CN104637788A - Selective area growing method for III-nitride micro graphic structure and structure - Google Patents

Abstract

The invention discloses a selective area growing method for III-nitride micro graphic structure and a structure. A carbon nanotube array is taken as a micrometer/nanometer composite size mask; nanometer grade growing windows in bundle clusters and micrometer grade growing windows among the bundle clusters are arranged at intervals; according to the remarkable difference between the growth rates of III-nitride in the micrometer grade growing windows and the nanometer grade growing windows, an III-nitride dual-size micro graphic structure in which micro graphic structures which are the same in shapes and are different in sizes are arranged at intervals can be made on the micrometer/nanometer composite size mask. By adopting the carbon nanotube mask, the advantage of nanoheteroepitaxy can be brought into full play, the crystal quality of a micro graphic structural material is improved, and the residual stress is lowered; the nanotube has the characteristics of high thermal conductivity and high electrical conductivity, so that the heat dissipation of subsequently-manufactured micro-electron and photoelectron devices and the improvement on the electric property are facilitated.

Description

Selected Area Growth Method and Structure of Group III Nitride Microscopic Pattern Structure

technical field

The invention relates to semiconductor optoelectronic technology, in particular to a method and structure for selective growth of a group III nitride double-sized microscopic pattern structure with carbon nanotubes as a mask, precise and controllable shape and size.

Background technique

Group III nitrides are a class of semiconductor materials with great application prospects. In addition to conventional thin film materials, in recent years, various micron or nanoscale group III nitrides and thin film materials with such micron or nanoscale pattern structures It also exhibits superior performance and wide application possibilities. The aforementioned microstructures include one-dimensional trench structures, two-dimensional island structures, or three-dimensional columnar structures. Such thin-film materials with microscopic graphic structures can be used as graphic templates to obtain high-quality thin-film materials, and can also be directly used to prepare microelectronic and optoelectronic devices in micron and nanometer scales.

At present, the methods for preparing the microscopic pattern structure of group III nitrides mainly include:

(1) Deposit a silicon dioxide or silicon nitride insulating layer by plasma-enhanced chemical vapor deposition PECVD and other methods, and then etch the insulating layer into a design pattern by photolithography, nanoimprinting, electron beam exposure, etc., and then use the selected area The growth method produces a thin film material with a microscopic pattern structure;

(2) Using a maskless method, small-sized metal materials such as nickel and iron are used as catalysts, or thin-film materials with microscopic pattern structures are prepared by self-assembly through stress modulation.

Among the above two types of existing methods, the thin film materials produced by the former have the advantages of good uniformity and good controllability, but the process is complicated and the cost is high, and it is still difficult to obtain a microscopic pattern structure with a characteristic size below 100nm on a large scale. . Although the latter has a relatively simple process and does not need to prepare a mask, the microscopic pattern structure produced has poor uniformity, poor controllability, and poor repeatability.

Contents of the invention

In order to solve the above existing problems in the prior art, the present invention proposes a III carbon nanotube array as a mask to grow microscopic pattern structures such as columns, cones, inverted trapezoids or strips with micron or nanoscale. The selective growth method of group nitrides; this method has the advantages of low cost, simple process, environmental protection, etc., and the shape and size of the graphics are flexible, adjustable, precise and controllable.

An object of the present invention is to provide a mask structure for a selective growth method of a III-nitride dual-size microscopic pattern structure.

The selected area growth structure of the group III nitride double-sized microscopic pattern structure of the present invention comprises: a substrate, a carbon nanotube mask and a group III nitride double-sized microscopic pattern structure; the carbon nanotube mask laid on the substrate consists of a single Each layer of carbon nanotube film is an array of carbon nanotubes arranged in parallel. These carbon nanotubes are aggregated to form a cluster structure arranged in parallel, and micron-scale growth is formed between adjacent clusters. Window, a nanoscale growth window is formed between multiple carbon nanotubes arranged in parallel in the bundle, thereby forming a micro/nano composite size mask with nanoscale growth windows and micron scale growth windows arranged alternately; on the carbon nanotube mask Growth of III-nitride dual-scale microscopic pattern structures.

The substrate is made of materials that can realize the growth of group III nitrides, such as gallium nitride substrates, sapphire substrates, silicon carbide substrates, silicon substrates, etc., or the substrates are made of gallium nitride substrates, sapphire substrates, carbide A silicon substrate or a composite substrate with a template layer grown on a silicon substrate with a thickness between 10nm and 100μm. The material of the template layer is one or more of gallium nitride GaN, aluminum nitride AlN and indium nitride InN kinds of alloys.

When preparing the above mask structure, first on the growth substrate of the carbon nanotube array, a layer of neatly arranged and uniformly sized nano-scale iron powder is deposited as a catalyst by electron beam evaporation, and then by low-pressure chemical vapor deposition LPCVD method, at low pressure Using acetylene as a carbon source at high temperature, an array composed of quasi-ordered, parallel-arranged carbon nanotubes is grown, and then transferred as a layer of carbon nanotube film to a substrate for growing group III nitrides. The carbon nanotube mask is composed of a single-layer or multi-layer carbon nanotube film. Each layer of carbon nanotube film is a quasi-ordered, parallel array of carbon nanotubes. The carbon nanotubes can be single-walled or multi-walled. , the size of a single carbon nanotube is between 10 and 100 nm, and these carbon nanotubes will aggregate with each other to form a cluster structure arranged in parallel. The distance between adjacent carbon nanotubes in the cluster is between 10 and 500 nm, which forms a nanoscale growth window for the subsequent growth of group III nitrides; the diameter of each cluster is between 1 and 10 μm, The distance between adjacent clusters is between 1 and 20 μm, which forms a micron-scale growth window for the subsequent growth of III-nitride. Thus, the nanometer-scale growth windows and the micrometer-scale growth windows are alternately arranged to form a micron/nano compound size mask. According to different substrates, the present invention selects different carbon nanotube mask structures according to different substrate crystal orientations and III-group nitride growth modes. The carbon nanotube mask can contain single-layer or multi-layer carbon nanotube films. The more layers are laid, the smaller the size of the growth window in the mask, that is, the mask can be changed by controlling the number of layers of carbon nanotube films laid. duty cycle. Therefore, the size of the mask can be precisely controlled according to the needs, and the crystal quality of the epitaxial film can be improved. Each layer of carbon nanotube film is a quasi-ordered, parallel array of carbon nanotubes, and the multilayer carbon nanotube films can be arranged in parallel, perpendicular or crossed at an acute angle as required, so that the multilayer carbon The nanotube film constructs a mask structure with any planar geometry such as rectangle, hexagon, parallelogram, etc.

As mentioned above, in the carbon nanotube mask structure of the present invention, there are both nano-scale growth windows within the cluster and micron-scale growth windows between the clusters, and the two are arranged alternately. The growth rate of Ill-nitrides within the nanoscale growth window is less than the growth rate of Ill-nitrides within the microscale growth window. Utilizing the significant difference in the growth rate of III-nitrides in the micron-scale growth window and the nano-scale growth window, two kinds of III-nitrides with the same shape and different sizes can be fabricated on the above-mentioned micro/nano-composite size mask. Nitride dual-size microscopic pattern structure. Further, by controlling the growth conditions and changing the ratio of the lateral growth rate to the vertical growth rate of Group III nitrides, the above-mentioned size differences can be reflected in the lateral, vertical, or lateral and longitudinal directions, that is, the height is the same but the diameter is different, and the height is different but the diameter Double-sized micrographic structures of the same or different heights and diameters. By using the above-mentioned unique mask structure and growth method, a double-sized microscopic pattern structure of group III nitrides can be obtained, which is difficult to achieve by other methods.

Another object of the present invention is to provide a method for selective growth of a III-nitride double-sized microscopic pattern structure.

The selective area growth method of the group III nitride double-sized microscopic pattern structure of the present invention comprises the following steps:

1) Select the substrate:

The substrate is made of materials that can realize the growth of group III nitrides, such as gallium nitride substrate, sapphire substrate, silicon carbide substrate, silicon substrate, etc.; or the substrate is made of gallium nitride substrate, sapphire substrate, carbide substrate, etc. A silicon substrate or a composite substrate on which a template layer with a thickness between 10nm and 100μm is grown, and the material of the template layer is an alloy of one or more of GaN, AlN and InN;

2) laying a carbon nanotube mask on the substrate:

The grown carbon nanotube film is peeled off from its growth substrate, and then a single layer or multi-layer carbon nanotube film is laid on the substrate as required to form a carbon nanotube mask, and the final carbon nanotube mask is formed In the above, the carbon nanotubes arranged in parallel will gather with each other to form a cluster structure arranged in parallel, and the distance between the carbon nanotubes in each cluster is on the order of nanometers, forming a nanoscale growth window; the distance between adjacent clusters The spacing is on the order of microns, forming micron-scale growth windows, and the nano-scale growth windows and micron-scale growth windows will be arranged alternately to form a micron/nano composite size mask;

3) On the substrate covered with the carbon nanotube mask, grow III-nitride double-sized microscopic pattern structure:

Using metal organic chemical vapor deposition MOCVD or molecular beam epitaxy MBE technology to grow III-nitride double-sized microscopic pattern structure.

Wherein, in step 2), in the carbon nanotube mask, the carbon nanotubes can be single-walled or multi-walled, the diameter of a single carbon nanotube is between 10 and 100 nm, and the distance between adjacent carbon nanotubes Between 10-500nm, a nanoscale growth window is formed; the diameter of each cluster is between 1-10 μm, and the distance between adjacent clusters is between 1-20 μm, forming a micron-scale growth window. For different substrates, different carbon nanotube mask structures are selected according to the substrate crystal orientation and crystal growth mode. The carbon nanotube mask can comprise a single-layer or multi-layer carbon nanotube film, each layer of carbon nanotube film is a quasi-ordered, parallel array of carbon nanotubes, and between the multi-layer carbon nanotube films can According to the needs, they are arranged in parallel, perpendicular or intersecting at an acute angle, so that the multi-layer carbon nanotube film can be used to construct a mask structure with any planar geometry such as rectangle, hexagon, parallelogram, etc.

In step 3), the growth is mainly divided into two steps, the first is the growth of the low-temperature buffer layer, followed by the high-temperature growth of the III-nitride. Use MOCVD to grow Group III nitrides. The low-temperature buffer layer uses Group III metal organics as the Group III source with a flow rate of 10-200 sccm, ammonia gas as the V group source with a flow rate of 50-8000 sccm, and a growth temperature of 500-600°C. The pressure is between 100 and 400 Torr, the carrier gas is hydrogen, and the buffer layer thickness ranges from 10 to 500 nm; followed by high-temperature growth of group III nitrides, using hydrogen, nitrogen or a mixture of the two as the carrier gas, to Group III metal organic matter is used as the source of Group III, and its flow rate is 10-500 sccm, and ammonia gas is used as the source of Group V, and the flow rate is 50-8000 sccm, and the molar ratio V/III of the group V source and the Group III source is 10-5000, The growth temperature is between 900-1100° C., and the pressure is between 75-500 Torr. By changing the above growth conditions, a micro- or nano-scale III-nitride double-sized microscopic pattern structure can be grown.

In step 3), if ammonia gas or nitrogen gas is introduced before the growth of group III nitrides for high-temperature nitriding, a columnar pattern with a planar top surface is formed; if no ammonia gas or nitrogen gas is introduced before the growth of group III nitrides Nitrogen, without high-temperature nitriding, will form a cone-shaped figure with a sharp top surface.

The present invention adopts a micron/nano composite size mask composed of a single-layer or multi-layer carbon nanotube film, and utilizes the difference in the growth rate of III-group nitrides in the micron-scale growth window and the nano-scale growth window to obtain different sizes. Group III nitride microscopic pattern structure.

Advantages of the present invention:

As far as the preparation process is concerned, the preparation of the carbon nanotube mask in the present invention has the advantages of simple process, low cost and environmental protection.

In terms of the properties and functions of the mask, compared with mask materials such as silicon dioxide and silicon nitride, carbon nanotubes have the following advantages:

(1) Stable chemical properties, high temperature resistance, high surface cleanliness;

(2) The size of the mask area and the window area in the carbon nanotube mask can vary in a larger range, the smallest can reach the nanometer level, and the largest can reach the micron level, so the resulting pattern has a wide range of size variation and is flexible and controllable;

(3) The shape of the mask pattern of the carbon nanotube mask is flexible and controllable, and a multilayer carbon nanotube film can be used to construct a mask structure with any plane geometry such as rectangle, hexagon, parallelogram, etc.;

(4) It is particularly worth mentioning that in the carbon nanotube mask structure of the present invention, there are both nano-scale growth windows within the cluster and micron-scale growth windows between the clusters, and the two are arranged alternately. When growing III-nitride materials on the above-mentioned mask structure, the difference in the growth rate of III-nitrides in the two growth windows is used to prepare two III-nitrides with the same shape and different size microscopic pattern structures arranged alternately Compound double-scale microscopic pattern structure.

(5) The use of carbon nanotube masks can give full play to the advantages of nano-heterogeneous epitaxy, improve the crystal quality of microscopic pattern structure materials, and reduce residual stress;

(6) Since carbon nanotubes have the characteristics of high thermal conductivity and high electrical conductivity, they are conducive to the improvement of heat dissipation and electrical properties of subsequent microelectronics and optoelectronic devices.

Description of drawings

Fig. 1 is a schematic diagram of laying a carbon nanotube mask according to an embodiment of the group III nitride double-size microscopic pattern structure selective growth method in the present invention;

2 is an exploded view of laying a carbon nanotube mask according to the embodiment of the selective growth method of the group III nitride double-sized microscopic pattern structure in the present invention;

3 is a schematic diagram of a GaN double-size micron hexagonal prism micro-pattern structure prepared according to Embodiment 1 of the selective growth method for a III-nitride double-size micro-pattern structure in the present invention, wherein (a) is a side view, and (b) is a top view;

4 is a schematic diagram of a GaN double-sized micron hexagonal pyramid microscopic pattern structure prepared according to Embodiment 2 of the selective growth method for a group III nitride double-sized microscopic pattern structure in the present invention;

5 is a schematic diagram of a GaN double-size micron inverted trapezoidal micro-pattern structure prepared according to Embodiment 3 of the selective growth method for a group-III nitride double-size micro-pattern structure in the present invention;

6 is a schematic diagram of a GaN micro/nano double-sized hexagonal prism micro-patterned structure prepared according to Embodiment 4 of the method for selective growth of a III-nitride double-sized micro-patterned micro-patterned structure in the present invention.

Detailed ways

The present invention will be further described through the embodiments below in conjunction with the accompanying drawings.

As shown in Figure 1, two layers of carbon nanotube films are laid on the substrate 1 as a carbon nanotube mask 2, and the two layers of carbon nanotube films are perpendicular to each other, and each layer of carbon nanotube films includes a plurality of clusters arranged in parallel structure, a micron-scale growth window 31 is formed between adjacent bundles, each bundle includes a plurality of carbon nanotubes arranged in parallel, a nanoscale growth window 32 is formed between adjacent carbon nanotubes, and the nanoscale growth window and The micron-scale growth windows are arranged alternately to form a micro/nano composite size mask.

Embodiment one

In this embodiment, a c-plane sapphire substrate is used as the substrate, and three layers of carbon nanotube films are laid on the substrate as a carbon nanotube mask to prepare a GaN double-sized micron hexagonal prism microscopic pattern structure. As shown in Figure 2, three layers of carbon nanotube arrays 21-23 are respectively laid on the substrate 1 as a carbon nanotube mask, the first layer 21 is perpendicular to the second layer 22, and the third layer 23 is perpendicular to the second layer; Each layer of carbon nanotube film includes a plurality of cluster structures arranged in parallel, the diameter of each cluster is between 2 and 4 μm, and the distance between adjacent clusters is between 2 and 4 μm, as a micron-scale growth window , the distance between adjacent carbon nanotubes in the bundle is 200-500nm, which are used as nanoscale growth windows to form a micron/nano composite size mask in which micronscale growth windows and nanoscale growth windows are arranged alternately.

The selective growth method of the GaN double-size micron hexagonal prism microscopic pattern structure in this embodiment includes the following steps:

1) The substrate 1 is a c-plane sapphire substrate.

2) laying a carbon nanotube mask on the substrate 1:

On the growth substrate of the carbon nanotube array, a layer of neatly arranged and uniformly sized nanoscale iron powder is deposited by electron beam evaporation as a catalyst, and then by LPCVD method, acetylene is used as a carbon source at low pressure and high temperature to grow quasi Orderly, parallel arrays of carbon nanotubes are peeled off and laid on the growth substrate of Group III nitrides; the formed carbon nanotubes are single-walled carbon nanotubes, and the diameter of a single carbon nanotube is 20nm Lay three layers of carbon nanotube film 21～23 on the substrate as the carbon nanotube mask, the carbon nanotube array in the first layer 21 is along the direction parallel to the substrate reference edge, the carbon nanotubes in the second layer 22 The tube array is along the direction perpendicular to the substrate reference edge The carbon nanotube array in the third layer 23 is along the direction parallel to the substrate reference edge; the final carbon nanotube array forms a cluster structure, and the diameter of each cluster is between 2 ~4μm, the distance between adjacent bundles is between 2~4μm, as a micron-scale growth window, the distance between adjacent carbon nanotubes in a bundle is 200-500nm, as a nanoscale growth window, Formation of micro/nanocomposite size masks.

3) On a substrate covered with a carbon nanotube mask, the GaN double-size micron hexagonal prism microscopic pattern structure is epitaxially grown by MOCVD technology:

a) In the MOCVD reaction chamber, under a hydrogen atmosphere, the pressure is 100 Torr, and the temperature is raised to 1050 ° C for in-situ cleaning treatment;

b) In a hydrogen atmosphere, the pressure is 300 Torr, the temperature is maintained at 1050 ° C, and ammonia gas is introduced as the V group source, and the flow rate is 8000 sccm, and the temperature is maintained for 10 minutes, and the substrate is subjected to high-temperature nitriding treatment;

c) In a hydrogen atmosphere, the pressure is 300 Torr, the temperature drops to 530°C, trimethylgallium TMGa is introduced as a III source, and its flow rate is 28 sccm, and ammonia gas is introduced as a V group source, and its flow rate is 3420 sccm, V/III 2300, grow a low-temperature GaN buffer layer with a thickness of 30nm, then turn off the Group III source, raise the temperature to 1050°C, and perform annealing;

d) Change the carrier gas to nitrogen, the pressure is 200 Torr, the temperature drops to 1000°C, trimethylgallium TMGa is introduced as the gallium source, and the flow rate is 65 sccm, and ammonia gas is introduced as the V group source, and the flow rate is 8000 sccm, V /III is 2330, and the growth thickness is 0.5μm high-quality GaN pattern template layer;

e) Under a nitrogen atmosphere, the pressure is 200 Torr, the temperature is 1060 ° C, trimethylgallium TMGa is introduced as the gallium source, and the flow rate is 65 sccm, and ammonia gas is introduced as the V group source, and the flow rate is 150 sccm, V/III is 45. GaN micro-hexagonal prisms of two sizes were grown in the micron-scale growth window and the nano-scale growth window respectively, with heights of 10 μm and 3 μm respectively, and the diameters of both were about 3 microns. Two kinds of micron hexagonal prisms were nested. The GaN double-sized micro-hexagonal prism microscopic pattern structure is shown in Figure 3.

Embodiment two

In this embodiment, the high-temperature nitriding process in embodiment one is canceled, that is, step b) in step 3) is cancelled, and other steps are the same as in embodiment one, and a GaN double-size micron hexagonal pyramid microscopic pattern structure can be obtained, as shown in Figure 4 shown.

Embodiment Three

In this embodiment, the c-plane sapphire substrate is used as the substrate, and four layers of carbon nanotube films are laid on the substrate as a carbon nanotube mask to prepare a GaN double-sized micron inverted trapezoidal microscopic pattern structure.

The selective growth method of the GaN double-size micron inverted trapezoidal micro-pattern structure in this embodiment includes the following steps:

1) Substrate 1 adopts c-plane sapphire.

2) laying a carbon nanotube mask on the substrate 1:

On the growth substrate of the carbon nanotube array, a layer of neatly arranged and uniformly sized nanoscale iron powder is deposited by electron beam evaporation as a catalyst, and then by LPCVD method, acetylene is used as a carbon source at low pressure and high temperature to grow quasi Ordered, parallel arrays of carbon nanotubes are peeled off and laid on the growth substrate of Group III nitrides; the formed carbon nanotubes are single-walled carbon nanotubes, and the diameter of a single carbon nanotube is 30nm ; Four layers of carbon nanotube films are respectively laid on the substrate as a carbon nanotube mask, the carbon nanotube arrays in the first layer and the third layer are all along the direction parallel to the reference side of the substrate, the second layer and the second layer The carbon nanotube arrays in the four layers are all along the direction perpendicular to the reference edge of the substrate; the final carbon nanotube array forms a cluster structure, the diameter of each cluster is 5 μm, and the distance between adjacent clusters is 5 μm, As a micron-scale growth window, the distance between adjacent carbon nanotubes in the bundle is 500nm, and as a nano-scale growth window, a micron/nano composite size mask is formed.

3) On a substrate covered with a carbon nanotube mask, a GaN double-size inverted trapezoidal microscopic pattern structure is grown by MOCVD:

a) In the MOCVD reaction chamber, under a hydrogen atmosphere, the pressure is 100 Torr, and the temperature is raised to 1050 ° C for in-situ cleaning treatment;

b) In a hydrogen atmosphere, the pressure is 300 Torr, the temperature is kept at 1060 ° C, and ammonia gas is introduced as the V group source, and the flow rate is 8000 sccm, and it is kept for 10 minutes, and the substrate is subjected to high-temperature nitriding treatment;

c) In a hydrogen atmosphere, the pressure is 300 Torr, the temperature drops to 530°C, trimethylgallium TMGa is introduced as the Group III source, and the flow rate is 28 sccm, and ammonia gas is introduced as the V group source, and the flow rate is 3420 sccm, V/ III is 2300, grow a low-temperature GaN buffer layer with a thickness of 50nm, then turn off the Group III source, and raise the temperature to 1060°C for annealing;

d) Change the carrier gas to nitrogen, the pressure is 200Torr, cool down to 1030°C, pass through trimethylgallium TMGa, the flow rate is 65 sccm, pass through ammonia gas as the V source, the flow rate is 8000 sccm, V/III is 2330 , grow a high-quality GaN graphic template layer with a thickness of 0.7 μm;

In a nitrogen atmosphere, the pressure is 300 Torr, the temperature is raised to 1050°C, trimethylgallium TMGa is introduced as a gallium source, and its flow rate is 65 sccm, and ammonia gas is introduced as a V group source, its flow rate is 150 sccm, V/III is 45, The pulsed growth method is used to alternately feed the III-group source and the V-group source, and gradually increase the flow of ammonia gas in a stepwise manner, so that V/III is gradually increased to 300, respectively in the micro-scale growth window and nano-scale growth. GaN inverted trapezoidal structures of two sizes are grown in the window, with heights of 8 μm and 2 μm respectively, and the two inverted trapezoidal structures are nested to form a GaN double-sized micron inverted trapezoidal microscopic pattern structure, as shown in Figure 5. Embodiment Four

In this embodiment, the substrate is a composite substrate in which an AlN nucleation layer with a thickness of 100 nm and an AlGaN prestressed layer with a thickness of 1 μm are grown on a silicon substrate with a (111) crystal plane, and three layers are laid on the composite substrate. A carbon nanotube film is used as a carbon nanotube mask to prepare a GaN double-sized micron/nano hexagonal prism microscopic pattern structure.

The selective growth method of the GaN dual-size micro/nano hexagonal prism microscopic pattern structure in this embodiment includes the following steps:

1) The substrate is a composite substrate in which an AlN nucleation layer with a thickness of 100nm and an AlGaN prestressed layer with a thickness of 1μm and a graded Al composition are grown on a (111) crystal plane silicon substrate.

2) laying a carbon nanotube mask on the composite substrate:

On the growth substrate of the carbon nanotube array, a layer of neatly arranged and uniformly sized nanoscale iron powder is deposited by electron beam evaporation as a catalyst, and then by LPCVD method, acetylene is used as a carbon source at low pressure and high temperature to grow quasi Orderly, parallel arrays of carbon nanotubes are peeled off and laid on the growth substrate of Group III nitrides; the formed carbon nanotubes are single-walled carbon nanotubes, and the diameter of a single carbon nanotube is 20nm ; Three layers of carbon nanotube films are laid on the substrate, the carbon nanotube arrays in the first and third layers are along the direction parallel to the reference edge of the substrate, and the carbon nanotube arrays in the second layer are along the direction perpendicular to the substrate Referring to the direction of the edge, the final carbon nanotubes form a cluster structure. The diameter of each cluster is 1 μm, and the distance between adjacent clusters is 2 μm. As a micron-scale growth window, the adjacent carbon in the cluster The distance between the nanotubes is 200nm, which acts as a nanoscale growth window to form a micro/nanocomposite size mask.

3) On a substrate covered with a carbon nanotube mask, the GaN micro/nano double-size hexagonal prism microscopic pattern structure is epitaxially grown by MOCVD technology:

a) In the MOCVD reaction chamber, under a hydrogen atmosphere, the pressure is 100 Torr, and the temperature is raised to 1050 ° C for in-situ cleaning treatment;

b) In a hydrogen atmosphere, the pressure is 200 Torr, the temperature is maintained at 1050 ° C, and ammonia gas is introduced as the V group source, and the flow rate is 8000 sccm, and the temperature is maintained for 10 minutes, and the substrate is subjected to high-temperature nitriding treatment;

c) Using a mixed gas of hydrogen and nitrogen at a ratio of 3:1 as the carrier gas, the pressure is 200 Torr, the temperature is 1050°C, TMGa is introduced as the Group III source at a flow rate of 65 sccm, and ammonia gas is introduced as the Group V source, The flow rate is 150 sccm, V/III is 50, and silane is passed through, and the flow rate is 30 sccm. GaN hexagonal prisms with the same height and different diameters are grown in the micro-scale growth window and the nano-scale growth window respectively. The former diameter is 2 μm, and the latter Each has a diameter of 300 nm and a height of 2 μm, and two hexagonal prism structures are nested to form a GaN double-sized micro/nano microscopic pattern structure, as shown in Fig. 6 .

Finally, it should be noted that the purpose of publishing the implementation is to help further understand the present invention, but those skilled in the art can understand that various replacements and modifications can be made without departing from the spirit and scope of the present invention and the appended claims. It is possible. Therefore, the present invention should not be limited to the content disclosed in the embodiments, and the protection scope of the present invention is subject to the scope defined in the claims.

Claims (10)

1. A method for selective growth of group III nitride double-sized microscopic pattern structures, characterized in that, the method for selective growth comprises the following steps: 1) Select the substrate: The substrate is made of materials that can realize the growth of group III nitrides, such as gallium nitride substrate, sapphire substrate, silicon carbide substrate, silicon substrate, etc.; or the substrate is made of gallium nitride substrate, sapphire substrate, carbide substrate, etc. A silicon substrate or a composite substrate on which a template layer with a thickness between 10nm and 100μm is grown, and the material of the template layer is an alloy of one or more of GaN, AlN and InN; 2) laying a carbon nanotube mask on the substrate: The grown carbon nanotube film is peeled off from its growth substrate, and then a single layer or multi-layer carbon nanotube film is laid on the substrate as required to form a carbon nanotube mask, and the final carbon nanotube mask is formed In the above, the carbon nanotubes arranged in parallel will gather with each other to form a cluster structure arranged in parallel, and the distance between the carbon nanotubes in each cluster is on the order of nanometers, forming a nanoscale growth window; the distance between adjacent clusters The spacing is on the order of microns, forming micron-scale growth windows, and the nano-scale growth windows and micron-scale growth windows will be arranged alternately to form a micron/nano composite size mask; 3) On the substrate covered with the carbon nanotube mask, grow III-nitride double-sized microscopic pattern structure: Using metal organic chemical vapor deposition MOCVD or molecular beam epitaxy MBE technology to grow III-nitride double-sized microscopic pattern structure. 2. The selected area growth method according to claim 1, characterized in that, in step 2), the carbon nanotubes are single-walled or multi-walled, and the diameter of a single carbon nanotube is between 10 and 100 nm, and the adjacent carbon nanotubes The distance between the carbon nanotubes is between 10 and 500nm, forming a nanoscale growth window. 3. The selective area growing method according to claim 1, characterized in that, in step 2), the diameter of each bundle is between 1 and 10 μm, and the distance between adjacent bundles is between 1 and 20 μm In between, a micron-scale growth window is formed. 4. The selective area growth method according to claim 1, characterized in that, in step 3), growth is divided into two steps, first a buffer layer is grown at a low temperature, and then a group III nitride double-sized microscopic pattern structure is grown at a high temperature. 5. The selective growth method according to claim 1, characterized in that, in step 3), if ammonia gas or nitrogen gas is passed through before growing the Group III nitride for high-temperature nitriding, the top surface is formed as a plane columnar pattern; if no ammonia or nitrogen gas is introduced before the growth of group III nitrides, and high-temperature nitriding is not performed, a cone-shaped pattern with a sharp top surface will be formed. 6. The selective area growth method according to claim 1, wherein in step 3), if ammonia gas or nitrogen gas is passed through before growing the Group III nitride for high-temperature nitriding, the top surface is formed as a plane columnar pattern; if no ammonia or nitrogen gas is introduced before the growth of group III nitrides, and high-temperature nitriding is not performed, a cone-shaped pattern with a sharp top surface will be formed. 7. A selected area growth structure of a group III nitride double-sized microscopic pattern structure, characterized in that, the selected area growth structure comprises: a substrate, a carbon nanotube mask and a group III nitride double-sized microscopic pattern structure; The carbon nanotube mask laid on the bottom is composed of a single-layer or multi-layer carbon nanotube film, each layer of carbon nanotube film is an array of carbon nanotubes arranged in parallel, and these carbon nanotubes are aggregated to form a cluster structure arranged in parallel , micron-scale growth windows are formed between adjacent clusters, and nano-scale growth windows are formed between multiple carbon nanotubes arranged in parallel inside the clusters, thus forming a micro/nano composite with nano-scale growth windows and micro-scale growth windows arranged alternately Dimensional mask; growing III-nitride double-sized microscopic pattern structure on the carbon nanotube mask. 8. The selective growth structure according to claim 7, wherein the carbon nanotubes are single-walled or multi-walled, and the diameter of a single carbon nanotube is between 10 and 100 nm, and the diameter between adjacent carbon nanotubes is 10-100 nm. The distance between them is between 10nm and 500nm, forming a nanoscale growth window. 9. The selective growth structure according to claim 7, wherein the diameter of each cluster is between 1 and 10 μm, and the distance between adjacent clusters is between 1 and 20 μm, forming micron-scale growth window. 10. The selective growth structure according to claim 7, wherein the substrate is one of gallium nitride substrate, sapphire substrate, silicon carbide substrate and silicon substrate, or the substrate is made of GaN substrate, sapphire substrate, silicon carbide substrate or silicon substrate is a composite substrate with a template layer with a thickness between 10nm and 100μm. The template layer is made of gallium nitride GaN, aluminum nitride AlN and one or more alloys of indium nitride InN.