CN117822102A - Stress relief epitaxial growth device and epitaxial growth method - Google Patents
Stress relief epitaxial growth device and epitaxial growth method Download PDFInfo
- Publication number
- CN117822102A CN117822102A CN202311866172.2A CN202311866172A CN117822102A CN 117822102 A CN117822102 A CN 117822102A CN 202311866172 A CN202311866172 A CN 202311866172A CN 117822102 A CN117822102 A CN 117822102A
- Authority
- CN
- China
- Prior art keywords
- chamber
- stress relief
- epitaxial growth
- stress
- silicon carbide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 76
- 239000000758 substrate Substances 0.000 claims abstract description 90
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims abstract description 86
- 229910010271 silicon carbide Inorganic materials 0.000 claims abstract description 86
- 238000006243 chemical reaction Methods 0.000 claims abstract description 76
- 239000012299 nitrogen atmosphere Substances 0.000 claims abstract description 17
- 239000013078 crystal Substances 0.000 claims abstract description 12
- 235000012431 wafers Nutrition 0.000 claims description 81
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 31
- 238000010438 heat treatment Methods 0.000 claims description 24
- 229910052757 nitrogen Inorganic materials 0.000 claims description 14
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 3
- 238000005273 aeration Methods 0.000 claims 1
- 239000000463 material Substances 0.000 abstract description 7
- 230000005540 biological transmission Effects 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 18
- 238000000927 vapour-phase epitaxy Methods 0.000 description 5
- 238000009792 diffusion process Methods 0.000 description 4
- 230000000630 rising effect Effects 0.000 description 4
- 230000008030 elimination Effects 0.000 description 3
- 238000003379 elimination reaction Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000000376 reactant Substances 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
Abstract
The invention discloses a stress relief epitaxial growth device, which is characterized in that a stress relief chamber is additionally arranged on a transmission path between a wafer transfer chamber and a reaction chamber, a silicon carbide substrate is taken out from an upper material loading chamber and a lower material loading chamber through a mechanical arm, then is transferred to the stress relief chamber through the wafer transfer chamber, and crystal lattices are repaired in the stress relief chamber through high temperature, low pressure and nitrogen atmosphere to perform stress relief treatment, and is transferred to the reaction chamber through the wafer transfer chamber to perform epitaxial growth after being taken out from the stress relief chamber, so that the aim of stress relief can be achieved, the process condition of epitaxial growth cannot be influenced, the thickness uniformity of an epitaxial wafer is improved, the quality of the epitaxial wafer is improved, and the stress relief epitaxial growth device is particularly suitable for epitaxial growth of large-size substrates such as 8 inches. The invention also discloses a stress relief epitaxial growth method.
Description
Technical Field
The invention relates to the technical field of homoepitaxial growth MOCVD of silicon carbide semiconductor materials, in particular to a stress relief epitaxial growth device and an epitaxial growth method suitable for large-size silicon carbide.
Background
MOCVD (Metal-organic Chemical Vapor Deposition) is a novel Vapor Phase Epitaxy (VPE) technology developed on the basis of Vapor Phase Epitaxy (VPE) and is a novel vapor phase epitaxy (CVD) technology. Currently, the main body structure of the silicon carbide epitaxial furnace using the technology in China generally comprises a loading and unloading chamber, a wafer transfer chamber and a reaction chamber, and the epitaxial device can be used for preparing 6-inch silicon carbide epitaxial wafers. However, the prepared silicon carbide epitaxial wafer is affected by the stress of the silicon carbide substrate, and the substrate deformation can occur during high-temperature epitaxial growth, so that the problems of poor uniformity of concentration, warping of the surface of the wafer, low quality of the crystal and the like are caused. Because the stress is not well restrained, the large-size epitaxial wafer can be influenced by the stress to be broken, and BPD (Basal plane Dislocation) defects in the epitaxial process can be caused by stress deformation. The aforementioned stress problems, tens of times that of a 6 inch substrate on a large size (e.g., 8 inch) substrate, have a serious impact on the performance of power device MOSFETs.
The existing silicon carbide epitaxial furnace directly transfers the substrate from the wafer transfer chamber to the reaction chamber, and the reaction chamber cannot achieve the process condition capable of eliminating the stress. The main reason is that the transition between the two process conditions cannot be completed in a short time in a single chamber, the stress relief is performed under separate gas, pressure and temperature conditions, which are set for epitaxial growth of silicon carbide, and the reaction chamber is used for epitaxial growth. If different process conditions are switched in the reaction chamber to realize two processes of stress relief and epitaxial growth, not only the quality of the subsequent epitaxial growth is affected, but also the efficiency of epitaxial growth is affected, and the process efficiency is reduced. In a word, the existing silicon carbide epitaxial furnace structure cannot be freely switched between two process conditions of stress relief and epitaxial growth, and the influence of stress on epitaxial growth quality cannot be well relieved.
Accordingly, there is a need to provide an epitaxial growth apparatus and an epitaxial growth method capable of eliminating stress to solve the above-mentioned problems.
Disclosure of Invention
The invention aims to provide a stress relief epitaxial growth device capable of relieving stress and improving the consistency uniformity of epitaxial wafer.
Another object of the present invention is to provide a stress relief epitaxial growth method capable of relieving stress and improving uniformity of thickness of epitaxial wafers.
In order to achieve the above purpose, the technical scheme of the invention is as follows: the stress relief epitaxial growth device comprises an upper blanking chamber, a wafer transfer chamber, a stress relief chamber, a reaction chamber and a manipulator, wherein the upper blanking chamber, the lower blanking chamber, the wafer transfer chamber, the stress relief chamber and the reaction chamber are connected through the manipulator, a silicon carbide substrate is taken out from the upper blanking chamber and the lower blanking chamber through the manipulator and is transferred to the stress relief chamber through the wafer transfer chamber, a crystal lattice is repaired in the stress relief chamber through high temperature, low pressure and nitrogen atmosphere to perform stress relief treatment, the silicon carbide substrate after the stress relief treatment is taken out from the stress relief chamber through the manipulator and is transferred to the reaction chamber to perform epitaxial growth through the wafer transfer chamber, and an epitaxial wafer obtained after the epitaxial growth is transferred to the upper blanking chamber through the wafer transfer chamber through the manipulator.
Preferably, the high temperature of the stress relief chamber is 1400 ℃ to 1500 ℃, the low pressure of the stress relief chamber is 10E-4Torr to 10E-6Torr, and the stress relief is performed in the stress relief chamber for 7.5 minutes. The average free path of molecules at low pressure is increased, so that the transportation process of gaseous molecules is accelerated, and the diffusion coefficient of reactive substances on the surface of a workpiece material is increased; and the heat treatment is carried out in the nitrogen atmosphere, so that the carrier concentration of the silicon carbide substrate is high, and nitrogen molecules can be rapidly diffused under low pressure, thereby repairing the original lattice mismatch of the silicon carbide substrate and further achieving the effect of eliminating stress.
Preferably, the temperature rise and the evacuation pressure in the stress relief chamber are synchronously carried out, ventilation is carried out after the temperature rise in the stress relief chamber reaches the high temperature required by the process from 600 ℃, and the flow of nitrogen is 30-50 slm.
Preferably, after the stress relief heat treatment is completed, the stress relief chamber is cooled to 1200 ℃ to remove the silicon carbide substrate.
Preferably, after the silicon carbide substrate is transferred to the reaction chamber, the reaction chamber is heated from 1200 ℃ to 1600 ℃ to perform epitaxial growth so as to obtain an epitaxial wafer, after the epitaxial growth is completed, the reaction chamber is cooled to 900 ℃, and then the epitaxial wafer is taken out of the reaction chamber through the manipulator and transferred to the loading and unloading chamber through the wafer transfer chamber.
Correspondingly, the invention also provides a stress relief epitaxial growth method, which comprises the following steps:
(1) The silicon carbide substrate is taken out from the loading and unloading chamber by the manipulator and is transferred to the stress relieving chamber through the sheet transferring chamber;
(2) Repairing the crystal lattice in the stress relieving chamber through high temperature, low pressure and nitrogen atmosphere to perform stress relieving treatment;
(3) The silicon carbide substrate is taken out of the stress relieving chamber by the manipulator and is transferred to the reaction chamber through the wafer transfer chamber for epitaxial growth so as to obtain an epitaxial wafer;
(4) And after the epitaxial growth is finished, the manipulator takes the epitaxial wafer out of the reaction chamber and transmits the epitaxial wafer to the loading and unloading chamber through the wafer transfer chamber.
Preferably, in the stress relief epitaxial growth method of the present invention, the step (2) includes the steps of:
(21) The stress eliminating chamber is heated from 600 ℃, and the heating and the evacuating pressure are synchronously carried out until the process requirements of high temperature and low pressure are met;
(22) The stress eliminating chamber is ventilated after reaching the temperature required by the process, and the flow of nitrogen is 30-50 slm; the heat treatment is carried out in the nitrogen atmosphere, and because the carrier concentration of the silicon carbide substrate is high, nitrogen molecules can be rapidly diffused under low pressure, so that the original lattice mismatch of the silicon carbide substrate is repaired, and the effect of eliminating stress is achieved;
(23) After the stress relief heat treatment is completed, the temperature in the stress relief chamber is reduced to 1200 ℃ to take out the silicon carbide substrate.
Preferably, in the stress relief epitaxial growth method of the present invention, the high temperature of the stress relief chamber is 1400 ℃ to 1500 ℃, the low pressure of the stress relief chamber is 10E-4Torr to 10E-6Torr, and the stress relief is performed in the stress relief chamber for 7.5 minutes. The average free path of molecules at low pressure is increased, so that the transportation process of gaseous molecules is accelerated, and the diffusion coefficient of reactive substances on the surface of a workpiece material is increased; and the heat treatment is carried out in the nitrogen atmosphere, so that the carrier concentration of the silicon carbide substrate is high, and nitrogen molecules can be rapidly diffused under low pressure, thereby repairing the original lattice mismatch of the silicon carbide substrate and further achieving the effect of eliminating stress.
Preferably, in the stress relief epitaxial growth method of the present invention, in the step (3), a length of time that the robot takes out the silicon carbide substrate from the stress relief chamber and transfers the silicon carbide substrate to the reaction chamber is 2 minutes or less, and the reaction chamber is heated from 1200 ℃ to 1600 ℃ to perform epitaxial growth to obtain an epitaxial wafer. The length of time from the stress relief chamber to the reaction chamber is controlled because after a long period of temperature dissipation, the stress suddenly changes after the temperature rises, and thus the transfer length is controlled to be less than 2 minutes.
Preferably, in the stress relief epitaxial growth method of the present invention, in the step (4), the reaction chamber is cooled to 900 ℃, and then the epitaxial wafer is taken out from the reaction chamber by the robot and transferred to the loading and unloading chamber through the wafer transfer chamber.
Compared with the prior art, the stress relief epitaxial growth device has the advantages that the stress relief chamber is additionally arranged between the wafer transfer chamber and the reaction chamber, so that the silicon carbide substrate is transferred to the stress relief chamber, the crystal lattice is repaired in the stress relief chamber through high temperature, low pressure and nitrogen atmosphere to relieve most of stress, and then the crystal lattice is transferred to the reaction chamber for epitaxial growth to obtain the epitaxial wafer, the stress relief purpose can be achieved, the process condition of epitaxial growth cannot be influenced, the thickness uniformity of the epitaxial wafer is improved, the quality of the epitaxial wafer is improved, and the stress relief epitaxial growth device is particularly suitable for epitaxial growth of large-size substrates such as 8 inches. In addition, the stress relief treatment in the stress relief chamber and the epitaxial growth in the reaction chamber are synchronously carried out, so that the process efficiency of the epitaxial growth is not affected.
Correspondingly, in the stress relief epitaxial growth method, the stress relief treatment step of repairing the crystal lattice in the stress relief chamber through high temperature, low pressure and nitrogen atmosphere is added, so that most of stress is relieved, the purpose of stress relief can be achieved, the process condition of epitaxial growth cannot be influenced, the thickness uniformity of an epitaxial wafer is improved, the quality of the epitaxial wafer is improved, and the method is particularly suitable for epitaxial growth of large-size substrates such as 8 inches; and simultaneously, when one silicon carbide substrate is subjected to epitaxial growth, the next silicon carbide substrate is subjected to stress relief step synchronously, and after the stress relief step is completed, the silicon carbide substrate is respectively switched, so that the cycle treatment is carried out, and the process efficiency of epitaxial growth is not affected.
Drawings
FIG. 1 is a schematic diagram of a stress relief epitaxial growth apparatus of the present invention.
Fig. 2 is a flow chart of a stress relief epitaxial growth method of the present invention.
Fig. 3 is a sub-flowchart of step S02 in fig. 2.
Detailed Description
Embodiments of the present invention will now be described with reference to the drawings, wherein like reference numerals represent like elements throughout. It should be noted that, the description of the azimuth or the positional relationship indicated by the present invention, such as up, down, left, right, front, back, etc., is based on the azimuth or the positional relationship shown in the drawings, and is only for convenience in describing the technical solution of the present application and/or simplifying the description, and does not indicate or imply that the device or element to be referred to must have a specific azimuth, be configured and operated in a specific azimuth, and therefore should not be construed as limiting the present application. First, second, etc. are described solely for distinguishing between technical features and should not be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of technical features indicated.
The stress relief epitaxial growth device 100 provided by the invention is particularly suitable for stress relief and epitaxial growth of large-size silicon carbide substrates such as 8 inches. But is not limited thereto and may be applied to epitaxial growth of silicon carbide substrates of other dimensions.
Referring to fig. 1, a stress relief epitaxial growth apparatus 100 of the present invention includes a loading and unloading chamber 110, a wafer transfer chamber 120, a stress relief chamber 130, a reaction chamber 140, and a robot (not shown). The stress relieving chamber 130 is disposed between the transfer paths of the wafer transferring chamber 120 and the reaction chamber 140, and the positional arrangement relationship among the loading and unloading chamber 110, the wafer transferring chamber 120, the stress relieving chamber 130 and the reaction chamber 140 is not particularly limited. The loading and unloading chamber 110, the transfer chamber 120, the stress relieving chamber 130 and the reaction chamber 140 are connected by the manipulator. In one embodiment, the loading and unloading chamber 110, the wafer transfer chamber 120 and the reaction chamber 140 are sequentially arranged, and the stress relief chamber 130 is adjacent to the wafer transfer chamber 120, so that the overall structure of the device is compact, and the time for transferring the silicon carbide substrate is shortened. In the present invention, the specific structure of the manipulator and the manner of connecting the components thereof are conventional structures in the art, and thus will not be described in detail.
In the production process, the silicon carbide substrate is taken out from the loading and unloading chamber 110 through the manipulator, is firstly transferred to the sheet transferring chamber 120 and then is transferred to the stress relieving chamber 130 through the sheet transferring chamber 120, and part of stress can be relieved in the stress relieving chamber 130 through heat treatment. The silicon carbide substrate after the stress relief treatment is taken out of the stress relief chamber 130 by the manipulator and is transferred to the wafer transfer chamber 120 again, then is transferred to the reaction chamber 140 by the wafer transfer chamber 120 for epitaxial growth, and an epitaxial wafer is obtained after the epitaxial growth is completed, and then is taken out by the manipulator and is transferred to the loading and unloading chamber 110 by the wafer transfer chamber 120, so that the process steps of stress relief and epitaxial growth are completed.
In the present invention, the structures of other parts related to epitaxial growth are similar to those of the conventional 8-inch epitaxial furnace, and thus will not be described in detail.
With continued reference to fig. 1, in the present invention, a special stress relief chamber 130 is added for relieving the stress of the silicon carbide substrate, and only a general heat treatment is performed in the stress relief chamber 130, that is, a work task of relieving about 40% of the stress can be completed without setting special process parameters and conditions. The transfer of the silicon carbide substrate from the loading and unloading chamber 110 and the transfer chamber 120 to the stress relief chamber 130 uses conventional process parameters, and thus will not be described in detail.
More preferably, the present invention specifically sets the process parameters within the stress relief chamber 130 to specifically achieve stress relief and enhance the effect of the relief. Specifically, the high temperature of the stress relief chamber 130 is set to 1400 ℃ to 1500 ℃, the low pressure of the stress relief chamber 130 is set to 10E-4Torr to 10E-6Torr, and nitrogen gas is introduced into the stress relief chamber 130 after the temperature in the stress relief chamber 130 is raised from 600 ℃ to the high temperature required for the process. And the duration of the stress relief performed by the silicon carbide substrate in the stress relief chamber 130 was set to 7.5 minutes. The average free path of molecules is increased under low pressure, so that the transportation process of gaseous molecules is accelerated, and the diffusion coefficient of the reactant on the surface of the workpiece material is increased; and the heat treatment is carried out in the nitrogen atmosphere, and because the carrier concentration of the substrate is high, nitrogen molecules can be rapidly diffused under low pressure, so that the original lattice mismatch of the silicon carbide substrate can be repaired, and the effect of eliminating stress is achieved. The invention can further achieve the work task of eliminating the stress by about 50% through the specific process parameter setting in the stress eliminating chamber 130, that is, the stress eliminating chamber 130 and the specific process condition setting in the stress eliminating chamber can achieve the effect of eliminating the stress by about 90% on the silicon carbide substrate, and the effect of eliminating the stress is better.
It should be understood that the process parameters of the stress relief chamber 130, such as high temperature, low pressure, and stress relief, may be controlled according to different substrates, and are not limited to the above embodiments.
With continued reference to fig. 1, in the present invention, the temperature rising and the evacuation pressure in the stress relief chamber 130 are performed synchronously, and when the temperature rising in the stress relief chamber 130 reaches the above-mentioned high temperature required by the process from 600 ℃, the operation of introducing nitrogen is performed, and the flow of nitrogen is preferably 30 to 50slm, and the heat treatment is performed under the nitrogen atmosphere, because the carrier concentration of the silicon carbide substrate is high, the nitrogen molecules can be rapidly diffused under low pressure, and the original lattice mismatch of the silicon carbide substrate is repaired, thereby achieving the stress relief effect.
Further, after the stress relieving heat treatment is completed in the stress relieving chamber 130, the temperature in the stress relieving chamber 130 is reduced to 1200 ℃, the silicon carbide substrate is taken out by a manipulator, and the silicon carbide substrate after the heat treatment is transferred to the reaction chamber 140 through the transfer chamber 120 for epitaxial growth. After the silicon carbide substrate is transferred into the reaction chamber 140, the temperature in the reaction chamber 140 is increased from 1200 ℃ to 1600 ℃ or so to perform epitaxial growth, so as to obtain an epitaxial wafer. In the present invention, the temperature settings in the stress relief chamber 130 and the reaction chamber 140 are adapted, and the time for transferring the stress relief chamber 130 to the reaction chamber 140 is shortened, so that the stress residue caused by the temperature can be reduced, and a better stress relief effect can be achieved.
Still further, in the present invention, the transfer time of the silicon carbide substrate from the stress relief chamber 130 to the wafer transfer chamber 120 to the reaction chamber 140 is not longer than 2 minutes. The reason is that the long transfer time can lead to temperature dissipation, and the temperature rising can lead to stress shock after long time temperature dissipation, so the duration of the silicon carbide substrate in the transfer process is controlled, the purpose is to reduce the stress change caused by temperature dissipation, and the effect of stress elimination is ensured.
Referring to fig. 1 again, in the present invention, after the epitaxial growth is completed, the reaction chamber 140 is cooled to 900 ℃, and then the epitaxial wafer is taken out from the reaction chamber 140 by the manipulator, and is transferred to the wafer transfer chamber 120 first, and then transferred to the loading and unloading chamber 110 through the wafer transfer chamber 120, so that the process steps of stress relief and epitaxial growth are completed. The stress relief in the stress relief chamber 130 and the epitaxial growth in the reaction chamber 140 may be performed simultaneously, specifically, the silicon carbide substrate subjected to the stress relief treatment is epitaxially grown in the reaction chamber 140, while a new silicon carbide substrate is transferred to the stress relief chamber 130 for stress relief, after the epitaxial growth is completed, the silicon carbide substrate subjected to the next stress relief treatment is transferred to the reaction chamber 140 for epitaxial growth, and then the next silicon carbide substrate is transferred to the stress relief chamber 130 for stress relief, so that the cycle treatment does not affect the efficiency of the epitaxial growth inside and outside the reaction chamber 140.
The present invention further provides a stress relief epitaxial growth method using the stress relief epitaxial growth apparatus 100 described above, as described below in conjunction with fig. 1-2. The stress relief epitaxial growth method is described in detail below. The stress relief epitaxial growth method of the invention comprises the following steps:
s01, taking the silicon carbide substrate out of the loading and unloading chamber by a manipulator, and transferring the silicon carbide substrate to the stress relieving chamber through the wafer transferring chamber;
in the present invention, a special stress relieving chamber 130 is added for relieving the stress of the silicon carbide substrate, and only a general heat treatment is required to be performed in the stress relieving chamber 130, that is, a working task of relieving about 40% of the stress can be completed without setting special process parameters and conditions. The silicon carbide substrate is taken out from the loading and unloading chamber 110, then transferred to the wafer transfer chamber 120, and then transferred from the wafer transfer chamber 120 to the stress relief chamber 130, wherein the existing process parameters are adopted in the process, so that the detailed description is omitted.
S02, repairing the crystal lattice in the stress relief chamber through high temperature, low pressure and nitrogen atmosphere so as to perform stress relief treatment;
in the present invention, the process parameters in the stress relief chamber 130 are specifically set to specifically achieve stress relief and improve the effect of the relief. Specifically, the high temperature of the stress relief chamber 130 is set to 1400 ℃ to 1500 ℃, the low pressure of the stress relief chamber 130 is set to 10E-4Torr to 10E-6Torr, and nitrogen gas is introduced into the stress relief chamber 130 after the temperature in the stress relief chamber 130 is raised from 600 ℃ to the high temperature required for the process. And the duration of the stress relief performed by the silicon carbide substrate in the stress relief chamber 130 was set to 7.5 minutes. The average free path of molecules is increased under low pressure, so that the transportation process of gaseous molecules is accelerated, and the diffusion coefficient of the reactant on the surface of the workpiece material is increased; and the heat treatment is carried out in the nitrogen atmosphere, and because the carrier concentration of the substrate is high, nitrogen molecules can be rapidly diffused under low pressure, so that the original lattice mismatch of the silicon carbide substrate can be repaired, and the effect of eliminating stress is achieved. The invention can further achieve the work task of eliminating the stress by about 50% through the specific process parameter setting in the stress eliminating chamber 130, that is, the stress eliminating chamber 130 and the specific process condition setting in the stress eliminating chamber can achieve the effect of eliminating the stress by about 90% on the silicon carbide substrate, and the effect of eliminating the stress is better.
It should be understood that the process parameters of the stress relief chamber 130, such as high temperature, low pressure, and stress relief, may be controlled according to different substrates, and are not limited to the above values.
S03, the silicon carbide substrate is taken out of the stress relief chamber by the manipulator and is transferred to the reaction chamber through the wafer transfer chamber for epitaxial growth so as to obtain an epitaxial wafer;
in the present invention, the length of time that the manipulator takes out the silicon carbide substrate from the stress relief chamber 130 and transfers the silicon carbide substrate to the reaction chamber 140 is less than or equal to 2 minutes, because the transfer time is longer, which can cause temperature dissipation, and the temperature rise after the long time of temperature dissipation can cause stress shock, so that the length of time that the silicon carbide substrate is transferred is controlled, in order to reduce the stress change caused by the temperature dissipation, and ensure the effect of stress relief.
Further, after the stress relieving heat treatment is completed in the stress relieving chamber 130, the temperature in the stress relieving chamber 130 is reduced to 1200 ℃, the silicon carbide substrate is taken out by a manipulator, and the silicon carbide substrate after the heat treatment is transferred to the reaction chamber 140 through the transfer chamber 120 for epitaxial growth. After the silicon carbide substrate is transferred into the reaction chamber 140, the temperature in the reaction chamber 140 is increased from 1200 ℃ to 1600 ℃ or so to perform epitaxial growth, so as to obtain an epitaxial wafer. In the present invention, the temperature settings in the stress relief chamber 130 and the reaction chamber 140 are adapted, and the time for transferring the stress relief chamber 130 to the reaction chamber 140 is shortened, so that the stress residue caused by the temperature can be reduced, and a better stress relief effect can be achieved.
And S04, after the epitaxial growth is finished, the manipulator takes out the epitaxial wafer from the reaction chamber and transmits the epitaxial wafer to the loading and unloading chamber through the wafer transfer chamber.
In the stress relief epitaxial growth method of the present invention, after the epitaxial growth is completed, the reaction chamber 140 is cooled to 900 ℃, and then the epitaxial wafer is taken out from the reaction chamber 140 by the manipulator and transferred to the loading and unloading chamber 110 through the wafer transfer chamber 120, so that the process steps of stress relief and epitaxial growth are completed. The stress relief in the stress relief chamber 130 and the epitaxial growth in the reaction chamber 140 may be performed simultaneously, specifically, the silicon carbide substrate subjected to the stress relief treatment is epitaxially grown in the reaction chamber 140, while a new silicon carbide substrate is transferred to the stress relief chamber 130 for stress relief, after the epitaxial growth is completed, the silicon carbide substrate subjected to the next stress relief treatment is transferred to the reaction chamber 140 for epitaxial growth, and then the next silicon carbide substrate is transferred to the stress relief chamber 130 for stress relief, so that the cycle treatment does not affect the efficiency of the epitaxial growth inside and outside the reaction chamber 140.
Referring to fig. 2, in the stress relief epitaxial growth method of the present invention, the step S02 includes the steps of:
s21, heating the stress relief chamber from 600 ℃, and synchronously carrying out heating and evacuating pressure until the process requirements of high temperature and low pressure are met;
s22, introducing nitrogen after the stress relieving chamber reaches the temperature required by the process, wherein the flow rate of the nitrogen is 30-50 slm; according to the invention, the heat treatment is carried out in the nitrogen atmosphere, and because the carrier concentration of the silicon carbide substrate is high, nitrogen molecules can be rapidly diffused under low pressure, so that the original lattice mismatch of the silicon carbide substrate is repaired, and the effect of eliminating stress is achieved;
and S23, after the stress elimination heat treatment is completed, the temperature in the stress elimination chamber is reduced to 1200 ℃ so as to take out the silicon carbide substrate.
In the present invention, the temperature in the stress relieving chamber 130 is reduced to 1200 ℃, the silicon carbide substrate is then taken out by a manipulator, the silicon carbide substrate after heat treatment is transferred to the reaction chamber 140 through the wafer transfer chamber 120, and the reaction chamber 140 is heated from 1200 ℃ to 1600 ℃ or so for epitaxial growth to obtain an epitaxial wafer. Therefore, the temperature settings in the stress relief chamber 130 and the reaction chamber 140 are compatible, and the time for transferring the stress relief chamber 130 to the reaction chamber 140 is shortened, so as to avoid the problem of temperature dissipation caused by longer transfer time, and further avoid the problem of sudden stress change caused by temperature rising after long-time temperature dissipation, thereby reducing the stress residue caused by temperature and realizing better stress relief effect.
In summary, since the stress relief epitaxial growth device 100 of the present invention adds the stress relief chamber 130 between the wafer transfer chamber 120 and the reaction chamber 140, the silicon carbide substrate is transferred to the stress relief chamber 130, and the crystal lattice is repaired in the stress relief chamber 130 by high temperature, low pressure and nitrogen atmosphere to relieve most of the stress, and then transferred to the reaction chamber 140 for epitaxial growth to obtain the epitaxial wafer, which not only achieves the purpose of stress relief, but also does not affect the process conditions of epitaxial growth, thereby improving the thickness uniformity of the epitaxial wafer and the quality of the epitaxial wafer, and being particularly suitable for epitaxial growth of large-sized substrates such as 8 inches. Moreover, the stress relief process in the stress relief chamber 130 is performed simultaneously with the epitaxial growth in the reaction chamber 140, without affecting the process efficiency of the epitaxial growth.
Correspondingly, in the stress relief epitaxial growth method, the stress relief treatment step of repairing the crystal lattice in the stress relief chamber 130 by high temperature, low pressure and nitrogen atmosphere is added, so that most of stress is relieved, the purpose of stress relief can be achieved, the process condition of epitaxial growth cannot be influenced, the thickness uniformity of an epitaxial wafer is improved, the quality of the epitaxial wafer is improved, and the method is particularly suitable for epitaxial growth of large-size substrates such as 8 inches. And when one silicon carbide substrate is epitaxially grown, the next silicon carbide substrate is synchronously subjected to stress relief steps, and after the stress relief steps are completed, the silicon carbide substrates are respectively switched, so that the cyclic treatment is carried out, and the process efficiency of epitaxial growth is not affected.
Other structures and methods of apparatus for epitaxial growth of silicon carbide according to the present invention are well known to those of ordinary skill in the art and will not be described in detail herein.
The foregoing description of the preferred embodiments of the present invention is not intended to limit the scope of the claims, which follow, as defined in the claims.
Claims (10)
1. The stress relief epitaxial growth device is characterized by comprising an upper blanking chamber, a wafer transfer chamber, a stress relief chamber, a reaction chamber and a manipulator, wherein the upper blanking chamber, the lower blanking chamber, the wafer transfer chamber, the stress relief chamber and the reaction chamber are connected through the manipulator, a silicon carbide substrate is taken out from the upper blanking chamber and the lower blanking chamber through the manipulator and is transferred to the stress relief chamber through the wafer transfer chamber, a crystal lattice is repaired in the stress relief chamber through high temperature, low pressure and nitrogen atmosphere to perform stress relief treatment, the silicon carbide substrate after the stress relief treatment is taken out from the stress relief chamber through the manipulator and is transferred to the reaction chamber to perform epitaxial growth through the wafer transfer chamber, and an epitaxial wafer obtained after the epitaxial growth is transferred to the upper blanking chamber through the wafer transfer chamber through the manipulator.
2. The stress relief epitaxial growth apparatus of claim 1, wherein the elevated temperature of the stress relief chamber is 1400 ℃ to 1500 ℃, the low pressure of the stress relief chamber is 10E "4 Torr to 10E" 6Torr, and the duration of stress relief in the stress relief chamber is 7.5 minutes.
3. The stress relief epitaxial growth apparatus of claim 1 or 2, wherein the temperature rise and the evacuation pressure in the stress relief chamber are performed simultaneously, the aeration is performed after the temperature rise in the stress relief chamber from 600 ℃ to a high temperature required for the process, and the flow rate of nitrogen gas is 30 to 50slm.
4. The stress relief epitaxial growth apparatus of claim 1 or 2, wherein after completion of the stress relief heat treatment, the stress relief chamber is cooled down to 1200 ℃ to remove the silicon carbide substrate.
5. The apparatus according to claim 1 or 2, wherein after the silicon carbide substrate is transferred to the reaction chamber, the reaction chamber is heated from 1200 ℃ to 1600 ℃ to perform epitaxial growth to obtain epitaxial wafers, after the epitaxial growth is completed, the reaction chamber is cooled to 900 ℃, and then the epitaxial wafers are taken out of the reaction chamber by the robot and transferred to the loading and unloading chamber through the wafer transfer chamber.
6. A method of stress relief epitaxial growth comprising the steps of:
(1) The silicon carbide substrate is taken out from the loading and unloading chamber by the manipulator and is transferred to the stress relieving chamber through the sheet transferring chamber;
(2) Repairing the crystal lattice in the stress relieving chamber through high temperature, low pressure and nitrogen atmosphere to perform stress relieving treatment;
(3) The silicon carbide substrate is taken out of the stress relieving chamber by the manipulator and is transferred to the reaction chamber through the wafer transfer chamber for epitaxial growth so as to obtain an epitaxial wafer;
(4) And after the epitaxial growth is finished, the manipulator takes the epitaxial wafer out of the reaction chamber and transmits the epitaxial wafer to the loading and unloading chamber through the wafer transfer chamber.
7. The method of stress relief epitaxial growth of claim 6, wherein step (2) comprises the steps of:
(21) The stress eliminating chamber is heated from 600 ℃, and the heating and the evacuating pressure are synchronously carried out until the process requirements of high temperature and low pressure are met;
(22) The stress eliminating chamber is ventilated after reaching the temperature required by the process, and the flow of nitrogen is 30-50 slm;
(23) After the stress relief heat treatment is completed, the temperature in the stress relief chamber is reduced to 1200 ℃ to take out the silicon carbide substrate.
8. The method of claim 6 or 7, wherein the stress relief epitaxial growth chamber has a high temperature of 1400 ℃ to 1500 ℃, the stress relief chamber has a low pressure of 10E "4 Torr to 10E" 6Torr, and the stress relief chamber is subjected to stress relief for a period of 7.5 minutes.
9. The method according to claim 6 or 7, wherein in the step (3), a period of time during which the silicon carbide substrate is taken out of the stress relief chamber and transferred to the reaction chamber by the robot is 2 minutes or less, and the reaction chamber is heated from 1200 ℃ to 1600 ℃ to perform epitaxial growth to obtain an epitaxial wafer.
10. The method of claim 6 or 7, wherein in the step (4), the reaction chamber is cooled to 900 ℃, and the epitaxial wafer is taken out of the reaction chamber by the robot and transferred to the loading and unloading chamber through the wafer transfer chamber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311866172.2A CN117822102A (en) | 2023-12-29 | 2023-12-29 | Stress relief epitaxial growth device and epitaxial growth method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311866172.2A CN117822102A (en) | 2023-12-29 | 2023-12-29 | Stress relief epitaxial growth device and epitaxial growth method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117822102A true CN117822102A (en) | 2024-04-05 |
Family
ID=90512968
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311866172.2A Pending CN117822102A (en) | 2023-12-29 | 2023-12-29 | Stress relief epitaxial growth device and epitaxial growth method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117822102A (en) |
-
2023
- 2023-12-29 CN CN202311866172.2A patent/CN117822102A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107675249B (en) | Diameter expanding growth method of single crystal diamond | |
| CN108428618B (en) | Gallium nitride growth method based on graphene insertion layer structure | |
| CN111041550B (en) | Gas phase doping crystal growth method based on VGF method | |
| JPWO2002097872A1 (en) | Semiconductor wafer manufacturing method and susceptor used therefor | |
| CN104846438B (en) | Growth method of aluminum indium nitride film | |
| CN111739791B (en) | Epitaxial structure of gallium nitride material and preparation method | |
| CN117822102A (en) | Stress relief epitaxial growth device and epitaxial growth method | |
| CN108447772B (en) | Manufacturing method of silicon epitaxial wafer for COO L MOS | |
| CN112795983A (en) | Multi-cavity semiconductor film epitaxial device | |
| JPH09246196A (en) | Silicon single crystal and manufacture of silicon single crystal thin film | |
| US10304678B1 (en) | Method for fabricating InGaP epitaxial layer by metal organic chemical vapor deposition (MOCVD) | |
| US8216921B2 (en) | Method for production of silicon wafer for epitaxial substrate and method for production of epitaxial substrate | |
| CN115881514A (en) | Method for manufacturing single crystal self-supporting substrate | |
| CN105006427A (en) | Method for growing high-quality gallium nitride epitaxial structure by using low-temperature transition layer | |
| CN111180311B (en) | Method for reducing Si concentration at interface of GaN substrate and epitaxial layer | |
| CN112744816A (en) | Preparation method of silicon carbide powder for silicon carbide single crystal growth | |
| CN112885708B (en) | Preparation method of silicon carbide homoepitaxial material | |
| CN113380604B (en) | 4H-SiC material with atomic level step morphology and etching method thereof | |
| CN113053735B (en) | BxAlyGa(1-x-y)N self-supporting single crystal substrate and preparation method thereof | |
| US20230245885A1 (en) | Semiconductor laminate and method for manufacturing semiconductor laminate | |
| CN108217636B (en) | Process gas assisted graphene hydrogen insertion layer growth method | |
| CN117832057A (en) | Epitaxial wafer growth method | |
| CN116219538A (en) | Silicon carbide seed crystal bonding and fixing method and structure | |
| CN115652429A (en) | Preparation method of alpha-phase gallium oxide crystal | |
| JPH03195016A (en) | Thermal cleaning method of si substrate; epitaxial growth and heat treatment apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |