Semiconductor manufacturing apparatus and method of controlling the same

Abstract

The invention provides semiconductor manufacturing equipment and a control method thereof, and the method comprises the steps: arranging a lifting bottom plate surrounding a rotating device outside a cavity, arranging a plurality of lifting mechanisms on the lifting bottom plate, and obtaining a plurality of out-of-cavity distances between the lifting bottom plate and a cavity bottom plate through a distance measurement device; the distances outside the cavities are synchronously obtained, whether base horizontal adjustment needs to be carried out or not is judged according to the distances outside the cavities, if yes, a target lifting mechanism needing lifting control and corresponding lifting control parameters are determined according to the distances outside the cavities, and the lifting control parameters comprise target compensation displacement; the current rotating speed of the base is obtained, and the running speed upper limit of running of the target lifting mechanism is obtained in the second calibration relation according to the current rotating speed of the base; and controlling the target lifting mechanism to obtain the target compensation displacement corresponding to the operation speed upper limit motion. When the base is leveled, the production takt and efficiency are prevented from being influenced, and the film forming quality on the substrate is prevented from being influenced.

Description

TECHNICAL FIELD

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

[0002] A semiconductor manufacturing equipment, for example, a MOCVD (Metal Organic Chemical Vapor Deposition) equipment applied to epitaxial growth of a semiconductor material layer, will frequently control a susceptor to rotate or lift due to process requirements or automatic wafer transfer requirements.

[0003] Controlling the consistency of the distance between the bearing top surface of the susceptor and the chamber reference surface below the gas injection device, that is, controlling the good levelness of the susceptor, plays an important role in the control of wafer transfer and film forming performance. If the device for controlling the lifting of the susceptor slips, parts are damaged, etc., the levelness of the susceptor will deviate. If it occurs in wafer transfer operation, the wafer or coated wafer will deviate when the manipulator extracts the wafer, which will easily damage the surface of the wafer or the coated surface. If it occurs in the process, once the levelness of the susceptor deviates beyond a certain limit, it will significantly affect the stability of the wafer temperature field and the gas flow field near the wafer, and is not conducive to film forming performance.

[0004] The prior art usually levels the susceptor after shutdown, for example, after shutdown, the cavity is opened to expose the susceptor and the chamber reference surface to the environment, and leveling is performed by optical ranging, etc. Obviously, it will significantly affect the production rhythm and efficiency; or in the scenario of controlling the lifting of the susceptor by using a lifting device containing a plurality of lead screws, after the susceptor is controlled to be in a stationary state, the length of each lead screw is controlled to level the susceptor inside the chamber. Although this method does not need to open the cavity, it will interrupt or even terminate the epitaxial growth process being normally performed, which not only affects the production rhythm and efficiency, but also significantly affects the film forming quality on the batch of wafers. SUMMARY

[0005] In order to solve the problem that the prior art for leveling the susceptor affects the production rhythm and efficiency and the film forming quality on the wafer, the present application provides a semiconductor manufacturing equipment and a control method thereof.

[0006] In order to achieve the above-mentioned purpose, the present application comprises the following technical solutions: In a first aspect, the present application provides a control method of a semiconductor manufacturing equipment, the semiconductor manufacturing equipment comprising a chamber with a susceptor, a rotary device penetrating the chamber and connected to the susceptor by a dynamic seal, a lifting bottom plate provided outside the chamber and provided with the rotary device, and a plurality of lifting mechanisms provided between the lifting bottom plate and a chamber bottom plate of the chamber to drive the susceptor to lift; the plane where the top surface of the susceptor is located and the chamber reference surface of the chamber have an intracavity distance therebetween. The control method comprises: S0: obtaining a second calibration relationship between a run-up threshold of the susceptor at different rotation speeds and an upper limit of the running speed of the lifting mechanism; S1: placing a wafer on the susceptor, controlling the rotating device to rotate the susceptor, and performing an epitaxial growth process on the wafer; During the execution of the epitaxial growth process in step S1, the method further comprises executing: S11: obtaining and determining the required susceptor horizontal adjustment according to each outer cavity spacing between the lifting bottom plate and the chamber bottom plate, obtaining each inner cavity spacing corresponding to each outer cavity spacing, and determining the target lifting mechanism and the corresponding lifting control parameter required for lifting control in combination with the target inner cavity spacing; S12: obtaining and matching the current rotation speed of the susceptor in the second calibration relationship to obtain the upper limit of the running speed; S13: controlling the target lifting mechanism to move according to the lifting control parameter and the matched upper limit of the running speed.

[0007] Further, when the range of each outer cavity spacing exceeds a preset range threshold, it is determined that the susceptor horizontal adjustment is required.

[0008] Further, in step S0, a first calibration relationship is also obtained, which is the corresponding relationship between each outer cavity spacing and the corresponding inner cavity spacing, and in step S11, the step of obtaining each inner cavity spacing corresponding to each outer cavity spacing comprises: obtaining each inner cavity spacing corresponding to each outer cavity spacing according to the first calibration relationship.

[0009] Further, before executing step S1, the step of obtaining the first calibration relationship at room temperature is executed, comprising: S01: controlling the chamber to maintain the process pressure required by the epitaxial growth process; S02: controlling each lifting mechanism to run to a certain position, obtaining each outer cavity spacing, and determining that the range of each outer cavity spacing obtained does not exceed the preset range threshold, then using an optical distance measuring device to obtain each inner cavity spacing and determine that the range of each inner cavity spacing does not exceed the preset range threshold; S03: taking the average of a plurality of outer cavity spacings as the calibrated outer cavity spacing, and taking the average of a plurality of inner cavity spacings as the corresponding calibrated inner cavity spacing; S04: controlling each lifting mechanism to rise or fall synchronously; Repeating steps S02 to S04.

[0010] Further, the range threshold does not exceed 0.05 millimeters.

[0011] Further, the lifting control parameter includes a target compensation distance and a target running direction, and the step S11 of determining the target lifting mechanism and the corresponding lifting control parameter includes: The target lifting mechanism and the target compensation distance are determined according to the target intracavity distance and the absolute value of the difference between each intracavity distance. The target running direction is determined according to the target intracavity distance and the positive and negative of the difference between each intracavity distance.

[0012] Further, the second calibration relationship includes: A radial runout corresponding relationship between the radial runout difference threshold of the susceptor at different rotation speeds not lower than a first rotation speed threshold and the upper limit of the running speed of the lifting mechanism, and an axial runout corresponding relationship between the axial runout difference threshold of the susceptor at different rotation speeds lower than the first rotation speed threshold and the upper limit of the running speed of the lifting mechanism.

[0013] Further, the axial runout difference threshold and the radial runout difference threshold are obtained, and the step S0 of obtaining the second calibration relationship at room temperature includes: P01: control the chamber to maintain the process pressure required by the epitaxial growth process; P02: control the rotation device to drive the susceptor to rotate at a fixed rotation speed, control each lifting mechanism to synchronously ascend or descend at different motion speeds in sequence, and monitor the axial runout difference and the radial runout difference of the susceptor at each running speed by using an optical distance measuring method; P03: select the running speed corresponding to the runout difference reaching or closest to the minimum value of the axial runout difference threshold and the radial runout difference threshold as the corresponding upper limit of the running speed at the fixed rotation speed; P04: control the rotation device to drive the susceptor to rotate at a rate increased to another fixed rotation speed; Repeat steps P02 to P04.

[0014] Further, the first rotation speed threshold is not lower than 400 rpm.

[0015] Further, after step P03 is completed, each extracavity distance is obtained and it is determined that the range does not exceed a preset range threshold, and then step P04 is executed, or: After step P03 is completed, each lifting mechanism is controlled to synchronously run to the initial position of the susceptor, and then each extracavity distance is obtained and it is determined that the range does not exceed a preset range threshold, and then step P04 is executed.

[0016] Further, the second calibration relationship comprises an axial runout corresponding relationship between the axial runout difference threshold of the base at different rotation speeds lower than the first rotation speed threshold and the upper limit of the operation speed of the lifting mechanism; In step S12, after judging that the current rotation speed of the base is lower than the first rotation speed threshold, the upper limit of the operation speed of the lifting mechanism corresponding to the current rotation speed of the base is obtained according to the axial runout corresponding relationship.

[0017] Further, the second calibration relationship comprises a radial runout corresponding relationship between the radial runout difference threshold of the base at different rotation speeds not lower than the first rotation speed threshold and the upper limit of the operation speed of the lifting mechanism; In step S12, after judging that the current rotation speed of the base is not lower than the first rotation speed threshold, the upper limit of the operation speed of the lifting mechanism corresponding to the current rotation speed of the base is obtained according to the radial runout corresponding relationship.

[0018] Further, the second calibration relationship comprises a radial runout corresponding relationship between the radial runout difference threshold of the base at different rotation speeds not lower than the first rotation speed threshold and the upper limit of the operation speed of the lifting mechanism; In step S12, after judging that the current rotation speed of the base is higher than the second rotation speed threshold, the current rotation speed of the base is adjusted to a target rotation speed between the first rotation speed threshold and the second rotation speed threshold, the second rotation speed threshold being higher than the first rotation speed threshold, and the upper limit of the operation speed of the lifting mechanism corresponding to the target rotation speed of the base is obtained according to the radial runout corresponding relationship.

[0019] Further, the first rotation speed threshold is not lower than 400 rpm, the second rotation speed threshold is not lower than 700 rpm, and the target rotation speed is close to the second rotation speed threshold compared with the first rotation speed threshold.

[0020] Further, the step of placing the substrate on the base comprises controlling each of the lifting mechanisms to operate at a preset working speed, so that the base performs lifting movement to perform the transmission step of the substrate or the coated substrate. The working speed is higher than each of the upper limits of the operation speed in the second calibration relationship.

[0021] In a second aspect, the present application provides a semiconductor manufacturing equipment, comprising: a chamber and a base, the base being arranged in the chamber; a rotating device, a dynamic seal penetrating through the bottom of the chamber and being rotationally connected to the base; a lifting bottom plate, located outside the chamber and surrounding the rotating device; A plurality of lifting mechanisms are arranged on the lifting base and connected to the chamber base to drive the susceptor to perform lifting movement by the rotating device; A distance measuring device is arranged to obtain a plurality of out-of-cavity distances between the lifting base and the chamber base; A master control device pre-stores a second calibration relationship, and is in communication connection with the rotating device, the distance measuring device and the lifting mechanism, wherein the second calibration relationship is a corresponding relationship between the run-up threshold of the susceptor at different rotating speeds and the upper limit of the running rate of the lifting mechanism.

[0022] Further, the bearing top surface of the susceptor faces the chamber top, the lifting mechanism comprises a lead screw extending along the chamber axis, the top end of the lead screw is fixed to the chamber base, and the bottom end is fixed to the lifting base, the number of the distance measuring devices is not less than the number of the lead screws, each distance measuring device is arranged in one-to-one correspondence near the connection between each lead screw and the chamber base, and / or near the connection between each lead screw and the lifting base.

[0023] By adopting the above technical scheme, the semiconductor manufacturing equipment and the control method thereof have the following beneficial effects: In the epitaxial growth process including controlling the rotating device to drive the susceptor to rotate by step S1, after it is judged that the horizontal adjustment of the susceptor is needed and the lifting mechanism needing lifting control and the corresponding lifting control parameters are obtained, the epitaxial growth process and the rotation of the susceptor controlled thereby do not need to be interrupted, but the motion rate of the corresponding lifting mechanism needing lifting control is controlled by judging the current rotating speed of the susceptor, so that the real-time leveling of the susceptor in the chamber is realized, the normal process is not disturbed, and good film forming quality of the wafer is also beneficial.

[0024] Specifically, the second calibration relationship is a corresponding relationship between the run-up threshold of the susceptor at different rotating speeds and the upper limit of the running rate of the lifting mechanism, and the run-up threshold is the maximum value of the run-up of the susceptor allowed by the epitaxial growth process at different rotating speeds. According to the current rotating speed of the susceptor, the upper limit of the running rate of the lifting mechanism is obtained in the second calibration relationship, and the motion of the lifting mechanism needing control is controlled by the upper limit of the running rate, so that the running rate of the lifting mechanism is selected as large as possible under the premise that the normal process is not disturbed, and the leveling of the susceptor is completed as quickly as possible, and the production efficiency is considered. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the semiconductor manufacturing equipment of the present application; Figure 2A flowchart for leveling the base in step S1 of the control method of the present application; Figure 3 A graph of the radial run-out difference threshold and the axial run-out difference threshold of the base at different rotational speeds in the present application; Figure 4 A flowchart for obtaining the second calibration relationship in the present application; Figure 5 A schematic diagram for obtaining the cavity-out distance and the cavity-in distance in the present application; Figure 6 A flowchart for obtaining the first calibration relationship in the present application. DETAILED DESCRIPTION

[0026] The embodiments of the present application will be described in detail with specific reference to certain embodiments thereof but it is understood that no limitation of the scope of the application is intended. The application can be practiced with the exact details as herein below using suitable methods and materials as known to those of ordinary skill. Those of ordinary skill in the art will readily understand that the application can be practiced with materials and methods other than those disclosed.

[0027] It should be noted that the diagrams provided in the embodiments only schematically illustrate the basic concept of the present application, and although only the components related to the present application are shown in the diagrams, the diagrams are not drawn according to the number, shape and size of the components in actual implementation, and the shape, number, positional relationship and proportion of each component in actual implementation can be changed at will under the premise of realizing the technical solution of the present application, and the component layout form can also be more complex.

[0028] As mentioned above, the base level does not meet the requirements, which will affect the film quality. The prior art usually levels the base after shutdown, for example, opening the cavity after shutdown to expose the base and the cavity reference surface to the environment, and leveling by optical ranging or the like. Obviously, it will significantly affect the production rhythm and efficiency. Or in the scenario of controlling the base lifting by the lifting device comprising a plurality of lead screws, after the base is controlled to be in a stationary state, the base inside is leveled by controlling the length of each lead screw outside the chamber structure. Although this method does not need to open the cavity, it will also interrupt or even terminate the epitaxial growth process being normally carried out, which not only affects the production rhythm and efficiency, but also significantly affects the film quality on the wafer of this batch.

[0029] Therefore, the present application provides a semiconductor manufacturing equipment and a control method thereof, which is used for real-time leveling of the base, especially the base in a rotating state, to avoid affecting the production rhythm and efficiency, and affecting the film quality on the wafer.

[0030] The semiconductor manufacturing equipment provided by the present application can be a chemical vapor deposition (CVD) equipment, further can be a plasma-enhanced chemical vapor deposition (PECVD) equipment, a metal-organic chemical vapor deposition (MOCVD) equipment, etc. The semiconductor manufacturing equipment provided by the present application can implement epitaxial growth process. It should be understood that the equipment is only exemplary.

[0031] As shown in Figure 1 The semiconductor manufacturing equipment provided by the present application comprises a chamber 1 with a susceptor 2, a rotating device 3 penetrating the bottom of the chamber 1 and rotatingly connecting the susceptor 2, a lifting base plate 4 outside the chamber 1 and surrounding the rotating device 3, a plurality of lifting mechanisms 5 provided on the lifting base plate 4 and connecting a chamber base plate 12 of the chamber 1, a plurality of outer chamber spacings between the lifting base plate and the chamber base plate, and a plurality of inner chamber spacings between the plane where the top surface of the susceptor is located and the reference plane of the chamber corresponding to the outer chamber spacings. The control method provided by the present application comprises: S0: obtaining a second calibration relationship; S1: placing a wafer on the susceptor and controlling the semiconductor manufacturing equipment to perform epitaxial growth process on the wafer.

[0032] In step S0, the second calibration relationship is the corresponding relationship between the run rate upper limit of the lifting mechanism and the runout threshold of the susceptor at different rotating speeds, and the runout threshold is the maximum runout value of the susceptor allowed by the epitaxial growth process at different rotating speeds.

[0033] In the process of performing the epitaxial growth process in step S1, the rotating device drives the susceptor to rotate.

[0034] In the process of performing the epitaxial growth process in step S1, the method further comprises a susceptor leveling step as shown in Figure 2 S11: obtaining each outer chamber spacing and determining whether the susceptor horizontal adjustment is needed according to each outer chamber spacing, if yes, obtaining each inner chamber spacing according to the target inner chamber spacing and each outer chamber spacing to determine the target lifting mechanism which needs to be controlled and the corresponding lifting control parameter; S12: obtaining the current rotating speed of the susceptor and obtaining the run rate upper limit of the target lifting mechanism running in the second calibration relationship according to the current rotating speed of the susceptor; S13: controlling the target lifting mechanism to move according to the lifting control parameter and the run rate upper limit obtained in step S12.

[0035] ​The technical solution of this application is described in detail below through specific embodiments.

[0036] Example 1 This embodiment provides a semiconductor manufacturing device for performing an epitaxial growth process on a substrate. Figure 1 The semiconductor manufacturing equipment shown (taking MOCVD equipment as an example) includes a chamber 1 with a base 2 provided therein, the chamber 1 including a chamber reference surface 11, a rotating device 3 with a dynamic seal passing through the bottom of the chamber 1 and rotatably connected to the base 2, a lifting base plate 4 located outside the chamber 1 and surrounding the rotating device 3, a plurality of lifting mechanisms 5 provided on the lifting base plate 4 and connected to the chamber bottom plate 12 of the chamber 1, distance measuring devices 6 arranged one-to-one near the connection between each lifting mechanism 5 and the chamber bottom plate 12, and / or near the connection between each lifting mechanism 5 and the lifting base plate 4, and also includes a main control device (not shown) that is communicatively connected to the rotating device 3, each distance measuring device 6 and each lifting mechanism 5.

[0037] In some embodiments, the substrate 100 is a wafer.

[0038] In some embodiments, the number of the lifting mechanisms 5 is at least three.

[0039] In some embodiments, the lifting mechanisms 5 are evenly arranged along the same circumferential direction on the chamber bottom plate 12 to ensure smooth lifting and lowering of the rotating device 3 .

[0040] In this embodiment, there are several extra-cavity distances between the lifting base plate 4 and the chamber bottom plate 12. There are intra-cavity distances between the plane where the top surface of the base 2 is located and the chamber reference plane 11 that correspond to the extra-cavity distances.

[0041] In some embodiments, the chamber reference surface 11 and the chamber bottom plate 12 are arranged horizontally.

[0042] The chamber 1 includes a top opening and an upper cover 13. During the process, the top opening is closed by the upper cover 13. The chamber reference surface 11 is located at the top opening and is used as a leveling reference during the installation of the base after the chamber is opened.

[0043] The bearing top surface of the base 2 faces the top of the chamber 1. The bearing top surface is used to bear the substrate 100 and to accommodate and limit it so that the substrate 100 can rotate with the base 2.

[0044] In some embodiments, the base 2 is preferably made of graphite and has a disc-shaped structure. In some embodiments, the surface of the graphite base 2 is covered with a silicon carbide layer.

[0045] During the epitaxial growth process, the rotating device will be controlled to drive the base supporting the substrate to be coated to rotate, which is beneficial to the uniformity of film formation. Figure 1As shown, the base 2 is supported in the chamber 1 by a base support device 9, and the rotary device 3 is connected to the base support device 9 after penetrating the chamber bottom plate 12. The rotary device 3 is used to drive the rotation of the base 2, so that the substrate 100 on the base 2 rotates with the base 2. The specific implementation is a conventional technical means in the art, which is not described here.

[0046] In some embodiments, the base support device 9 is arranged at the middle of the bottom surface of the base 2, extends towards the rotary device 3 and is connected thereto, so as to drive the rotation of the base 2 in a central manner. The specific implementation is a conventional technical means in the art.

[0047] The lifting mechanism 5 is used to control the lifting or lowering of the base. The lifting mechanism 5 is arranged outside the chamber 1 and is fixedly connected to the rotary device 3. Specifically, the lifting mechanism 5 surrounds the rotary device 3. One end of the lifting mechanism 5 is fixed on the chamber bottom plate 12 and extends towards the lifting bottom plate 4 and is fixedly arranged on the lifting bottom plate 4. Since the rotary device 3 is arranged in the chamber 1 in a dynamic sealing manner, the lifting movement of the lifting bottom plate 4 can also synchronously drive the synchronous movement of the rotary device 3, thereby driving the lifting of the base 2.

[0048] In some embodiments, referring to Figure 1 , the lifting mechanism 5 includes a lead screw 51 and a driving mechanism 52. The driving mechanism 52 is arranged on the lead screw 51, the lead screw 51 is fixedly arranged on the lifting bottom plate 4, extends towards the chamber bottom plate 12 and is fixedly arranged on the chamber bottom plate 12. In some specific embodiments, the top end of the lead screw 51 is fixed to the chamber bottom plate 12 through a fixing seat (the fixing seat allows the lead screw to rotate, but restricts the axial movement thereof), the lead screw 51 is fixed to the lifting bottom plate 4 through a nut and a flange or a connecting block, and the bottom end of the lead screw 51 is connected to the driving mechanism 52 (such as a servo motor or a stepping motor) through a shaft coupling. When the driving mechanism 52 is started, the lead screw 51 is driven to rotate, the nut of the lead screw 51 is driven to move linearly along the lead screw 51 because it cannot rotate, thereby driving the lifting bottom plate 4 to move towards or away from the chamber bottom plate 12, so as to drive the rotary device 3 to move towards or away from the upper cover 13 synchronously, and thereby drive the base 2 to lift or lower through the rotary device 3. The specific adaptation of the fixing seat on the chamber bottom plate and the lead screw, and the specific adaptation of the lead screw, the nut and the flange or the connecting block are conventional technical means in the art, which are not described here.

[0049] In some embodiments, the lead screw 51 extends axially along the chamber 1, and the chamber reference surface 11 and the load-bearing top surface of the base 2 are both perpendicular to the axial direction of the chamber 1.

[0050] In Figure 1In the shown example, three lifting mechanisms 5 are provided on the lifting base 4, and each lifting mechanism 5 is driven by an independent driving mechanism 52. However, it should be understood that the present embodiment is not limited thereto. Each lifting mechanism 5 can also be driven by the same driving mechanism 52.

[0051] As described in the background, the consistency of the distance between the carrying top surface of the susceptor and the chamber reference surface below the gas injection device, i.e. the good levelness of the susceptor, plays an important role in the control of the substrate and the film forming performance.

[0052] Especially for epitaxial growth process, it is well known in the art that epitaxial growth has high requirements on the precision of the substrate temperature control. For example, in the case of using MOCVD equipment to grow GaN layer on silicon substrate to prepare light emitting diode (LED), if the deviation of the substrate temperature is controlled to be 1 degree Celsius, the central wavelength of the LED will deviate more than 1 nm from the central wavelength required by the process design, which will seriously change the light emitting performance of the prepared LED, for example, the red shift of the central wavelength of the LED will make it impossible to obtain the blue LED that is originally required.

[0053] The semiconductor manufacturing equipment, for example, the MOCVD equipment, is provided with a heating device below the susceptor to heat the susceptor, and the susceptor transmits heat to the substrate to control the temperature. There is a certain distance between the heating device and the susceptor to avoid interfering with the movement (e.g. lifting or rotating) of the susceptor. According to the requirements of the process on the temperature and the precision control, the distance between the heating device and the susceptor, the heating power, the size characteristics of the susceptor and the related theories of heat conduction are reasonably designed to realize the precise control of the temperature of the substrate, which is beneficial to the uniformity of the temperature field near the top surface of the susceptor.

[0054] In addition, the interaction between the gas flow field formed by the process gas provided by the gas injection device above the carrying top surface of the susceptor and the temperature field near the top surface of the susceptor is complementary. In order to facilitate process adjustment, it is usually controlled that the susceptor has good levelness, and then the distance between the heating device and the susceptor is reasonably designed. If the levelness of the susceptor changes and exceeds a certain limit and cannot be adjusted in time, it will obviously have an adverse effect on the temperature field and the flow field, and the temperature of the substrate surface will change.

[0055] In the prior art, optical ranging methods are used in the process, for example, a spray hole of a gas injection device emits a probe light to the susceptor, and the distance between the susceptor and the reference surface of the chamber is monitored in real time according to the reflected light beam information. However, due to the high temperature of the epitaxial process, the high-temperature process gas in the chamber will affect the probe light emitted by the optical ranging device and the reflected light. The data obtained by the same optical ranging device for the same position on the susceptor under high-temperature and normal-temperature environments are different, and the ranging error cannot be ignored.

[0056] Therefore, the present application relies on the ranging device 6 to obtain a plurality of out-of-chamber distances between the lifting base plate 4 and the chamber base plate 12, and the change of the out-of-chamber distance is used to obtain the change of the in-chamber distance in the epitaxial growth process.

[0057] The measurement accuracy of the ranging device 6 can be adaptively selected according to the requirement of the level control of the susceptor 2. For example, the measurement accuracy can be 0.001 mm.

[0058] In the embodiment, as shown in Figure 1 The ranging device 6 can be a reflection type sensor, and the transmitting end and the receiving end of each ranging device 6 are correspondingly arranged on the chamber base plate 12 and the lifting base plate 4. In some specific embodiments, each ranging device 6 on the chamber base plate 12 is correspondingly arranged near the connection between each lead screw 51 and the chamber base plate 12, and each ranging device 6 on the lifting base plate 4 is correspondingly arranged near the connection between each lead screw 51 and the lifting base plate 4.

[0059] In some embodiments, the ranging device 6 can also be a reflection type sensor, and each ranging device 6 is correspondingly arranged near the connection between each lead screw 51 and the chamber base plate 12, or near the connection between each lead screw 51 and the lifting base plate 4.

[0060] The ranging device 6 of the embodiment can be a laser sensor or an infrared sensor, and no specific limitation is made to this, as long as it can realize accurate ranging of the out-of-chamber distance between the lifting base plate 4 and the chamber base plate 12.

[0061] In the example shown in Figure 1 The heating device 7 of the embodiment is supported by a heating support device 71 supporting the heating device 7. The heating support device 71 is arranged in the rotating device 3 through the chamber base plate 12, but does not rotate with the rotating device 3. The specific implementation is a conventional technical means in the art.

[0062] In some embodiments, the rotating device 3 is arranged in the center of the susceptor 2 in a center driving manner, the heating device 7 is supported by the heating support device 71 and arranged around the support device below the susceptor 2, and the bottom of the heating support device is arranged on the inner bottom surface of the chamber. The specific implementation is a conventional technical means in the art.

[0063] In the embodiment, an elastic sealing member 8 is further arranged between the chamber bottom plate 12 and the lifting bottom plate 4, and the elastic sealing member 8 forms a sealed space with the chamber bottom plate 12 and the lifting bottom plate 4, so as to realize the sealing of the chamber 1. Specifically, the two ends of the elastic sealing member 8 are respectively arranged on the chamber bottom plate 12 and the lifting bottom plate 4 in a sealing manner around the rotating device 3. The elastic sealing member 8 is hollow inside to allow the rotating device 3 to penetrate through.

[0064] In some embodiments, the elastic sealing member 8 is a bellows.

[0065] In the embodiment, the lifting control, the rotation control and the leveling control of the pedestal 2 are all controlled by the main control device.

[0066] In some embodiments, the main control device pre-stores the second calibration relationship.

[0067] In some embodiments, the main control device pre-stores the first calibration relationship and the second calibration relationship.

[0068] Specifically, the first calibration relationship is a corresponding relationship between the outer distances of the cavities and the inner distances of the cavities.

[0069] In some embodiments, the main control device further monitors and controls the process of epitaxial growth.

[0070] When the substrate 100 is placed on the pedestal 2, the main control device controls the semiconductor manufacturing equipment to perform the epitaxial growth process on the substrate 100. During the epitaxial growth process, the rotating device 3 drives the pedestal 2 to rotate, and the following steps are performed simultaneously: acquiring the outer distances of the cavities and determining whether the pedestal leveling needs to be adjusted according to the outer distances of the cavities, if yes, acquiring the corresponding inner distances of the cavities according to the outer distances of the cavities and the first calibration relationship, so as to determine the target lifting mechanism which needs to be controlled and the corresponding lifting control parameters, the lifting control parameters including the target compensation displacement; acquiring the current rotating speed of the pedestal 2 and acquiring the upper limit of the running speed of the target lifting mechanism in the second calibration relationship according to the current rotating speed of the pedestal 2; and finally controlling the target lifting mechanism to move the corresponding target compensation displacement at the acquired upper limit of the running speed.

[0071] Embodiment 2 The embodiment provides a method for acquiring the second calibration relationship.

[0072] The second calibration relationship is a corresponding relationship between the jump threshold values of the pedestal 2 at different rotating speeds and the upper limits of the running speeds of the lifting mechanisms 5, and the jump threshold value is the maximum value of the pedestal jump allowed by the epitaxial growth process at different rotating speeds. In the rotation control of the rotating device 3, the extent of the wobble of the susceptor varies at different rotation speeds. The wobble of the susceptor can be divided into axial wobble (i.e. the case where the susceptor wobbles up and down along its axial direction, e.g. the vertical direction) and radial wobble (i.e. the case where the susceptor wobbles left and right along its radial direction, e.g. the horizontal direction). As long as the susceptor has a certain speed, the axial wobble and the radial wobble exist simultaneously, and the extent of each wobble varies with the rotation speed in different trends, as shown in Figure 3 FIG. 3, where the abscissa is the rotation speed of the susceptor in rpm (revolutions per minute), and the ordinate is the wobble difference in millimeters. It can be seen that the radial wobble tends to dominate at high rotation speeds, and the axial wobble tends to dominate at low rotation speeds. Figure 3

[0073] The second calibration relationship of the present embodiment includes a radial wobble correspondence relationship between the radial wobble difference threshold of the susceptor 2 at different rotation speeds not lower than the first rotation speed threshold and the upper limit of the operation speed of the lifting mechanism, and an axial wobble correspondence relationship between the axial wobble difference threshold of the susceptor 2 at different rotation speeds lower than the first rotation speed threshold and the upper limit of the operation speed of the lifting mechanism.

[0074] In the rotation speed adjustment, after adjusting the axial wobble, the corresponding radial wobble condition will be alleviated. It is considered comprehensively that the first rotation speed threshold is not lower than 400 rpm.

[0075] The present embodiment uses the optical distance measuring method to test the wobble difference of the radial wobble and the axial wobble of the susceptor. As mentioned above, there is a non-negligible measurement error in the distance measurement of the high-temperature chamber using the optical distance measuring method. Therefore, the present application drives the susceptor to rotate at room temperature for calibration.

[0076] The present embodiment obtains the second calibration relationship at room temperature, as shown in Figure 4 FIG. 4, and the specific steps are as follows: P01: control the chamber 1 to maintain the process pressure required by the epitaxial growth process; P02: control the rotating device 3 to drive the susceptor 2 to rotate at a fixed rotation speed, control the lifting mechanisms 5 to synchronously ascend or descend at sequentially increased different operation speeds, and use the optical distance measuring method to monitor the axial wobble difference and the radial wobble difference of the susceptor at each operation speed; P03: select the operation speed corresponding to the wobble difference reaching or closest to the minimum of the axial wobble difference threshold and the radial wobble difference threshold as the corresponding upper limit of the operation speed at the fixed rotation speed; P04: control the rotating device 3 to increase the rotation speed of the susceptor 2 to another fixed rotation speed; Repeat steps P02 to P04 until a preset stopping condition is reached, and obtain the second calibration relationship.

[0077] ​Since the rotation device drives the susceptor to rotate in the process, not only the gravity of the susceptor itself needs to be overcome, but also the influence of the pressure in the cavity on the rotation of the susceptor. Compared with the same lifting adjustment of the susceptor while rotating the susceptor under the process pressure, the susceptor jumping conditions are different. Therefore, in step P01, the control maintains the process pressure required for epitaxial growth in the chamber 1. The calibration of the second calibration relationship of P02 to P04 is carried out under this pressure atmosphere.

[0078] In step P02, specifically, the rotation device 3 drives the susceptor 2 to rotate at a fixed rotation speed, first controls each lifting mechanism 5 to rise to the first position (for example, 1 millimeter) at a speed of V1, and monitors the axial jump difference and the radial jump difference of the susceptor in this test process; then control each lifting mechanism 5 to rise to the second position (for example, 1 millimeter) again at a speed of V2 higher than V1, and monitor the axial jump difference and the radial jump difference of the susceptor in this process, repeat the above process, increase the speed each time. More specifically, since the axial jump difference threshold and the radial jump difference threshold are empirical values obtained according to the requirements of the epitaxial growth process, this step is tested until the monitored axial jump difference and the radial jump difference of the susceptor are higher than the corresponding axial jump difference threshold and the radial jump difference threshold.

[0079] After the step of calibrating the corresponding relationship between the running speed of different lifting mechanisms 5 and the jump difference at a fixed rotation speed, the control of the rotation device driving the susceptor to rotate is increased to another fixed rotation speed, and the above calibration process is repeated.

[0080] In some embodiments, after the step of calibrating the corresponding relationship between the running speed of different lifting mechanisms 5 and the jump difference at a fixed rotation speed (P02 and P03), the distance between each cavity is obtained by the distance measuring device, and it is judged that the range (i.e. the difference between the maximum and minimum values in the group of data) of the distance between each cavity does not exceed the predetermined range threshold, which proves that the levelness of the susceptor meets the requirements, and then the control of the rotation device driving the susceptor to rotate is increased to another fixed rotation speed (P04), so as to avoid the problem that the deviation of the levelness of the susceptor caused by the previous calibration process affects the accuracy of the subsequent calibration.

[0081] In some embodiments, after the steps (P02 and P03) of calibrating the relationship between the running speed of the different lifting mechanisms 5 and the runout difference at a fixed rotating speed are completed, the control is performed to run each of the lifting mechanisms synchronously to the initial position of the base, and then the outer distance of each cavity is obtained and it is determined whether the range is not more than the preset range threshold, and then step P04 is performed. For the case where the initial distance between the base and the reference surface of the cavity is small, the position of the base lifting is not limited and cannot be debugged to complete the data (there is no lifting space when the distance exceeds the runout threshold).

[0082] In some embodiments, the base is preferably controlled to rise for calibration to avoid the case where the base is continuously lowered and easily interferes with the movement of the heating device.

[0083] In some embodiments, for the epitaxial growth process with very high temperature control accuracy, in order to ensure the effectiveness and rapid controllability of the heat transfer from the heating device to the base, the distance between the heating device and the base is generally 4-6 mm. In this case, in order to avoid the calibration of the base lowering being limited by the distance between the base and the heating device and being unable to obtain complete data, the base can be first raised to the upper limit position and then the calibration of the base lowering is controlled.

[0084] In the above calibration process, in the case of the base 2 being empty, an optical distance measuring device is used to emit a distance measuring light beam to the rotating base 2, and distance measuring information in the test time is obtained, so as to calculate the runout difference of the base based on the distance measuring information. When the axial runout difference needs to be obtained, the distance measuring light beam is incident to the top surface of the base 2 along the upper side of the base 2; when the radial runout difference needs to be obtained, the distance measuring light beam is incident to the side wall of the base 2 along the radial direction of the base 2.

[0085] More specifically, an optical ranging device emits probe light vertically toward the top surface of the susceptor through an optical window on the gas injection device and the spray channel. The optical ranging device receives feedback light information and converts the probe light and feedback light information into corresponding voltage signals. Through appropriate data processing, a histogram of the voltage change over time and the height values ​​of each susceptor can be obtained. The specific data processing methods and implementation of the optical ranging device are conventional in the art. For example, the optical ranging device can be a laser rangefinder or a blue light ranging instrument. Based on the change in each susceptor height value over the test time, the individual runout differences (the absolute value of the difference between the test height value and the initial height value, where the initial height value is the susceptor height value measured at a susceptor rotation speed of 0) can be obtained. The average of the individual runout differences is the runout difference value for the corresponding axial runout at that rotation speed. Similarly, an optical ranging device emits probe light vertically toward the susceptor sidewall through an optical window on the sidewall of chamber 1. Data processing based on the received feedback light information and the emitted probe light information can be performed to determine the radial distances of the susceptor sidewall from the light outlet. According to the change of each radial distance during the test time, the runout difference corresponding to the radial runout at the speed can be obtained. Figure 3 As shown, as the speed increases, the axial runout difference decreases and becomes more stable, while the radial runout difference increases and becomes more pronounced. At high speeds, radial runout dominates (possibly due to high centrifugal force), while at low speeds, axial runout dominates (possibly due to the base weight, which is higher relative to the centrifugal force).

[0086] It is well known to those skilled in the art that structural factors such as the degree of gear backlash of the speed reducer of the rotating machine, the stability of the connection between the support shaft and the bearing device, etc. make it impossible to avoid the radial runout and axial runout of the susceptor. For epitaxial growth processes, the rotation of the susceptor also has the effect of dragging the gas flow field to mix homogeneously, which is conducive to the film quality. The rotation, runout of the susceptor, combined with factors such as temperature and pressure, all play a role in the final film quality on the substrate. In the design of epitaxial growth processes, there are requirements for the radial runout threshold and the axial runout threshold. Generally, the relevant runout threshold requirements are proposed according to the specific epitaxial growth process and product performance requirements. For example, in the case of a silicon carbide homoepitaxial growth process on a 6-inch silicon carbide substrate, the product requires that the number of basal plane dislocations and stacking fault dislocations of the silicon carbide epitaxial layer be below 20. In the process design, the process speed is 900 rpm, the process pressure is 100 mbar, the process gas provided by the gas injection device is 200 sccm~ 400 sccm of silane, 70 sccm~ 150 sccm of propane, and 2000 sccm~ 5000 sccm of hydrogen chloride, the control requirement for the axial runout is higher than that for the radial runout, the axial runout difference is controlled to be below 0.5 mm, and the radial runout difference is controlled to be below 0.8 mm. For the acquisition of the second calibration relationship corresponding to this epitaxial growth process, in step P02, under the condition that the susceptor rotates at 900 rpm and the pressure in the chamber 1 is 100 mbar, the lifting mechanisms are controlled to run upward at a rate of 0.1 mm / s for 1 mm, in this process, the axial runout and radial runout of the susceptor are obtained respectively corresponding to the runout difference, and compared with the control difference required by the process, if it is judged that it does not exceed the process requirement, after confirming that the susceptor runs smoothly, the lifting mechanisms are controlled to run upward at a rate of 0.2 mm / s for 1 mm, in this process, the runout of the susceptor is continuously obtained and judged whether it meets the process requirement. Repeat this process until the axial runout difference and the radial runout difference obtained by testing under the control of the lifting mechanisms at a rate of 0.4 mm / s are close to the process requirement, and the axial runout difference and the radial runout difference obtained by testing under the control of the lifting mechanisms at a rate of 0.5 mm / s exceed the difference required by the process, that is, 0.4 mm / s is used as the upper limit of the running rate of each lifting mechanism used for real-time leveling of the susceptor under the current rotation speed of the susceptor (900 rpm).

[0087] In addition, in the process of monitoring the axial runout difference and the radial runout difference, if the monitored axial runout difference exceeds the corresponding runout difference threshold required by the process, and the radial runout difference has not yet exceeded the corresponding runout difference threshold required by the process, the corresponding lifting mechanism control rate at which the axial runout difference exceeds the limit required by the process is used as the test endpoint. Conversely.

[0088] Furthermore, considering that the present application needs to level the susceptor in real time during the epitaxial growth process, i.e. when the susceptor is in a rotating state, the jumping of the susceptor in this case is obviously more significant than the jumping of the susceptor in a rotating state only. If the lifting speed of each lifting mechanism is not effectively controlled, the degree of jumping of the susceptor will significantly interfere with the process gas flow field and affect the film forming quality. Based on the above reasons, in order to control the rotation of the susceptor driven by the rotating device and control the lifting mechanism to realize real-time leveling of the susceptor inside the chamber without interfering with the normal process, the corresponding relationship between the jumping threshold of the susceptor at different rotation speeds and the upper limit of the running speed of the lifting mechanism needs to be used to select the appropriate upper limit of the running speed of the lifting mechanism.

[0089] However, the conventional technique in the art stops the rotation of the susceptor and then controls the lifting movement, which obviously affects the stability of the gas flow field above the top surface of the susceptor (a suitable rotation speed of the susceptor forms a drag mixing of the gas flow field above the top surface of the susceptor, which is beneficial to the uniformity of film forming). The selection of the appropriate upper limit of the running speed of the lifting mechanism balances the influence of the jumping of the susceptor and the lifting efficiency, realizes the rapid leveling of the susceptor without interrupting the normal process, and maximizes the reduction or even avoids the adverse effects of the leveling of the susceptor 2 on the semiconductor material layer being grown during the process.

[0090] Embodiment 3 The present embodiment specifically provides a control process before epitaxial growth.

[0091] Step S1 includes placing a wafer 100 on the susceptor 2 and controlling the semiconductor manufacturing equipment to perform an epitaxial growth process on the wafer.

[0092] In step S1, the step of placing a wafer on the susceptor includes controlling each lifting mechanism to run at a preset working speed, so that the susceptor performs lifting movement to perform the transmission step of the wafer or the coated wafer.

[0093] In the present embodiment, the chamber 1 is provided with a gas injection device to provide process gas to the load-bearing top surface of the susceptor, an exhaust device to exhaust exhaust gas from the chamber 1, and a pressure maintaining device to maintain the pressure state in the chamber 1. The specific implementation is a conventional technical means in the art.

[0094] The main control device pre-stores process program information, which includes steps for performing a wafer transfer preparation step, moving the coated wafer out of the chamber, and transferring the wafer to be coated onto the susceptor 2, performing a preparation step for the epitaxial growth process, and performing the epitaxial growth process. Specifically, after one round of epitaxial growth process is completed, the main control device controls the gas injection device to provide a chemically inert purge gas into the chamber 1, controls the rotation device 3 to stop rotating so that the susceptor 2 is in a stationary state, and controls the heating device to stop working to cool down to a wafer transfer temperature. After the pressure inside the chamber 1 is equalized, the main control device controls the wafer transfer port of the chamber 1 to be in an open state, controls the susceptor to rise to a wafer transfer position opposite the wafer transfer port, transfers the coated wafer out of the susceptor, transfers the wafer to be coated into the susceptor from the wafer transfer port, and then controls the susceptor to descend to a working position. After the main control device controls the wafer transfer port to be in a closed state, the main control device controls the gas injection device and the exhaust device to make the pressure inside the chamber 1 reach a process pressure, controls the heating device to make the process temperature meet the process temperature requirements, drives the susceptor to rotate, and then controls the gas injection device to provide process gas for epitaxial growth into the chamber 1 to perform the epitaxial growth process.

[0095] In this application, the lifting mechanism 5 drives the rotation device 3 to move up and down, thereby driving the susceptor to rise or descend. The lifting control of the susceptor is performed between the epitaxial growth processes of adjacent rounds. Since the susceptor does not need to rotate, in order to accelerate the process rhythm and improve production efficiency, the working speed of the lifting mechanism driving the susceptor to move up and down does not need to consider the jumping of the susceptor, and is executed at the maximum working speed of the driving mechanism. That is, the working speed is higher than the upper limit of each operating speed in the second calibration relationship.

[0096] Similarly, taking the specific silicon carbide epitaxial growth process described in Embodiment 2 as an example, the movement speed of the lifting mechanism 5 moving up and down is controlled at 3-5 mm / s under a chamber internal pressure of 100 mbar.

[0097] Embodiment 4 The embodiment provides a method for obtaining a first calibration relationship. The first calibration relationship is a corresponding relationship between each of the chamber external distances and the corresponding chamber internal distances.

[0098] The meaning of each chamber external distance and the corresponding chamber internal distance is that, assuming there are three lifting mechanisms 5, taking the first lifting mechanism 5 as an example, the lifting mechanism 5 is vertically connected between the lifting bottom plate and the chamber bottom plate (the lifting bottom plate and the chamber bottom plate are horizontally parallel, and the lifting mechanism 5 is perpendicular to the two plates), then as Figure 5As shown, the distance between the two ends of the vertical connecting part outside the cavity is recorded as the first cavity outside distance X01, the distance between the two ends of the virtual structure extending along the cavity axis from the base bearing top surface to the cavity reference surface is recorded as the first cavity inside distance Y01, and X01 corresponds to Y01. Similarly, the second cavity outside distance X02 and its corresponding second cavity inside distance Y02 are obtained, as well as the corresponding third cavity outside distance X03 and its corresponding third cavity inside distance Y03.

[0099] Also in order to avoid the influence of hot gas in the chamber on the ranging accuracy in the calibration process, the first calibration relationship is obtained at room temperature in the embodiment, for example, Figure 6 As shown, the specific steps include: S01: control the chamber to maintain the process pressure required by the epitaxial growth process; S02: control each lifting mechanism 5 to run to a certain position, obtain each cavity outside distance, and judge that the range of each obtained cavity outside distance does not exceed the preset range threshold, then use the optical ranging device to obtain each cavity inside distance and judge that the range of each cavity inside distance does not exceed the preset range threshold; S03: use the average value of a plurality of cavity outside distances as the calibrated cavity outside distance, and use the average value of a plurality of cavity inside distances as the corresponding calibrated cavity inside distance; S04: control each lifting mechanism to rise or fall synchronously.

[0100] Repeat steps S02 to S04 until all cavity outside distances that need to be calibrated are completed, and obtain the first calibration relationship.

[0101] The reason for step S01 to control the process pressure in the chamber 1 is described in the analysis of step P01 in embodiment 2, which is not repeated here.

[0102] In step S02, the range of a plurality of cavity outside distances between the lifting bottom plate 4 and the chamber bottom plate 12 is controlled to not exceed the preset range threshold. In theory, when the range of each cavity outside distance meets the requirements, the corresponding cavity inside distance should also meet the requirements.

[0103] In step S02, after determining that the range of the plurality of cavity outer distances meets the requirement, the range of the plurality of cavity inner distances obtained by the optical distance measuring device is also determined, so as to further confirm that the related installation structure of the chamber and the support base is stable, and there is no base levelness problem caused by the structure itself. If the cavity outer distance meets the range requirement, but the cavity inner distance does not meet the range requirement, the calibration process of the first calibration relationship should be stopped, and whether the cavity support base structure has a problem causing the base to be unstable should be checked. If the further confirmation of the range of the cavity inner distance is not performed in step S02, the base with poor levelness will jump under the long-time process rotation control in the subsequent process, which not only affects the process epitaxial quality, but also easily affects the process safety.

[0104] In some embodiments, the range threshold is not more than 0.05 mm.

[0105] In some more specific embodiments, the average of the plurality of cavity outer distances (X01, X02,..., X0m) is taken as the calibration cavity outer distance, and the average of the plurality of cavity inner distances (Y01, Y02,..., Y0m) is taken as the corresponding calibration cavity inner distance.

[0106] Embodiment 5 The present embodiment provides that in the process of performing the epitaxial process in step S1, the following steps are also performed synchronously: S11: Obtain each cavity outer distance and determine whether base level adjustment is needed according to each cavity outer distance. If so, obtain each cavity inner distance according to the target cavity inner distance and each cavity inner distance, determine the target lifting mechanism that needs to be controlled in lifting and the corresponding lifting control parameter according to the target cavity inner distance and each cavity inner distance, and the lifting control parameter includes the target compensation displacement.

[0107] S12: Obtain the current rotation speed of the base and obtain the upper limit of the running speed of the target lifting mechanism in the second calibration relationship according to the current rotation speed of the base.

[0108] S13: Control the target lifting mechanism to move according to the lifting control parameter and the upper limit of the running speed obtained in step S12.

[0109] Specifically, in step S11, whether base level adjustment is needed is determined by the following steps: determining whether the range of each cavity outer distance exceeds a preset range threshold. If so, it is determined that base level adjustment is needed, otherwise, it is determined that base level adjustment is not needed.

[0110] In some embodiments, the range threshold is not more than 0.05 mm.

[0111] In step S11, the intra-cavity distances are obtained in the following manner: according to the outer-cavity distances and the first calibration relationship, the intra-cavity distances corresponding to the outer-cavity distances are obtained. Specifically, the outer-cavity distances are matched with the outer-cavity distances calibrated in the first calibration relationship, and the calibrated intra-cavity distances corresponding to the matched outer-cavity distances are taken as the intra-cavity distances corresponding to the outer-cavity distances.

[0112] In step S11, the lift control parameters include target compensation distances and target running directions. In this embodiment, the target lift mechanisms that need to be controlled and the corresponding lift control parameters are determined in the following manner: first, the target lift mechanisms and the target compensation distances corresponding thereto are determined according to the absolute values of the differences between the target intra-cavity distance and the intra-cavity distances; and then, the target running directions are determined according to the positive and negative of the differences between the target intra-cavity distance and the intra-cavity distances.

[0113] Specifically, first, the differences between the intra-cavity distances and the target intra-cavity distance are obtained, and when the absolute values of the differences exceed the allowable error range, the lift mechanisms corresponding to the intra-cavity distances are taken as the target lift mechanisms that need to be controlled, and the absolute values of the differences are taken as the target compensation distances corresponding to the target lift mechanisms; and then, the positive and negative of the differences are determined, and when the differences are positive, it indicates that the position of the target lift mechanism is too high, and the target running direction corresponding thereto should be downward, and vice versa, which indicates that the position of the target lift mechanism is too low, and the target running direction corresponding thereto should be upward.

[0114] In some embodiments, the target intra-cavity distance is an average distance value determined according to process requirements.

[0115] As described above, the radial runout of the susceptor tends to dominate at high rotation speeds, the axial runout of the susceptor tends to dominate at low rotation speeds, the rotation speed of the susceptor in the epitaxial growth process is usually controlled to be high to facilitate the mixing of the gas flow field above the susceptor, and it is found in process debugging that the corresponding radial runout condition is alleviated after the axial runout condition of the susceptor is alleviated. Therefore, the upper limit of the running speed of the corresponding lift mechanism is selected according to the radial runout corresponding relationship at low rotation speeds (i.e., below the first rotation speed threshold), and the upper limit of the running speed of the corresponding lift mechanism is selected according to the axial runout corresponding relationship at high rotation speeds (i.e., not lower than the second rotation speed threshold).

[0116] Based on this, when it is determined in step S12 that the current rotation speed of the susceptor 2 is lower than the first rotation speed threshold, the upper limit of the running speed of the corresponding lift mechanism at the current rotation speed of the susceptor 2 is obtained according to the aforementioned axial runout corresponding relationship. When it is determined in step S12 that the current rotation speed of the susceptor is not lower than the first rotation speed threshold, the upper limit of the running speed of the corresponding lift mechanism at the current rotation speed of the susceptor 2 is obtained according to the radial runout corresponding relationship. Thus, the upper limit of the running speed that is best adapted to the influence of the runout at the current rotation speed of the susceptor can be obtained.

[0117] In addition, as the higher the rotation speed of the susceptor, the more serious the radial runout, and the radial runout is more serious than the axial runout, the adjustable window of the lifting speed of the lifting mechanism 5 is reduced, and the speed is very low. Therefore, in order to improve the lifting efficiency and ensure safety, when the rotation speed of the susceptor 2 is too high, it is preferred to reduce the rotation speed of the susceptor 2 first, and then determine the upper limit of the running speed. That is, when the step S12 judges that the current rotation speed of the susceptor 2 is not lower than the second rotation speed threshold, the current rotation speed of the susceptor 2 is adjusted to a target rotation speed between the first rotation speed threshold and the second rotation speed threshold, and then the upper limit of the running speed of the lifting mechanism corresponding to the target rotation speed of the susceptor is obtained according to the radial runout corresponding relationship, and the second rotation speed threshold is higher than the first rotation speed threshold.

[0118] In this way, the largest lifting speed of the lifting mechanism within the allowable range of the susceptor runout is obtained, the influence of the susceptor runout and the lifting efficiency are balanced, the rapid leveling of the susceptor is considered on the premise that the normal process is not interrupted, and the adverse effects of the leveling of the susceptor 2 on the growing semiconductor material layer during the process are minimized or even avoided.

[0119] Preferably, the difference between the second rotation speed threshold and the first rotation speed threshold is not more than 400 rpm, the second rotation speed threshold is not less than 700 rpm, and the target rotation speed is close to the second rotation speed threshold compared with the first rotation speed threshold.

[0120] In the embodiment, in the epitaxial growth process including controlling the rotating device 3 to rotate the susceptor 2, after judging that the horizontal adjustment of the susceptor is needed and obtaining the target lifting mechanism and the corresponding lifting control parameters that need to be controlled, the epitaxial growth process or even the rotation of the susceptor controlled thereby does not need to be interrupted. Instead, the motion speed of the target lifting mechanism that needs to be controlled is selected by judging the current rotation speed of the susceptor 2, the real-time leveling of the susceptor 2 in the chamber 1 is realized, the normal process is not disturbed, and the good film quality of the substrate is also beneficial.

[0121] Specifically, the provided second calibration relationship is a corresponding relationship between the runout threshold of the susceptor 2 at different rotation speeds and the upper limit of the running speed of the control lifting mechanism, and the runout threshold is the maximum value of the susceptor runout allowed by the epitaxial growth process at different rotation speeds. The upper limit of the running speed of the lifting mechanism 5 corresponding to the current rotation speed of the susceptor 2 is obtained in the second calibration relationship, and the motion of the target lifting mechanism that needs to be controlled is controlled by the upper limit of the running speed, which can further select the largest running speed of the lifting mechanism without disturbing the normal process, so as to complete the leveling of the susceptor 2 as quickly as possible, and the production efficiency is considered.

[0122] Although the specific embodiments of the present application have been described above, it is understood by those skilled in the art that the present application is only illustrated by way of example, and the scope of protection of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to the embodiments without departing from the principles and essence of the present application, and such changes and modifications fall within the scope of protection of the present application.

Claims

1. A control method for semiconductor manufacturing equipment, characterized in that: The semiconductor manufacturing equipment includes a chamber with a base disposed therein, a dynamic seal passing through the chamber and connected to a rotating device of the base, a lifting base disposed outside the chamber on the rotating device, and a plurality of lifting mechanisms disposed on the lifting base and the chamber bottom plate of the chamber to drive the base to move up and down; There is an intra-cavity distance between the plane where the top surface of the base is located and the chamber reference plane of the chamber; The control method includes: S0: Obtaining a second calibration relationship between the beating threshold value of the base at different rotational speeds and the upper limit of the operating speed of the lifting mechanism; S1: placing a substrate on the base, controlling the rotating device to drive the base to rotate, and performing an epitaxial growth process on the substrate; During the epitaxial growth process in step S1, the following steps are also performed: S11: After determining that the base needs to be adjusted horizontally based on the extra-cavity distances between the lifting base plate and the chamber bottom plate, obtaining the intra-cavity distances corresponding to the extra-cavity distances, and determining the target lifting mechanism and corresponding lifting control parameters that need to be lifted and lowered based on the target intra-cavity distances; S12: Obtaining and matching the current rotation speed of the base in the second calibration relationship to obtain an upper limit of the operating speed; S13: Control the target lifting mechanism to move according to the lifting control parameters to match the obtained upper limit of the operating speed.

2. The control method according to claim 1, wherein: When the range of the outer cavity spacing exceeds a preset range threshold, it is determined that the base needs to be adjusted horizontally.

3. The control method according to claim 1, wherein: In step S0, it also includes obtaining a first calibration relationship, which is the correspondence between each of the extra-cavity spacings and the corresponding intra-cavity spacings. In step S11, the step of obtaining each intra-cavity spacing corresponding to each of the extra-cavity spacings includes: obtaining the corresponding intra-cavity spacings according to each of the extra-cavity spacings and the first calibration relationship.

4. The control method according to claim 3, wherein: The step of obtaining the first calibration relationship is performed at room temperature, comprising: S01: controlling the process pressure in the chamber to maintain the process required by the epitaxial growth process; S02: controlling each lifting mechanism to move to a certain position, obtaining each extra-cavity spacing and determining that the range of each extra-cavity spacing obtained does not exceed a preset range threshold, and then using an optical distance measuring device to obtain each intra-cavity spacing and determining that the range of each intra-cavity spacing does not exceed a preset range threshold; S03: taking an average value of the plurality of extra-cavity spacings as a calibrated extra-cavity spacing, and taking an average value of the plurality of intra-cavity spacings as a corresponding calibrated intra-cavity spacing; S04: Controlling the lifting mechanisms to rise or fall synchronously; Repeat steps S02 to S04.

5. The control method according to any one of claims 2 or 4, characterized in that: The extreme difference threshold does not exceed 0.05 mm.

6. The control method according to claim 1, wherein: The lifting control parameters include a target compensation distance and a target running direction. In step S11, the step of determining a target lifting mechanism that needs to be lifted and lowered and the corresponding lifting control parameters includes: Determining the target lifting mechanism and the corresponding target compensation distance according to the absolute value of the difference between the target intra-cavity spacing and each of the intra-cavity spacings; The corresponding target running direction is determined according to the positive or negative value of the difference between the target intra-cavity spacing and each of the intra-cavity spacings.

7. The control method according to claim 1, wherein: The second calibration relationship includes: a corresponding relationship between a radial runout difference threshold of the base at different rotational speeds not lower than a first rotational speed threshold and an upper limit of an operation speed of the lifting mechanism; A corresponding relationship between an axial runout difference threshold of the base at different rotational speeds lower than the first rotational speed threshold and an upper limit of an operation speed of the lifting mechanism.

8. The control method according to claim 7, wherein: The method further includes obtaining an axial runout difference threshold and a radial runout difference threshold. In step S0, the step of obtaining the second calibration relationship is performed at room temperature, including: P01: controlling the process pressure in the chamber to maintain the process required by the epitaxial growth process; P02: Controlling the rotating device to drive the base to rotate at a fixed speed, controlling each of the lifting mechanisms to synchronously ascend or descend at different and increasing motion speeds, and using optical ranging to monitor the axial runout difference and radial runout difference of the base at each operating speed; P03: selecting the operating speed corresponding to the runout difference that reaches or is closest to the minimum of the axial runout difference threshold and the radial runout difference threshold as the corresponding upper limit of the operating speed at the fixed speed; P04: Control the rotation device to increase the rotation speed of the base to another fixed rotation speed; Repeat steps P02 to P04.

9. The control method according to claim 7, wherein: The first speed threshold is not less than 400 rpm.

10. The control method according to claim 7, wherein: After step P03 is completed, after obtaining the distances outside the cavities and determining that the range thereof does not exceed the preset range threshold, step P04 is then executed, or: After step P03 is completed, each lifting mechanism is controlled to synchronously move to the initial position of the base, each cavity outer spacing is obtained and it is determined that the range thereof does not exceed the preset range threshold, and then step P04 is executed.

11. The control method according to claim 1, wherein: The second calibration relationship includes: a corresponding relationship between an axial runout difference threshold value of the base at different rotational speeds lower than the first rotational speed threshold value and an upper limit of an operation speed of the lifting mechanism; In step S12, after determining that the current rotation speed of the base is lower than the first rotation speed threshold, the upper limit of the operating speed of the lifting mechanism corresponding to the current rotation speed of the base is obtained according to the axial runout correspondence.

12. The control method according to claim 1, wherein: The second calibration relationship includes: a radial runout correspondence between a radial runout difference threshold of the base at different rotational speeds not lower than a first rotational speed threshold and an upper limit of an operation speed of the lifting mechanism; In step S12, after determining that the current rotation speed of the base is not lower than the first rotation speed threshold, the upper limit of the operating speed of the lifting mechanism corresponding to the current rotation speed of the base is obtained according to the radial runout correspondence.

13. The control method according to claim 1, wherein: The second calibration relationship includes: a radial runout correspondence between a radial runout difference threshold of the base at different rotational speeds not lower than a first rotational speed threshold and an upper limit of an operation speed of the lifting mechanism; In step S12, after determining that the current rotational speed of the base is higher than the second rotational speed threshold, the current rotational speed of the base is adjusted to a target rotational speed between the first rotational speed threshold and the second rotational speed threshold, and the upper limit of the operating speed of the lifting mechanism corresponding to the target rotational speed of the base is obtained according to the radial runout correspondence, and the second rotational speed threshold is higher than the first rotational speed threshold.

14. The control method according to claim 13, wherein: The first speed threshold is not less than 400 rpm, the second speed threshold is not less than 700 rpm, and the target speed is closer to the second speed threshold than the first speed threshold.

15. The control method according to claim 1, wherein: In step S1, the step of placing the substrate on the base includes: controlling each of the lifting mechanisms to operate at a preset working rate so that the base performs a lifting movement to perform a substrate or coated substrate transport step; The working rate is higher than the upper limit of each operating rate in the second calibration relationship.

16. A semiconductor manufacturing device, characterized in that: include: a chamber and a base, wherein the base is disposed in the chamber; A rotating device, wherein the dynamic seal passes through the bottom of the chamber and is rotatably connected to the base; A lifting base plate is located outside the chamber and surrounds the rotating device; A plurality of lifting mechanisms are provided on the lifting bottom plate and connected to the chamber bottom plate of the chamber to drive the base to perform lifting motion through the rotating device; a distance measuring device, used for obtaining a plurality of distances outside the cavity between the lifting base plate and the cavity bottom plate; The main control device has a pre-stored second calibration relationship and is communicatively connected to the rotating device, each of the distance measuring devices, and each of the lifting mechanisms. The second calibration relationship is the correspondence between the beating threshold of the base at different rotational speeds and the upper limit of the operating speed of the lifting mechanism.

17. The semiconductor manufacturing equipment according to claim 16, wherein: The bearing top surface of the base faces the top of the chamber, and the lifting mechanism includes a screw extending axially along the chamber, the top end of the screw is fixed to the chamber bottom plate, and the bottom end is fixed to the lifting bottom plate. The number of the distance measuring devices is not less than the number of the screws, and each of the distance measuring devices is arranged in a one-to-one correspondence near the connection between each of the screws and the chamber bottom plate, and / or is arranged in a one-to-one correspondence near the connection between each of the screws and the lifting bottom plate.

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