Group III Nitride Structure and Its Fabrication Method

Abstract

The present application provides a group-III nitride structure and a manufacturing method thereof. In the manufacturing method, first, a first mask layer is formed on a substrate; using the first mask layer as a mask, a first epitaxial growth is performed to form an unhealed second group-III nitride epitaxial layer; then, at least a second mask layer is formed on the second group-III nitride epitaxial layer; using the second mask layer as a mask, a second epitaxial growth is performed on the second group-III nitride epitaxial layer to laterally grow a third group-III nitride epitaxial layer, and the third group-III nitride epitaxial layer heals the second group-III nitride epitaxial layer; thereafter, a third epitaxial growth is performed on the third group-III nitride epitaxial layer to form a fourth group-III nitride epitaxial layer. Since the dislocations in the second group-III nitride epitaxial layer are mainly dislocations extending in the thickness direction, the lateral growth thereof can block the continuous upward extension of the dislocations, thereby significantly reducing the dislocation density of the third and fourth group-III nitride epitaxial layers.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and particularly to a group-III nitride structure and a manufacturing method thereof. Background Art

[0002] Group-III nitrides are the third-generation new semiconductor materials after the first- and second-generation semiconductor materials such as Si and GaAs. Among them, GaN, as a wide-bandgap semiconductor material, has many advantages, such as a high saturation drift velocity, a large breakdown voltage, excellent carrier transport performance, and the ability to form ternary alloys such as AlGaN and InGaN and quaternary alloys such as AlInGaN, and it is easy to fabricate a PN junction based on GaN. In view of this, in recent years, GaN-based materials and semiconductor devices have been widely and deeply studied, and the technology of growing GaN-based materials by MOCVD (Metal-organic Chemical Vapor Deposition) has become increasingly mature; in the research of semiconductor devices, remarkable achievements and great developments have been made in the research of optoelectronic devices such as GaN-based LEDs and LDs and microelectronic devices such as GaN-based HEMTs.

[0003] With the gradual in-depth application of GaN-based materials in power devices / display devices, the demand for the dislocation density of GaN-based materials by end products has been further increased, while the dislocation surface density of GaN-based materials epitaxially grown on a mainstream GaN-based epitaxial substrate of aluminum oxide (Al2O3) by using a mainstream MOCVD epitaxial device in the traditional mode is about 1 - 3E8 / cm^3. In order to manufacture GaN-based power devices with higher voltage resistance and GaN-based LEDs with longer wavelength bands, it is necessary to further reduce the dislocation density of GaN-based materials.

[0004] In view of this, it is necessary to provide a new group-III nitride structure and a manufacturing method thereof to meet the above requirements. Summary of the Invention

[0005] The invention object of the present invention is to provide a group-III nitride structure and a manufacturing method thereof, which reduce the dislocation density of group-III nitride materials and improve the performance of group-III nitride semiconductor devices.

[0006] To achieve the above object, the first aspect of the present invention provides a manufacturing method of a group-III nitride structure, including:

[0007] Forming a first mask layer on a substrate; using the first mask layer as a mask to perform a first epitaxial growth to grow and form a second group-III nitride epitaxial layer on the substrate and the first mask layer, and the second group-III nitride epitaxial layer located on the first mask layer is not healed;

[0008] Form a second mask layer at least on the second group-III nitride epitaxial layer; using the second mask layer as a mask, perform a second epitaxial growth on the second group-III nitride epitaxial layer to laterally grow a third group-III nitride epitaxial layer, and the third group-III nitride epitaxial layer heals the second group-III nitride epitaxial layer;

[0009] Perform a third epitaxial growth on the third group-III nitride epitaxial layer to grow and form a fourth group-III nitride epitaxial layer on the third group-III nitride epitaxial layer and the second mask layer.

[0010] It should be noted that in the present invention, the lateral direction refers to: the direction perpendicular to the thickness direction of the second group-III nitride epitaxial layer.

[0011] Optionally, a first group-III nitride epitaxial layer is provided on the substrate; the first mask layer is formed on the first group-III nitride epitaxial layer, and the first epitaxial growth is performed on the first group-III nitride epitaxial layer.

[0012] Optionally, the first group-III nitride epitaxial layer replaces the substrate; the first mask layer is formed on the first group-III nitride epitaxial layer, and the first epitaxial growth is performed on the first group-III nitride epitaxial layer.

[0013] Optionally, the second mask layer is further formed on the first mask layer, and the third group-III nitride epitaxial layer is grown on the second mask layer.

[0014] Optionally, the material of the first mask layer includes at least one of silicon dioxide and silicon nitride; and / or the material of the second mask layer includes at least one of silicon dioxide and silicon nitride.

[0015] Optionally, the materials of the second group-III nitride epitaxial layer, the third group-III nitride epitaxial layer, and the fourth group-III nitride epitaxial layer are the same, including at least one of GaN, AlN, AlGaN, InGaN, and AlInGaN.

[0016] Optionally, the epitaxial growth process of the second group-III nitride epitaxial layer, and / or the third group-III nitride epitaxial layer, and / or the fourth group-III nitride epitaxial layer includes at least one of atomic layer deposition, chemical vapor deposition, molecular beam epitaxial growth, plasma-enhanced chemical vapor deposition, low-pressure chemical vapor deposition, and metal organic chemical vapor deposition.

[0017] Optionally, the epitaxial growth processes of the second group-III nitride epitaxial layer, the third group-III nitride epitaxial layer, and the fourth group-III nitride epitaxial layer are all metalorganic chemical vapor deposition; the growth of the second group-III nitride epitaxial layer, the formation of the second mask layer, the growth of the third group-III nitride epitaxial layer, and the fourth group-III nitride epitaxial layer are carried out in the same metalorganic chemical vapor deposition equipment.

[0018] Optionally, when the fourth group-III nitride epitaxial layer located on the second mask layer is not healed, a fifth group-III nitride epitaxial layer is further grown and formed on the second mask layer and the fourth group-III nitride epitaxial layer.

[0019] Optionally, it further includes: growing and forming an LED structure on the fifth group-III nitride epitaxial layer.

[0020] Optionally, it further includes: growing and forming an LED structure on the fourth group-III nitride epitaxial layer.

[0021] Optionally, it further includes: growing and forming an LED structure on the fourth group-III nitride epitaxial layer.

[0022] Optionally, the formation method of the first group-III nitride epitaxial layer includes: epitaxially growing the first group-III nitride epitaxial layer on a substrate.

[0023] Optionally, the substrate includes at least one of sapphire, silicon carbide, and silicon.

[0024] The second aspect of the present invention provides a group-III nitride structure, including:

[0025] A substrate, having a first mask layer on the substrate;

[0026] A second group-III nitride epitaxial layer, located on the first mask layer and the substrate, the second group-III nitride epitaxial layer is not healed, and a second mask layer is provided on the second group-III nitride epitaxial layer;

[0027] A third group-III nitride epitaxial layer, located on the first mask layer, for healing the second group-III nitride epitaxial layer;

[0028] A fourth group-III nitride epitaxial layer, located on the third group-III nitride epitaxial layer and the second mask layer, and the

[0001] crystal orientation of the second group-III nitride epitaxial layer, the third group-III nitride epitaxial layer, and the fourth group-III nitride epitaxial layer is parallel to the thickness direction of the substrate.

[0029] Optionally, it further includes: a first group-III nitride epitaxial layer, the first group-III nitride epitaxial layer being located on the substrate or replacing the substrate; the first mask layer being located on the first group-III nitride epitaxial layer, and the second group-III nitride epitaxial layer being connected to the first group-III nitride epitaxial layer.

[0030] Optionally, it further includes: a first group-III nitride epitaxial layer, the first group-III nitride epitaxial layer replacing the substrate; the first mask layer being located on the first group-III nitride epitaxial layer, and the second group-III nitride epitaxial layer being connected to the first group-III nitride epitaxial layer.

[0031] Optionally, the materials of the second group-III nitride epitaxial layer, the third group-III nitride epitaxial layer and the fourth group-III nitride epitaxial layer are the same, including at least one of GaN, AlN, AlGaN, InGaN and AlInGaN.

[0032] Optionally, the second mask layer is further provided on the first mask layer, and the third group-III nitride epitaxial layer is located on the second mask layer.

[0033] Optionally, the material of the first mask layer includes at least one of silicon dioxide and silicon nitride; and / or the material of the second mask layer includes at least one of silicon dioxide and silicon nitride.

[0034] Optionally, the second group-III nitride epitaxial layer is an in-situ second group-III nitride epitaxial layer; and / or the second mask layer is an in-situ second mask layer; and / or the third group-III nitride epitaxial layer is an in-situ third group-III nitride epitaxial layer; and / or the fourth group-III nitride epitaxial layer is an in-situ fourth group-III nitride epitaxial layer.

[0035] Optionally, the fourth group-III nitride epitaxial layer on the second mask layer is not healed, and a fifth group-III nitride epitaxial layer is provided on the second mask layer and the fourth group-III nitride epitaxial layer.

[0036] Optionally, it further includes an LED structure located on the fifth group-III nitride epitaxial layer.

[0037] Optionally, it further includes an LED structure located on the fourth group-III nitride epitaxial layer.

[0038] Optionally, it further includes a substrate, and the first group-III nitride epitaxial layer is located on the substrate.

[0039] Optionally, the substrate includes at least one of sapphire, silicon carbide and silicon.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] 1) In the method for fabricating a group-III nitride structure according to the present invention, a first mask layer is first formed on a substrate; using the first mask layer as a mask, a first epitaxial growth is performed to grow a second group-III nitride epitaxial layer on the substrate and the first mask layer, and the second group-III nitride epitaxial layer on the first mask layer is not healed; then at least a second mask layer is formed on the second group-III nitride epitaxial layer; using the second mask layer as a mask, a second epitaxial growth is performed on the second group-III nitride epitaxial layer to laterally grow a third group-III nitride epitaxial layer, and the third group-III nitride epitaxial layer heals the second group-III nitride epitaxial layer; thereafter, a third epitaxial growth is performed on the third group-III nitride epitaxial layer to grow a fourth group-III nitride epitaxial layer on the third group-III nitride epitaxial layer and the second mask layer. Since the dislocations in the second group-III nitride epitaxial layer are mainly line dislocations in the

[0001] crystal direction, that is, dislocations extending in the thickness direction of the second group-III nitride epitaxial layer, the second epitaxial growth with a lateral growth direction can block the dislocations from continuing to extend upward, thereby significantly reducing the dislocation density of the third group-III nitride epitaxial layer and the fourth group-III nitride epitaxial layer.

[0042] 2) In an alternative embodiment, a) a first group-III nitride epitaxial layer is provided on the substrate; or b) the first group-III nitride epitaxial layer replaces the substrate. In this embodiment, the first mask layer is formed on the first group-III nitride epitaxial layer, and the first epitaxial growth is an epitaxial growth on the first group-III nitride epitaxial layer. Compared with selectively growing the second group-III nitride epitaxial layer directly on the substrate, the second group-III nitride epitaxial layer in this embodiment is formed by epitaxially growing on the first group-III nitride epitaxial layer, which can reduce the defects of the second group-III nitride epitaxial layer.

[0043] 3) In an alternative embodiment, the second mask layer is also formed on the first mask layer, and the third group-III nitride epitaxial layer is grown on the second mask layer. In this embodiment, for the second mask layer deposited over the entire surface, only the second mask layer on the sidewalls of the second group-III nitride epitaxial layer needs to be removed.

[0044] 4) In an alternative embodiment, a) the second group-III nitride epitaxial layer, the third group-III nitride epitaxial layer, and the fourth group-III nitride epitaxial layer have the same material, or b) at least two of the second group-III nitride epitaxial layer, the third group-III nitride epitaxial layer, and the fourth group-III nitride epitaxial layer have different materials. The materials of the second group-III nitride epitaxial layer, and / or the third group-III nitride epitaxial layer, and / or the fourth group-III nitride epitaxial layer may include at least one of GaN, AlN, AlGaN, InGaN, and AlInGaN. The specific materials of the second group-III nitride epitaxial layer, the third group-III nitride epitaxial layer, and the fourth group-III nitride epitaxial layer may be determined according to the function, and the specific functions may include: the substrate, buffer layer, barrier layer, or channel layer in a device, etc.

[0045] 5) In an alternative embodiment, the epitaxial growth processes of the second Group-III nitride epitaxial layer, the third Group-III nitride epitaxial layer, and the fourth Group-III nitride epitaxial layer are all metal-organic chemical vapor deposition (MOCVD); the growth of the second Group-III nitride epitaxial layer, the formation of the second mask layer, the growth of the third Group-III nitride epitaxial layer, and the fourth Group-III nitride epitaxial layer are carried out in the same metal-organic chemical vapor deposition equipment (MOCVD equipment). In other words, the second Group-III nitride epitaxial layer is an in-situ second Group-III nitride epitaxial layer, the second mask layer is an in-situ second mask layer, the third Group-III nitride epitaxial layer is an in-situ third Group-III nitride epitaxial layer, and the fourth Group-III nitride epitaxial layer is an in-situ fourth Group-III nitride epitaxial layer. The advantage of in-situ processing is that it can reduce process complexity, reduce the transfer process between multiple processes in different equipment, and avoid the interference of pollution sources in the process on the quality of the second Group-III nitride epitaxial layer, the third Group-III nitride epitaxial layer, and the fourth Group-III nitride epitaxial layer.

[0046] 6) In an alternative embodiment, when the fourth Group-III nitride epitaxial layer located on the second mask layer is not healed, a fifth Group-III nitride epitaxial layer is further grown on the second mask layer and the fourth Group-III nitride epitaxial layer. When the material of the fifth Group-III nitride epitaxial layer is different from that of the fourth Group-III nitride epitaxial layer, this solution can effectively release the stress in the fifth Group-III nitride epitaxial layer and reduce the dislocations and V-shaped pits in the fifth Group-III nitride epitaxial layer.

[0047] 7) In an alternative embodiment, an LED structure is further grown on the fourth Group-III nitride epitaxial layer / fifth Group-III nitride epitaxial layer. The LED structure may include an N-type semiconductor layer, a P-type semiconductor layer, and a quantum well layer located between the N-type semiconductor layer and the P-type semiconductor layer. In other words, the second Group-III nitride epitaxial layer, the third Group-III nitride epitaxial layer, and the fourth Group-III nitride epitaxial layer serve as the substrate of the LED structure, or the second Group-III nitride epitaxial layer, the third Group-III nitride epitaxial layer, the fourth Group-III nitride epitaxial layer, and the fifth Group-III nitride epitaxial layer serve as the substrate of the LED structure, and green LEDs, yellow LEDs, red LEDs, and even infrared LEDs can be fabricated. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a flowchart of the method for fabricating a Group-III nitride structure according to the first embodiment of the present invention;

[0049] Figures 2 to 5 is Figure 1 the schematic diagram of the intermediate structure corresponding to the process in

[0050] Figure 6 a schematic cross-sectional structure diagram of the Group-III nitride structure according to the first embodiment of the present invention;

[0051] Figure 7It is a schematic diagram of an intermediate structure corresponding to a method for fabricating a group-III nitride structure according to the second embodiment of the present invention;

[0052] Figure 8 It is a schematic cross-sectional structure diagram of a group-III nitride structure according to the second embodiment of the present invention;

[0053] Figure 9 It is a schematic cross-sectional structure diagram of a group-III nitride structure according to the third embodiment of the present invention;

[0054] Figure 10 It is a schematic diagram of an intermediate structure corresponding to a method for fabricating a group-III nitride structure according to the fourth embodiment of the present invention;

[0055] Figure 11 It is a schematic cross-sectional structure diagram of a group-III nitride structure according to the fourth embodiment of the present invention;

[0056] Fig.12 It is a schematic cross-sectional structure diagram of a group-III nitride structure according to the fifth embodiment of the present invention;

[0057] Figure 13 It is a schematic cross-sectional structure diagram of a group-III nitride structure according to the sixth embodiment of the present invention;

[0058] Figure 14 It is a schematic cross-sectional structure diagram of a group-III nitride structure according to the seventh embodiment of the present invention.

[0059] For ease of understanding the present invention, all the reference numerals appearing in the present invention are listed below:

[0060] Group-III nitride structures 1, 2, 3, 4, substrate 105, 6, 7

[0061] First group-III nitride epitaxial layer 11, first mask layer 12

[0062] Second group-III nitride epitaxial layer 13, in-situ second group-III nitride epitaxial layer 13'

[0063] Second mask layer 14, in-situ second mask layer 14'

[0064] Third group-III nitride epitaxial layer 15, in-situ third group-III nitride epitaxial layer 15'

[0065] Fourth group-III nitride epitaxial layer 16, in-situ fourth group-III nitride epitaxial layer 16'

[0066] Fifth group-III nitride epitaxial layer 17, LED structure 18 Detailed implementation manners

[0067] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention is made with reference to the accompanying drawings.

[0068] Figure 1 is a flowchart of a method for fabricating a group-III nitride structure according to the first embodiment of the present invention. Figures 2 to 5 is Figure 1 a schematic diagram of an intermediate structure corresponding to the process in Figure 6 is a schematic cross-sectional structure diagram of a group-III nitride structure according to the first embodiment of the present invention.

[0069] First, referring to Figure 1 step S1 in Figure 2 and as shown in Figure 3 , a first mask layer 12 is formed on the first group-III nitride epitaxial layer 11; referring to Figure 3 , with the first mask layer 12 as a mask, a first epitaxial growth is performed on the first group-III nitride epitaxial layer 11 to form a second group-III nitride epitaxial layer 13, and the second group-III nitride epitaxial layer 13 located on the first mask layer 12 is not healed.

[0070] Referring to Figure 2 and as shown in this embodiment, the first group-III nitride epitaxial layer 11 can be formed on a substrate 10. The substrate 10 can be at least one of sapphire, silicon carbide, and silicon, and this embodiment does not limit this.

[0071] The group-III nitride material of the first group-III nitride epitaxial layer 11 can be AlN, or can be at least one of GaN, AlGaN, InGaN, and AlInGaN, and this embodiment does not limit this. AlN can be used as a nucleation layer. The first group-III nitride epitaxial layer 11 has dislocations, and the dislocations are mainly line dislocations in the

[0001] crystal orientation, that is, dislocations extending in the thickness direction of the first group-III nitride epitaxial layer 11.

[0072] In step S1, the first group-III nitride epitaxial layer 11 formed on the substrate 10 can be an existing structure, or step S1 can include: epitaxially growing the first group-III nitride epitaxial layer 11 on the substrate 10.

[0073] The formation process of the first group-III nitride epitaxial layer 11 can include: atomic layer deposition (ALD), or chemical vapor deposition (CVD), or molecular beam epitaxy (MBE), or plasma enhanced chemical vapor deposition (PECVD), or low pressure chemical vapor deposition (LPCVD), or metal organic chemical vapor deposition, or a combination thereof.

[0074] In some embodiments, the first group-III nitride epitaxial layer 11 after the stripping of the substrate 10 may be the first group-III nitride epitaxial layer 11 in step S1.

[0075] The material of the first mask layer 12 may include at least one of silicon dioxide and silicon nitride.

[0076] The material of the second group-III nitride epitaxial layer 13 may be the same as or different from that of the first group-III nitride epitaxial layer 11. The material of the second group-III nitride epitaxial layer 13 may be at least one of GaN, AlN, AlGaN, InGaN, and AlInGaN, and this embodiment does not limit this.

[0077] The formation process of the second group-III nitride epitaxial layer 13 may refer to the formation process of the first group-III nitride epitaxial layer 11. The first epitaxial growth includes growth in the lateral and thickness directions.

[0078] Then, referring to Figure 1 step S2 in Figure 4 and as shown in Figure 5 , a second mask layer 14 is formed on the second group-III nitride epitaxial layer 13; referring to

[0079] shown in

[0080] Figure 4 , using the second mask layer 14 as a mask, a second epitaxial growth is performed on the second group-III nitride epitaxial layer 13 to form a third group-III nitride epitaxial layer 15 by lateral growth, and the third group-III nitride epitaxial layer 15 heals the second group-III nitride epitaxial layer 13.

[0081] Referring to Figure 5 shown in

[0082] , since the second mask layer 14 shields the second group-III nitride epitaxial layer 13, when a second epitaxial growth is performed on the second group-III nitride epitaxial layer 13, growth in the thickness direction is not possible, and only lateral growth occurs. Since the dislocations in the second group-III nitride epitaxial layer 13 are mainly dislocations extending in the thickness direction, lateral growth can block the continued upward extension of the dislocations in the thickness direction, thereby significantly reducing the dislocation density of the third group-III nitride epitaxial layer 15.The material of the third group-III nitride epitaxial layer 15 may be the same as or different from that of the second group-III nitride epitaxial layer 13. The material of the third group-III nitride epitaxial layer 15 may be at least one of GaN, AlN, AlGaN, InGaN, and AlInGaN, and this embodiment does not limit this.

[0083] The formation process of the third group-III nitride epitaxial layer 15 may refer to the formation process of the first group-III nitride epitaxial layer 11.

[0084] Then, referring to Figure 1 step S3 in Figure 6 as shown, the third group-III nitride epitaxial layer 15 is subjected to a third epitaxial growth to grow and form a fourth group-III nitride epitaxial layer 16 on the third group-III nitride epitaxial layer 15 and the second mask layer 14.

[0085] The third epitaxial growth includes growth in the lateral and thickness directions.

[0086] The material of the fourth group-III nitride epitaxial layer 16 may be the same as or different from that of the third group-III nitride epitaxial layer 15. The material of the fourth group-III nitride epitaxial layer 16 may be at least one of GaN, AlGaN, InGaN, and AlInGaN, and this embodiment does not limit this.

[0087] The functions of the fourth group-III nitride epitaxial layer 16, the third / group-II nitride epitaxial layer 15 / second group-III nitride epitaxial layer 13, and the first group-III nitride epitaxial layer 11 may be the same or different. For example, the first group-III nitride epitaxial layer 11 may be a substrate in the device, the second group-III nitride epitaxial layer 13 and the third group-III nitride epitaxial layer 15 may be nucleation layers in the device, and the fourth group-III nitride epitaxial layer 16 may be a buffer layer, a barrier layer, or a channel layer, etc. in the device. The buffer layer can reduce the screw dislocation (TD) density in the upper semiconductor layer and the TD bending caused by the lateral growth mechanism. Another example is that the first group-III nitride epitaxial layer 11, the second group-III nitride epitaxial layer 13, and the third group-III nitride epitaxial layer 16 may be nucleation layers in the device, the fourth group-III nitride epitaxial layer 16 may be a buffer layer, a barrier layer, or a channel layer, etc. in the device; or the first group-III nitride epitaxial layer 11 may be a substrate in the device, the second group-III nitride epitaxial layer 13 and the third group-III nitride epitaxial layer 15 may be nucleation layers and buffer layers in the device, and the fourth group-III nitride epitaxial layer 16 may be a barrier layer or a channel layer, etc. in the device.

[0088] Figure 6 is a schematic cross-sectional structure diagram of the group-III nitride structure according to the first embodiment of the present invention.

[0089] Referring to Figure 6As shown, the group-III nitride structure 1 of this embodiment includes:

[0090] A first group-III nitride epitaxial layer 11, on which a first mask layer 12 is provided;

[0091] A second group-III nitride epitaxial layer 13, located on the first mask layer 12 and the first group-III nitride epitaxial layer 11, and the second group-III nitride epitaxial layer 13 is not healed. A second mask layer 14 is provided on the second group-III nitride epitaxial layer 13;

[0092] A third group-III nitride epitaxial layer 15, located on the first mask layer 12, for healing the second group-III nitride epitaxial layer 13;

[0093] A fourth group-III nitride epitaxial layer 16, located on the third group-III nitride epitaxial layer 15 and the second mask layer 14. The

[0001] crystal orientation of the first group-III nitride epitaxial layer 11, the second group-III nitride epitaxial layer 13, the third group-III nitride epitaxial layer 15, and the fourth group-III nitride epitaxial layer 16 is parallel to the thickness direction.

[0094] It can be seen that since the second mask layer 14 shields the second group-III nitride epitaxial layer 13, when epitaxial growth is performed on the second group-III nitride epitaxial layer 13, growth cannot occur in the thickness direction and only occurs laterally. Since the dislocations in the first group-III nitride epitaxial layer 11 and the second group-III nitride epitaxial layer 13 mainly extend in the thickness direction, lateral growth can block the continued upward extension of the dislocations in the thickness direction, thereby significantly reducing the dislocation density of the third group-III nitride epitaxial layer 15 and the fourth group-III nitride epitaxial layer 16.

[0095] The materials of the first group-III nitride epitaxial layer 11, the second group-III nitride epitaxial layer 13, the third group-III nitride epitaxial layer 15, and the fourth group-III nitride epitaxial layer 16 can be the same or different. The materials of the first group-III nitride epitaxial layer 11, and / or the second group-III nitride epitaxial layer 13, and / or the third group-III nitride epitaxial layer 15, and / or the fourth group-III nitride epitaxial layer 16 can be at least one of GaN, AlN, AlGaN, InGaN, and AlInGaN. This embodiment does not limit this.

[0096] The functions of the first group-III nitride epitaxial layer 11, and / or the second group-III nitride epitaxial layer 13, and / or the third group-III nitride epitaxial layer 15, and / or the fourth group-III nitride epitaxial layer 16 can be the same or different. The first group-III nitride epitaxial layer 11, and / or the second group-III nitride epitaxial layer 13, and / or the third group-III nitride epitaxial layer 15, and / or the fourth group-III nitride epitaxial layer 16 can be a substrate, a buffer layer, a barrier layer, or a channel layer in a device, etc.

[0097] The material of the second mask layer 14 can be selected as a material that can inhibit the growth of the second group-III nitride epitaxial layer 13. For example, it can include at least one of silicon dioxide and silicon nitride. The material of the first mask layer 12 can be selected as a material on which the second group-III nitride epitaxial layer 13 can adhere. For example, it can include at least one of silicon dioxide and silicon nitride.

[0098] In addition, referring to Figure 6 As shown, in this embodiment, the first group-III nitride epitaxial layer 11 can be located on the substrate 10. The substrate 10 can be at least one of sapphire, silicon carbide, and silicon, and this embodiment does not limit this.

[0099] In some embodiments, the first group-III nitride epitaxial layer 11 can be the first group-III nitride epitaxial layer 11 after the substrate 10 is peeled off.

[0100] Figure 7 is a schematic diagram of an intermediate structure corresponding to the manufacturing method of the group-III nitride structure according to the second embodiment of the present invention. Figure 8 is a schematic cross-sectional structure diagram of the group-III nitride structure according to the second embodiment of the present invention. Referring to Figure 7 and Figure 8 As shown, the group-III nitride structure 2 and its manufacturing method in this embodiment are substantially the same as those of the group-III nitride structure 1 and its manufacturing method in the Figures 1 to 6 embodiment, with the only difference being that in step S2, the second mask layer 14 is further formed on the first mask layer 12, and the third group-III nitride epitaxial layer 15 is grown and formed on the second mask layer 14.

[0101] In this embodiment, in step S2, only the second mask layer 14 on the sidewalls of the second group-III nitride epitaxial layer 13 needs to be removed.

[0102] Figure 9 is a schematic cross-sectional structure diagram of the group-III nitride structure according to the third embodiment of the present invention. Referring to Figure 9 As shown, the group-III nitride structure 3 in this embodiment, Figure 1 and Figure 8 are substantially the same as the group-III nitride structures 1 and 2 in the

[0103] correspondingly, the manufacturing method of the group-III nitride structure 3 in this embodiment is the same as that in the Figures 1 to 6 embodiment, Figure 7 and Figure 8The manufacturing methods of the Group-III nitride structures 1 and 2 of the embodiments are substantially the same, with the only difference being that: in step S1, the growth of the second Group-III nitride epitaxial layer 13, in step S2, the formation of the second mask layer 14 and the growth of the third Group-III nitride epitaxial layer 15, and in step S3, the growth of the fourth Group-III nitride epitaxial layer 16 are carried out in the same MOCVD equipment.

[0104] Carrying out in the same MOCVD equipment, that is, in-situ, has the advantage that: it can reduce process complexity, reduce the transfer process between multiple processes in different equipment, and avoid the interference of pollution sources in the process with the quality of the second Group-III nitride epitaxial layer 13, the third Group-III nitride epitaxial layer 15, and the fourth Group-III nitride epitaxial layer 16.

[0105] Figure 10 It is a schematic diagram of an intermediate structure corresponding to the manufacturing method of the Group-III nitride structure of the fourth embodiment of the present invention. Figure 11 It is a schematic cross-sectional structure diagram of the Group-III nitride structure of the fourth embodiment of the present invention. Refer to Figure 10 And Figure 11 As shown, the Group-III nitride structure 4 of the present embodiment and its manufacturing method are substantially the same as those of the Group-III nitride structures 1, 2, and 3 and their manufacturing methods of the Figures 1 to 9 embodiments, with the only difference being that: the substrate 10 replaces the first Group-III nitride epitaxial layer 11. In other words, in step S1, the first mask layer 12 is formed on the substrate 10, and the second Group-III nitride epitaxial layer 13 formed by the first epitaxial growth is a selective growth on the substrate 10.

[0106] Fig.12 It is a schematic cross-sectional structure diagram of the Group-III nitride structure of the fifth embodiment of the present invention. Refer to Fig.12 As shown, the Group-III nitride structure 5 of the present embodiment and its manufacturing method are substantially the same as those of the Group-III nitride structures 1, 2, 3, and 4 and their manufacturing methods of the Figures 1 to 11 embodiments, with the only difference being that: an LED structure 18 is further grown on the fourth Group-III nitride epitaxial layer 16.

[0107] The LED structure 18 may include: an N-type semiconductor layer, a P-type semiconductor layer, and a quantum well layer located between the N-type semiconductor layer and the P-type semiconductor layer.

[0108] The N-type semiconductor layer is used to provide electrons, and the P-type semiconductor layer is used to provide holes, so that the electrons and holes recombine and emit light in the quantum well layer. The N-type semiconductor layer and / or the P-type semiconductor layer may include group III nitride materials. The group III nitride materials may be at least one of GaN, AlGaN, InGaN, and AlInGaN. The N-type ions in the N-type semiconductor layer may be at least one of Si ions, Ge ions, Sn ions, Se ions, or Te ions. The P-type doping ions in the P-type semiconductor layer may be at least one of Mg ions, Zn ions, Ca ions, Sr ions, or Ba ions.

[0109] In some embodiments, the N-type semiconductor layer may be close to the fourth group III nitride epitaxial layer 16, and the P-type semiconductor layer may be far from the fourth group III nitride epitaxial layer 16. In other embodiments, the P-type semiconductor layer may also be close to the fourth group III nitride epitaxial layer 16, and the N-type semiconductor layer may be far from the fourth group III nitride epitaxial layer 16.

[0110] The quantum well layer may be a single quantum well layer or a multi-quantum well layer.

[0111] The formation process of the LED structure 18 may refer to the formation process of the fourth group III nitride epitaxial layer 16.

[0112] Figure 13 It is a schematic cross-sectional structure diagram of the group III nitride structure of the sixth embodiment of the present invention. Refer to Figure 13 As shown, the group III nitride structure 6 of this embodiment and its manufacturing method are substantially the same as those of the group III nitride structures 1, 2, 3, and 4 of Figures 1 to 11 the embodiment, the difference is only that when the fourth group III nitride epitaxial layer 16 on the second mask layer 14 is not healed, a fifth group III nitride epitaxial layer 17 is also grown on the second mask layer 14 and the fourth group III nitride epitaxial layer 16.

[0113] The material of the fifth group III nitride epitaxial layer 17 is different from that of the fourth group III nitride epitaxial layer 16.

[0114] Specifically, the type of elements included in the material of the fifth group III nitride epitaxial layer 17 may be more than that of the material of the fourth group III nitride epitaxial layer 16. For example, when the material of the fourth group III nitride epitaxial layer 16 is GaN, the fifth group III nitride epitaxial layer 17 at least further includes at least one of Al and In elements. When the material of the fourth group III nitride epitaxial layer 16 is AlN, the fifth group III nitride epitaxial layer 17 at least further includes at least one of Ga and In elements.

[0115] The material of the fifth group III nitride epitaxial layer 17 may be at least one of AlGaN, InGaN, and AlInGaN.

[0116] The solution of this embodiment can also be combined with Figure 9 the solution of the embodiment, that is, the fifth group-III nitride epitaxial layer 17 is an in-situ fifth group-III nitride epitaxial layer. The growth of the fifth group-III nitride epitaxial layer and the growth of the fourth group-III nitride epitaxial layer 16 in step S3 are carried out in the same MOCVD equipment.

[0117] The solution of this embodiment can effectively release the stress in the fifth group-III nitride epitaxial layer 17 and reduce the dislocations and V-shaped pits in the fifth group-III nitride epitaxial layer 17. When the fifth group-III nitride epitaxial layer 17 is directly grown on the second mask layer 14 and the third group-III nitride epitaxial layer 15, V-shaped pits will be formed on the second mask layer 14.

[0118] Figure 14 It is a schematic cross-sectional structure diagram of the group-III nitride structure of the seventh embodiment of the present invention. Refer to Figure 14 As shown, the group-III nitride structure 7 of this embodiment and its manufacturing method are substantially the same as those of Figure 13 the group-III nitride structure 6 of the embodiment and its manufacturing method, the only difference being that: an LED structure 18 is also grown on the fifth group-III nitride epitaxial layer 17.

[0119] For the specific structure and formation method of the LED structure 18, reference can be made to Fig.12 the specific structure and formation method of the LED structure 18 in the embodiment.

[0120] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be determined by the scope defined by the claims.

Claims

1. A method for fabricating a group III nitride structure, characterized in that Including: Forming a first mask layer (12) on a substrate (10); using the first mask layer (12) as a mask to perform a first epitaxial growth to grow and form a second group-III nitride epitaxial layer (13) on the substrate (10) and the first mask layer (12), and the second group-III nitride epitaxial layer (13) on the first mask layer (12) is not healed, wherein the first epitaxial growth includes growth in the lateral and thickness directions; Forming at least a second mask layer (14) on the second group-III nitride epitaxial layer (13); using the second mask layer (14) as a mask to perform a second epitaxial growth on the second group-III nitride epitaxial layer (13) to laterally grow and form a third group-III nitride epitaxial layer (15), and the third group-III nitride epitaxial layer (15) heals the second group-III nitride epitaxial layer (13); Performing a third epitaxial growth on the third group-III nitride epitaxial layer (15) to grow and form a fourth group-III nitride epitaxial layer (16) on the third group-III nitride epitaxial layer (15) and the second mask layer (14).

2. The manufacturing method of the group III nitride structure according to claim 1, characterized in that The substrate (10) has a first group-III nitride epitaxial layer (11) or the first group-III nitride epitaxial layer (11) replaces the substrate (10); the first mask layer (12) is formed on the first group-III nitride epitaxial layer (11), and the first epitaxial growth is an epitaxial growth on the first group-III nitride epitaxial layer (11).

3. The manufacturing method of the group III nitride structure according to claim 1 or 2, characterized in that, The second mask layer (14) is also formed on the first mask layer (12), and the third group-III nitride epitaxial layer (15) is grown and formed on the second mask layer (14).

4. The manufacturing method of the Group III nitride structure according to claim 1 or 2, characterized in that, The material of the first mask layer (12) includes at least one of silicon dioxide and silicon nitride; and / or the material of the second mask layer (14) includes at least one of silicon dioxide and silicon nitride.

5. The manufacturing method of the group III nitride structure according to claim 1 or 2, characterized in that, The materials of the second group-III nitride epitaxial layer (13), the third group-III nitride epitaxial layer (15), and the fourth group-III nitride epitaxial layer (16) are the same, including at least one of GaN, AlN, AlGaN, InGaN, and AlInGaN.

6. The manufacturing method of the group III nitride structure according to claim 1 or 2, characterized in that, The epitaxial growth process of the second group-III nitride epitaxial layer (13), and / or the third group-III nitride epitaxial layer (15), and / or the fourth group-III nitride epitaxial layer (16) includes at least one of atomic layer deposition method, chemical vapor deposition method, molecular beam epitaxial growth method, plasma enhanced chemical vapor deposition method, low pressure chemical vapor deposition method, and metal organic chemical vapor deposition method.

7. The manufacturing method of the group III nitride structure according to claim 6, characterized in that, The epitaxial growth processes of the second group-III nitride epitaxial layer (13), the third group-III nitride epitaxial layer (15), and the fourth group-III nitride epitaxial layer (16) are all metalorganic chemical vapor deposition; the growth of the second group-III nitride epitaxial layer (13), the formation of the second mask layer (14), the growth of the third group-III nitride epitaxial layer (15), and the fourth group-III nitride epitaxial layer (16) are carried out in the same metalorganic chemical vapor deposition equipment.

8. The manufacturing method of the group III nitride structure according to claim 1 or 2, characterized in that, When the fourth group-III nitride epitaxial layer (16) located on the second mask layer (14) is not healed, a fifth group-III nitride epitaxial layer (17) is also grown on the second mask layer (14) and the fourth group-III nitride epitaxial layer (16).

9. The manufacturing method of the Group III nitride structure according to claim 8, characterized in that, Further comprising: Growing an LED structure (18) on the fifth group-III nitride epitaxial layer (17).

10. The manufacturing method of the group III nitride structure according to claim 1 or 2, characterized in that, Further comprising: Growing an LED structure (18) on the fourth group-III nitride epitaxial layer (16).

11. The manufacturing method of the group III nitride structure according to claim 1 or 2, characterized in that, The substrate (10) includes at least one of sapphire, silicon carbide, and silicon.

12. A group III nitride structure, characterized in that, Comprising: A substrate (10) having a first mask layer (12) thereon; A second group-III nitride epitaxial layer (13) located on the first mask layer (12) and the substrate (10), and the second group-III nitride epitaxial layer (13) is not healed. Wherein, the second group-III nitride epitaxial layer (13) is obtained by the first epitaxial growth, and the first epitaxial growth includes growth in the lateral and thickness directions. A second mask layer (14) is provided on the second group-III nitride epitaxial layer (13); A third group-III nitride epitaxial layer (15) located on the first mask layer (12) for healing the second group-III nitride epitaxial layer (13); A fourth group-III nitride epitaxial layer (16) located on the third group-III nitride epitaxial layer (15) and the second mask layer (14). The [0001] crystal orientation of the second group-III nitride epitaxial layer (13), the third group-III nitride epitaxial layer (15), and the fourth group-III nitride epitaxial layer (16) is parallel to the thickness direction of the substrate (10).

13. The group-III nitride structure according to claim 12, characterized in that, Further comprising: A first group-III nitride epitaxial layer (11), the first group-III nitride epitaxial layer (11) is located on the substrate (10) or replaces the substrate (10); the first mask layer (12) is located on the first group-III nitride epitaxial layer (11), and the second group-III nitride epitaxial layer (13) is connected to the first group-III nitride epitaxial layer (11).

14. The group-III nitride structure according to claim 12 or 13, characterized in that, The second group-III nitride epitaxial layer (13), the third group-III nitride epitaxial layer (15), and the fourth group-III nitride epitaxial layer (16) are made of the same material, including at least one of GaN, AlN, AlGaN, InGaN, and AlInGaN.

15. The group-III nitride structure according to claim 12 or 13, characterized in that, The second mask layer (14) is further provided on the first mask layer (12), and the third group-III nitride epitaxial layer (15) is located on the second mask layer (14).

16. The Group III nitride structure according to claim 12 or 13, characterized in that, The material of the first mask layer (12) includes at least one of silicon dioxide and silicon nitride; and / or the material of the second mask layer (14) includes at least one of silicon dioxide and silicon nitride.

17. The group-III nitride structure according to claim 12 or 13, characterized in that, The second group-III nitride epitaxial layer (13) is an in-situ second group-III nitride epitaxial layer (13'); and / or the second mask layer (14) is an in-situ second mask layer (14'); and / or the third group-III nitride epitaxial layer (15) is an in-situ third group-III nitride epitaxial layer (15'); and / or the fourth group-III nitride epitaxial layer (16) is an in-situ fourth group-III nitride epitaxial layer (16').

18. The group-III nitride structure according to claim 12 or 13, characterized in that, The fourth group-III nitride epitaxial layer (16) on the second mask layer (14) is not healed, and a fifth group-III nitride epitaxial layer (17) is provided on the second mask layer (14) and the fourth group-III nitride epitaxial layer (16).

19. The group-III nitride structure according to claim 18, wherein, Further included is: An LED structure (18) located on the fifth group-III nitride epitaxial layer (17).

20. The group-III nitride structure according to claim 12 or 13, characterized in that, Further included is: An LED structure (18) located on the fourth group-III nitride epitaxial layer (16).

21. The group-III nitride structure according to claim 12 or 13, characterized in that, The substrate (10) includes at least one of sapphire, silicon carbide, and silicon.

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