereby achieving a miniaturized design of the mounting base 296.

[0093] As shown in Figure 3, the end of the temperature sensor 293 has a first distance (in the X-axis direction of Figure 3) from the first temperature measurement area B, and the side of the temperature sensor 293 has a second distance (in the Y-axis direction of Figure 3) from the outer surface 2901 of the pressure gauge. Research shows that temperature changes in the first temperature measurement area B cause a small fluctuation in the output voltage U0, while temperature changes in the outer surface 2901 of the pressure gauge cause a larger fluctuation in the output voltage U0. Therefore, the first distance is greater than the second distance, resulting in a more accurate comprehensive temperature measurement result Tc, further improving the measurement accuracy of the gas pressure in the fluid pipeline 280 and ensuring the safety of wafer processing. As shown in Figure 4, the control unit 295 includes a signal processing module 2951 and an A / D conversion module 2952. The signal processing module 2951 is electrically connected to the output terminal of the Wheatstone bridge, amplifying and filtering the voltage signal output by the Wheatstone bridge. The A / D conversion module 2952 converts the amplified and filtered voltage signal into a corresponding digital signal.

[0094] The calculation unit 294 is also signal-connected to the A / D conversion module 2952. Based on the aforementioned digital signals, the calculation unit 294 calculates and generates the corresponding air pressure value P0 (this is prior art and will not be described in detail here). The calculation unit 294 also compensates for the air pressure value P0 based on the calibration temperature value Tc, and finally obtains the calibration pressure value P1.

[0095] In this embodiment, Where Tj is the set reference temperature value, and p is the compensation coefficient.

[0096] As shown in Figure 2, the control valve 298 is installed on the fluid line 280 and located upstream of the branch line 281. As shown in Figures 2 and 4, the control valve 298 is connected to the control unit 295 via wireless or wired signals. The control unit 295 is also electrically connected to the computing unit 294 (either wired or wireless). Based on the calibration pressure value P1 generated by the computing unit 294 and the required fluid line pressure value, a drive signal is generated. This drive signal is used to adjust the opening of the control valve 298, thereby controlling the flow rate of helium gas supplied to the back side of the wafer. This ensures that the wafer W is maintained at the set temperature during the process, improving the wafer processing yield. In this invention, the control unit 295 uses a proportional-integral-derivative adjustment method to adjust the valve opening of the control valve 298.

[0097] As shown in Figures 2 and 4, the flow sensor 299 is electrically connected to the control unit 295 (either wired or wireless connection is acceptable). The flow sensor 299 measures the air flow rate in the fluid line 280 and provides the measurement result to the control unit 295. The measurement result from the flow sensor 299 can be used to monitor whether the pressure gauge 290 is malfunctioning. For example, if the calibration pressure value output by the calculation unit 294 is low, while the air flow rate measured by the flow sensor 299 is high, the pressure gauge 290 is generally considered to be malfunctioning.

[0098] As shown in Figures 2 and 4, the communication module 220 is connected between the control unit 295 and the host computer 230 to realize wired / wireless data transmission between the control unit 295 and the host computer 230.

[0099] In one embodiment, the temperature sensor 293, which simultaneously measures the contact area A and the first temperature measuring area B, can be split into two separate temperature sensors to measure the contact area A and the first temperature measuring area B separately.

[0100] In another embodiment, the temperature sensor 293 may also have a first temperature probe 2931 and a second temperature probe 2932. As shown in FIG9, the first temperature probe 2931 is opposite to the first temperature measuring area B on the branch pipe 281, and the temperature value Ta of the first temperature measuring area B is collected through the first temperature probe 2931. The second temperature probe 2932 is opposite to the outer surface 2901 of the pressure gauge, and the temperature value Tb of the outer surface 2901 of the pressure gauge is collected through the second temperature probe 2932. In this invention, by collecting the temperature values ​​Ta and Tb respectively, the weighted processing of the temperature signals is facilitated, making the obtained calibration temperature value Tc' more accurate.

[0101] To improve measurement accuracy, the first temperature probe 2931 is positioned at a first distance (in the X-axis direction of Figure 9) from the first temperature measurement area B, and the second temperature probe 2932 is positioned at a second distance (in the Y-axis direction of Figure 9) from the outer surface 2901 of the pressure gauge. Since the temperature of the outer surface 2901 of the pressure gauge has a stronger correlation with the output voltage U0, the first distance is made greater than the second distance, resulting in a more accurate calibration temperature value Tc'. This further improves the measurement accuracy of the gas pressure in the fluid pipeline 280 and ensures the safety of wafer processing.

[0102] The calculation unit 294 is connected to the first temperature probe 2931 and the second temperature probe 2932. Based on the temperature values ​​Ta and Tb measured by the first temperature probe 2931 and the second temperature probe 2932, the calibration temperature value is calculated. Where α and β are the weighting coefficients for temperature values ​​Ta and Tb, respectively. Then, the calculation unit 294 compensates for the air pressure value P0 measured by the pressure gauge 290 based on the calibration temperature value Tc', to obtain the calibration pressure value. .

[0103] According to another aspect of the present invention, a pressure controller is provided, as shown in FIG10. In this embodiment, the pressure controller further includes a heating unit 2907. The heating unit 2907 surrounds the pressure gauge 290.

[0104] The control unit 295 controls the heating power of the heating unit 2907 based on the comprehensive temperature measurement result Tc (or the calibration temperature value Tc'), so that the absolute value of the difference between Tc and the preset temperature value (i.e., the aforementioned reference temperature value Tj) is less than the set temperature difference threshold (at this time). In a straightforward manner, by heating the pressure gauge 290 through the heating unit 2907, the overall temperature measurement result Tc is equal to the reference temperature value Tj, thus eliminating the need for temperature compensation calculation for the air pressure value P0; or it can reduce temperature fluctuations to a smaller range, making temperature compensation more accurate.

[0105] As shown in Figure 10, in this embodiment, a heat insulation layer 2908 is provided outside the heating unit 2907. The portion of the heat insulation layer 2908 near the fluid conduit 280 has a first thickness, and the portion away from the fluid conduit 280 has a second thickness, with the first thickness being greater than the second thickness. The thicker the heat insulation layer 2908, the less heat loss is transferred from the heating unit 2907 to the housing 291, resulting in a better heating effect on the pressure gauge 290. Compared to the portion of the pressure gauge 290 away from the fluid conduit 280, the portion near the fluid conduit 280 has a lower temperature and therefore requires more heat to heat. The variation in the thickness of the heat insulation layer 2908 helps to reduce the temperature gradient of the pressure gauge 290 and improves the accuracy of the calibrated pressure value.

[0106] At the same time, it should be emphasized that the temperature control of wafer W is quite sensitive to the temperature of the cooling gas in the gas channel. The heating unit 2907 will inevitably release heat to the end of the fluid pipe 280 near the gas channel, which will disrupt the temperature control system's control of the temperature of the cooling gas in the gas channel and is not conducive to wafer temperature control.

[0107] Therefore, the portion of the insulation layer 2908 near the fluid conduit 280 has a first thickness, and the portion of the insulation layer 2908 away from the fluid conduit 280 has a second thickness, with the first thickness being greater than the second thickness. This effectively prevents the heating unit 2907 from heating the fluid conduit 280 and simultaneously reduces the temperature gradient of the pressure gauge 290, providing a dual effect.

[0108] As the process changes, the required air pressure in the fluid pipeline will also change, thus altering the temperature field around the pressure gauge 290. This will cause a change in the correlation between the temperature of the first temperature measurement area B and the output voltage U0. In another embodiment, as shown in FIG11, a drive device 2934 can also be installed in the temperature measurement hole on the side wall of the mounting base. The drive device 2934 drives the temperature sensor 293 to move towards and away from the branch pipeline 281 based on the command signal of the control unit 295. By adjusting the magnitude of the first distance, the correlation between the temperature of the first temperature measurement area B and the output voltage U0 can be adjusted.

[0109] In another embodiment, as shown in FIG12, a spacer cavity 282 is provided between the mounting base 296 and the mounting groove of the fluid pipeline 280. The spacer cavity 282 can be supported by a spacer boss (not shown) in the mounting groove. The spacer boss can be provided on the mounting groove, on the mounting base 296, or as a separate heat insulation component. An air cushion layer is formed by the spacer cavity 282 to separate the mounting base 296 from the mounting groove, so that the two do not come into contact. Thus, the air cushion layer can play a heat insulation role, inhibiting heat transfer between the pipe wall of the fluid pipeline 280 and the mounting base 296, so as to avoid the mounting base 296 being overcooled by the low temperature pipe wall of the fluid pipeline 280.

[0110] In one embodiment, the upper end face of the spacer cavity 282 is sealed by a seal 283, and the spacer cavity 282 is in a vacuum environment. This can further reduce heat transfer between the mounting base 296 and the fluid line 280, reduce the temperature gradient of the mounting base 296, and thus reduce the temperature gradient of the pressure gauge 290.

[0111] In one embodiment, the lower portion of the heating unit 2907 is located within the spaced cavity 282. The heating unit 2907 surrounds the entire mounting base 296 and pressure gauge 290, providing overall heating to both. By controlling the heating power of the heating unit 2907, the comprehensive measurement result Tc of the temperature sensor 293 reaches the reference temperature value Tj, eliminating the need for temperature compensation calculations for the air pressure value P0. Since both the mounting base 296 and the pressure gauge 290 are heated simultaneously, the temperature difference between them is further reduced, thus decreasing the temperature gradient of the environment surrounding the pressure gauge 290 and making temperature compensation more accurate.

[0112] In one embodiment, the heating unit 2907 does not contact the mounting slot. This avoids heat exchange between the heating unit 2907 and the mounting slot, preventing the mounting slot from negatively impacting the heating efficiency of the heating unit 2907 and the heating effect of the heating unit 2907 on the mounting slot. Since the fluid in the fluid line 280 is relatively sensitive to temperature, directly affecting the downstream wafer temperature control, keeping the heating unit 2907 separate from the mounting slot reduces the impact of the heating unit 2907 on the fluid temperature in the fluid line 280, ensuring the stability and consistency of the wafer temperature control.

[0113] In one embodiment, a heat insulation layer 2908 is further provided on the exterior of the heating unit 2907. This further enhances the heat insulation between the heating unit 2907 and the mounting groove, improves the temperature control efficiency of the heating unit 2907 for the pressure gauge 290, and reduces the impact on the fluid temperature in the fluid pipeline 280, ensuring the stability and consistency of wafer temperature control. Preferably, the heat insulation layer 2908 does not contact the mounting groove to further improve the heat insulation effect.

[0114] In summary, the pressure controller of the present invention can overcome the influence of complex ambient temperature on the measurement results of the large-range pressure gauge 290, and compensate for the measurement results of the pressure gauge 290 by using the measurement results of the temperature sensor 293, which significantly improves the measurement accuracy of the large-range strain gauge in its low-pressure measurement range (less than 1 / 5 of the maximum range), and meets the actual needs of air pressure control in the fluid pipeline 280.

[0115] The present invention also provides a semiconductor processing apparatus, which can be any semiconductor processing apparatus with a chuck for fixing a wafer W, comprising: The reaction chamber is equipped with an electrostatic chuck to support and fix the wafer W to be processed. The electrostatic chuck has multiple gas channels inside, and cooling gas is supplied to the multiple gas channels through a fluid pipe 280 connected to an external cooling gas source. The multiple gas channels are connected in parallel with a branch pipe 281, so the gas pressure in the gas channels can be determined by measuring the gas pressure value of the branch pipe 281. And a pressure controller as described in this invention, which is used to control the air pressure value in the fluid line 280.

[0116] In one embodiment, when the wafer W is fixed to the electrostatic chuck, the pressure controller maintains a constant gas pressure in the gas channel.

[0117] In one embodiment, when wafer W is fixed to the electrostatic chuck, the flow sensor 299 of the pressure controller is also used to detect the fixing quality of wafer W by the electrostatic chuck. Ideally, when the electrostatic chuck adsorbs wafer W, the wafer W is completely adhered to the upper surface of the electrostatic chuck, meaning the wafer W is completely adsorbed by the electrostatic chuck, resulting in the best fixing quality. Since wafer W is completely adhered to the upper surface of the electrostatic chuck, the gas channel outlet is blocked by wafer W. When the pressure controller detects that the gas pressure in branch pipe 281 reaches a preset value, it can close the control valve 298 to prevent the cooling gas in the gas channel from conducting and maintain a constant pressure. Therefore, the cooling gas in the gas channel can act as a heat exchange medium, and the multiple gas channels are equivalent to a heat pipe structure exchanging heat with the outside. It is understood that the measurement value of the flow sensor 299 is zero at this time, meaning that the control valve 298 is not conducting.

[0118] However, in actual use, issues such as wafer W warping due to heat or the presence of particles on the contact surface between wafer W and the electrostatic chuck may occur, resulting in incomplete adhesion between wafer W and the electrostatic chuck, leading to poor fixation quality. Because wafer W is not completely adhered to the electrostatic chuck, the gas channel outlet is not completely blocked by wafer W, creating a leakage gap. This causes a drop in gas pressure within the gas channel. To maintain a constant gas pressure, the pressure controller opens control valve 298 to replenish gas into the channel. At this time, control valve 298 is open, and the flow sensor 299 reads a non-zero value. Therefore, the flow sensor 299 detects the fixation quality of the electrostatic chuck on wafer W.

[0119] The present invention also provides a pneumatic pressure control method for a semiconductor processing device as described in the present invention, as shown in FIG13, comprising the following steps:

[0120] Step S1: Based on the process within the reaction chamber, drive the temperature sensor to the designated position in the temperature measuring hole;

[0121] Step S2: The calculation unit generates the corresponding air pressure value based on the measurement results of the pressure gauge, and compensates the air pressure value based on the measurement results of the temperature sensor to obtain the calibration pressure value;

[0122] Step S3: The controller adjusts the opening degree of the control valve based on the calibration pressure value.

[0123] In one embodiment, as shown in FIG14, step S1 further includes:

[0124] Based on the process within the reaction chamber, the temperature sensor is driven to a designated position in the temperature measuring hole; the controller controls the heating power of the heating unit based on the measurement results of the temperature sensor, so that the absolute value of the difference between the temperature value measured by the temperature sensor and the preset temperature value is less than the set temperature difference threshold.

[0125] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of protection of the claims.

[0126] 1: Semiconductor processing equipment 10: Reaction Chamber 101: Reaction chamber sidewall 102: Opening W: Wafer 110: Gas spray head 111: Gas supply device 120: Electrostatic chuck 121: Base 122: Dielectric layer 123: Electrode 124: Cooling fluid passage 125: Gas Channel 126: DC power supply 140: Radio Frequency Power Supply 150: Exhaust pump 160: High-pressure tank 170: Carburetor 180: Fluid Pipeline 190, 290: Pressure gauge 220: Communication Module 230: Host computer 280: Fluid piping 281: Branch Pipeline 2901: Pressure gauge temperature measuring outer surface 2902: Flange 291: Shell 293: Temperature sensor 2931: First temperature probe 2932: Second temperature probe 294: Computing Unit 295: Control Unit 2951: Signal Processing Module 2952: A / D Conversion Module 296: Mounting bracket 2961: Area 1 298: Control valve 299: Flow sensor A: Contact area B: First temperature measurement area U0: Output voltage Ia: Current R1, R2, R3, R4: Varistors 2903: Insulation layer 2904: Pressure-sensitive membrane layer 2905: Base 2906: Arched cavity 2907: Heating Unit 2908: Insulation layer X, Y: Axis 2934: Drive unit 282: Spacer Cavity 283: Seals S1~S3: Steps

Claims

1. A pressure controller disposed on a fluid pipeline for conveying a process fluid, the process fluid having a maximum conveying pressure of a first pressure, the pressure controller comprising: a housing covering the fluid pipeline to form an installation space for the pressure controller, the fluid pipeline having a branch extending toward the housing; a pressure gauge disposed within the housing and mounted at the end of the branch, the mounting base having a first region, the first region being the projection area of ​​the pressure gauge on the mounting base, the branch at least partially located within the first region; the pressure gauge having a maximum range pressure of a second pressure, the second pressure being at least 5 times the first pressure; a temperature sensor having a temperature measuring hole on the side wall of the mounting base, the temperature sensor being located in the temperature measuring hole and at least partially disposed within the first region, the end of the temperature sensor facing the branch, the side of the temperature sensor facing the bottom surface of the pressure gauge; and a calculation unit electrically connected to the pressure gauge and the temperature sensor, for compensating the measurement result of the pressure gauge based on the measurement result of the temperature sensor to obtain a calibrated pressure value. Let P0 represent the measurement result of the pressure gauge, Tc represent the measurement result of the temperature sensor, P1 represent the calibration pressure value, Tj represent the set reference temperature value, and p represent the compensation coefficient; ; a control valve is installed on the fluid pipeline and located upstream of the branch pipeline; a control unit adjusts the opening of the control valve based on the calibration pressure value so that the calibration pressure value remains constant for a certain period of time.

2. The pressure controller as described in claim 1, wherein, It also includes a drive unit disposed within the mounting base, which drives the temperature sensor to move in a direction approaching or away from the branch pipeline based on the command signal from the control unit.

3. The pressure controller as claimed in claim 1, wherein, The pressure gauge includes a pressure-sensitive diaphragm and four pressure-sensitive resistors; the pressure-sensitive diaphragm deforms according to the air pressure in the branch pipeline; the four pressure-sensitive resistors are disposed on the pressure-sensitive diaphragm and form a Wheatstone bridge, the Wheatstone bridge outputting a voltage signal corresponding to the deformation.

4. The pressure controller as described in claim 3, wherein, Two of the four varistors are located in the positive strain region of the pressure-sensitive film layer, and the other two varistors are located in the negative strain region of the pressure-sensitive film layer.

5. The pressure controller as described in claim 3, wherein, The pressure-sensitive film layer is also provided with a conformal insulating layer; the four varistors are disposed on the insulating layer.

6. The pressure controller as claimed in claim 3, wherein, The pressure gauge also includes a rigid substrate; the pressure-sensitive diaphragm is arranged in an arch shape on the substrate.

7. The pressure controller as claimed in claim 6, wherein, A vacuum arched cavity is formed between the pressure-sensitive membrane layer and the substrate.

8. The pressure controller as claimed in claim 3, wherein, The distance between any two points on the pressure-sensitive membrane layer is no greater than 2 cm.

9. The pressure controller as claimed in claim 1, wherein, The outer surface of the shell is coated with thermal insulation material.

10. The pressure controller as claimed in any one of claims 1 to 9 further includes a heating unit disposed around the pressure gauge.

11. The pressure controller as claimed in claim 10, wherein, The heating unit is provided with a heat insulation layer.

12. The pressure controller as claimed in claim 11, wherein, The portion of the insulation layer near the fluid conduit has a first thickness, and the portion of the insulation layer away from the fluid conduit has a second thickness, wherein the first thickness is greater than the second thickness.

13. The pressure controller as claimed in claim 10, wherein, The temperature sensor includes a first temperature probe and a second temperature probe; the first temperature probe is opposite to the side wall of the branch pipe, and the second temperature probe is opposite to the bottom surface of the pressure gauge; the calculation unit calculates a calibration temperature value based on the temperature value measured by the first temperature probe and the temperature value measured by the second temperature probe; the calculation unit calculates a calibration pressure value based on the calibration temperature value.

14. The pressure controller as claimed in claim 10, wherein, The control unit controls the heating power of the heating unit based on the temperature value measured by the temperature sensor, so that the absolute value of the difference between the temperature value measured by the temperature sensor and the preset temperature value is less than the set temperature difference threshold.

15. The pressure controller as claimed in claim 3, wherein, The control unit includes: a signal processing module for amplifying and filtering the voltage signal; an A / D conversion module for converting the amplified and filtered voltage signal into a corresponding digital signal; and a calculation unit for calculating and generating a pressure value corresponding to the digital signal, and compensating the pressure value based on the temperature value measured by the temperature sensor to obtain the calibration pressure value.

16. The pressure controller as claimed in claim 1, wherein, It also includes a flow sensor located upstream of the control valve and electrically connected to the control unit.

17. The pressure controller as claimed in claim 1, wherein, It also includes a communication module, whose electrical signal connection is set between the control unit and the host computer to realize data transmission between the control unit and the host computer.

18. The pressure controller as claimed in claim 1, wherein, The end of the temperature sensor is at a first distance from the side wall of the branch pipe, and the side of the temperature sensor is at a second distance from the bottom surface of the pressure gauge. The first distance is greater than the second distance.

19. The pressure controller as described in any one of claims 1 to 9, wherein, An installation groove is provided on the wall of the fluid pipeline, and the mounting base is installed in the installation groove and is submerged in the wall of the fluid pipeline.

20. The pressure controller as claimed in claim 19, wherein, There is a spacer cavity between the mounting base and the mounting groove.

21. The pressure controller as claimed in claim 20, wherein, The upper surface of the spacer cavity is sealed, and the spacer cavity is in a vacuum environment.

22. The pressure controller as claimed in claim 20 further includes a heating unit, the heating unit being at least partially located within the spacer cavity.

23. The pressure controller as claimed in claim 22, wherein, The heating unit does not contact the mounting slot.

24. The pressure controller as claimed in claim 22, wherein, The heating unit is covered with a heat insulation layer.

25. The pressure controller as claimed in claim 24, wherein, The heat insulation layer does not contact the mounting groove.

26. A semiconductor processing apparatus, comprising: a reaction chamber, wherein an electrostatic chuck is provided inside the reaction chamber for supporting and fixing a wafer to be processed; the electrostatic chuck is provided with a plurality of gas channels, and cooling gas is supplied to the plurality of gas channels through a fluid conduit connected to an external cooling gas source; the plurality of gas channels are connected in parallel with branch conduits; a pressure controller as described in any one of claims 1 to 25; the pressure controller is used to control the gas pressure value of the gas channels.

27. The semiconductor processing apparatus as claimed in claim 26, wherein, When the wafer is fixed to the electrostatic chuck, the pressure controller maintains a constant gas pressure in the gas channel.

28. The semiconductor processing apparatus as claimed in claim 27, wherein, When the wafer is fixed to the electrostatic chuck, the flow sensor is used to detect the quality of the electrostatic chuck's fixation of the wafer.

29. A pressure control method for a semiconductor processing apparatus as claimed in any one of claims 26 to 28, the pressure control method comprising the steps of: driving a temperature sensor to a designated position in a temperature sensing orifice based on a process within a reaction chamber; a calculation unit generating a corresponding pressure value based on a pressure gauge measurement result, and compensating the pressure value based on the temperature sensor measurement result to obtain a calibration pressure value; letting P0 represent the pressure gauge measurement result, Tc represent the temperature sensor measurement result, P1 represent the calibration pressure value, Tj represent a set reference temperature value, and p represent a compensation coefficient; and a controller adjusting the opening of a control valve based on the calibration pressure value.

30. The air pressure control method as described in claim 29, wherein, Before generating the air pressure value, the process further includes: the controller controlling the heating power of the heating unit based on the measurement results of the temperature sensor, so that the absolute value of the difference between the temperature value measured by the temperature sensor and the preset temperature value is less than the set temperature difference threshold.

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