TW201414888A - A method for fabricating III-nitride with zinc-blende structure and an epitaxy structure having III-nitride with zinc-blende structure - Google Patents

Abstract

A method for fabricating III-nitride with zinc-blende structure is disclosed. The method prepares a γ -Ga2O3 substrate and controls the fabrication temperature as being lower than 420 degree Celsius, with a ratio of III-group elements to nitride being less than 2.0 to epitaxy grow a layer of III-nitride with zinc-blende structure on the γ -Ga2O3 substrate. Furthermore, an epitaxy structure having III-nitride with the zinc-blende structure is disclosed. The epitaxy structure comprises a γ -Ga2O3 substrate and a layer of III-nitride with zinc-blende structure. The γ -Ga2O3 substrate has a surface on which the layer of III-nitride is mounted.

Description

Method for producing zinc-mineral structure tri-family nitride and tri-family nitrogen having sphalerite structure Epitaxial structure

The present invention relates to a method for producing a zinc oxide structure of a zinc blende structure, and more particularly to a method for growing a zinc oxide structure of a zinc oxide structure on a gallium trioxide substrate.

According to gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN) and its alloys, aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), aluminum indium nitride (AlInN), etc. Group III nitride (III-Nitride) semiconductors have the characteristics of direct wide band gap and, therefore, can be used to fabricate light-emitting elements such as light-emitting diodes (LEDs) or laser diodes (LDs), etc. The document gives an example of the characteristics of a Group III nitride semiconductor, as shown in Table 1:

It can be known from the documents listed in Table 1 that the stable crystal structure of the Group III nitride semiconductor is a wurtzite structure [see Reference 1]. However, a light-emitting element made of a wurtzite-structured group III nitride semiconductor is affected by a strong built-in electric field in the c-axis direction of the crystal, and the quantum well band structure of the light-emitting element is tilted, resulting in a decrease in luminous efficiency. For the Quantum Confined Stark Effect (QCSE) [see Reference 2].

In order to avoid the above-mentioned quantum-limited Stark effect, quantum wells can be grown in non-polar (ie, M-plane and A-plane GaN) or semi-polar (ie, non-[0001] directions). The GaN film) is used to eliminate the band displacement problem caused by the electrostatic field inside the crystal [see Reference 3]. Among them, although non-polar GaN (ie, M-plane and A-plane GaN) can overcome the influence of built-in electric field. However, since the a-axis and c-axis crystal growth rates differ greatly, lattice mismatch will result, resulting in a large number of lattice defects.

In order to overcome the problems caused by the difference in crystal growth rate, the Group III nitride semiconductor can be grown into a zinc-blende structure for forming a cubic structure. However, the sphalerite structure of the Group III nitride semiconductor is an unstable crystal structure in nature, and is not easily grown in a high temperature environment (greater than 420 ° C), and the growth process conditions are not easily controlled [see the reference document for details). 4]. If a conventional trigonal nitride epitaxial growth technique, such as Hydride Vapor Phase Epitaxy (HVPE) or Metal-Organic Vapor Phase Epitaxy (MOVPE), Due to the large temperature change of the epitaxial process, the zinc-phosphorus structure of the sphalerite structure is easily converted into a wurtzite structure, and therefore, it is difficult to obtain a single phase phase of the sphalerite structure of the group III nitride epitaxial film. See Ref. 5 for details. In view of this, only the Molecular Beam Epitaxy (MBE) can be used to grow a sphalerite-structured Group III nitride semiconductor in a low temperature environment (about less than 420 ° C) [see Reference 6].

Among them, the conditions for the success or failure of the sphalerite structure of the Group III nitride semiconductor, in addition to the epitaxial technique, the degree of lattice matching between the substrate and the Group III nitride film is the most important during the epitaxial growth process. factor.

For example, gallium arsenide (GaAs) (100), tantalum carbide (3C-SiC) (100), and magnesium oxide (MgO) (100), which are currently most commonly used for growing substrates [see Ref. 7~9] For example, the degree of lattice matching between 3C-SiC and GaN or AlN is better. However, the band gap of 3C-SiC is 2.35 eV, and the wavelength of 527.6 nm (nm) belongs to the range of yellow wavelength. When the visible light wavelength emitted by the light-emitting element is less than 527.6 nm, the visible light will be absorbed by the 3C-SiC substrate, and since the SiC single crystal is manufactured at a high temperature and its structure is a poly-type crystal structure, etc., The acquisition of the substrate is not easy and the price is relatively high. In addition, the use of gallium arsenide substrate causes arsenic precipitation (contamination) and poor lattice matching, and the use of magnesium oxide substrate is also disadvantageous for the growth of zinc blende structure tri-family due to its high manufacturing temperature. . In addition, bismuth (Si) can also be used as a tri-family nitride Crystal substrate, but its production process is complicated, it is not easy to reduce manufacturing costs.

In summary, in addition to the "three types of nitrides that do not easily grow sphalerite structure", there are still doubts about "absorbing visible light", "causing pollution" and "manufacturing process". In actual use, different limitations and shortcomings are derived. There are inconveniences and further improvements are needed to enhance their practicality.

The object of the present invention is to improve the above disadvantages to provide a method for producing a zinc oxide structure of a zinc blende structure, using gamma-phase gallium trioxide as a substrate for growing a zinc blende structure of a zinc blende structure to reduce sphalerite The lattice defects of the structure tri-family nitride can effectively improve the luminous efficiency of the light-emitting element.

A second object of the present invention is to provide an epitaxial structure having a sphalerite structure of a group III nitride, using gamma phase gallium dioxide as a substrate to reduce lattice defects in a zinc oxide structure of a zinc oxide structure. It can be used to improve the luminous efficiency of the light-emitting element.

The method for manufacturing a sphalerite structure group III nitride of the present invention comprises the steps of: preparing a gamma-phase di-gallium oxide substrate; and controlling the process temperature to be less than 420 degrees, and the tri-family elements and nitrogen in the surrounding environment The ratio is less than 2.0, and the tri-semenide layer of a sphalerite structure is epitaxially grown on the gamma-phase gallium oxide substrate.

Wherein, the zinc trichloride structure tri-family nitride layer has a growth temperature of 350 to 420 degrees.

Wherein the ratio of the triad element to nitrogen ranges from 1.0 to 2.0.

Wherein the sphalerite structure tri-family nitride layer is a sphalerite structure nitrogen Gallium layer.

Wherein, the zinc-nitride structure group III nitride layer is a sphalerite structure aluminum nitride layer.

Wherein, the tribolite layer of the sphalerite structure is a zinc iodide structure indium nitride layer.

Wherein, the zinc trichloride nitride layer of the sphalerite structure is a sphalerite structure aluminum nitride gallium layer.

Wherein, the tribolite layer of the sphalerite structure is a zinc oxide structure indium gallium nitride layer.

Wherein, the tribolite layer of the sphalerite structure is a zinc iodide layer of a sphalerite structure.

Wherein, the gamma-phase digallium trioxide substrate is subjected to nitriding treatment to form a gallium nitride buffer layer, and the sphalerite structure group III nitride layer is epitaxially grown on the gallium nitride buffer layer.

Wherein, the γ-phase gallium oxide gallium substrate is prepared in a vacuum environment, and an β-phase lithium gallate substrate is subjected to an annealing process to convert the β-phase lithium gallate substrate into the γ phase three-oxide Two gallium substrates.

An epitaxial structure having a zinc-mineral structure of a group III nitride, comprising: a gamma-phase gallium oxide substrate having a grown surface; and a sphalerite structure group III nitride layer disposed in the gamma phase III The growth surface of the GaN substrate.

Wherein, the γ phase gallium oxide gallium substrate is provided with a gallium nitride buffer layer, and the growth surface is located on the surface of the gallium nitride buffer layer.

The above and other objects, features and advantages of the present invention will become more <RTIgt; (annealing) means a heat treatment process in which a material is exposed to a high temperature environment and then slowly cooled after a period of time, comprising three stages: heating the material to a heating temperature, holding or dipping (soaking) It is understood by those of ordinary skill in the art to which the temperature is to be heated and the material is cooled to a cooling temperature (e.g., room temperature, etc.).

The term "nitridation" as used throughout the present invention refers to a surface treatment technique in which a nitrogen atom is reacted with a material to be nitrided to form a nitride under conditions of a certain temperature and a certain medium, and is a technique of the present invention. Those with ordinary knowledge in the field can understand.

Please refer to FIG. 1 , which is a manufacturing flow diagram of a preferred embodiment of a method for producing a zinc-series structure of a zinc blende structure according to the present invention, wherein the method for producing a zinc-series structure of a zinc-zinc structure of the present invention can be The subsequent steps S1 and S2 are performed by a conventional Plasma Assisted Molecular Beam Epitaxy (PA-MBE), wherein the structure and operation method of the conventional plasma assisted molecular beam epitaxy system are well known. The artist can understand that it is not described here.

In the step S1, a γ-phase gallium oxide substrate (γ-Ga ₂ O ₃ ) is prepared. In detail, the γ phase gallium oxide gallium substrate can be taken from the prepared γ phase gallium oxide gallium substrate, or a self-prepared manner, preferably in a vacuum environment, a β-phase lithium gallate ( The β-LiGaO ₂ substrate is subjected to an annealing process to convert the β-phase lithium gallate substrate into the γ-phase gallium oxide gallium substrate, wherein the equipment and technology required for performing the annealing process are technical fields to which the present invention pertains Those having ordinary knowledge can understand that only one example will be described here.

For example, first, the β-phase lithium gallate substrate is heated to a heating temperature, for example, 850 to 1100 degrees (° C.), and then the β-phase lithium gallate substrate is maintained at the heating temperature until a hold is maintained. Time, for example: 2 hours, after which the β-phase lithium gallate substrate is cooled to a cooling temperature, for example, 25 degrees), and the β-phase lithium gallate substrate is decomposed into lithium atoms to form the γ phase trioxide Gallium substrate 1 (as shown in Fig. 2), the γ phase gallium oxide substrate 1 has a growth surface 11 for epitaxial growth of a group III nitride having a sphalerite structure (III-nitride with zinc -blende structure).

Wherein, after the gamma-phase di-arsenide substrate 1 is prepared, the gamma-phase di-arsenide substrate 1 is preferably subjected to nitriding treatment, so that the γ-phase gallium oxide substrate 1 forms a nitrogen. a GaN buffering layer 12, wherein the growth surface 11 is located on the surface of the gallium nitride buffer layer 12. Since the gallium nitride buffer layer 12 has nitrogen atoms, the gallium nitride buffer layer 12 can be used. To grow the above-mentioned group III nitride having a zinc blende structure, thereby reducing the crystal between the gamma-phase di-gallium oxide substrate 1 and its product (for example, the above-mentioned group III nitride having a zinc blende structure) Defects.

The step S2 satisfies the growth condition of a sphalerite structure, and epitaxially grows a tri-semenide layer of a sphalerite structure on the gamma-phase gallium oxide substrate, for example, a sphalerite structure gallium nitride layer (GaN). a semiconductor film such as an aluminum nitride layer (AlN), an indium nitride layer (InN), an aluminum gallium nitride layer (AlGaN), an indium gallium nitride layer (InGaN), or an aluminum indium nitride layer (AlInN), but This is limited. Wherein, the sphalerite structure growth condition refers to the epitaxial growth of the group III nitride In the process, if the control process temperature is less than 420 degrees (° C.), and the ratio of the tri-group (IIIA) element to nitrogen in the surrounding environment is less than 2.0, the sphalerite structure tri-family nitride layer can be epitaxially grown in the γ On a phase of a gallium trioxide substrate, wherein the group III nitride will stably form a zinc blende structure during growth without being converted into a wurtzite structure, which has the usual knowledge in the technical field to which the present invention pertains. It can be understood that it is not described here. In this embodiment, the tri-group element is exemplified by a gallium (Ga) element for fabricating the sphalerite structure gallium nitride layer, and the other sphalerite structure tri-family nitride layer can be manufactured in the same manner. . Wherein, a conventional plasma assisted molecular beam epitaxy system (not shown) can be used in a Ga-rich condition, for example, in a gallium/nitrogen ratio (Ga/N ratio). In an environment having a range of 1.0 to 2.0, maintaining the temperature of the environment at a growth temperature, for example, 350 to 420 degrees, causing epitaxial growth of the gamma-phase gallium oxide substrate 1 to the sphalerite structure group III nitride Layer 2 (as shown in Fig. 2), for example, a sphalerite structure of a group III nitride film, such that the gamma phase gallium oxide substrate 1 and the sphalerite structure group III nitride layer 2 together form a flash An epitaxial structure of a group III nitride of a zinc ore structure, for example, an epitaxial film, etc., wherein during the epitaxial growth process, since the temperature of the environment is maintained at the growth temperature, the trigonal nitride of the sphalerite structure can be ensured. Layer 2 does not transform into a wurtzite structure.

Please refer to FIG. 3a, which is a TEM bright-field view of the episulfide structure of the zinc nitride layer of the present invention, which is epitaxially grown on a gamma-phase gallium oxide substrate. DP01 in Fig. 3a is a selected area diffraction pattern of a sphalerite structure gallium nitride layer (as shown in Fig. 3b), and DP02 in Fig. 3a is a sphalerite structure gallium nitride layer and γ phase trioxide The interfacial diffraction pattern of the gallium substrate (as shown in Fig. 3c), DP03 in Fig. 3a is the selected area diffraction pattern of the gamma phase galvanic oxide substrate (as shown in Fig. 3d), in Fig. 3c In the middle, the red dotted line and the yellow dotted line respectively represent the lattice diffraction point positions of the γ phase gallium oxide and the zinc blende structure gallium nitride, and the zinc blende structure is shown because the red dotted line and the yellow dotted line in the figure almost overlap. The lattice of the gallium nitride layer (as shown in Fig. 3e) is similar to the lattice of the gamma-phase gallium trioxide (as shown in Fig. 3f). Therefore, it can be known that the gamma-phase gallium oxide is very suitable as A substrate for growing a sphalerite structure of a gallium nitride epitaxial film. By the steps disclosed in the preferred embodiment of the method for producing a zinc oxide structure of a zinc blende structure of the present invention, it is indeed possible to epitaxially crystallize the gamma-phase gallium oxide substrate (γ-Ga ₂ O ₃ ) (100). The sphalerite structure gallium nitride layer (zb-GaN) (100) is grown.

Similarly, if the elements in the environment are replaced by nitrogen and aluminum, the zinc nitride structure aluminum nitride layer can be grown; if the elements in the environment are replaced by nitrogen and indium, the zinc sulfide structure nitridation can be grown. Indium layer; if the elements in the environment are replaced by nitrogen, aluminum and gallium, the zinc nitride structure of the zinc blende structure can be grown; if the elements in the environment are replaced by nitrogen, indium and gallium, it can be grown. The indium gallium nitride layer of the zinc ore structure; if the elements in the environment are replaced by nitrogen, aluminum and indium, the zinc nitride indium nitride layer of the zinc blende structure can be grown.

In addition, the following is an example of the γ-phase gallium oxide (γ-Ga ₂ O ₃ ) substrate and a zinc blende structure gallium nitride layer (zb-GaN), an aluminum nitride layer (zb-AlN), and nitridation. The degree of lattice matching between indium layers (zb-InN).

As shown in Table 2, among the sphalerite structure gallium nitride layer, the aluminum nitride layer and the indium nitride layer, the minimum lattice mismatch ratio is only 6%, and therefore, the sphalerite structure of the present invention a method for producing a group III nitride, using the γ phase gallium oxide gallium substrate to grow the zinc blende structure group III nitride layer, and the zinc blende structure group III nitride layer and the γ phase gallium oxide gallium substrate The reduction of lattice defects between the three can be used to fabricate a III-nitride semiconductor device, such as a light-emitting diode such as a light-emitting diode or a laser diode, thereby enhancing the light-emitting element. Luminous efficiency. Wherein, if the sphalerite structure group III nitride layer 2 is grown on the gallium nitride buffer layer 12 of the gamma phase gallium oxide gallium substrate 1, the zinc sulfide structure group III nitride layer can be further reduced. 2 a lattice defect between the gamma phase gallium oxide substrate 1 and the gamma phase.

The main features of the preferred embodiment of the method for producing the sphalerite structure of the group III nitride of the present invention are as follows: a conventional plasma assisted molecular beam epitaxy system can be used at the growth temperature. The sphalerite structure gallium nitride layer (GaN), the aluminum nitride layer (AlN), the indium nitride layer (InN), and the gamma-phase gallium oxide substrate are grown at 350 to 600 degrees. a zinc oxide structure group III nitride layer such as an aluminum gallium nitride layer (AlGaN), an indium gallium nitride layer (InGaN) or an aluminum indium nitride layer (AlInN), and the sphalerite structure group III nitride layer does not In the process of growth, it is transformed into a wurtzite structure to avoid the difference in the growth rate of the wurtzite structure crystals and the problems caused by the built-in electric field.

Therefore, a preferred embodiment of the method for producing a sphalerite structure of a group III nitride according to the present invention is to use gamma-phase gallium trioxide as a substrate for a zinc oxide layer of a zinc sphalerite structure, and to oxidize the gamma phase. The digallium substrate and the sphalerite structure tri-family nitride layer may together constitute the epitaxial structure of the triad-nitride structure having a zinc blende structure to reduce the lattice defects of the sphalerite structure tri-family nitride layer, which is effective The luminous efficiency of the light-emitting element is improved, and the problems caused by the current fabrication of the light-emitting element using the wurtzite-structured group III nitride semiconductor are solved.

A preferred embodiment of the method for producing a sphalerite structure of a group III nitride according to the present invention is to use gamma-phase gallium trioxide as a substrate for a zinc oxide structure of a zinc blende structure to reduce the zinc oxide structure of the zinc group. The lattice defect between the compound and the substrate can effectively improve the luminous efficiency of the light-emitting element, and can be directly introduced into an existing semiconductor process, which is an effect of the present invention.

A preferred embodiment of the epitaxial structure of the group III nitride having a zinc blende structure is formed by a gamma phase gallium oxide gallium substrate to form a sphalerite structure group III nitride to reduce the sphalerite structure The lattice defect between the nitride and the gamma-phase di-gallium oxide substrate can be used to improve the luminous efficiency of the light-emitting element and serve as a raw material for the light-emitting element, which is an effect of the present invention.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

〔this invention〕

1‧‧‧γ phase gallium oxide substrate

11‧‧‧Growth surface

12‧‧‧ gallium nitride buffer layer

2‧‧‧Zincite structure triad nitride layer

Fig. 1 is a flow chart showing the manufacture of a preferred embodiment of the method for producing a zinc oxide structure of a sphalerite structure of the present invention.

Fig. 2 is a schematic view showing the structure of a preferred embodiment of the epitaxial structure of the group III nitride having a sphalerite structure according to the present invention.

Fig. 3a is a TEM bright-field view of the epitaxially grown gallium nitride layer of the present invention grown on a gamma-phase gallium oxide substrate.

Figure 3b: Selected area diffraction pattern of the sphalerite structure gallium nitride layer of the present invention.

Figure 3c: Interfacial diffraction pattern of the zinc oxide structure gallium nitride layer of the present invention and the gamma phase gallium oxide substrate.

Figure 3d: Selected area diffraction pattern of the gamma phase gallium oxide gallium substrate of the present invention.

Figure 3e is a schematic diagram of the crystal lattice of the (100) crystal plane of the sphalerite structure of the present invention.

Fig. 3f is a schematic view showing the crystal lattice of the crystal face of the γ phase gallium oxide gallium substrate (100) of the present invention.

Claims (13)

A method for manufacturing a zinc-series structure of a tri-family nitride comprises the steps of: preparing a gamma-phase gallium oxide substrate; and controlling the process temperature to be less than 420 degrees, and the ratio of the tri-family element to nitrogen in the surrounding environment is less than 2.0, epitaxial growth of a zinc-mineral structure tri-family nitride layer on the gamma-phase di-gallium oxide substrate. The method for producing a sphalerite structure group III nitride according to claim 1, wherein the sphalerite structure group III nitride layer has a growth temperature of 350 to 420 degrees. The method for producing a zinc blende structure group III nitride according to claim 1, wherein the ratio of the group III element to nitrogen ranges from 1.0 to 2.0. The method for producing a zinc blende structure group III nitride according to claim 1, wherein the zinc blende structure group III nitride layer is a sphalerite structure gallium nitride layer. The method for producing a zinc blende structure group III nitride according to claim 1, wherein the zinc blende structure group III nitride layer is a sphalerite structure aluminum nitride layer. The method for producing a sphalerite structure group III nitride according to claim 1, wherein the sphalerite structure group III nitride layer is a sphalerite structure indium nitride layer. The method for producing a sphalerite structure group III nitride according to claim 1, wherein the sphalerite structure group III nitride layer is a zinc flash Mineral structure aluminum nitride gallium layer. The method for producing a zinc blende structure group III nitride according to claim 1, wherein the zinc blende structure group III nitride layer is a sphalerite structure indium gallium nitride layer. The method for producing a sphalerite structure group III nitride according to claim 1, wherein the sphalerite structure group III nitride layer is a sphalerite structure aluminum nitride indium layer. The method for producing a sphalerite structure group III nitride according to claim 1, wherein the γ phase gallium oxide substrate is subjected to nitridation treatment to form a gallium nitride buffer layer, the sphalerite The structure tri-family nitride layer is epitaxially grown on the gallium nitride buffer layer. The method for producing a zinc-zinc oxide structure of a group III nitride according to the first aspect of the invention, wherein the γ-phase gallium dioxide substrate is prepared in a vacuum environment, and a β-phase lithium gallate substrate is used. An annealing process is performed to convert the β-phase lithium gallate substrate into the γ-phase gallium oxide substrate. An epitaxial structure having a zinc-mineral structure of a group III nitride, comprising: a gamma-phase gallium oxide substrate having a grown surface; and a sphalerite structure group III nitride layer disposed in the gamma phase III The growth surface of the GaN substrate. The epitaxial structure having a zinc blende structure of a group III nitride according to claim 12, wherein the gamma-phase gallium oxide substrate is provided with a gallium nitride buffer layer, and the grown surface is located in the gallium nitride layer The surface of the buffer layer.