CN117845323A - Device and method for preparing gallium oxide wafer with multilayer structure - Google Patents

Abstract

The invention provides a device and a method for preparing a gallium oxide wafer with a multilayer structure, the structure comprises a device for preparing the gallium oxide wafer with the multilayer structure, and the device comprises a plurality of MOCVD deposition units, a conveying structure and a ceramic deposition seat structure which are arranged side by side, wherein the MOCVD deposition units comprise a shell, a metal source air inlet, an oxygen source air inlet and a heater, the lower end of the shell is opened, the metal source air inlet and the oxygen source air inlet are opened at the upper end of the shell, the metal source air inlet and the oxygen source air inlet are communicated with an inner cavity of the shell, gas filled into the inner cavity of the shell by the metal source air inlet and the oxygen source air inlet can be flushed out from the lower end of the shell, the lower end of the shell is in corresponding gas atmosphere, the heater is fixedly arranged at the lower part of the inner cavity of the shell, the heater is used for keeping the lower part of the inner cavity of the shell at high temperature, the conveying structure is positioned below the MOCVD deposition units, and the upper surface of the conveying structure is in clearance fit with the lower end of the shell. The invention can finish the multi-layer deposition of the wafer in a pipeline way at one time.

Description

Device and method for preparing gallium oxide wafer with multilayer structure

Technical Field

The invention relates to the technical field of water cleaning, in particular to a device and a method for preparing a gallium oxide wafer with a multilayer structure.

Background

MOCVD (metal organic chemical vapor deposition) equipment is a key equipment for producing semiconductor materials. It deposits the desired material on the surface of the crystal by reacting the metal organic compound with a gas on the surface of the substrate. The MOCVD apparatus is generally composed of a reaction chamber, a heater, a gas delivery system and a control system. In the reaction chamber, the metal organic compound and the gas are delivered to the surface of the substrate and then heated by a heater to promote the reaction. The control system is then used to monitor and adjust the reaction conditions to ensure that the desired materials are accurately deposited.

In the preparation process of the wafer with the multilayer structure, the existing MOCVD equipment can only deposit one substrate at a time, after deposition, the substrate needs to be taken out of the MOCVD equipment and put into another MOCVD equipment for secondary deposition, and so on until the multilayer structure is deposited on the substrate. The process is complex to operate, and the deposited layer contacts air during substrate transfer, and can be polluted by other substances, so that the quality of the wafer is affected.

Disclosure of Invention

The invention provides a device and a method for preparing a gallium oxide wafer with a multilayer structure, which can finish the multilayer deposition of the wafer in a pipeline way at one time.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

the utility model provides a device of preparation multilayer structure gallium oxide wafer, including a plurality of MOCVD deposition unit that set up side by side, conveying structure and ceramic deposition seat structure, wherein, MOCVD deposition unit includes the shell, the metal source air inlet, oxygen source air inlet and heater, the shell lower extreme opening, the metal source air inlet, the oxygen source air inlet is seted up in the shell upper end, the metal source air inlet, oxygen source air inlet and shell inner chamber intercommunication, the gas that the shell inner chamber was filled in metal source air inlet, the oxygen source air inlet can be followed the shell lower extreme and dashed, make the shell lower extreme be in corresponding gaseous atmosphere, heater fixed mounting is in the lower part of shell inner chamber, the heater is used for keeping the lower part high temperature of shell inner chamber, conveying structure is located MOCVD deposition unit below, conveying structure upper surface and shell lower extreme clearance fit, and conveying structure upper surface and shell lower extreme's clearance just are enough ceramic deposition seat structure pass through, the range direction of MOCVD deposition unit is suited with conveying structure's transmission direction, ceramic deposition seat structure is fixed on conveying structure upper surface, ceramic deposition seat structure includes a plurality of deposition seat upper surface is used for placing the substrate material of waiting to process.

In order to optimize the technical scheme, the specific measures adopted further comprise:

the number of the MOCVD deposition units is four, the four MOCVD deposition units are distributed at equal intervals from left to right, the four MOCVD deposition units are respectively a first deposition unit, a second deposition unit, a third deposition unit and a fourth deposition unit, and correspondingly, after the substrate materials to be processed are respectively deposited by the four MOCVD deposition units, the gallium oxide wafer for depositing four growth layers is obtained, and the four growth layers are respectively a piezoelectric film layer, a gallium oxide main body layer, a gallium oxide doped layer and a gallium oxide epitaxial layer from bottom to top.

The upper end of the shell is provided with a purified gas filling port which is used for filling purified gas into the inner cavity of the shell.

The MOCVD deposition units are mutually fixed through a support ring, the support ring is mutually fixed with external equipment through a support frame, and the MOCVD deposition units are fixed above the conveying structure through the cooperation of the support ring and the support frame.

The conveying structure is a stainless steel conveying belt, and comprises a driving motor, wherein the driving motor is in transmission connection with the stainless steel conveying belt, and the driving motor can drive the stainless steel conveying belt to move.

The conveying belt of the conveying structure moves from left to right, the conveying structure is provided with manipulators on the left and right sides of the MOCVD deposition unit, and when the ceramic deposition seat structure is positioned near the manipulators, the manipulators can place substrate materials to be processed on the deposition seat or take gallium oxide wafers off the deposition seat.

The ceramic deposition seat structure comprises a deposition seat, a ceramic support and a ceramic support fixing plate, wherein the deposition seat is fixed on the ceramic support, the ceramic support is fixedly connected with the ceramic support fixing plate, and the ceramic support fixing plate is detachably and fixedly arranged on the surface of the stainless steel conveyor belt.

The deposition seat is made of graphite material; the heater is a resistive heater.

The method for preparing the gallium oxide wafer with the multilayer structure comprises the following steps of:

step one, a conveying structure moves a ceramic deposition seat structure to the lower part of an MOCVD deposition unit, a substrate material to be processed is positioned at an opening at the lower end of a shell of the first deposition unit, and argon is filled into an inner cavity of the shell through a purifying gas filling port of each MOCVD deposition unit, so that the substrate material to be processed is in an inert gas atmosphere;

step two, the heater of the first deposition unit carries out high-temperature treatment on the substrate material to be processed, the metal source air inlet of the first deposition unit is filled with an organic metal source, the oxygen source air inlet is filled with oxygen and water, and a piezoelectric film layer is grown on the substrate material to be processed;

moving the conveying structure rightward for a preset distance to enable the substrate material to be processed to be positioned at the opening of the lower end of the shell of the second deposition unit, performing high-temperature treatment on the substrate material to be processed by a heater of the second deposition unit, introducing an organic metal source into a metal source air inlet of the second deposition unit, introducing oxygen and water into an oxygen source air inlet, and regrowing a gallium oxide main body layer on a piezoelectric film layer of the substrate material to be processed;

moving the conveying structure rightward for a preset distance to enable the substrate material to be processed to be positioned at the opening of the lower end of the shell of the third deposition unit, performing high-temperature treatment on the substrate material to be processed by a heater of the third deposition unit, introducing an organic metal source into a metal source air inlet of the third deposition unit, introducing oxygen and water into an oxygen source air inlet, and regrowing a gallium oxide doped layer on a gallium oxide main body layer of the substrate material to be processed;

and fifthly, moving the feeding structure to the right for a preset distance to enable the substrate material to be processed to be positioned at the opening of the lower end of the shell of the fourth deposition unit, performing high-temperature treatment on the substrate material to be processed by a heater of the fourth deposition unit, introducing an organic metal source into a metal source air inlet of the fourth deposition unit, introducing oxygen and water into an oxygen source air inlet, and regrowing a gallium oxide epitaxial layer on a gallium oxide doped layer of the substrate material to be processed, wherein the substrate material to be processed which grows in four layers is a gallium oxide wafer.

The heating temperature of the heater of the first deposition unit is 300-600 ℃, and the organic metal source introduced into the metal source air inlet of the first deposition unit is diethyl gallium or trimethyl gallium; the heating temperature of the heater of the second deposition unit is 800-1200 ℃, and the organic metal source introduced into the metal source air inlet of the second deposition unit is diethyl gallium or trimethyl gallium; the heating temperature of the heater of the third deposition unit is 950 ℃, and the organic metal source is Zn, mg, niO mixed gas which is introduced into the metal source air inlet of the third deposition unit; the heating temperature of the heater of the fourth deposition unit is 1000 ℃, and the organic metal source introduced into the metal source air inlet of the fourth deposition unit is diethyl gallium or trimethyl gallium.

The invention has the following advantages:

the invention can finish the multilayer deposition of the wafer at one time in a pipeline way, can rapidly prepare the gallium oxide piezoelectric film, the gallium oxide main body, the gallium oxide doped layer and the gallium oxide epitaxy, and can meet the application requirements of preparing the gallium oxide material of the power device.

The substrate material is not easy to contact with external impurities in the transfer process, and the gallium oxide-based power device prepared by the equipment has the variation coefficient of film thickness lower than 5%.

The gallium oxide wafer for preparing the acoustic power device by adopting the method is convenient for mass production, has lower finished products and has good application prospect in the field of power chips.

Drawings

FIG. 1 is a schematic view of the external structure of the device of the present invention;

FIG. 2 is a schematic view of the internal structure of the device of the present invention;

FIG. 3 is a schematic view of an exploded construction of the apparatus of the present invention;

fig. 4 is a schematic view of a ceramic deposition seat structure.

Name of the label in the figure: the MOCVD deposition unit 1, the housing 11, the metal source gas inlet 12, the oxygen source gas inlet 13, the heater 14, the support ring 15, the support frame 16, the purge gas inlet 17, the transfer structure 2, the robot 21, the ceramic deposition seat structure 3, the deposition seat 31, the ceramic support 32, and the ceramic support fixing piece 33.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described and illustrated below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden on the person of ordinary skill in the art based on the embodiments provided herein, are intended to be within the scope of the present application.

It is apparent that the drawings in the following description are only some examples or embodiments of the present application, and it is possible for those of ordinary skill in the art to apply the present application to other similar situations according to these drawings without inventive effort. Moreover, it should be appreciated that while such a development effort might be complex and lengthy, it would nevertheless be a routine undertaking of design, fabrication, or manufacture for those of ordinary skill having the benefit of this disclosure, and thus should not be construed as having the benefit of this disclosure.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is to be expressly and implicitly understood by those of ordinary skill in the art that the embodiments described herein can be combined with other embodiments without conflict.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. Reference to "a," "an," "the," and similar terms herein do not denote a limitation of quantity, but rather denote the singular or plural. The terms "comprising," "including," "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed or may include additional steps or elements not expressly listed or inherent to such process, method, article, or apparatus. The terms "connected," "coupled," and the like in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "plurality"/"a number" as used herein refers to two or more. "and/or" describes an association relationship of an association object, meaning that there may be three relationships, e.g., "a and/or B" may mean: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship. The terms "first," "second," "third," and the like, as used herein, are merely distinguishing between similar objects and not representing a particular ordering of objects.

As shown in fig. 1 to 4, the apparatus for preparing a gallium oxide wafer with a multilayer structure according to the present invention mainly includes a MOCVD deposition unit 1, a transfer structure 2, a ceramic deposition base structure 3, and the like, and in this embodiment, since the deposition layers of the gallium oxide wafer to be prepared are four layers, the number of MOCVD deposition units 1 is four, and in actual use, the number of MOCVD deposition units 1 may be set as needed, for example, when the deposition layers of the wafer are three layers, the number of MOCVD deposition units 1 is three. In the vicinity of the apparatus for producing a gallium oxide wafer of a multilayer structure, a negative pressure source for sucking and discharging the exhaust gas flowing out of the MOCVD deposition unit 1 is provided.

The MOCVD deposition unit 1 comprises a shell 11, a metal source air inlet 12, an oxygen source air inlet 13, a heater 14, a supporting ring 15, supporting frames 16, a purified gas filling port 17 and other structures, wherein the lower end of the shell 11 is opened, the metal source air inlet 12, the oxygen source air inlet 13 and the purified gas filling port 17 are arranged at the upper end of the shell 11, the metal source air inlet 12, the oxygen source air inlet 13 and the inner cavity of the shell 11 are communicated, the heater 14 is fixedly arranged at the lower part of the inner cavity of the shell 11, the supporting ring 15 is respectively connected with the two supporting frames 16 front and back, and the supporting frames 16 are fixed on the ground through supporting legs.

The conveyor 2 mainly comprises a conveyor belt and a manipulator 21, the conveyor belt is a stainless steel conveyor belt, the conveyor belt is in transmission connection with a drive motor, and the electric motor is connected to the conveyor belt through a gear and chain system, ensuring a smooth and accurate movement of the conveyor belt. The robot 21 adopts a 6-axis robot, which has 6 degrees of freedom, can flexibly move and operate in space, and is suitable for various complex assembly and processing tasks. The robot 21 may also be a SCARA robot, delta robot, or the like.

The ceramic deposition seat structure 3 comprises structures such as a deposition seat 31, a ceramic support 32, a ceramic support fixing piece 33 and the like, the number of the deposition seats 31 is four, and a plurality of ceramic deposition seat structures 3 are arranged on a transmission belt, and only one ceramic deposition seat structure is shown in the embodiment. The deposition seat 31 is fixed on the ceramic support 32, the ceramic support 32 is fixedly connected with the ceramic support fixing piece 33, and the ceramic support fixing piece 33 is detachably and fixedly arranged on the surface of the stainless steel conveyor belt.

In this embodiment, the conveyor belt, which is made of stainless steel, is the core, its length and width being dependent on the size of the wafers being processed.

All the components of the embodiment are controlled by a computer control system which can precisely control the speed of the motor, the loading and unloading operations of the manipulator, the temperature and pressure of the growth chamber and other parameters according to preset parameters.

The invention also provides a method for preparing the gallium oxide wafer with the multilayer structure, which comprises the following steps:

purifying in the cavity: the feeding structure 2 moves the ceramic deposition seat structure 3 to the lower part of the MOCVD deposition units 1, the substrate material to be processed is positioned at the opening of the lower end of the shell 11 of the first deposition unit, and the purifying gas filling inlet 17 of each MOCVD deposition unit 1 fills argon into the inner cavity of the shell 11 to enable the substrate material to be processed to be in inert gas atmosphere;

oxide piezoelectric film growth: and (3) performing piezoelectric film growth in the first cavity, wherein an organic metal source (such as diethyl gallium) is introduced into the metal source air inlet 12, oxygen and water are introduced into the oxygen source air inlet 13, and the interior of MOCVD is controlled to be kept at 300-600 ℃ at the moment, and the growth is performed for 60min, wherein the growth thickness is 10 mu m.

And (3) transferring the substrate: the ceramic deposition seat structure 3 is moved by means of a conveyor belt, the substrate material to be processed is moved to the lower part of the second MOCVD cavity,

and growing a gallium oxide main body layer, namely introducing diethyl gallium (trimethylgallium and the like) into a metal source air inlet 12 of the second MOCVD cavity, introducing oxygen and water into an oxygen source air inlet 13, and controlling the inside of the second MOCVD to keep 800-1200 ℃ at the moment, and growing for 10min, wherein the growing thickness is 1 mu m.

And (3) transferring the substrate: the ceramic deposition seat structure 3 is moved by a conveyor belt mode, the substrate material to be processed is moved to the lower part of the third MOCVD cavity,

growing a gallium oxide doped layer: and (3) growing a gallium oxide doped layer in the third MOCVD cavity, introducing Zn, mg, niO into the metal source air inlet 12, and carrying out Zn, mg, niO proportional growth by doping different gas components, and introducing oxygen and water into the oxygen source air inlet 13 to obtain the gallium oxide doped layer with the required surface morphology. At this time, MOCVD was controlled to maintain a temperature of 950℃and a growth thickness of about 200nm was performed for 2 minutes.

And (3) transferring the substrate: the ceramic deposition seat structure 3 is moved by a conveyor belt mode, the substrate material to be processed is moved to the lower part of the fourth MOCVD cavity,

and (3) growing a gallium oxide epitaxial layer, namely introducing diethyl gallium (trimethylgallium and the like) into a metal source air inlet 12 of the fourth MOCVD cavity, introducing oxygen and water into an oxygen source air inlet 13, and controlling the inside of the fourth MOCVD to keep 1000 ℃ at the moment, and growing for 1min to obtain the gallium oxide wafer with the multilayer structure, wherein the growing thickness is about 200nm.

And (5) taking out the wafer: the ceramic deposition seat structure 3 is moved by means of a conveyor belt, and the gallium oxide wafer with the multilayer structure is taken down from the deposition seat 31 by a manipulator, so that the preparation of the gallium oxide wafer with the multilayer structure is completed.

While preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the spirit or scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims and the equivalents thereof, the present application is intended to cover such modifications and variations.

Claims (10)

1. A device for preparing a gallium oxide wafer with a multilayer structure is characterized in that: including a plurality of MOCVD deposition units (1) that set up side by side, conveying structure (2) and ceramic deposition seat structure (3), wherein MOCVD deposition unit (1) include shell (11), metal source air inlet (12), oxygen source air inlet (13) and heater (14), shell (11) lower extreme opening, metal source air inlet (12), oxygen source air inlet (13) set up in shell (11) upper end, metal source air inlet (12), oxygen source air inlet (13) and shell (11) inner chamber intercommunication, metal source air inlet (12), oxygen source air inlet (13) fill the gas of shell (11) inner chamber and can dash out from shell (11) lower extreme, the lower end of the shell (11) is in a corresponding gas atmosphere, the heater (14) is fixedly arranged at the lower part of the inner cavity of the shell (11), the heater (14) is used for keeping the lower part of the inner cavity of the shell (11) at high temperature, the conveying structure (2) is positioned below the MOCVD deposition unit (1), the upper surface of the conveying structure (2) is in clearance fit with the lower end of the shell (11), the clearance between the upper surface of the conveying structure (2) and the lower end of the shell (11) is just enough for the ceramic deposition seat structure (3) to pass through, the arrangement direction of the MOCVD deposition unit (1) is matched with the transmission direction of the conveying structure (2), the ceramic deposition seat structure (3) is fixed on the upper surface of the conveying structure (2), the ceramic deposition seat structure (3) comprises a plurality of deposition seats (31), and the upper surface of the deposition seats (31) is used for placing substrate materials to be processed.

2. The apparatus for preparing a gallium oxide wafer having a multilayer structure according to claim 1, wherein: the number of the MOCVD deposition units (1) is four, the four MOCVD deposition units (1) are distributed at equal intervals from left to right, the four MOCVD deposition units (1) are respectively a first deposition unit, a second deposition unit, a third deposition unit and a fourth deposition unit, and correspondingly, the substrate material to be processed is respectively deposited by the four MOCVD deposition units (1) to obtain a gallium oxide wafer with four growth layers, and the four growth layers are respectively a piezoelectric film layer, a gallium oxide main body layer, a gallium oxide doped layer and a gallium oxide epitaxial layer from bottom to top.

3. The apparatus for preparing a gallium oxide wafer having a multilayer structure according to claim 2, wherein: the upper end of the shell (11) is provided with a purified gas filling inlet (17), and the purified gas filling inlet (17) is used for filling purified gas into the inner cavity of the shell (11).

4. An apparatus for preparing a gallium oxide wafer having a multilayer structure according to claim 3, wherein: the MOCVD deposition units (1) are mutually fixed through the support rings (15), the support rings (15) are mutually fixed with external equipment through the support frames (16), and the MOCVD deposition units (1) are fixed above the conveying structure (2) by the cooperation of the support rings (15) and the support frames (16).

5. The apparatus for preparing a gallium oxide wafer with a multilayer structure according to claim 4, wherein: the conveying structure (2) is a stainless steel conveying belt, the conveying structure (2) comprises a driving motor, the driving motor is in transmission connection with the stainless steel conveying belt, and the driving motor can drive the stainless steel conveying belt to move.

6. The apparatus for preparing a gallium oxide wafer with a multilayer structure according to claim 5, wherein: the conveying belt of the conveying structure (2) moves from left to right, the conveying structure (2) is provided with manipulators (21) on the left and right sides of the MOCVD deposition unit (1), and when the ceramic deposition seat structure (3) is located near the manipulators (21), the manipulators (21) can place a substrate material to be processed on the deposition seat (31) or take a gallium oxide wafer off the deposition seat (31).

7. The apparatus for preparing a gallium oxide wafer with a multilayer structure according to claim 6, wherein: the ceramic deposition seat structure (3) comprises a deposition seat (31), a ceramic support (32) and a ceramic support fixing piece (33), wherein the deposition seat (31) is fixed on the ceramic support (32), the ceramic support (32) is fixedly connected with the ceramic support fixing piece (33), and the ceramic support fixing piece (33) is detachably and fixedly arranged on the surface of the stainless steel conveyor belt.

8. The apparatus for preparing a gallium oxide wafer having a multilayer structure according to claim 1, wherein: the deposition seat (31) is made of graphite material; the heater (14) is a resistance heater.

9. The method for preparing the gallium oxide wafer with the multilayer structure is characterized by comprising the following steps of: an apparatus for preparing a gallium oxide wafer having a multilayer structure according to claim 3, comprising the steps of:

step one, a conveying structure (2) moves a ceramic deposition seat structure (3) to the lower part of an MOCVD deposition unit (1), a substrate material to be processed is positioned at an opening at the lower end of a shell (11) of the first deposition unit, and a purifying gas filling inlet (17) of each MOCVD deposition unit (1) fills argon into the inner cavity of the shell (11) to enable the substrate material to be processed to be in an inert gas atmosphere;

step two, a heater (14) of a first deposition unit carries out high-temperature treatment on a substrate material to be processed, a metal source air inlet (12) of the first deposition unit is filled with an organic metal source, an oxygen source air inlet (13) is filled with oxygen and water, and a piezoelectric film layer grows on the substrate material to be processed;

moving the conveying structure (2) rightward for a preset distance to enable the substrate material to be processed to be positioned at the opening of the lower end of the shell (11) of the second deposition unit, performing high-temperature treatment on the substrate material to be processed by the heater (14) of the second deposition unit, introducing an organic metal source into the metal source air inlet (12) of the second deposition unit, introducing oxygen and water into the oxygen source air inlet (13), and growing a gallium oxide main body layer on the piezoelectric film layer of the substrate material to be processed;

moving the conveying structure (2) rightward for a preset distance to enable the substrate material to be processed to be positioned at the opening of the lower end of the shell (11) of the third deposition unit, performing high-temperature treatment on the substrate material to be processed by the heater (14) of the third deposition unit, introducing an organic metal source into the metal source air inlet (12) of the third deposition unit, introducing oxygen and water into the oxygen source air inlet (13), and growing a gallium oxide doped layer on the gallium oxide main body layer of the substrate material to be processed;

and fifthly, moving the conveying structure (2) rightward for a preset distance to enable the substrate material to be processed to be positioned at the opening of the lower end of the shell (11) of the fourth deposition unit, performing high-temperature treatment on the substrate material to be processed by using the heater (14) of the fourth deposition unit, introducing an organic metal source into the metal source air inlet (12) of the fourth deposition unit, introducing oxygen and water into the oxygen source air inlet (13), and regrowing a gallium oxide epitaxial layer on the gallium oxide doped layer of the substrate material to be processed, wherein the substrate material to be processed which grows in four layers is the gallium oxide wafer.

10. The method for preparing a gallium oxide wafer with a multilayer structure according to claim 9, wherein: the heating temperature of the first deposition unit heater (14) is 300-600 ℃, and the organic metal source introduced into the metal source air inlet (12) of the first deposition unit is diethyl gallium or trimethyl gallium; the heating temperature of the second deposition unit heater (14) is 800-1200 ℃, and the organic metal source introduced into the metal source air inlet (12) of the second deposition unit is diethyl gallium or trimethyl gallium; the heating temperature of the third deposition unit heater (14) is 950 ℃, and the organic metal source introduced by the metal source air inlet (12) of the third deposition unit is Zn, mg, niO mixed gas; the heating temperature of the fourth deposition unit heater (14) is 1000 ℃, and the organic metal source introduced into the metal source air inlet (12) of the fourth deposition unit is diethyl gallium or trimethyl gallium.