A reaction device suitable for preparing high-In content InGaN material

Abstract

The present invention discloses a reaction device suitable for preparing InGaN materials with high In content, the reaction device comprises a reaction chamber, a sample stage device, a beam source furnace, a gas ionizer, a vacuum system and a heating device, wherein: the heating device comprises a substrate heating device and a chamber heating device. The reaction device provided by the present invention arranges a substrate heating device and a reflective cup with a cooling pipe on a heater carrier plate, so that the heating beam and the radiant heat are focused on the surface of the substrate, thereby improving the heating power utilization rate, isolating the direct irradiation of the heating light source to various components in the chamber, and reducing the risk of damage to the components due to excessive temperature. The reaction device provided by the present invention also has many advantages such as low energy consumption, large output, and excellent material quality.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor thin film epitaxial growth, and in particular to a reaction device suitable for preparing high-In component InGaN material. Background Art

[0002] Nitride materials are widely used in light-emitting diodes, electronic devices, solar cells and other fields due to their excellent properties.

[0003] In the currently commonly used metal organic chemical vapor deposition method, when preparing InGaN materials with high In content, too high growth temperature is easy to cause In desorption, which is not conducive to In incorporation; relatively low growth temperature is not conducive to the decomposition of NH3, and it is impossible to provide sufficient N source, so it is difficult to prepare InGaN materials with an In content higher than 30%. In addition, the high vacuum environment that cannot be achieved by the MOCVD equipment used in the preparation of materials by metal organic chemical vapor deposition is easy to introduce impurities such as C, H, and O, affecting the growth quality of the material. Plasma-assisted molecular beam epitaxy (RF-MBE) growth technology generates nitrogen plasma through a radio frequency power supply, which can provide sufficient N source and can achieve the growth of InGaN materials with high In content under low temperature conditions. However, in the currently commonly used RF-MBE growth device, since the sample stage can only rotate with the heater, this will seriously affect the number of substrates placed, which is not conducive to large-scale production. Atomic layer deposition is a method that can coat a substance layer by layer on the surface of a substrate in the form of a single atomic film, and can grow nitride materials with excellent film quality at a lower temperature, but its shortcomings are also obvious, such as extremely slow deposition rate, which cannot be mass-produced. Other common material preparation devices include magnetron sputtering, hydride vapor phase epitaxy, evaporation table, etc., but it is difficult to prepare complex InGaN / GaN quantum well structures and cannot meet the requirements. Summary of the invention

[0004] The object of the present invention is to provide a reaction device suitable for preparing InGaN materials with high In content, which can provide high vacuum and low temperature atmosphere and solve the problems of low production capacity and difficulty in growing high In content materials in the prior art.

[0005] The object of the present invention is achieved in that:

[0006] A reaction device suitable for preparing high-In content InGaN material, characterized by comprising a reaction chamber, a gas ionizer, a beam source furnace, a sample stage device, a vacuum system and a heating device, wherein:

[0007] A sample stage device is provided at the top of the reaction chamber, and the sample stage device includes a sample stage rotating device and a slide holder, the slide holder is used to hold the substrate, and the sample stage rotating device drives the slide holder to rotate and revolve;

[0008] A heating device is provided in the reaction chamber, and the heating device includes a substrate heating device for heating the substrate and a cavity heating device for baking the cavity; a plurality of substrate heating devices are arranged on the reaction chamber bottom plate in the reaction chamber, and the substrate heating device is a focusing radiation heating device, including a heating light source, a reflective cup and a heater carrier plate, the bottom end of the heater carrier plate is fixed on the reaction chamber bottom plate in the reaction chamber, the bottom end of the reflective cup is fixed on the heater carrier plate, and is in a vertical state, and the reflective cup and the heater carrier plate together form a semi-enclosed space that is open upward and only the top end is available for light to emit; the heating light source is arranged in the semi-enclosed space together enclosed by the reflective cup and the heater carrier plate; the reflective cup is a double-layer structure The invention discloses a structure in which a hollow interlayer is arranged between the inner surface and the outer surface of the reflective cup, a cooling pipe is introduced from the heater carrier plate into the reflective cup, and is wrapped in the interlayers on the inner and outer surfaces of the reflective cup. Different cooling media are introduced into the cooling pipe to control the temperature of the reflective cup and the heater carrier plate, so as to avoid the reflective cup and the heater carrier plate from heating the surrounding components. The temperature of the heater carrier plate and the reflective cup can be controlled between 0 and 100° C. by controlling the cooling medium and flow rate in the cooling pipe. A cavity heating device is arranged above the middle of the bottom plate of the reaction cavity, and is located between the gas ionizer, the beam source furnace and the substrate heating device. The cavity heating device heats the entire reaction cavity by a thermal radiation method.

[0009] The vacuum system for evacuating the reaction chamber includes three groups of pumps: a mechanical pump, a molecular pump and a cryogenic pump, wherein: the molecular pump is arranged outside the reaction chamber, and the input end of the molecular pump is arranged on the left wall of the middle part of the reaction chamber to connect with the reaction chamber, the mechanical pump is used as the front pump of the molecular pump, and the input end of the mechanical pump is connected to the output end of the molecular pump; the cryogenic pump is arranged outside the reaction chamber, and the input end of the cryogenic pump is arranged at the top outside the reaction chamber to connect with the reaction chamber; the vacuum system cooperates with the cavity baking effect of the cavity heating device to achieve a higher background vacuum;

[0010] A plurality of beam source furnaces and a plurality of gas ionizers are vertically placed on the bottom plate of the reaction chamber, and the gas ionizers, the beam source furnaces and the substrate heating device are all located directly below the arc line formed by the rotation of the wafer carrier.

[0011] The number of substrates that can be held by the wafer rack is 1 to 7, and the number of wafer racks is 1 to 9. The placement positions of the wafer racks are all located on a circular arc line of a concentric circle, and they also revolve along this circular arc line when rotating.

[0012] The number of gas ionizers is 1 to 4, which are used to provide anions required for growth.

[0013] The number of beam source furnaces is 1 to 6, which are used to provide various cations required for growth.

[0014] The number of substrate heating devices is 3 to 12, and the substrate heating devices are evenly arranged on the bottom plate of the reaction chamber, and a gas ionizer or a beam source furnace is respectively placed on the left and right sides of each substrate heating device.

[0015] The inner surface of the reflective cup is parabolic.

[0016] The heating light source is located at the parabolic focus of the inner surface of the reflective cup. The reflective cup can focus the heating light beam and radiant heat generated by the heating light source to the substrate to avoid heating the entire reaction chamber.

[0017] The heating light source is an infrared quartz radiation lamp or a halogen lamp.

[0018] Cooperating with the reaction chamber baking function of the chamber heating device, the vacuum system can pump the background vacuum to 1×10 -6 Below Pa.

[0019] The present invention uses a high-purity metal element as a metal source, obtains metal cations by evaporating through a beam source furnace, uses a gas ionizer to ionize ammonia or nitrogen by high-frequency induction to obtain nitrogen ions, and finally grows InGaN materials under low pressure and at a substrate temperature below 300°C, thereby being able to prepare InGaN materials with an In component higher than 30%.

[0020] The device for preparing high-In component InGaN materials provided by the present invention has a low operating temperature, and the energy consumption during operation is much lower than that of a traditional MOCVD device. By providing a reflective cup with a cooling pipe, the light beam and radiant heat generated by the heating light source are focused on the wafer carrier, further improving the utilization rate of the heating power of the heating light source; at the same time, the reflective cup provided with a cooling pipe can act as a cold shield and isolate the direct irradiation of the heating light source to various components in the reaction chamber, reducing the risk of damage to the components due to excessive temperature. In addition, the present invention can simultaneously maintain the temperature of substrates on multiple wafer carriers and realize the rotation of the wafer carriers, which can effectively improve the production capacity while ensuring the growth of materials.

[0021] The present invention can produce the following effects:

[0022] 1. It can grow high-In content InGaN materials in a low-temperature and high-vacuum atmosphere, which is beneficial to avoid material growth quality problems caused by impurity elements such as C, H, and O;

[0023] 2. By setting up two heating devices, the purpose of energy saving and protection of other components in the reaction chamber can be achieved to a greater extent;

[0024] 3. Compared with RF-MBE, more substrates can be placed at a time, and the output is high;

[0025] 4. Low energy consumption and excellent material quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of the present invention;

[0027] Figure 2 It is a top view schematic diagram of the reaction chamber bottom plate, beam source furnace, gas ionizer, and substrate heating device;

[0028] Figure 3 It is a schematic diagram of a substrate heating device of the present invention;

[0029] Among them: 1-reaction chamber, 11-reaction chamber bottom plate, 2-gas ionizer, 3-beam source furnace, 4-sample stage device, 41-sample stage rotating device, 42-slide holder, 5-substrate heating device, 51-heating light source, 52-heater carrier, 53-reflective cup, 531-cooling pipeline, 6-vacuum system, 61-mechanical pump, 62-molecular pump, 63-cryogenic pump, 7-cavity heating device. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are further described below in conjunction with the accompanying drawings in the embodiments of the present invention. In addition, the accompanying drawings of the present invention are all simplified and non-precisely proportioned, and are only used to conveniently and clearly assist in explaining the present invention.

[0031] A reaction device suitable for preparing high-In content InGaN material, comprising a reaction chamber 1, a gas ionizer 2, a beam source furnace 3, a sample stage device 4, a substrate heating device 5, a vacuum system 6 and a chamber heating device 7, wherein:

[0032] The sample stage device 4 is arranged at the top of the reaction chamber 1, and includes a sample stage rotating device 41 and a wafer carrier 42. A hollow groove is provided on the wafer carrier 42 for holding the substrate. The wafer carrier 42 is fixed to the bracket at the lower end of the sample stage rotating device 41 through a chimeric structure. The upper end of the sample stage rotating device 41 is movably mounted on a circular rotating track through a magnetic coupling rotor. One end of the magnetic coupling rotor rotates under the action of the gear and drives the wafer carrier 42 to rotate together.

[0033] The substrate heating device 5 and the cavity heating device 7 both use a thermal radiation method for heating, wherein the substrate heating device 5 is a focusing type thermal radiation heating device, which is used for heating the substrate during the reaction process. The substrate heating device 5 comprises a heating light source 51, a heater carrier plate 52 and a reflective cup 53. The bottom end of the heater carrier plate 52 is fixed on the reaction chamber bottom plate 11 in the reaction chamber 1, and the reflective cup 53 is fixed on the heater carrier plate 52 in a vertical state. The reflective cup 53 and the heater carrier plate 52 together form a semi-enclosed space that is open upward and only has the top for light to emit. The heating light source 51 is fixed on the heater carrier plate 52 and is located at the parabolic focus of the inner surface of the reflective cup 53. The reflective cup 53 is a double-layer structure. A cooling pipe 531 with a built-in cooling medium is introduced from the heater carrier plate 52 into the reflective cup 53 and is wrapped in the interlayer on the inner and outer surfaces of the reflective cup 53. The temperature of the heater carrier plate 52 and the reflective cup 53 can be controlled by controlling the cooling medium and flow rate in the cooling pipe 531. 0~100℃; the light emitted by the substrate heating device 5 can just cover the rotation path of the wafer carrier 42 on the bracket of the entire sample stage rotating device 41, which ensures that the substrate on the wafer carrier 42 is always in a heated state during the rotation process, and avoids heating the entire reaction chamber 1, thereby maximizing the heating power utilization rate of the heating light source 51; the cavity heating device 7 is arranged above the middle of the reaction chamber bottom plate 11 in the reaction chamber 1, and is located in the middle of the gas ionizer 2, the beam source furnace 3, and the substrate heating device 5. The cavity heating device 7 uses a thermal radiation method to bake and heat the entire reaction chamber 1 before the reaction, and cooperates with the vacuum system 6 to more effectively remove the gas adsorbed on the inner wall of the reaction chamber 1, thereby improving the background vacuum of the reaction chamber 1; the baking temperature of the cavity heating device 7 is lower than 200℃, and during the baking process, the components in the reaction chamber 1 are not in an operating state, and baking in this state will not cause damage to other components in the reaction chamber 1.

[0034] The six substrate heating devices 5 are evenly arranged on the bottom plate 11 of the reaction chamber, and are respectively placed between the two gas ionizers 2 and the four beam source furnaces 3 .

[0035] The gas ionizer 2 , the beam source furnace 3 and the substrate heating device 5 are all located directly below the arc line formed by the rotation of the wafer carrier 42 .

[0036] The vacuum system 6 for evacuating the reaction chamber 1 includes three groups of pumps: a mechanical pump 61, a molecular pump 62 and a cryogenic pump 63, wherein: the molecular pump 62 is arranged outside the reaction chamber 1, and the input end of the molecular pump 62 is arranged on the left wall of the middle part of the reaction chamber 1 to connect with the reaction chamber 1; the mechanical pump 61 is used as a pre-stage pump of the molecular pump 2, and the input end of the mechanical pump 61 is connected to the output end of the molecular pump 62; the cryogenic pump 63 is arranged outside the reaction chamber 1, and the input end of the cryogenic pump 63 is arranged at the top outside the reaction chamber 1 to connect with the reaction chamber 1; when the whole vacuum system is working, the background vacuum can be evacuated to 1×10 -6 Below Pa.

[0037] The number of substrates that the wafer rack 42 can hold is 1 to 7, and the number of wafer racks 42 is 1 to 9. The placement positions of the wafer racks 42 are all located on an arc line of a concentric circle, and they also revolve along this arc line when rotating.

[0038] The gas ionizer 2 is used to provide anions required for growth, and the beam source furnace 3 is used to provide various cations required for growth.

[0039] The inner surface of the reflective cup 53 is parabolic, and the reflective cup 53 vertically reflects the light emitted through the focus of the parabola, and finally focuses the light onto the substrate at a smaller divergence angle.

[0040] The heating light source 51 is disposed on the heater carrier 52 and is located at the parabolic focus of the inner surface of the reflective cup 53. The reflective cup 53 can focus the heating beam and radiant heat generated by the heating light source 51 onto the substrate to avoid heating the entire reaction chamber 1.

[0041] The heating light sources of the cavity heating device 5 and the substrate heating device 6 are infrared quartz radiation lamps or halogen lamps. The two sets of heating devices have different uses, so as to achieve the purpose of energy saving.

[0042] The reaction device can realize the growth of InGaN material when the substrate temperature is lower than 300°C, and can prepare InGaN material with In component higher than 30%.

[0043] Before material preparation, the cavity heating device 7 is turned on first, and the mechanical pump 61 and the molecular pump 62 are used to remove the gas adsorbed on the inner wall of the cavity. Then, the cavity heating device 7 is turned off and the cryogenic pump 63 is turned on to increase the background vacuum of the reaction cavity 1. During the material growth process, the vacuum system 6 continues to operate to maintain the vacuum required for the reaction process. Then, the substrate heating device 5 and the sample stage rotating device 41 are turned on to heat the substrate on the carrier 42. After reaching the predetermined temperature, the gas ionizer 2 and the beam source furnace 3 are turned on to respectively provide the anions and cations required for material growth. When the substrate on the carrier 42 passes over the gas ionizer 2 and the beam source furnace 3 in turn, the anions and cations arrive at the surface of the substrate in turn and are deposited layer by layer to achieve material growth.

[0044] The above is only a preferred embodiment of the invention, but the scope of the invention is not limited to the drawings. Any changes made according to the concept of the invention, or modified into equivalent embodiments with equivalent changes, which still do not exceed the spirit or scope covered by the description and drawings, should be within the protection scope of the invention.

Claims

1. A reaction device suitable for preparing high-In content InGaN materials, characterized in that: It includes a reaction chamber, a gas ionizer, a beam source furnace, a sample stage device, a vacuum system and a heating device, wherein: A sample stage device is provided at the top of the reaction chamber, and the sample stage device includes a sample stage rotating device and a wafer carrier, the wafer carrier is used to hold the substrate, and the sample stage rotating device drives the wafer carrier to rotate; A heating device is provided in the reaction chamber, and the heating device includes a substrate heating device for heating the substrate and a cavity heating device for baking the cavity; a plurality of substrate heating devices are arranged on the reaction chamber bottom plate in the reaction chamber, and the substrate heating device is a focusing radiation heating device, including a heating light source, a reflective cup and a heater carrier plate, the bottom end of the heater carrier plate is fixed on the reaction chamber bottom plate in the reaction chamber, the reflective cup is fixed on the heater carrier plate, and is in a vertical state, and the reflective cup and the heater carrier plate together form a semi-enclosed space which is open upward and only the top end is available for light to emit; the heating light source is arranged in the semi-enclosed space together surrounded by the reflective cup and the heater carrier plate; the reflective cup is a double-layer structure, A hollow interlayer is provided between the inner surface and the outer surface of the reflective cup. A cooling pipe is introduced from the heater carrier into the reflective cup and is wrapped in the interlayers on the inner and outer surfaces of the reflective cup. Different cooling media are introduced into the cooling pipe to control the temperature of the reflective cup and the heater carrier, so as to avoid the reflective cup and the heater carrier from heating the surrounding components. The temperature of the heater carrier and the reflective cup can be controlled between 0 and 100°C by controlling the cooling medium and flow rate in the cooling pipe. A cavity heating device is provided above the middle of the bottom plate of the reaction cavity and is located between the gas ionizer, the beam source furnace and the substrate heating device. The cavity heating device heats the entire reaction cavity by a thermal radiation method. The vacuum system for evacuating the reaction chamber includes three groups of pumps: a mechanical pump, a molecular pump and a cryogenic pump, wherein: the molecular pump is arranged outside the reaction chamber, and the input end of the molecular pump is arranged on the left wall of the middle part of the reaction chamber to connect with the reaction chamber, the mechanical pump is used as the front pump of the molecular pump, and the input end of the mechanical pump is connected to the output end of the molecular pump; the cryogenic pump is arranged outside the reaction chamber, and the input end of the cryogenic pump is arranged at the top outside the reaction chamber to connect with the reaction chamber; the vacuum system cooperates with the cavity baking effect of the cavity heating device to achieve a higher background vacuum; A plurality of beam source furnaces and a plurality of gas ionizers are vertically placed on the bottom plate of the reaction chamber, and the gas ionizers, the beam source furnaces and the substrate heating device are all located directly below the arc line formed by the rotation of the wafer carrier.

2. The reaction device for preparing high-In content InGaN material according to claim 1, characterized in that: The number of substrates that can be held by the wafer rack is 1 to 7, and the number of wafer racks is 1 to 9. The placement positions of the wafer racks are all located on a circular arc line of a concentric circle, and they also revolve along this circular arc line when rotating.

3. The reaction device for preparing high-In content InGaN material according to claim 1, characterized in that: The number of gas ionizers is 1 to 4, which are used to provide anions required for growth.

4. The reaction device for preparing high-In content InGaN material according to claim 1, characterized in that: The number of beam source furnaces is 1 to 6, which are used to provide the cations required for growth.

5. The reaction device for preparing high-In content InGaN material according to claim 1, characterized in that: The number of substrate heating devices is 3 to 12, and the substrate heating devices are evenly arranged on the bottom plate of the reaction chamber, and a gas ionizer or a beam source furnace is respectively placed on the left and right sides of each substrate heating device.

6. The reaction device for preparing high-In content InGaN material according to claim 1, characterized in that: The inner surface of the reflective cup is parabolic.

7. The reaction device for preparing high-In content InGaN material according to claim 1, characterized in that: The heating light source is located at the parabolic focus of the inner surface of the reflector cup.

8. The reaction device for preparing high-In content InGaN material according to claim 6, characterized in that: The heating light source is an infrared quartz radiation lamp or a halogen lamp.

9. The reaction device for preparing high-In content InGaN material according to claim 1, characterized in that: The vacuum system can reduce the background vacuum to 1×10 -6 Below Pa.

10. The reaction device for preparing high-In content InGaN material according to claim 1, characterized in that: The growth of InGaN material can be achieved at a substrate temperature below 300°C, and InGaN material with an In component higher than 30% can be prepared.

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