CN108878265A - A method of growing mono-crystal gallium nitride film on Si (100) substrate - Google Patents

Abstract

The invention discloses a method for growing a single crystal gallium nitride film on a Si (100) substrate, comprising: forming an amorphous _SiO2 layer on the Si (100) substrate; transferring single crystal graphene to the Si ( 100)/SiO ₂ substrate; pretreat the surface of single crystal graphene to generate dangling bonds; grow AlN nucleation layer; epitaxially grow GaN film. Since the Si(100) surface reconfiguration produces two kinds of dangling bonds, resulting in inconsistency in the in-plane orientation of the grains during nitride growth and the inability to form a single crystal, the present invention shields the information of the two kinds of dangling bonds on the substrate surface with an amorphous _SiO2 layer, Graphene provides the hexagonal template required for nitride epitaxial growth, and a continuous and uniform high-quality GaN single crystal film is obtained by epitaxy, which lays a good foundation for the integration of GaN-based devices and Si-based devices.

Description

A method of growing single crystal gallium nitride film on Si(100) substrate

technical field

The invention belongs to the technical field of semiconductors, and relates to a method for growing a single crystal gallium nitride thin film on a Si (100) substrate.

Background technique

The third-generation semiconductor materials represented by GaN have the characteristics of large band gap, high breakdown electric field strength, high saturation electron drift velocity, high thermal conductivity and strong radiation resistance, which can meet the requirements of modern electronic technology for high temperature, Performance requirements such as high frequency, high power and radiation resistance. Its white and purple light-emitting diodes, short-wavelength lasers and ultraviolet detectors are widely used in the fields of white light illumination, ultraviolet band sterilization, high-speed color laser printing and solar blind band detection; its microwave power devices are due to high power density and extreme operating temperature , so that the antenna of the same size has a longer distance and search capability; its power electronic devices have lower loss and higher efficiency, and play an energy-saving role in the power generation, transmission, transformation, distribution and dispatching of the power system, greatly reducing power loss.

Due to the scarcity of homogeneous substrates, heteroepitaxy has become the mainstream method for GaN materials and device epitaxy. Among heteroepitaxy substrates, Si substrates have the advantages of large size, low cost and good thermal conductivity, and GaN-based devices and modules are compatible with existing complementary metal-oxide-semiconductor fabrication processes for Si integrated circuits. The integration of GaN-based devices and Si-based microelectronic devices will provide a wider space for integrated circuit design and application, which is the development trend of GaN materials and devices. However, the Si (100) substrate used in the Si integrated circuit industry cannot grow single-crystal GaN materials. This is due to the four-fold symmetry of the surface atoms of Si(100), and the surface reconstruction produces two kinds of dangling bonds, resulting in inconsistent in-plane orientations of the grains during nitride growth.

There is currently no effective solution to the problem of inconsistent in-plane orientation of grains caused by Si(100) surface reconstruction when growing GaN. In reporting work, such as V.Lebedev, et al., J. Crystal Growth 230, 426 (2001); S. Joblot, et al., J. Crystal Growth 280, 44 (2005); F. Schulze, et al., Appl .Phys.Lett.87, 133505 (2005), The only solution is to solve the substrate surface reconstruction problem using a beveled Si(100) substrate. However, the off-cutting of the substrate leads to anisotropy of properties such as carrier mobility in Si materials, which cannot be practically applied, thus limiting the integrated development of GaN-based devices and Si-based devices.

Contents of the invention

In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a method for growing a single _- crystal gallium nitride film on a Si (100) substrate. Dangling bond information, followed by transferable two-dimensional graphene to provide the hexagonal template required for nitride epitaxial growth, generating dangling bonds by surface pretreatment of graphene, and depositing an AlN nucleation layer to grow high-quality GaN single crystals film. The invention can realize the growth of single-crystal GaN film on the Si (100) substrate, and lays a good foundation for the integration of GaN-based devices and Si-based devices.

Technical scheme of the present invention is as follows:

A method for growing a monocrystalline gallium nitride film on a Si(100) substrate, comprising the following steps:

Step ₁ : forming an amorphous SiO layer on a Si(100) substrate;

Step 2: transfer the single crystal graphene to the Si(100)/SiO obtained in step 1 _On the substrate;

Step 3: Pretreating the surface of the single crystal graphene to generate dangling bonds;

Step 4: growing an AlN nucleation layer on the pretreated single crystal graphene;

Step 5: epitaxially grow a GaN single crystal thin film on the AlN nucleation layer.

Preferably, the method for forming the amorphous SiO ₂ layer in step 1 is chemical vapor deposition or thermal oxidation, and the thickness of the SiO ₂ layer is 50 nm-1 μm.

Preferably, the number of layers of the single crystal graphene is 1-4 layers. It is usually single-crystal graphene grown by metal-organic compound vapor deposition (MOVCD) or chemical vapor deposition (CVD).

In step 3, it is preferable to pretreat the surface of the single crystal graphene by plasma etching or nitriding treatment. Wherein, the gas for performing plasma etching on the surface of the single crystal graphene is nitrogen, the plasma power is 50-500W, and the etching time is 1-100min. The method for nitriding the surface of single crystal graphene is _NH3 etching, preferably under high temperature hydrogen atmosphere, _NH3 etching, the etching temperature is 1000-1300°C, the flow rate of _NH3 is 100-8000sccm, and the etching time is 1-100min.

The growth method of the AlN nucleation layer and the GaN single crystal thin film is selected from one of metal organic compound vapor deposition, molecular beam epitaxy, hydride vapor phase epitaxy and chemical vapor deposition.

Preferably, the MOVCD method is used to grow the AlN nucleation layer, the growth temperature is 800-1200° C., the growth pressure is 10-200 mbar, the V/III ratio is 150-1500, and the thickness of the AlN nucleation layer is 1-100 nm.

Preferably, the MOVCD method is used to epitaxially grow the GaN single crystal film, the growth temperature is 1000-1200° C., the growth pressure is 10-200 mbar, the V/III ratio is 500-5000, and the growth rate is 1 μm/h-5 μm/h.

The method for growing a single crystal gallium nitride film on a Si(100) substrate of the present invention has the following beneficial effects:

(1) By introducing an amorphous _SiO2 layer and a single-crystal graphene layer, the two kinds of dangling bond information caused by the surface reconstruction of Si(100) are effectively shielded, and a hexagonal template is provided for the growth of nitrides;

(2) By pretreating the graphene surface, dangling bonds are formed, which provide nucleation sites for subsequent epitaxial nitrides;

(3) Increase the nucleation density on the graphene surface by depositing AlN compatible with the epitaxial GaN process as a nucleation layer, and provide nucleation sites for the epitaxial GaN single crystal thin film.

Description of drawings

Fig. 1 is a flowchart of a method for growing a single crystal gallium nitride film on a Si (100) substrate according to the present invention.

Fig. 2 is the (002) plane XRDθ/2θ scanning curve (A) and (102) plane of the GaN grown on the Si(100) substrate of the present invention Sweep curve (B).

Fig. 3 is a scanning electron micrograph of the surface morphology of GaN grown on a Si (100) substrate according to the present invention.

Fig. 4 is an atomic force microscope picture of the surface morphology of GaN grown on a Si (100) substrate according to the present invention.

Detailed ways

In order to clarify the purpose, technical solutions and advantages of the present invention, the present invention will be further described in detail below in combination with two specific embodiments and with reference to the accompanying drawings. Implementations not shown or described in the accompanying drawings are forms known to those of ordinary skill in the technical field. Additionally, while illustrations of parameters including particular values may be provided herein, it should be understood that the parameters need not be exactly equal to the corresponding values, but rather may approximate the corresponding values within acceptable error margins or design constraints.

Example 1:

As shown in Figure 1, growing a single crystal gallium nitride film on a Si(100) substrate includes the following steps:

Step 1: Forming an amorphous SiO ₂ layer on the Si(100) substrate by thermal oxidation method, the thickness of the SiO ₂ layer is 50nm-1μm.

Step 2: transfer the graphene to the Si(100)/SiO ₂ layer, the transferred graphene is single crystal graphene, and the number of graphene layers is 1-4 layers.

Step 3: using a plasma cleaner to etch the graphene transferred to Si(100)/SiO ₂ , the etching gas is nitrogen, the plasma power is 50-500W, and the etching time is 1-100min;

Step 4: Si(100)/SiO ₂ /graphene is pretreated to deposit an AlN nucleation layer, the deposition temperature is 800-1200°C, and the thickness of the AlN nucleation layer is 1-100nm;

Step 5: epitaxially grow a GaN thin film on the AlN nucleation layer, the growth temperature is 1000-1200° C., and the growth rate is 1 μm/h-5 μm/h.

Example 2:

Step 1: An amorphous SiO ₂ layer is grown on a Si(100) substrate by plasma chemical vapor deposition (PECVD), and the thickness of the SiO ₂ layer is 50 nm-1 μm.

Step 2: transfer the graphene to the Si(100)/SiO ₂ layer, the transferred graphene is single crystal graphene, and the number of graphene layers is 1-4 layers.

Step 3: In the metal organic compound vapor phase epitaxy reaction chamber, the surface of graphene is etched with NH ₃ under high temperature hydrogen atmosphere to form dangling bonds. _The temperature of NH ₃ etching under high temperature hydrogen atmosphere is 1000-1300°C The flow rate is 100-8000sccm, and the etching time is 1-100min;

Step 4: After pretreatment of Si(100)/SiO ₂ /graphene, in-situ deposition of an AlN nucleation layer, the deposition temperature is 800-1200°C, and the thickness of the AlN nucleation layer is 1-100nm;

Step 5: epitaxially grow a GaN thin film on the AlN nucleation layer, the growth temperature is 1000-1200° C., and the growth rate is 1 μm/h-5 μm/h.

(002) plane XRDθ/2θ scanning curve and (102) plane of GaN grown on Si(100) substrate by the above method The scanning curve is shown in Figure 2, indicating that GaN on the Si (100) substrate is a single crystal. The scanning electron microscope photos and atomic force microscope photos of the grown GaN surface topography are shown in Figure 3 and Figure 4, respectively. It can be seen that GaN forms a continuous and uniform film on the Si(100) substrate, and the atomic steps on the GaN surface The morphology is obvious, and dislocation outcrops are few.

The two specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and should not be used to limit In the present invention, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A method for growing a monocrystalline gallium nitride film on a Si(100) substrate, comprising the following steps: 1) Forming an amorphous SiO ₂ layer on a Si(100) substrate; 2) single crystal graphene is transferred to the Si(100)/SiO that step ₁ ) obtains on the substrate; 3) Pretreating the surface of single crystal graphene to generate surface dangling bonds; 4) growing an AlN nucleation layer on the pretreated single crystal graphene; 5) Epitaxial growth of GaN single crystal film on the AlN nucleation layer. 2. The method according to claim 1, characterized in that, step 1) forms an amorphous SiO ₂ layer by chemical vapor deposition or thermal oxidation, and the thickness of the SiO ₂ layer is 50 nm-1 μm. 3. The method according to claim 1, characterized in that, step 2) the number of layers of the transferred single crystal graphene is 1-4 layers. 4. the method for claim 1, is characterized in that, step 3) adopts the method for plasma etching or nitriding to carry out pretreatment to single crystal graphene surface. 5. The method according to claim 4, wherein the gas used for plasma etching the surface of the single crystal graphene is nitrogen, the plasma power is 50-500W, and the etching time is 1-100min. 6. method as claimed in claim 4 is characterized in that, the method that nitriding is carried out to the single crystal graphene surface is NH ₃ etching. 7. The method according to claim 6, characterized in that, the surface of the single crystal graphene is etched with NH under a high _- temperature hydrogen atmosphere, the etching temperature is 1000-1300° C., and the NH flow is _100-8000 sccm. The eclipse time is 1-100min. 8. The method as claimed in claim 1, characterized in that, step 4) growth AlN nucleation layer and step 5) method of growing GaN single crystal thin film is selected from metal organic compound vapor deposition, molecular beam epitaxy, hydride vapor phase epitaxy and one of chemical vapor deposition. 9. The method according to claim 1, characterized in that, step 4) grows the AlN nucleation layer by metal-organic compound vapor deposition, the growth temperature is 800-1200°C, the growth pressure is 10-200mbar, and the V/III ratio The thickness of the AlN nucleation layer is 1-100nm. 10. The method according to claim 1, wherein step 5) epitaxially grows a GaN single crystal thin film by metal-organic compound vapor deposition method, the growth temperature is 1000-1200°C, the growth pressure is 10-200mbar, V/III The ratio is 500-5000, and the growth rate is 1 μm/h-5 μm/h.