Temperature control method for asymmetric furnace body, and semiconductor process device

Abstract

Provided in the present application are a temperature control method for an asymmetric furnace body, and a semiconductor process device. For asymmetric temperature-controlled tube sections of an asymmetric furnace body, the output power of a secondary loop dense zone is calculated on the basis of the output power of a secondary loop sparse zone of each asymmetric temperature-controlled tube section and a preset coefficient corresponding to the asymmetric temperature-controlled tube section in a current process task, and heating elements in a dense heating zone of the asymmetric temperature-controlled tube section are controlled to perform heating on the basis of the output power of the secondary loop dense zone. Thus, the output power of the secondary loop dense zone of each asymmetric temperature-controlled tube section changes with the output power of the secondary loop sparse zone thereof, thereby avoiding the existing problem of mutual interference between a heating temperature field of auxiliary heating tubes in a furnace body and a heating temperature field of the furnace body, and thus improving the consistency of furnace body temperature field distribution, and meeting the device requirements of "rapid temperature rise and easy temperature control" for semiconductor process devices.

Description

Temperature control method of asymmetric furnace body and semiconductor process equipment TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor, in particular to a temperature control method of asymmetric furnace body and semiconductor process equipment. BACKGROUND

[0002] With the development of photovoltaic technology, the furnace body in the photovoltaic equipment is developing towards "large capacity and short cycle", and the furnace body warm-up time is continuously shortened. At present, the semiconductor process equipment such as photovoltaic PECVD (Plasma Enhanced Chemical Vapor Deposition) equipment usually adopts the method of increasing auxiliary heating pipes in the furnace body for heating, but the service life of the auxiliary heating pipe is short, which leads to high maintenance cost, in addition, the output power of the auxiliary heating pipe also interferes with the temperature measurement of the current temperature of the main loop of the furnace body, thereby affecting the temperature control of the furnace body, and further affecting the product quality of the photovoltaic equipment. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a temperature control method of asymmetric furnace body and semiconductor process equipment to alleviate the above problems and improve the uniformity of the temperature field distribution of the asymmetric furnace body.

[0004] In a first aspect, the embodiments of the present application provide a temperature control method of asymmetric furnace body, the asymmetric furnace body comprising a plurality of asymmetric temperature control pipe segments, each asymmetric temperature control pipe segment having a sparse heating zone and a dense heating zone; wherein the distribution density of the heating elements in the dense heating zone is greater than the distribution density of the heating elements in the sparse heating zone; the method comprising:

[0005] For any asymmetric temperature control pipe segment, the current temperature of the main loop sparse zone is obtained, the output power of the main loop sparse zone is determined according to the current temperature of the main loop sparse zone and the temperature setting value of the main loop sparse zone, and the output power of the main loop sparse zone is set to the temperature setting value of the auxiliary loop sparse zone through a cascade strategy; wherein the current temperature of the main loop sparse zone is used to represent the current temperature inside the furnace body reaction chamber in the sparse heating zone of the asymmetric temperature control pipe segment;

[0006] The current temperature of the auxiliary loop sparse zone is obtained, the output power of the auxiliary loop sparse zone is determined according to the current temperature of the auxiliary loop sparse zone and the temperature setting value of the auxiliary loop sparse zone, and the heating elements in the sparse heating zone are controlled to heat according to the output power of the auxiliary loop sparse zone; wherein the current temperature of the auxiliary loop sparse zone is used to represent the current temperature of the heating elements outside the furnace body reaction chamber in the sparse heating zone of the asymmetric temperature control pipe segment;

[0007] The preset coefficient corresponding to the current process task is determined for the asymmetric temperature control pipe section, the output power of the dense zone of the secondary loop is calculated according to the output power of the sparse zone of the secondary loop and the preset coefficient, and the heating elements in the dense heating zone of the asymmetric temperature control pipe section are controlled to heat according to the output power of the dense zone of the secondary loop.

[0008] In some embodiments, before the step of determining the output power of the sparse zone of the secondary loop according to the current temperature of the sparse zone of the secondary loop and the temperature setting value of the sparse zone of the secondary loop, the method further comprises: calibrating the current temperature of the sparse zone of the secondary loop based on a preset reference value according to a preset calibration mode, and determining the output power of the sparse zone of the secondary loop according to the calibrated current temperature of the sparse zone of the secondary loop and the temperature setting value of the sparse zone of the secondary loop; wherein the preset calibration mode comprises a manual calibration mode and an automatic calibration mode.

[0009] In some embodiments, the step of calibrating the current temperature of the sparse zone of the secondary loop based on a preset reference value comprises: calculating a difference between the preset reference value and the current temperature of the sparse zone of the secondary loop, and calibrating the current temperature of the sparse zone of the secondary loop according to the difference, so that the calibrated current temperature of the sparse zone of the secondary loop is equal to the preset reference value.

[0010] In some embodiments, after the step of calculating the difference between the preset reference value and the current temperature of the sparse zone of the secondary loop, the method further comprises: if the absolute value of the difference is greater than a preset deviation threshold, generating an alarm prompt information to prompt to check the outer couple for monitoring the current temperature of the heating element outside the furnace reaction chamber in the sparse heating zone.

[0011] In some embodiments, the asymmetric furnace body has an inner couple for monitoring the current temperature inside the furnace reaction chamber in the sparse heating zone of the asymmetric temperature control pipe section and an outer couple for monitoring the current temperature of the heating element outside the furnace reaction chamber in the sparse heating zone of the asymmetric temperature control pipe section; before the step of obtaining the current temperature of the sparse zone of the secondary loop, the method further comprises: obtaining a temperature field parameter of the asymmetric furnace body; wherein the temperature field parameter comprises at least one of the following: the inner couple temperature, the outer couple temperature and the output power of the heating element; if the difference between the temperature field parameter and the corresponding preset threshold is not greater than the preset error, it is determined that the asymmetric furnace body reaches a preset steady state condition; and when the asymmetric furnace body reaches the preset steady state condition, the current temperature of the sparse zone of the secondary loop is obtained.

[0012] In some embodiments, the preset coefficient comprises a proportional coefficient and a bias parameter, and the step of calculating the output power of the dense zone of the secondary loop according to the output power of the sparse zone of the secondary loop and the preset coefficient comprises: linearly calculating the output power of the dense zone of the secondary loop according to the output power of the sparse zone of the secondary loop, the proportional coefficient and the bias parameter.

[0013] In some embodiments, the step of linearly calculating the output power of the dense zone of the secondary loop according to the output power of the sparse zone of the secondary loop, the proportional coefficient and the bias parameter comprises:

[0014] The calculation formula of the secondary circuit dense zone output power is as follows: y=a*x+b

[0015] Wherein, y represents the secondary circuit dense zone output power, x represents the secondary circuit sparse zone output power, a represents a proportional coefficient, and b represents a bias parameter.

[0016] In some embodiments, before the step of calculating the secondary circuit dense zone output power according to the secondary circuit sparse zone output power and the preset coefficient, the method further comprises: determining a process type of a current process task performed by the asymmetric furnace body, and determining the proportional coefficient and the bias parameter in a preset coefficient set according to the process type; wherein the process type comprises one of the following: wafer loading, temperature rising, vacuum pumping, leak hunting, pressure adjusting, deposition, nitrogen filling, and wafer unloading.

[0017] In a second aspect, the embodiments of the present application further provide a semiconductor process equipment, comprising a controller and an asymmetric furnace body; wherein the controller is configured to control the temperature of the asymmetric furnace body by using the method of the first aspect.

[0018] In a third aspect, the embodiments of the present application further provide a computer readable storage medium, and the computer readable storage medium stores a computer program, and the computer program is configured to execute the steps of the method of the first aspect when run by a processor.

[0019] The embodiments of the present application bring the following beneficial effects:

[0020] The embodiment of the present application provides a temperature control method of an asymmetric furnace body and a semiconductor process equipment. For each asymmetric temperature control pipe segment of the asymmetric furnace body, first, the main loop sparse zone output power is determined according to the current temperature of the main loop sparse zone and the main loop sparse zone temperature setting value, and the main loop sparse zone output power is matched to the secondary loop sparse zone temperature setting value through a cascade strategy; then, the current temperature of the secondary loop sparse zone is obtained, the secondary loop sparse zone output power is determined according to the current temperature of the secondary loop sparse zone and the secondary loop sparse zone temperature setting value, and the heating element in the sparse heating zone is controlled to heat according to the secondary loop sparse zone output power; and the secondary loop dense zone output power is calculated according to the secondary loop sparse zone output power and a preset coefficient corresponding to a current process task of the asymmetric temperature control pipe segment, and the heating element in the dense heating zone is controlled to heat according to the secondary loop dense zone output power. The above temperature control method, for each asymmetric temperature control pipe segment, calculates the secondary loop dense zone output power of the asymmetric temperature control pipe segment according to the secondary loop sparse zone output power of the asymmetric temperature control pipe segment and a preset coefficient corresponding to a current process task of the asymmetric temperature control pipe segment, and controls the heating element in the dense heating zone of the asymmetric temperature control pipe segment to heat according to the secondary loop dense zone output power, so that the secondary loop dense zone output power of each asymmetric temperature control pipe segment follows the change of the secondary loop sparse zone output power, the problem of mutual interference between the heating of the auxiliary heating pipe of the furnace body and the heating of the furnace body is avoided, the consistency of the furnace body temperature field distribution is improved, and the equipment requirements of the semiconductor process equipment, such as fast heating and good temperature control, are met.

[0021] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and achieved by the structures particularly pointed out in the description and the appended drawings.

[0022] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are specifically described below, and the accompanying drawings are described in detail as follows. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0024] Fig. 1 is a front view of a cross section of an existing furnace body provided by the embodiment of the present application;

[0025] Fig. 2 is a temperature control principle diagram of an existing furnace body provided by the embodiment of the present application;

[0026] Fig. 3 is a front view of a cross section of an asymmetric furnace body according to an embodiment of the present application;

[0027] Fig. 4 is a flow chart of a temperature control method for an asymmetric furnace body according to an embodiment of the present application;

[0028] Fig. 5 is a temperature control topology diagram of an asymmetric furnace body of a photovoltaic PECVD device according to an embodiment of the present application;

[0029] Fig. 6 is a temperature control strategy diagram of an asymmetric furnace body according to an embodiment of the present application;

[0030] Fig. 7 is a working principle diagram of a temperature automatic calibration strategy according to an embodiment of the present application;

[0031] Fig. 8 is a side view of an asymmetric furnace body according to an embodiment of the present application;

[0032] Fig. 9 is a comparison result diagram of process inner and outer temperature and heating power trends of different asymmetric temperature control tube segments according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0034] For a conventional semiconductor process equipment such as a photovoltaic PECVD device, the structure of the furnace body is shown in Fig. 1, which includes a main heater 11, an auxiliary heater 12, a wafer carrying device 13 and a quartz tube 14. The furnace filaments of the main heater 11 are uniformly distributed, the auxiliary heater 12 is distributed in the upper and lower spaces inside the furnace body, and the wafer carrying device 13, also known as a graphite boat load, is arranged inside the furnace body. In actual application, the main heater 11 and the plurality of auxiliary heaters 12 jointly heat the graphite boat load. In addition, an inner couple 15 is arranged in the quartz tube 14 for monitoring the temperature of the furnace body, and an outer couple 16 is vertically inserted at the position of the furnace filaments of the main heater 11 outside the furnace body for monitoring the temperature of the furnace filaments. Thus, the temperature of the furnace body is controlled according to the furnace body temperature monitored by the inner couple 15 and the furnace filament temperature monitored by the outer couple 16.

[0035] Specifically, as shown in FIG. 2, the control principle of the furnace body temperature is as follows: through the cascade control of the inner loop (main loop) monitoring the temperature in the furnace body and the outer loop (secondary loop) monitoring the temperature of the heating wire, the control mode of the auxiliary heater 12 is a single loop temperature control monitoring the temperature of the auxiliary heating pipe. In the furnace body temperature control, the main loop outputs the main loop output power MOP based on the current temperature of the inner loop, i.e. the current temperature of the main loop MPV and the main loop temperature set value MSP, through PID (Proportional Integral Derivative) control; and the main loop output power MOP is then adjusted to the secondary loop temperature set value SSP through a cascade strategy, and the secondary loop outputs the power (i.e. the secondary loop output power SOP) to the furnace heating wire load based on the secondary loop temperature set value SSP and the current temperature of the secondary loop SPV (i.e. the current temperature monitored by the outer loop), so as to realize the furnace heating.

[0036] In addition, in the temperature control of the auxiliary heater, an auxiliary heating couple is arranged in the auxiliary heater to detect the current temperature of the auxiliary heating loop APV, and the auxiliary heating loop outputs the power (i.e. the auxiliary heating loop output power AOP) to the auxiliary heating wire load based on the current temperature of the auxiliary heating loop APV and the auxiliary heating loop temperature set value ASP through PID control, so as to realize the auxiliary heating wire heating.

[0037] Therefore, in the furnace body temperature control scheme of the existing photovoltaic PECVD device, the furnace body temperature control and the temperature control of the auxiliary heater are two independent temperature field controls, and the furnace body heating wire and the auxiliary heating pipe are heated at the same time in the process to realize the rapid and uniform re-warming of the silicon wafer load. However, the above-mentioned temperature control scheme has the following disadvantages: (1) lacking of temperature calibration strategy, which cannot compensate for the difference in temperature field consistency between the furnace pipes from the control mode, thereby causing inconsistent temperature control programs, inconsistent process files and inconsistent process effects between different furnace pipes of the photovoltaic device; (2) the temperature difference between the inner and outer loops of different furnace pipes is inconsistent in the steady state, and the temperature control parameters need to be adjusted separately for each pipe, which increases the difficulty and workload of temperature control in process debugging; (3) although the furnace cascade temperature control and the auxiliary heating temperature control are independent of each other, there is an interference problem, as shown in FIG. 2, the lead wire from the auxiliary heating wire to the current temperature of the main loop MPV indicates that the output of the auxiliary heating wire will interfere with the temperature measurement of the current temperature of the main loop, i.e. the auxiliary heating temperature field and the furnace body temperature field exist coupling interference, thereby affecting the temperature control of the furnace body and further affecting the product quality of the photovoltaic device.

[0038] Therefore, in order to alleviate the above at least part of the problem, the embodiments of the present application provide a temperature control method of an asymmetric furnace body and a semiconductor process equipment. For each asymmetric temperature control pipe segment, the output power of the dense area of the secondary circuit of the asymmetric temperature control pipe segment is calculated according to the output power of the sparse area of the secondary circuit of the asymmetric temperature control pipe segment and a preset coefficient corresponding to a current process task, and the heating elements in the dense heating area 301 of the asymmetric temperature control pipe segment are controlled to heat according to the output power of the dense area of the secondary circuit, so that the output power of the dense area of the secondary circuit of each asymmetric temperature control pipe segment follows the change of the output power of the sparse area of the secondary circuit, the problem of mutual interference between the heating of the auxiliary heating pipe of the furnace body and the heating of the furnace body is avoided, the consistency of the furnace body temperature field distribution is improved, and the equipment requirements of the semiconductor process equipment for "fast heating and good temperature control" are met.

[0039] In order to facilitate the understanding of the embodiments, the semiconductor process equipment provided by the embodiments of the present application will be introduced in detail first. The semiconductor process equipment includes a controller and an asymmetric furnace body. The controller is used to control the temperature of the asymmetric furnace body by using the temperature control method of the asymmetric furnace body described below, so as to adjust the temperature distribution in the asymmetric furnace body to a preset temperature distribution (such as uniform distribution). The semiconductor process equipment can not only adapt to various temperature requirements, but also does not need to add auxiliary heaters and other equipment and stop to replace the heating elements, thereby reducing energy consumption and equipment cost and improving the production efficiency of the semiconductor process equipment.

[0040] The asymmetric furnace body is designed in multiple segments and can be formed by splicing at least one cylindrical heating block. That is, the asymmetric furnace body includes multiple asymmetric temperature control pipe segments. Each asymmetric temperature control pipe segment has a sparse heating area 302 and a dense heating area 301. Therefore, the asymmetric furnace body includes multiple sparse heating areas 302 and multiple dense heating areas 301. The multiple sparse heating areas 302 are connected in series, and the multiple dense heating areas 301 are connected in series. The distribution density and / or resistance of the heating elements in the sparse heating area 302 and the dense heating area 301 are different. The distribution density of the heating elements in the dense heating area 301 is greater than that in the sparse heating area 302. The sparse heating area 302 and the dense heating area 301 are independently powered. It should be noted that the heating elements in the dense heating area 301 and the sparse heating area 302 are preferably heating wires.

[0041] As shown in FIG. 3, in the asymmetric furnace body, a dense heating zone 301, a sparse heating zone 302, a heating wire 303, a heating wire outgoing line 304, and a graphite boat 50 disposed in the main heating block are included. The dense heating zone 301 is located on the upper and lower sides in FIG. 3, and the sparse heating zone 302 is located on the left and right sides in FIG. 3, in other words, in the embodiment shown in FIG. 3, a plurality of dense heating zones 301 and a plurality of sparse heating zones 302 are alternately disposed in the circumferential direction of the furnace body, in addition, a plurality of silicon wafers 501 are disposed on the graphite boat 50, a refractory material 305 is disposed outside the heating wire 303, and the sparse heating zone 302 and the dense heating zone 301 of each asymmetric temperature control tube segment are separately led out of the outgoing line when the heating wire 303 is arranged in a wire winding manner, that is, the heating wire in the upper dense heating zone 301 is a single outgoing line, the heating wire in the lower dense heating zone 301 is a single outgoing line, the heating wire in the left sparse heating zone 302 is a single outgoing line, and the heating wire in the right sparse heating zone 302 is a single outgoing line.

[0042] In actual application, the sparse heating zone 302 located on the left and right sides in FIG. 3 is closer to the silicon wafer 501, and the radiation surface has a larger radiation heat transfer angle coefficient to the silicon wafer 501, therefore, the sparse heating zone 302 has a lower radiation heat but a higher heat transfer efficiency; the dense heating zone 301 located on the upper and lower sides in FIG. 3 is farther from the silicon wafer 501, and the radiation surface has a smaller radiation heat transfer angle coefficient to the silicon wafer 501, therefore, the dense heating zone 301 has a higher radiation heat but a lower heat transfer efficiency. Taking the graphite boat 50 as an example, considering the rectangular structure of the graphite boat 50, the height in the up-down direction is smaller than the width in the left-right direction, when heated in a circularly symmetric heating furnace, there is a temperature difference between the middle and the two sides of the graphite boat 50, for the asymmetric heating furnace, each asymmetric temperature control tube segment includes a sparse heating zone 302 and a dense heating zone 301 in the circumferential direction, the distribution density and / or resistance of the heating elements of the sparse heating zone 302 and the dense heating zone 301 are different, and the sparse heating zone 302 and the dense heating zone 301 are independently powered and controlled. The sparse heating zone 302 and the dense heating zone 301 radiate different amounts of heat under the same length and power supply conditions, and ultimately generate a relatively uniform heat field inside the graphite boat 50, and the temperature of the middle silicon wafer and the temperature of the silicon wafer on both sides tend to be consistent.

[0043] It should be noted that, according to actual control needs, the heating block (i.e., the asymmetric temperature control tube segment) can be divided into two heating zones, four heating zones, or more heating zones. The heating wire 303 can be led out to the outside of the refractory material 305 and connected to the terminal. To ensure the safety and reliability of the heating wire 303 when it is connected and led out across the sparse and dense heating zones, the heating wire 303 is sleeved with an insulating ceramic tube when it is connected across the zones, and is solidified in the refractory material 305 through a wet forming technology.

[0044] In addition, the asymmetric furnace body further comprises a plurality of uniform heating zones, such as the heating blocks arranged at the furnace mouth or the furnace tail, which can comprise a plurality of uniform heating zones, the distribution density or resistance of the heating elements in each uniform heating zone is the same, and each uniform heating zone is independently powered and controlled. The embodiments of the present application mainly describe the control of the plurality of sparse heating zones 302 and the plurality of dense heating zones 301 of the plurality of asymmetric temperature control pipe sections in the asymmetric furnace body, so that the temperature distribution in the asymmetric furnace body reaches uniform distribution. For the control of the uniform heating zone, reference can be made to the prior art, and the embodiments of the present application will not be described in detail here.

[0045] Therefore, in actual application, by controlling the heating power of the sparse heating zone 302 and the dense heating zone 301 of each asymmetric temperature control pipe section, the temperature distribution in the asymmetric furnace body can be adjusted to a preset temperature distribution (such as uniform distribution), so that various different temperature requirements can be adapted, without adding auxiliary heaters and other equipment and stopping for replacement of heating elements, thereby reducing energy consumption and equipment cost and improving the production efficiency of the semiconductor process equipment.

[0046] Embodiment one

[0047] Based on the above asymmetric furnace body, the embodiments of the present application provide a temperature control method of an asymmetric furnace body; as shown in FIG. 4, the method comprises the following steps:

[0048] In step S402, for any asymmetric temperature control pipe section, the current temperature of the main loop sparse zone is obtained, the output power of the main loop sparse zone is determined according to the current temperature of the main loop sparse zone and the temperature setting value of the main loop sparse zone, and the output power of the main loop sparse zone is adjusted to the temperature setting value of the auxiliary loop sparse zone through a cascade strategy.

[0049] The current temperature of the main loop sparse zone is used to represent the current temperature of the inside of the furnace reaction cavity monitored by the inner pair in the sparse heating zone 302 of the asymmetric temperature control pipe section. For each asymmetric temperature control pipe section, as shown in FIG. 3, the actual temperature of the corresponding area of the sparse heating zone 302 is monitored, and the actual temperature is taken as the current temperature of the main loop sparse zone of the asymmetric temperature control pipe section, so that the actual heating condition of the sparse heating zone 302 of the asymmetric temperature control pipe section is reflected through the current temperature of the main loop sparse zone of the asymmetric temperature control pipe section. It should be noted that, for the sake of convenience, the embodiments of the present application take any asymmetric temperature control pipe section as an example, and the remaining asymmetric temperature control pipe sections can refer to the asymmetric temperature control pipe section, and the embodiments of the present application will not be described in detail here.

[0050] After the controller obtains the current temperature of the main loop sparse zone, the current temperature of the main loop sparse zone and the preset main loop sparse zone temperature setting value are calculated, such as PID calculation, to obtain the main loop sparse zone output power, and the main loop sparse zone output power is matched to the secondary loop sparse zone temperature setting value through a cascade strategy. It should be noted that the cascade strategy can match the main loop sparse zone output power to the secondary loop sparse zone temperature setting value through the existing cascade temperature control formula, and the embodiments of the present application will not be described in detail here.

[0051] In step S404, the current temperature of the secondary loop sparse zone is obtained, the secondary loop sparse zone output power is determined according to the current temperature of the secondary loop sparse zone and the secondary loop sparse zone temperature setting value, and the heating element in the sparse heating zone 302 is controlled to heat according to the secondary loop sparse zone output power.

[0052] For the asymmetric temperature control pipe section, after the controller matches the above-mentioned main loop sparse zone output power to the secondary loop sparse zone temperature setting value through the cascade strategy, the current temperature of the secondary loop sparse zone of the asymmetric temperature control pipe section is also obtained, and the secondary loop sparse zone output power is determined according to the current temperature of the secondary loop sparse zone and the secondary loop sparse zone temperature setting value, such as PID determination of the secondary loop sparse zone output power, and the heating element in the sparse heating zone 302 of the asymmetric temperature control pipe section is controlled to heat according to the secondary loop sparse zone output power, thereby realizing the heating of the reaction cavity inside the asymmetric furnace body.

[0053] The current temperature of the secondary loop sparse zone is used to represent the current temperature of the heating element outside the furnace body reaction cavity monitored by the outer coupling in the sparse heating zone 302 of the asymmetric temperature control pipe section, as shown in FIG. 3, the outer coupling is used to monitor the current temperature of the heating element (such as a heating wire) in the sparse heating zone 302, and the current temperature of the heating element is called the current temperature of the secondary loop sparse zone, so as to react to the actual heating of the heating element according to the current temperature. Therefore, by monitoring the current temperature of the secondary loop sparse zone of each asymmetric temperature control pipe section of the asymmetric furnace body, the actual heating of the heating element in the sparse heating zone 302 of each asymmetric temperature control pipe section can be easily grasped.

[0054] In step S406, the preset coefficient of the asymmetric temperature control pipe section corresponding to the current process task is determined, the secondary loop dense zone output power is calculated according to the secondary loop sparse zone output power and the preset coefficient, and the heating element in the dense heating zone 301 of the asymmetric temperature control pipe section is controlled to heat according to the secondary loop dense zone output power.

[0055] After determining the output power of the sparse area of ​​the secondary loop of the asymmetric temperature control tube segment, the controller also determines the preset coefficient corresponding to the current process task of the asymmetric temperature control tube segment, and calculates the output power of the dense area of ​​the secondary loop based on the output power of the sparse area of ​​the secondary loop and the preset coefficient. Thus, through the dense area branch output strategy, not only is the power of the dense heating area 301 adjusted to follow the change of the sparse heating area 302, but the preset coefficient also corresponds not only to the asymmetric temperature control tube segment, but also to the current process task of the asymmetric temperature control tube segment, ensuring the control accuracy of the power of the dense heating area 301; it also ensures that the power of the dense heating area 301 of each asymmetric temperature control tube segment only follows the change of its sparse heating area 302, avoiding mutual interference between multiple asymmetric temperature control tube segments, avoiding the problem of mutual interference between the auxiliary heating tube heating and the furnace body heating temperature field in existing furnace bodies, thereby improving the consistency of the furnace body temperature field distribution and meeting the equipment requirements of "fast heating and good temperature control" for semiconductor process equipment.

[0056] In one embodiment, before determining the output power of the secondary circuit shunting zone based on the current temperature of the secondary circuit shunting zone and the set value of the secondary circuit shunting zone temperature, the method further includes: calibrating the current temperature of the secondary circuit shunting zone based on a preset reference value according to a preset calibration method, and determining the output power of the secondary circuit shunting zone based on the calibrated current temperature of the secondary circuit shunting zone and the set value of the secondary circuit shunting zone temperature; wherein, the preset calibration method includes a manual calibration method and an automatic calibration method.

[0057] In practical applications, for any asymmetric temperature control tube segment, the current temperature of the main circuit sparse zone monitored by the internal coupler in the sparse heating zone 302 is used as the current temperature inside the reaction chamber of the reactor body, that is, the actual temperature ultimately transmitted to the inside of the reaction chamber by the heating element in the sparse heating zone 302; the current temperature of the secondary circuit sparse zone monitored by the external coupler in the sparse heating zone 302 is used as the current temperature of the heating element outside the reaction chamber of the reactor body, that is, the actual heating temperature of the heating element in the sparse heating zone 302. Due to temperature transmission, there will be a difference between the two. If the output power of the secondary circuit sparse zone is determined directly based on the current temperature of the secondary circuit sparse zone and the set value of the secondary circuit sparse zone temperature, it will lead to an error in the output power of the secondary circuit sparse zone, which in turn leads to an error in the output power of the secondary circuit dense zone determined according to the dense zone branch output strategy, thereby reducing the temperature control accuracy of the semiconductor process equipment.

[0058] Therefore, the preset reference value is used to calibrate the current temperature of the sparse area of the secondary loop, so that the current temperature of the sparse area of the secondary loop after calibration is equal to the preset reference value, the internal and external temperature difference of each asymmetric temperature control pipe segment is reduced, the internal and external temperature difference consistency of the plurality of asymmetric temperature control pipe segments is achieved, and the temperature field consistency of the plurality of asymmetric temperature control pipe segments is improved.

[0059] In addition, in the process of calibrating the current temperature of the sparse area of the secondary loop based on the preset reference value, a calibration mode, i.e., the preset calibration mode, can be set, and the current temperature of the sparse area of the secondary loop is calibrated according to the preset calibration mode. The preset calibration mode includes a manual calibration mode and an automatic calibration mode. In the manual calibration mode, an operator manually inputs the preset reference value, and calibrates the current temperature of the sparse area of the secondary loop according to the preset reference value. In the automatic calibration mode, a one-key calibration function such as a calibration button is set in the semiconductor process equipment, and the controller automatically calibrates the current temperature of the sparse area of the secondary loop according to the preset reference value in response to a trigger operation of the user on the calibration button. Therefore, in the process of calibrating the current temperature of the sparse area of the secondary loop based on the preset reference value, different preset calibration modes can be used to meet different working condition calibration scenes, and the temperature control application scene of the asymmetric furnace body is enriched.

[0060] In an embodiment, the step of calibrating the current temperature of the sparse area of the secondary loop based on the preset reference value includes calculating a difference between the preset reference value and the current temperature of the sparse area of the secondary loop, and calibrating the current temperature of the sparse area of the secondary loop according to the difference, so that the current temperature of the sparse area of the secondary loop after calibration is equal to the preset reference value.

[0061] Specifically, since the asymmetric furnace body includes a plurality of asymmetric temperature control pipe segments, the current temperature of the sparse area of the secondary loop of each asymmetric temperature control pipe segment can be the same or different, which will cause the internal and external temperature difference of the plurality of asymmetric temperature control pipe segments to be different, and affect the temperature field consistency between the plurality of asymmetric temperature control pipe segments. Therefore, the current temperature of the sparse area of the secondary loop of the plurality of asymmetric temperature control pipe segments is calibrated by the same preset reference value in the embodiment of the application, i.e., the difference between each current temperature of the sparse area of the secondary loop and the preset calibration value is calculated, and the current temperature of the sparse area of the secondary loop is calibrated according to the difference, so that the current temperature of the sparse area of the secondary loop after calibration is equal to the preset reference value, the internal and external temperature difference of each asymmetric temperature control pipe segment is reduced, the internal and external temperature difference consistency of the plurality of asymmetric temperature control pipe segments is achieved, and the temperature field consistency of the plurality of asymmetric temperature control pipe segments is improved.

[0062] It should be noted that the preset reference value can be determined according to the outer-jacket temperature history values of the plurality of asymmetric temperature control pipe sections under the same inner-jacket temperature steady state, such as taking the maximum value of the plurality of outer-jacket temperature history values as the preset reference value, or taking the average value of the plurality of outer-jacket temperature history values as the preset reference value, etc., which can be set according to actual conditions.

[0063] In an embodiment, after the step of calculating the difference between the preset reference value and the current temperature of the secondary loop sparse region, the method further comprises: if the absolute value of the difference is greater than the preset deviation threshold, generating an alarm prompt information to prompt the inspection of the outer-jacket in the sparse heating zone 302.

[0064] Specifically, for each asymmetric temperature control pipe section, after the controller calculates the difference between the preset reference value and the current temperature of the secondary loop sparse region of the asymmetric temperature control pipe section, it further judges whether the absolute value of the difference is greater than the preset deviation threshold. If not, the current temperature of the secondary loop sparse region is calibrated based on the difference, so that the calibrated current temperature of the secondary loop sparse region is equal to the preset reference value. Otherwise, if the absolute value of the difference is greater than the preset deviation threshold, the controller does not need to calibrate the current temperature of the secondary loop sparse region according to the difference, but generates an alarm prompt information to prompt the operator to inspect the outer-jacket (or the monitoring device where the outer-jacket is located) in the sparse heating zone 302 of the asymmetric temperature control pipe section, thereby ensuring the normal operation of the semiconductor process equipment.

[0065] It should be noted that the preset deviation threshold can also be referred to as a deviation limit value, and its value range is preferably 50-100°C, which can be set according to actual conditions.

[0066] In an embodiment, before the step of obtaining the current temperature of the secondary loop sparse region, the method further comprises: obtaining the temperature field parameters of the asymmetric furnace body; wherein the temperature field parameters include at least one of the following: inner-jacket temperature, outer-jacket temperature and output power of the heating element; if the difference between the temperature field parameters and the corresponding preset threshold is not greater than the preset error, it is determined that the asymmetric furnace body reaches the preset steady state condition; and when the asymmetric furnace body reaches the preset steady state condition, the current temperature of the secondary loop sparse region is obtained.

[0067] Specifically, for any asymmetric temperature control pipe section of the asymmetric furnace body, before calibrating the current temperature of the secondary loop sparse area thereof, it is also necessary to ensure that the current temperature of the secondary loop sparse area is the value of the asymmetric furnace body under the preset steady state condition. Wherein, whether the asymmetric furnace body is under the preset steady state condition is determined by the temperature field parameters, which include at least one of the following: the inner couple temperature, the outer couple temperature and the output power of the heating element. When the difference between the temperature field parameters and the corresponding preset threshold is not greater than the preset error, the difference between the inner couple temperature and the corresponding preset threshold is not greater than the preset error, the difference between the outer couple temperature and the corresponding preset threshold is not greater than the preset error, and the difference between the output power of the heating element and the corresponding preset threshold is not greater than the preset error, that is, the inner couple temperature, the outer couple temperature and the output power of the heating element all tend to be stable at the corresponding preset threshold, it is determined that the asymmetric furnace body reaches the preset steady state condition; otherwise, if the difference between at least one temperature field parameter and the corresponding preset threshold is greater than the preset error, it is determined that the asymmetric furnace body does not reach the preset steady state condition. At this time, it is still necessary to continue to determine whether the asymmetric furnace body reaches the preset steady state condition, until the asymmetric furnace body reaches the preset steady state condition, and the current temperature of the secondary loop sparse area at this time is obtained.

[0068] It should be noted that the above preset error can be the same value, or each temperature field parameter can correspond to a preset error value, which can be set according to actual conditions.

[0069] Therefore, in the temperature control of the asymmetric furnace body, the current temperature of the secondary loop sparse area of each asymmetric temperature control pipe section under the preset steady state condition is calibrated and corrected by the preset reference value, so that the current temperature of the secondary loop sparse area of each asymmetric temperature control pipe section after calibration is equal to the preset reference value, the inner and outer couple temperature difference of each asymmetric temperature control pipe section is reduced, the inner and outer couple temperature difference consistency of multiple asymmetric temperature control pipe sections is realized, and the temperature field consistency of multiple asymmetric temperature control pipe sections is improved.

[0070] In addition to the above calibration of the current temperature of the secondary loop sparse area under the preset steady state condition, in order to avoid the temperature field interference of the dense heating area 301 and the sparse heating area 302 of each asymmetric temperature control pipe section, the power of the dense heating area 301 of each asymmetric temperature control pipe section is controlled, that is, the secondary loop dense area output power is calculated according to the secondary loop sparse area output power of each asymmetric temperature control pipe section and the preset coefficient corresponding to the current process task of the asymmetric temperature control pipe section, and the heating element in the dense heating area 301 is controlled to heat according to the secondary loop dense area output power, achieving the effect that the power of the dense heating area 301 follows the change of the sparse heating area 302 and is adjustable.

[0071] The preset coefficient includes a proportional coefficient and a bias parameter. The step of calculating the output of the dense zone of the secondary circuit according to the output of the sparse zone of the secondary circuit and the preset coefficient includes: linearly calculating the output power of the dense zone of the secondary circuit according to the output power of the sparse zone of the secondary circuit, the proportional coefficient and the bias parameter.

[0072] Specifically, the calculation formula of the output power of the dense zone of the secondary circuit is as follows: y = a * x + b (1)

[0073] Wherein, y represents the output power of the dense zone of the secondary circuit, x represents the output power of the sparse zone of the secondary circuit, a represents the proportional coefficient, and b represents the bias parameter.

[0074] Therefore, through the above formula (1), the power of the dense heating zone 301 (i.e. the output power y of the dense zone of the secondary circuit) of each asymmetric temperature control pipe section can be adjusted to follow the change of the sparse heating zone 302 (i.e. the output power x of the sparse zone of the secondary circuit), and the preset coefficient not only corresponds to the asymmetric temperature control pipe section, but also corresponds to the current process task of the asymmetric temperature control pipe section, thereby ensuring the control accuracy of the power of the dense heating zone 301; thereby not only avoiding the mutual interference of the temperature fields of the dense heating zone 301 and the sparse heating zone 302, but also avoiding the mutual interference of the temperature fields of multiple asymmetric temperature control pipe sections, thereby improving the consistency of the temperature field distribution of multiple asymmetric temperature control pipe sections in the furnace body.

[0075] In an embodiment, before the step of calculating the output of the dense zone of the secondary circuit according to the output of the sparse zone of the secondary circuit and the preset coefficient, the method further includes: determining the process type of the current process task performed by the asymmetric furnace body, and determining the proportional coefficient and the bias parameter in the preset coefficient set according to the process type; wherein the process type includes one of the following: loading, heating, vacuumizing, leak detecting, pressure adjusting, depositing, nitrogen filling and unloading.

[0076] Specifically, a preset coefficient set and a preset corresponding relationship are also pre-stored in the controller; the preset coefficient set includes a plurality of preset coefficients, each preset coefficient includes a proportional coefficient and a bias parameter, and the preset corresponding relationship is used to represent the correspondence between the process type and the preset coefficient. Therefore, for the asymmetric furnace body, the controller also needs to first determine the process type of the current process task performed by the asymmetric furnace body, and then determine the proportional coefficient and the bias parameter in the preset coefficient set according to the process type, that is, according to the process type and the preset corresponding relationship, the proportional coefficient and the bias parameter corresponding to the process type are searched in the preset coefficient set, so as to calculate the dense zone output power of the secondary loop according to the sparse zone output power of the secondary loop, the searched proportional coefficient and the bias parameter. Not only the effect that the power of the dense heating zone 301 of each asymmetric temperature control pipe section can follow the change of the sparse heating zone 302 and be adjustable is realized, but also the change of the power of the dense heating zone 301 meets the process type of the current process task performed by the asymmetric furnace body at this time, thereby improving the control accuracy of the power of the dense heating zone 301 of the asymmetric temperature control pipe section, and further improving the uniformity of the temperature field distribution of the plurality of asymmetric temperature control pipe sections in the furnace body, thereby meeting the equipment requirements of the semiconductor process equipment “fast heating and good temperature control”.

[0077] In summary, the temperature control method of the asymmetric furnace body provided in the embodiments of the present application calculates the dense zone output power of the secondary loop of each asymmetric temperature control pipe section according to the sparse zone output power of the secondary loop and the preset coefficient corresponding to the current process task of the asymmetric temperature control pipe section, and controls the heating elements in the dense heating zone 301 of the asymmetric temperature control pipe section to heat according to the dense zone output power of the secondary loop until the temperature distribution in the asymmetric furnace body reaches uniform distribution, thereby realizing that the dense zone output power of the secondary loop of each asymmetric temperature control pipe section follows the change of the sparse zone output power of the secondary loop, avoiding the problem of mutual interference between the heating of the auxiliary heating pipe and the heating temperature field of the furnace body, thereby improving the uniformity of the temperature field distribution of the furnace body, and further meeting the equipment requirements of the semiconductor process equipment “fast heating and good temperature control”.

[0078] Embodiment two

[0079] On the basis of the above-mentioned method embodiments, another temperature control method of an asymmetric furnace body is also provided in the embodiments of the present application. The method focuses on the photovoltaic PECVD equipment with an asymmetric furnace body structure without auxiliary heating, and controls the temperature of the asymmetric furnace body through two control modes of temperature automatic calibration and dense zone branch output strategy, so as to improve the uniformity of the temperature field of the plurality of asymmetric temperature control pipe sections in the asymmetric furnace body, avoid the problem of mutual interference between the heating of the auxiliary heating pipe and the heating temperature field of the furnace body, and thereby meet the equipment requirements of the photovoltaic PECVD equipment “fast heating and good temperature control”.

[0080] Specifically, the asymmetric furnace body temperature control principle of the photovoltaic PECVD device is as follows: through the cascade control of the inner loop (main loop) monitoring the temperature of the corresponding region of the sparse heating zone 302 inserted into the furnace body and the outer loop (secondary loop) monitoring the temperature of the furnace wire vertically inserted into the furnace body sparse heating zone 302, the furnace body sparse heating zone 302 furnace wire temperature monitoring interface adds an automatic temperature calibration function to correct the outer loop monitoring temperature of the sparse heating zone 302 in the steady state of the furnace body, so as to improve the consistency of the temperature field between the furnace pipes; at the same time, the dense heating zone 301 heating control realizes the power following of the dense heating zone 301 to the change of the sparse heating zone 302 through the dense zone branch output strategy, which avoids the mutual interference problem of the existing furnace body auxiliary heating pipe heating and the furnace heating temperature field, and improves the uniform distribution of the asymmetric furnace temperature field.

[0081] In the asymmetric furnace body temperature control, for any asymmetric temperature control pipe section, as shown in FIG. 5, first, the main loop outputs the main loop sparse zone output power SMOP based on the inner loop current temperature, i.e., the main loop sparse zone current temperature SMPV and the main loop sparse zone temperature set value SMSP through PID control; then, the main loop sparse zone output power SMOP is adjusted to the secondary loop sparse zone temperature set value SSSP through a cascade strategy; in the secondary loop, the secondary loop sparse zone current temperature SSPV under the preset steady state condition is calibrated and corrected through temperature automatic calibration, and the calibrated secondary loop sparse zone current temperature SSPV and the secondary loop sparse zone temperature set value SSSP are output through PID control to obtain the secondary loop sparse zone output power SSOP, which is output to the sparse heating zone 302 to heat the wire load, thereby realizing the heating of the sparse heating zone 302 of the asymmetric furnace body.

[0082] At the same time, the heating control of the dense heating zone 301 is realized through the dense zone branch output strategy, in which the secondary loop sparse zone output power SSOP is mapped to the dense heating zone 301 output, i.e., the secondary loop dense zone output power DSOP, and the secondary loop dense zone output power is adjusted through the preset coefficient corresponding to the current process task of the asymmetric temperature control pipe section, so as to realize the power following of the dense heating zone 301 to the change of the sparse heating zone 302 and the adjustable effect, which not only avoids the mutual interference of the temperature fields of the dense heating zone 301 and the sparse heating zone 302, but also avoids the mutual interference of the temperature fields between multiple asymmetric temperature control pipe sections, improves the consistency of the temperature field distribution of multiple asymmetric temperature control pipe sections in the furnace body, and finally realizes the rapid and uniform heating of the graphite boat load.

[0083] Therefore, compared with the existing furnace temperature control scheme shown in Figure 2, the temperature control method for the asymmetric furnace body provided in this application embodiment, as shown in Figure 6, mainly includes two parts: an automatic temperature calibration strategy and a dense zone branch output strategy. The automatic temperature calibration strategy is used to reduce the internal and external temperature differences of multiple asymmetric temperature control tube segments, thereby achieving consistency of the internal and external temperature differences of multiple asymmetric temperature control tube segments and improving the temperature field consistency of multiple asymmetric temperature control tube segments. The dense zone branch output strategy is used to achieve the effect that the output of the dense heating zone 301 of each asymmetric temperature control tube segment of the asymmetric furnace body changes with the change of the sparse heating zone 302 and is adjustable. This not only avoids the mutual interference of the temperature fields of the dense heating zone 301 and the sparse heating zone 302, but also avoids the mutual interference of the temperature fields between multiple asymmetric temperature control tube segments, improving the temperature field distribution consistency of multiple asymmetric temperature control tube segments in the furnace body, thereby meeting the equipment requirements of "fast heating and good temperature control" for photovoltaic PECVD equipment.

[0084] Specifically, the two strategies will be described in detail below:

[0085] (1) Automatic Temperature Calibration Strategy: As shown in Figure 7, this strategy first determines the calibration interface as the external couple temperature of the condenser heating zone 302 based on the cascade temperature control principle, that is, calibrating the external couple temperature of the condenser zone under steady state (i.e., the current temperature of the secondary loop condenser zone); then, it is necessary to determine the calibration algorithm and calibration-related variables, including the confirmation of the calibration reference value (i.e., the preset reference value); finally, the calibration methods include manual calibration and automatic calibration. Manual calibration allows manual input of the calibration values ​​of each asymmetric temperature-controlled tube segment, which is suitable for debugging or testing environments. Automatic calibration can realize one-click calibration of the current temperature of the secondary loop condenser zone of multiple asymmetric temperature-controlled tube segments, which is suitable for equipment debugging before delivery in a mass production environment. The specific working process of the automatic temperature calibration strategy is as follows:

[0086] ①Determine the calibration interface; based on the existing cascade temperature control principle, the current temperature SSPV of the sparse zone of the secondary loop, i.e. the outer couple temperature of the sparse zone, is used as the input of the temperature control loop of the secondary loop, which affects the actual power output of the furnace body, and further affects the reheat time and reheat effect of the process, which is the key link in the temperature control of the furnace body. If the difference in the outer couple temperature of multiple asymmetric temperature control pipe sections is large under steady state, it will cause the reheat time and reheat effect of multiple asymmetric temperature control pipe sections to be inconsistent, thereby affecting the temperature control parameters, process formula and process effect of multiple asymmetric temperature control pipe sections. Each asymmetric temperature control pipe section needs to be adjusted separately, which increases the difficulty and workload of temperature control in process debugging. Therefore, it is necessary to develop a calibration function for the outer couple temperature under steady state, set a calibration interface at the current temperature SSPV of the sparse zone of the secondary loop, and calibrate and correct the current temperature SSPV of the sparse zone of the secondary loop of multiple asymmetric temperature control pipe sections through the same calibration reference value. After calibration, the current temperature SSPV of the sparse zone of the secondary loop of each asymmetric temperature control pipe section is equal to the preset reference value, which reduces the inner-outer couple temperature difference of each asymmetric temperature control pipe section, realizes the consistency of the inner-outer couple temperature difference of multiple asymmetric temperature control pipe sections, and further improves the consistency of the temperature field of multiple asymmetric temperature control pipe sections.

[0087] It should be noted that the number of multiple asymmetric temperature control pipe sections is preferably 6, and the multiple asymmetric temperature control pipe sections can be arranged in the same semiconductor process equipment or in different semiconductor process equipment. The actual situation can be considered for arrangement.

[0088] ②Determine the calibration method; when the furnace temperature stabilizes at the set temperature, and all temperature field parameters such as inner couple temperature, outer couple temperature and heating wire output power tend to be stable without oscillation, at this time, it is determined that the asymmetric furnace is in steady state (i.e. the preset steady state condition is met), and the outer couple temperature of the sparse zone (i.e. the current temperature of the sparse zone of the secondary loop) and its calibration interface of each asymmetric temperature control pipe section under steady state are determined. How to calibrate and compensate it is the key of the temperature automatic calibration strategy.

[0089] In the calibration algorithm, in addition to the sparse zone outer couple temperature under steady state, the calibration reference value also needs to be determined, i.e. the calibration reference value. The selection of the calibration reference value should be based on the sample data of the outer couple temperature of multiple asymmetric temperature control pipe sections under the same inner couple temperature steady state, so that it is more universal and applicable. The calibration algorithm is that the calibration value is the difference between the calibration reference value and the sparse zone outer couple temperature under steady state, i.e. calibration value = calibration reference value - sparse zone outer couple temperature (under steady state). After calibration, the sparse zone outer couple temperature of each asymmetric temperature control pipe section is uniformly compensated to the calibration reference value, so that the inner-outer couple temperature difference of multiple asymmetric temperature control pipe sections tends to be consistent, and the difference and process reheat effect of multiple asymmetric temperature control pipe sections are eliminated, which improves the consistency of the temperature field of multiple asymmetric temperature control pipe sections.

[0090] ③ Manual calibration function; after determining the calibration reference value, the calibration value is manually input into the temperature control algorithm logic according to the calibration algorithm to eliminate the internal and external temperature difference of the multiple asymmetric temperature control pipe sections, and then the temperature recovery effect verification of the multiple asymmetric temperature control pipe sections after manual calibration is performed.

[0091] Specifically, in the manual calibration function, first, the calibration reference value is selected based on the internal and external coincidence steady-state data of the multiple asymmetric temperature control pipe sections. The selection condition requires that the internal coincidence temperature and the temperature control parameters of each asymmetric temperature control pipe section are consistent. The selection of the calibration reference value needs to be based on the analysis of the furnace body steady-state data of the multiple asymmetric temperature control pipe sections. Generally, the higher value is taken from the external coincidence temperature of the furnace body steady-state of the multiple asymmetric temperature control pipe sections to ensure that the calibration reference value meets the steady-state characteristics of the batch furnace body and reduces the overshoot phenomenon after temperature recovery. Taking four asymmetric temperature control pipe sections of five temperature zones as an example, the calibration reference values are 475℃, 460℃, 455℃, 455℃ and 470℃ respectively. The calibration value is obtained based on the calibration algorithm and is manually input into the temperature control algorithm logic to calibrate the temperature of the outer zone of the multiple asymmetric temperature control pipe sections in each temperature zone. Among them, the multiple asymmetric temperature control pipe sections include A pipe section, B pipe section, C pipe section and D pipe section. The manual calibration values of each pipe section are shown in Table 1 as follows:

[0092] Table 1

[0093] In addition, after the above manual calibration, the temperature recovery time and the overshoot amount of each asymmetric temperature control pipe section are verified. The temperature recovery time refers to the time from opening the cavity door for feeding to the internal coincidence temperature returning to the set value. In addition, when the internal coincidence temperature returns to the set value, due to the hysteresis of the furnace temperature field under dynamic conditions, the internal coincidence temperature will exceed the set value by a certain range and then slowly stabilize around the set value. Therefore, the overshoot amount is the highest value of the internal coincidence temperature exceeding the set value during the temperature recovery stage. For testing the calibration effect, the temperature recovery effect of each asymmetric temperature control pipe section before calibration is shown in Table 2 as follows:

[0094] Table 2

[0095] According to Table 2, the temperature recovery overshoot amount of each asymmetric temperature control pipe section is large and inconsistent, and the temperature field consistency between the asymmetric temperature control pipe sections is poor, which brings great difficulty to process debugging. After the above manual calibration, the temperature recovery effect of each asymmetric temperature control pipe section after calibration is shown in Table 3 as follows:

[0096] Table 3

[0097] According to Table 3, after manual calibration, the temperature returning effect of each asymmetric temperature control tube section is consistent and the overshoot is small (not more than 2℃), which can meet the requirement of PECVD process temperature window ±5℃, and greatly improves the temperature field consistency of multiple asymmetric temperature control tube sections.

[0098] It should be noted that the overshoot data of each asymmetric temperature control tube section in Table 2 above can be counted according to the temperature curve data in the process, which is the highest value of the temperature exceeding the set value in the temperature returning stage before statistical calibration. Table 1 is the calibration value of manual calibration of each asymmetric temperature control tube section. After calibration and process test, the overshoot of each asymmetric temperature control tube section can be counted as shown in Table 3, so as to verify the effect of manual calibration by comparing the overshoot data of Table 2 before calibration and the overshoot data of Table 3 after calibration.

[0099] ④ Automatic calibration function; first determine the automatic calibration development requirements, including: adding an automatic calibration button in the controller such as the host computer configuration page, and marking the automatic calibration conditions (the temperature of each asymmetric temperature control tube section rises to the process temperature, and the inner couple stabilizes within ±1℃, that is, when the asymmetric furnace body reaches steady state, the automatic calibration button can be clicked), adding the outer couple calibration reference value configuration of each asymmetric temperature control tube section (modifiable), writing the calibration value into the outer couple calibration interface based on the calibration algorithm, and the automatic calibration enable condition (the inner couple set value of each asymmetric temperature control tube section is set to the process temperature, and the absolute value of the automatic calibration value of each asymmetric temperature control tube section is ≤ the deviation limit value), at this time, after determining the automatic calibration development requirements, the one-key calibration function software development is carried out, including calibration value display, calibration button configuration and manual / automatic calibration function switching.

[0100] In addition, if the absolute value of the automatic calibration value of a certain asymmetric temperature control tube section is > the deviation limit value, it means that the outer couple deviation of the asymmetric temperature control tube section is large, at this time, automatic compensation is not allowed, and the controller generates an alarm prompt information to prompt the staff to check the outer couple in the additional heating area 302 of the asymmetric temperature control tube section and its related hardware, so as to ensure the normal operation of the semiconductor process equipment.

[0101] Therefore, there is no essential difference between manual calibration and automatic calibration, and the calibration logic is the same. In actual application, the calibration method can be selected arbitrarily, such as one-key implementation through automatic calibration, which is more convenient, but may cause differences in individual furnace bodies. At this time, manual adjustment can be made to the individual furnace body differences through manual calibration, that is, through the automatic calibration + automatic calibration method, the temperature field consistency of multiple asymmetric temperature control tube sections in the semiconductor process equipment is further improved, and different working condition calibration scenes are met.

[0102] It should be noted that in actual application, the temperature automatic calibration strategy is not performed every time, but only in some scenarios, including the debugging scenario before the semiconductor process equipment is shipped, the scenario of replacing the furnace body of the semiconductor process equipment, and the scenario of changing the external hardware of the semiconductor process equipment. The specific settings can be made according to actual conditions.

[0103] (2) Dense branch output strategy; in the asymmetric furnace temperature control, how to avoid the temperature field interference between the dense heating zone 301 and the sparse heating zone 302, and how to control the heating power of the dense heating zone 301 are the keys to the temperature control of the dense heating zone 301. Therefore, the dense branch output strategy is used to realize that the power of the dense heating zone 301 follows the change of the sparse heating zone 302, and the problem of mutual interference between the existing furnace auxiliary heating pipe heating and furnace heating temperature field is avoided.

[0104] In the dense branch output strategy, the output power of the sparse heating zone 302 is linearly mapped to the output power of the dense heating zone 301, and the branch output is adjusted by adjusting the proportional coefficient and the bias parameter, so as to realize the effect that the power of the dense heating zone 301 follows the change of the sparse heating zone 302 and is adjustable, and the heating of the dense heating zone 301 of the asymmetric furnace is realized. Compared with the existing temperature control scheme, in the dense branch output strategy, the dense heating zone 301 does not perform single-loop temperature control, so as to avoid the risk of consistency of the thermocouple temperature measurement of the dense heating zone 301.

[0105] In addition, the preset coefficient set and the preset corresponding relationship are also pre-stored in the controller, and the corresponding relationship between each process type and the proportional coefficient a and the bias parameter b is shown in Table 4:

[0106] Table 4

[0107] Therefore, after determining the process type of the asymmetric furnace for performing the current process task, the corresponding proportional coefficient a and bias parameter b are searched in Table 4 according to the process type, and then the secondary loop dense zone output power is linearly calculated according to formula (1). Since the dense heating zone 301 and the sparse heating zone 302 are one-to-one corresponding in the asymmetric temperature control pipe segment, after the secondary loop sparse zone output power of a certain asymmetric temperature control pipe segment is determined, the output of the dense heating zone 301 corresponding to the asymmetric temperature control pipe segment, i.e. the secondary loop dense zone output power, can be determined according to formula (1), so as to realize the effect that the power of the dense heating zone 301 of the asymmetric temperature control pipe segment follows the change of the corresponding sparse heating zone 302 and is adjustable, thereby realizing the heating of the dense heating zone 301 of the asymmetric furnace. Not only the mutual interference between the dense heating zone 301 and the sparse heating zone 302 is avoided, but also the mutual interference between multiple asymmetric temperature control pipe segments is avoided, and the temperature field distribution consistency of multiple asymmetric temperature control pipe segments in the furnace is improved.

[0108] For example, as shown in FIG. 8, the asymmetric furnace body includes a furnace mouth position, a furnace tail position, and a graphite boat position; wherein, in the horizontal direction of the single furnace body, it is divided into a plurality of asymmetric temperature control pipe sections, such as the furnace mouth position being zone 1 (i.e. asymmetric temperature control pipe section 1), the furnace tail position being zone 7 (i.e. asymmetric temperature control pipe section 7), and the graphite boat position including the middle 5 asymmetric temperature control pipe sections, i.e. zones 2-6, and each asymmetric temperature control pipe section including a sparse heating zone 302 and a dense heating zone 301. In addition, each asymmetric temperature control pipe section also corresponds to a set of proportional coefficients a and bias parameters b in the process task of different process types, and the sub-circuit dense zone output power y and the sub-circuit sparse zone output power x of each asymmetric temperature control pipe section establish a mapping relationship of formula (1). It should be noted that zones 1 and 7 can also be divided into sparse heating zones 302 and dense heating zones 301, which can be set according to actual conditions.

[0109] For example, when the proportional coefficient a1 and the bias parameter b1 correspond to zone 1 of the furnace mouth area, when the process type is wafer loading and temperature rising, after the furnace pipe cavity door is opened, a large amount of heat is dissipated in the cavity, the furnace body needs to be quickly warmed up, and the ratio of each dense heating zone 301 of the asymmetric furnace body is greater than 1, so as to ensure that the dense heating zone 301 maintains high power output in the warming-up stage, so that the middle part of the graphite boat and the silicon wafer load is quickly heated, wherein the proportional coefficient a1 and the proportional coefficient a2 correspond to the furnace mouth area, and the heat dissipation of the furnace mouth area is relatively large compared with the middle and tail areas of the furnace, so as to increase the output ratio of the dense heating zone 301 to make the furnace mouth area have high power output, and ensure that the warming-up time of each asymmetric temperature control pipe section is consistent; the bias parameter 3 corresponds to the graphite block of the double-graphite-boat load, and the mass is large and the heat capacity is higher than that of other areas of the graphite boat, so as to set a certain value of the bias to ensure the lower limit of the output power of the asymmetric temperature control pipe section corresponding to the graphite block of the graphite boat, which is beneficial to the rapid heating of the graphite block, so as to uniformly and quickly heat the whole graphite boat in the warming-up stage. Therefore, for wafer loading and temperature rising in the warming-up stage, the dense heating zone 301 needs to be set to a high ratio value for the rapid heating of the middle area of the graphite boat, which replaces the auxiliary heating function in the existing furnace body, and the middle asymmetric temperature control pipe section of the furnace body can be set to a certain value of the bias for the rapid heating of the graphite block load of the graphite boat, thereby reducing the interference of heat absorption of the graphite block on the heating of the silicon wafer.

[0110] Similarly, when the process type is deposition, the graphite boat and silicon wafer load have basically reached the process temperature. At this time, by reducing the ratio of the dense heating zone 301 (<1), the heating power of the dense heating zone 301 is reduced to be consistent with the heating power of the sparse heating zone 302, so that the heating heat of the dense and sparse zones of the furnace is uniform, ensuring a uniform and stable temperature field in the chamber during the process. Therefore, for the deposition step and other process stages, the ratio of the dense heating zone 301 needs to be set to a value less than 1, i.e., a < 1, to meet the temperature field requirements for uniform heating of the graphite boat and silicon wafer during the process. By adjusting the ratio coefficient and bias parameter of each asymmetric temperature control tube segment in the process type, the performance of the asymmetric furnace can be fully utilized to achieve uniform and rapid temperature recovery of the graphite boat and silicon wafer load, which is beneficial to improving the production cycle of photovoltaic PECVD and meeting the equipment requirements of "high capacity and short cycle time".

[0111] Therefore, based on the aforementioned asymmetric furnace temperature control method, which includes an automatic temperature calibration strategy and a dense zone branch output strategy, the process recovery effect and process indicators are verified. Here, we take asymmetric temperature control tube section 2 and asymmetric temperature control tube section 3 as examples. The process recovery effect is shown in Figure 9. Curve S1 represents the external couple temperature of the dense heating zone 301 of asymmetric temperature control tube section 2, curve S2 represents the external couple temperature of the dense heating zone 301 of asymmetric temperature control tube section 3, curve S3 represents the external couple temperature of the sparse heating zone 302 of asymmetric temperature control tube section 2, curve S4 represents the external couple temperature of the sparse heating zone 302 of asymmetric temperature control tube section 3, curve S5 represents the internal couple temperature of the sparse heating zone 302 of asymmetric temperature control tube section 2, curve S6 represents the internal couple temperature of the sparse heating zone 302 of asymmetric temperature control tube section 3, curve S7 represents the output power of the sparse heating zone 302 of asymmetric temperature control tube section 2, and curve S8 represents the output power of the sparse heating zone 302 of asymmetric temperature control tube section 3. Therefore, under the same process, the internal and external couplings and heating power of the asymmetric temperature control tube section 2 and the asymmetric temperature control tube section 3 are basically consistent, realizing the temperature field consistency among multiple asymmetric temperature control tube sections.

[0112] Furthermore, during process validation, before implementing the aforementioned asymmetric furnace temperature control method, the tunneling layer thickness results for the PE-poly process are shown in Table 5 below:

[0113] Table 5

[0114] As shown in Table 5 above, before implementing the asymmetric furnace temperature control method, the thickness consistency of the PE-poly tunneling layer between tubes was poor, with a difference greater than 0.1 nm. After implementing the above temperature control strategy, the PE-poly process tunneling layer thickness results are shown in Table 6 below:

[0115] Table 6

[0116] According to the above Table 6, after the above asymmetric furnace body temperature control method is implemented, the film thickness difference between the tubes in the PE-poly tunneling layer film thickness is within 0.03 nm, the film thickness uniformity between the tubes is high, which is conducive to the unification of the process formula between the multiple asymmetric temperature control tube segments, thereby greatly reducing the process debugging difficulty of the multiple asymmetric temperature control tube segments.

[0117] In summary, the temperature control method of the asymmetric furnace body provided in the embodiments of the present application includes a temperature automatic calibration strategy and a dense area branch output strategy, which can not only improve the consistency of the temperature field between the multiple asymmetric temperature control tube segments, but also can use a set of temperature control parameters between the multiple asymmetric temperature control tube segments, unify the temperature control program parameters and process file formula, and further greatly reduce the temperature debugging difficulty and debugging workload of mass production process, improve the use experience and product reputation of customer process debugging; in addition, the dense area branch output strategy can also save the maintenance cost caused by the auxiliary heating tube form, and at the same time, avoid the mutual interference problem between the existing furnace body auxiliary heating tube heating and furnace body heating temperature field, thereby improving the consistency of the temperature field distribution of the multiple asymmetric temperature control tube segments, and further meeting the equipment requirements of fast temperature rise and good temperature control of the photovoltaic PECVD equipment.

[0118] The semiconductor process equipment provided in the embodiments of the present application has the same technical features as the temperature control method of the asymmetric furnace body provided in the above embodiments, so it can also solve the same technical problems and achieve the same technical effects.

[0119] The embodiments also provide a machine readable storage medium, which stores machine executable instructions, and the machine executable instructions cause the processor to implement the above temperature control method of the asymmetric furnace body when the machine executable instructions are called and executed by the processor.

[0120] The computer program product of the temperature control method of the asymmetric furnace body and the semiconductor process equipment provided in the embodiments of the present application includes a computer readable storage medium storing program codes, and the instructions included in the program codes can be used to execute the method described in the foregoing method embodiments, and the specific implementation can be referred to the method embodiments, which will not be described here.

[0121] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above described system and device can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0122] In addition, in the description of the embodiments of the present application, unless explicitly defined and limited otherwise, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be electrically connected; can be directly connected, can be indirectly connected through an intermediate medium, and can be internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0123] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a nonvolatile computer readable storage medium executable by a processor. Based on this understanding, the technical solutions of the present application or the part of the prior art or the part of the technical solutions that essentially contribute to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various program code storage media.

[0124] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0125] Finally, it should be noted that the above-described embodiments are merely specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, but not to limit the same. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that any skilled person in the art can still modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some of the technical features, within the technical scope disclosed by the present application. The modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

A temperature control method of an asymmetric furnace body, the asymmetric furnace body comprising a plurality of asymmetric temperature control pipe segments, each of the asymmetric temperature control pipe segments having a sparse heating zone and a dense heating zone; wherein, The distribution density of the heating elements in the dense heating zone is greater than the distribution density of the heating elements in the sparse heating zone; characterized in that the method comprises: For any asymmetric temperature control pipe section, the current temperature of the main loop sparse zone is obtained, the output power of the main loop sparse zone is determined according to the current temperature of the main loop sparse zone and the temperature setting value of the main loop sparse zone, and the output power of the main loop sparse zone is matched to the temperature setting value of the secondary loop sparse zone through a cascade strategy; wherein the current temperature of the main loop sparse zone is used to represent the current temperature inside the furnace reaction chamber in the sparse heating zone of the asymmetric temperature control pipe section; The current temperature of the secondary loop sparse zone is obtained, the output power of the secondary loop sparse zone is determined according to the current temperature of the secondary loop sparse zone and the temperature setting value of the secondary loop sparse zone, and the heating elements in the sparse heating zone are controlled to heat according to the output power of the secondary loop sparse zone; wherein the current temperature of the secondary loop sparse zone is used to represent the current temperature of the heating elements outside the furnace reaction chamber in the sparse heating zone of the asymmetric temperature control pipe section; The preset coefficient corresponding to the current process task of the asymmetric temperature control pipe section is determined, the output power of the secondary loop dense zone is calculated according to the output power of the secondary loop sparse zone and the preset coefficient, and the heating elements in the dense heating zone of the asymmetric temperature control pipe section are controlled to heat according to the output power of the secondary loop dense zone. The method of claim 1, wherein Before the step of determining the output power of the secondary loop sparse zone according to the current temperature of the secondary loop sparse zone and the temperature setting value of the secondary loop sparse zone, the method further comprises: According to a preset calibration mode, the current temperature of the secondary loop sparse zone is calibrated based on a preset reference value, and the output power of the secondary loop sparse zone is determined according to the calibrated current temperature of the secondary loop sparse zone and the temperature setting value of the secondary loop sparse zone; wherein the preset calibration mode includes a manual calibration mode and an automatic calibration mode. The method according to claim 2, characterized in that The step of calibrating the current temperature of the secondary loop sparse zone based on the preset reference value comprises: The difference between the preset reference value and the current temperature of the secondary loop sparse zone is calculated, and the current temperature of the secondary loop sparse zone is calibrated according to the difference, so that the calibrated current temperature of the secondary loop sparse zone is equal to the preset reference value. The method according to claim 3, characterized in that After the step of calculating the difference between the preset reference value and the current temperature of the secondary loop sparse zone, the method further comprises: If the absolute value of the difference is greater than a preset deviation threshold, an alarm prompt information is generated to prompt the inspection of the outer couple for monitoring the current temperature of the heating elements outside the furnace reaction chamber in the sparse heating zone. The method of claim 1, wherein The asymmetric furnace body has an inner couple for monitoring the current temperature inside the furnace reaction chamber in the sparse heating zone of the asymmetric temperature control pipe section and an outer couple for monitoring the current temperature of the heating elements outside the furnace reaction chamber in the sparse heating zone of the asymmetric temperature control pipe section; Before the step of obtaining the current temperature of the secondary loop sparse zone, the method further comprises: Obtaining the temperature field parameters of the asymmetric furnace body; wherein the temperature field parameters include at least one of the following: inner couple temperature, outer couple temperature and output power of the heating elements; If the difference between the temperature field parameter and the corresponding preset threshold is not greater than a preset error, it is determined that the asymmetric furnace body reaches a preset steady state condition; and when the asymmetric furnace body reaches the preset steady state condition, the current temperature of the sparse area of the secondary loop is obtained. The method of claim 1, wherein The preset coefficient includes a proportional coefficient and a bias parameter, and the step of calculating the output power of the dense area of the secondary loop according to the output power of the sparse area of the secondary loop and the preset coefficient includes: The output power of the dense area of the secondary loop is linearly calculated according to the output power of the sparse area of the secondary loop, the proportional coefficient and the bias parameter. The method according to claim 6, characterized in that The step of linearly calculating the output power of the dense area of the secondary loop according to the output power of the sparse area of the secondary loop, the proportional coefficient and the bias parameter includes: The calculation formula of the output power of the dense area of the secondary loop is as follows: y=a*x+b Wherein, y represents the output power of the dense area of the secondary loop, x represents the output power of the sparse area of the secondary loop, a represents the proportional coefficient, and b represents the bias parameter. The method according to claim 6, characterized in that Before the step of calculating the output power of the dense area of the secondary loop according to the output power of the sparse area of the secondary loop and the preset coefficient, the method further includes: Determining the process type of the current process task performed by the asymmetric furnace body, and determining the proportional coefficient and the bias parameter in a preset coefficient set according to the process type; wherein the process type includes one of the following: loading, warming up, vacuumizing, leak hunting, pressure regulating, depositing, nitrogen filling and unloading. A semiconductor process apparatus characterized by comprising: The controller is used to control the temperature of the asymmetric furnace body by using the method of any one of claims 1-8. A computer-readable storage medium, characterized by, The computer readable storage medium stores a computer program, and the computer program is run by the processor to execute the steps of the method of any one of claims 1-8. The computer readable storage medium stores a computer program, and the computer program is run by the processor to execute the steps of the method of any one of claims 1-8.

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