Group iii nitride epitaxial layer and method for manufacturing the same, and semiconductor device

Abstract

The application provides a III-nitride epitaxial layer and a manufacturing method thereof, and a semiconductor device. The III-nitride epitaxial layer comprises a substrate layer, a nucleation layer, and a III-nitride transition region. The transition region comprises a first transition layer, M first transition units, and N second transition units, M0, N0, M+N2. The first transition unit comprises a second transition layer and a third transition layer, and the second transition unit comprises a fourth transition layer and a fifth transition layer. The second transition layer, the third transition layer, the fourth transition layer and the fifth transition layer comprise a first III element and a second III element. The difference between the contents of the second III element in the second transition layer and the third transition layer and the difference between the contents of the second III element in the fourth transition layer and the fifth transition layer are both greater than or equal to 35% and less than or equal to 45%. By arranging the first transition unit and the second transition unit in the III-nitride transition region, the dislocation density is reduced, and the overall thickness of the epitaxial layer is reduced.

Description

Technical Field

[0001] This application relates to the field of group III-V semiconductor technology, specifically to a group III nitride epitaxial layer and its manufacturing method, as well as semiconductor devices. Background Technology

[0002] Group III-V compound semiconductors can be used to form various semiconductor devices, such as lasers, high-power field-effect transistors (FETs), and high electron mobility transistors (HEMTs). Group III-V semiconductors are epitaxially formed on a substrate. There is a significant difference in lattice constant between the group III-V semiconductor and the substrate, and the defects in the epitaxial layer are mainly dislocations. Multiple transition layers are placed between the functional layers (e.g., channel layers) of the group III-V semiconductor and the substrate. The content of group III elements in these transition layers gradually decreases, thereby reducing dislocations in the epitaxial layer. However, the total thickness of these multiple transition layers is relatively large. Summary of the Invention

[0003] This application provides a group III nitride epitaxial layer, a method for manufacturing the same, and a semiconductor device. The first and second transition units in the epitaxial layer both include interfaces with a significant difference in the content of group III elements, reducing dislocation density and decreasing the overall thickness of the epitaxial layer.

[0004] According to one aspect of this application, a group III nitride epitaxial layer includes: a substrate layer, a nucleation layer on the substrate layer, and a group III nitride transition region on the nucleation layer.

[0005] The nucleation layer is located on the substrate and includes Group III elements and nitrogen. A Group III nitride transition region is located on the nucleation layer. The Group III nitride transition region includes a first transition layer, M first transition units, and N second transition units, where M and N are integers. 0, N 0, M+N 2. The first transition unit includes a second transition layer and a third transition layer, with the third transition layer located above the second transition layer. Both the second and third transition layers include elements from Group I III and Group II III. The content of Group II III elements in the second transition layer is greater than that in the third transition layer, and the difference in the content of Group II III elements between the second and third transition layers is greater than or equal to 35% and less than or equal to 45%. The second transition unit includes a fourth transition layer and a fifth transition layer, with the fifth transition layer located above the fourth transition layer. Both the fourth and fifth transition layers include elements from Group I III and Group II III. The content of Group II III elements in the fourth transition layer is greater than that in the fifth transition layer, and the difference in the content of Group II III elements between the fourth and fifth transition layers is greater than or equal to 35% and less than or equal to 45%.

[0006] In some embodiments, the content of the second group III element in the second transition layer is greater than or equal to 57.5% and less than or equal to 62.5%, and the content of the second group III element in the third transition layer is greater than or equal to 20% and less than or equal to 25%.

[0007] In some embodiments, the content of the second group III element in the fourth transition layer is greater than or equal to 37.5% and less than or equal to 42.5%, and the content of the second group III element in the fifth transition layer is greater than 0 and less than or equal to 2.5%.

[0008] In some embodiments, the difference in the content of the second group III element between the second transition layer and the third transition layer is greater than or equal to 37.5% and less than or equal to 42.5%, and the difference in the content of the second group III element between the fourth transition layer and the fifth transition layer is greater than or equal to 37.5% and less than or equal to 42.5%.

[0009] In some embodiments, the first transition layer is formed directly on the nucleation layer, and the content of the second group III element in the first transition layer is greater than or equal to 99%.

[0010] In some embodiments, M=1, N=1, the second transition layer of the first transition unit is located on the first transition layer, and the fourth transition layer of the second transition unit is located on the third transition layer of the first transition unit.

[0011] In some embodiments, M 2, N=0, M first transition units are stacked on the first transition layer.

[0012] In some embodiments, M=0, N 2. N second transition units are stacked on the first transition layer.

[0013] In some embodiments, M 1, N 1, N M, M first transition units are stacked on the first transition layer, and N second transition units are stacked on top of M first transition units.

[0014] In some embodiments, the group III nitride epitaxial layer further includes a channel layer and a barrier layer, wherein the channel layer is located on the group III nitride transition region and the barrier layer is located on the channel layer.

[0015] In some embodiments, the thickness of the group III nitride transition region is greater than or equal to 240 nm and less than or equal to 7200 nm.

[0016] In some embodiments, each of the second, third, and fifth transition layers includes: an island structure and a flat structure, wherein the flat structure covers the island structure.

[0017] In some embodiments, the thickness of the island structure is less than or equal to 30% of the total thickness of the transition layer corresponding to the island structure.

[0018] In some embodiments, the first group III element is Ga, and the second group III element is Al.

[0019] According to another aspect of this application, a semiconductor device is provided, including the aforementioned group III nitride epitaxial layer.

[0020] According to another aspect of this application, a method for manufacturing a group III nitride epitaxial layer is provided, comprising: A nucleation layer is formed on the substrate, and the nucleation layer includes Group III elements and nitrogen. A group III nitride transition region is formed on the nucleation layer. The group III nitride transition region includes a first transition layer, M first transition units, and N second transition units, where M and N are integers. 0, N 0, M+N 2, The first transition unit includes a second transition layer and a third transition layer, with the third transition layer located above the second transition layer. Both the second and third transition layers include elements from Group I III and Group II III. The content of Group II III elements in the second transition layer is greater than that in the third transition layer. The difference in the content of Group II III elements between the second and third transition layers is greater than or equal to 35% and less than or equal to 45%. The second transition unit includes a fourth transition layer and a fifth transition layer. The fifth transition layer is located above the fourth transition layer. The fourth and fifth transition layers include elements from Group I III and elements from Group II III. The content of elements from Group II III in the fourth transition layer is greater than that in the fifth transition layer. The difference in the content of elements from Group II III in the fourth and fifth transition layers is greater than or equal to 35% and less than or equal to 45%.

[0021] In some embodiments, the content of the second group III element in the second transition layer is greater than or equal to 57.5% and less than or equal to 62.5%, and the content of the second group III element in the third transition layer is greater than or equal to 20% and less than or equal to 25%.

[0022] In some embodiments, the content of the second group III element in the fourth transition layer is greater than or equal to 37.5% and less than or equal to 42.5%, and the content of the second group III element in the fifth transition layer is greater than 0 and less than or equal to 2.5%.

[0023] In some embodiments, the difference in the content of the second group III element between the second transition layer and the third transition layer is greater than or equal to 37.5% and less than or equal to 42.5%, and the difference in the content of the second group III element between the fourth transition layer and the fifth transition layer is greater than or equal to 37.5% and less than or equal to 42.5%.

[0024] In some embodiments, the first transition layer is formed directly on the nucleation layer, and the content of the second group III element in the first transition layer is greater than or equal to 99%.

[0025] In some embodiments, M=1, N=1, the second transition layer of the first transition unit is located on the first transition layer, and the fourth transition layer of the second transition unit is located on the third transition layer of the first transition unit.

[0026] In some embodiments, M 2, N=0, M first transition units are stacked on the first transition layer.

[0027] In some embodiments, M=0, N 2. N second transition units are stacked on the first transition layer.

[0028] In some embodiments, M 1, N 1, N M, M first transition units are stacked on the first transition layer, and N second transition units are stacked on top of M first transition units.

[0029] In some embodiments, the manufacturing method further includes forming a channel layer and a barrier layer, wherein the channel layer is located on the group III nitride transition region and the barrier layer is located on the channel layer.

[0030] In some embodiments, the thickness of the group III nitride transition region is greater than or equal to 240 nm and less than or equal to 7200 nm.

[0031] In some embodiments, the method of forming a nucleation layer on a substrate includes: controlling the temperature of an epitaxial reaction chamber in a first temperature range, and controlling the ratio of the intake volume of a gas containing nitrogen to a gas containing a second group III element in the epitaxial reaction chamber in a first interval, so as to form a nucleation layer.

[0032] In some embodiments, a method for forming a first transition layer of a group III nitride transition region on a nucleation layer includes: controlling the temperature of an epitaxial reaction chamber in a second temperature range, and controlling the ratio of the intake volume of a gas containing nitrogen to a gas containing a second group III element in a first interval to form a first transition layer, wherein the value of the second temperature range is greater than the value of the first temperature range.

[0033] In some embodiments, forming the second and third transition layers of the first transition unit includes: controlling the temperature of the epitaxial reaction chamber within a second temperature range; adaptively controlling the intake amounts of a gas containing nitrogen, a gas containing a first group III element, and a gas containing a second group III element in the epitaxial reaction chamber to form the second transition layer; maintaining the temperature of the epitaxial reaction chamber within the second temperature range; and adaptively adjusting the intake amounts of the gas containing nitrogen, the gas containing a first group III element, and the gas containing a second group III element in the epitaxial reaction chamber to form the third transition layer.

[0034] In some embodiments, forming the fourth and fifth transition layers of the second transition unit includes: maintaining the temperature of the epitaxial reaction chamber within a second temperature range; adaptively adjusting the intake amounts of the gas containing nitrogen, the gas containing a first group III element, and the gas containing a second group III element in the epitaxial reaction chamber to form the fourth transition layer; maintaining the temperature of the epitaxial reaction chamber within a second temperature range; and adaptively adjusting the intake amounts of the gas containing nitrogen, the gas containing a first group III element, and the gas containing a second group III element in the epitaxial reaction chamber to form the fifth transition layer.

[0035] In some embodiments, the methods for forming the second transition layer, the third transition layer, and the fifth transition layer all include: forming an island-like structure; and forming a flat structure covering the island-like structure.

[0036] In some embodiments, the thickness of the island structure is less than or equal to 30% of the overall thickness of the transition layer corresponding to the island structure.

[0037] In some embodiments, island-like structures are epitaxially formed on the first transition layer using the Volmer-Weber pattern, and flat structures are epitaxially formed using the Frank-van der Merwe pattern.

[0038] This application provides a group III nitride epitaxial layer, a method for manufacturing the same, and a semiconductor device. The group III nitride epitaxial layer includes a substrate layer, a nucleation layer, and a group III nitride transition region located on the nucleation layer. The group III nitride transition region includes a first transition layer, M first transition units, and N second transition units, where M and N are integers. 0, N 0, M+N 2. The first transition unit includes a second and a third transition layer, and the second transition unit includes a fourth and a fifth transition layer. All five transition layers include elements from Group I III and Group II III. The difference in the content of Group II III elements between the second and third transition layers, and between the fourth and fifth transition layers, is greater than or equal to 35% and less than or equal to 45%. The interface between the first and second transition units has a significant difference in the content of Group II III elements, which reduces the dislocation density and decreases the overall thickness of the epitaxial layer. Attached Figure Description

[0039] The above and other objects, features, and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which: Figure 1 This is a cross-sectional view of a semiconductor device according to an embodiment of this application; Figure 2 This is a cross-sectional view of another semiconductor device according to an embodiment of this application; Figure 3 This is a cross-sectional view of another semiconductor device according to an embodiment of this application; Figure 4 This is a cross-sectional view of another semiconductor device according to an embodiment of this application; Figure 5 and Figure 6 The method for forming the transition layer is shown. Detailed Implementation

[0040] The present application is described below based on embodiments, but it is not limited to these embodiments. In the detailed description of the present application below, certain specific details are described in detail. Those skilled in the art can fully understand the present application without these details. To avoid obscuring the substance of the present application, well-known methods, processes, flows, elements, and circuits are not described in detail.

[0041] Furthermore, those skilled in the art should understand that the proportions shown in the accompanying drawings are only one embodiment, and other embodiments are not necessarily implemented to scale.

[0042] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] For ease of explanation, spatially related terms such as “inner,” “outer,” “below,” “below,” “lower,” “above,” “upper,” etc., are used herein to describe the relationship between one element or feature illustrated in the figure and another. It will be understood that spatially related terms may be intended to encompass different orientations of the device in use or operation besides those depicted in the figure. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially related descriptive terms used herein should be interpreted accordingly.

[0044] Unless the context explicitly requires it, words such as "including" or "contains" throughout the application should be interpreted as including rather than exclusive or exhaustive; that is, meaning "including but not limited to".

[0045] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0046] This application provides a semiconductor device comprising a group III nitride epitaxial layer. Exemplarily, the semiconductor device is a high electron mobility transistor (HEMT), and the group III nitride epitaxial layer comprises the channel layer of the HEMT. The group III element may be boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0047] Figure 1 This is a cross-sectional view of an exemplary semiconductor device. The semiconductor device includes a group III nitride epitaxial layer 1. The group III nitride epitaxial layer 1 includes: a substrate layer 100, a nucleation layer 200, and a group III nitride transition region 2.

[0048] For example, substrate 100 is a silicon substrate, silicon carbide substrate, sapphire substrate, etc. Nucleation layer 200 is located on substrate 100, and nucleation layer 200 includes at least a Group III element and nitrogen (N) element. For example, nucleation layer 200 is an aluminum nitride layer formed at a low temperature, which can be formed by metal-organic chemical vapor deposition (MOCVD) at 800°C. It forms at a temperature of 920℃. The nucleation layer 200 can prevent Ga melt-back.

[0049] The group III nitride transition region 2 includes: a first transition layer 110, M first transition units 21, and N second transition units 22, where M and N are integers, M... 0, N 0, 2 M+N 250.

[0050] The first transition unit 21 includes a second transition layer and a third transition layer. The third transition layer is located above the second transition layer. Both the second and third transition layers include Group I III elements and Group II III elements. Both the second and third transition layers also include nitrogen. The content of Group II III elements in the second transition layer is greater than that in the third transition layer, and the difference in the content of Group II III elements between the second and third transition layers is greater than or equal to 35% and less than or equal to 45%.

[0051] The second transition unit 22 includes a fourth transition layer and a fifth transition layer. The fifth transition layer is located above the fourth transition layer. Both the fourth and fifth transition layers include elements from Group I III and Group II III. Both the fourth and fifth transition layers also include nitrogen. The content of Group II III elements in the fourth transition layer is greater than that in the fifth transition layer, and the difference in the content of Group II III elements between the fourth and fifth transition layers is greater than or equal to 35% and less than or equal to 45%.

[0052] Preferably, the difference in the content of Group III elements between the second and third transition layers is greater than or equal to 37.5% and less than or equal to 42.5%, and the difference in the content of Group III elements between the fourth and fifth transition layers is greater than or equal to 37.5% and less than or equal to 42.5%.

[0053] The term "Group II III element content" in describing Group III-V nitrides (e.g., AlGaN) is defined as the ratio of the number of Group II III atoms to the total number of Group III elements (Group I III elements + Group II III elements) in the layer. For example, the composition of the transition layer is determined by the chemical formula (A... x B 1-xN description, 0 x 100%. A represents Group III elements, B represents Group III elements, and N represents nitrogen. x represents the content of Group III elements in the transition layer.

[0054] The second and third transition layers, as well as the fourth and fifth transition layers, all exhibit significant differences in the content of Group III elements. This large-scale difference induces dislocation annihilation, causing dislocations to randomly cancel each other out in the third and fifth transition layers, thus reducing the dislocation density. This large-scale difference in Group III element content also generates strong internal stress fields at the lattice interfaces (the interfaces between the second and third transition layers, and between the fourth and fifth transition layers). This stress forces vertically upward-extending threading dislocations to bend and tilt. When these dislocations enter the third and fifth transition layers, their lateral extension significantly increases the probability of them intersecting, thereby promoting the random cancellation or fusion of dislocations with opposite Burgers vectors. This mechanism forms an effective dislocation filter, significantly reducing the dislocation density propagated to the top channel layer and improving the overall crystal quality.

[0055] In existing technologies, to release the lattice mismatch and thermal stress between the channel layer and the substrate layer, a very thick and numerous graded buffer region needs to be grown. In the direction from the substrate layer to the channel layer, the content of Group III elements in the multiple transition layers of the graded buffer gradually decreases. This application introduces a large-span difference in the content of Group III elements between the transition layers, enabling a faster and more efficient transition from the bottom layer with a high content of Group III elements to the top layer with a low content of Group III elements, using fewer transition layers. This highly efficient stress release and transition mechanism overcomes the thickness limitations of existing designs, significantly reducing the total thickness of the Group III nitride transition region. By reducing the number of layers and the total thickness of the Group III nitride transition region, the epitaxial growth time of the Group III nitride transition region 2 is shortened, and the consumption of expensive precursors (such as TMGa and TMAl) is directly reduced, thereby lowering the overall manufacturing cost.

[0056] For example, the first transition layer 110 is formed directly on the nucleation layer 200, and the first transition layer 110 includes at least a Group III element and nitrogen. The content of the Group III element in the first transition layer 110 is greater than or equal to 99%.

[0057] For example, the content of Group III elements in the second transition layer is greater than or equal to 57.5% and less than or equal to 62.5%; the content of Group III elements in the third transition layer is greater than or equal to 20% and less than or equal to 25%; the content of Group III elements in the fourth transition layer is greater than or equal to 37.5% and less than or equal to 42.5%; and the content of Group III elements in the fifth transition layer is greater than 0 and less than or equal to 2.5%.

[0058] For example, the first group III element is gallium (Ga), and the second group III element is aluminum (Al).

[0059] For example, 2 M+N 250, The total thickness of the group III nitride transition region 2 is greater than or equal to 240 nm and less than or equal to 7200 nm.

[0060] like Figure 1 As shown, the group III nitride epitaxial layer 1 further includes a channel layer 140 located on the group III nitride transition region 2. The channel layer 140 includes a first group III element and a nitrogen group element. For example, the channel layer 140 is an undoped GaN layer. The content of the second group III element in the transition layer in the group III nitride transition region 2 that is in contact with the channel layer 140 is less than or equal to 5%.

[0061] like Figure 1 As shown, the group III nitride epitaxial layer 1 further includes a barrier layer 150 located on the channel layer 140. The channel layer 140 and the barrier layer 150 form a heterojunction, inducing a high concentration of two-dimensional electron gas at their interface through a polarization effect. The two-dimensional electron gas serves as a conductive channel for the semiconductor device. The concentration of the two-dimensional electron gas can be controlled by adjusting the gate voltage, thereby changing the conductivity. For example, the channel layer 140 is a binary compound composed of nitrogen and a group I III element, and the barrier layer 150 is a ternary compound composed of nitrogen, a group I III element, and a group II III element.

[0062] like Figure 1 As shown, the semiconductor device also includes a gate structure 160 for regulating the concentration of a two-dimensional electron gas. In some embodiments, the gate structure 160 includes a P-type gate 161 and a gate metal layer 162 located on the P-type gate 161. The P-type gate 161 is, for example, a magnesium-doped GaN layer. The material of the gate metal layer 162 is, for example, TiN, Ti, AlCu, TaN, etc. By applying a voltage to the gate metal layer 162, the concentration of the two-dimensional electron gas below the gate structure can be regulated, thereby controlling the switching of the semiconductor device between an on state and an off state.

[0063] In some embodiments, the semiconductor device is normally off, meaning that when no voltage is applied to the gate structure 160, there is no two-dimensional electron gas on the upper surface of the channel layer 140, and the semiconductor device is in an off state. In other embodiments, the semiconductor device is normally on, meaning that when a voltage is applied to the gate structure 160, there is no two-dimensional electron gas on the upper surface of the channel layer 140, and the semiconductor device is in an off state.

[0064] like Figure 1 As shown, the semiconductor device further includes a dielectric layer 170 covering the gate structure 160. The dielectric layer 170 is an insulating layer, and its material is, for example, silicon oxide or silicon nitride. The semiconductor device also includes a source structure 181 and a drain structure 182. The source structure 181 and the drain structure 182 extend through the dielectric layer 170 and the barrier layer 150, and their bottom ends extend to the channel layer 140.

[0065] The overall content of Group III elements in the first transition unit 21 is greater than that in the second transition unit 22. The number of the first transition unit 21 and the number of the second transition unit 22 in the Group III nitride transition region 2 can be set according to the application requirements of the semiconductor device.

[0066] In some embodiments, M 1, N 1, N M first transition units 21 are stacked on the first transition layer 110, and N second transition units 22 are stacked on the M first transition units 21. For example, in... Figure 2 In the embodiment, M=1, N=1, the second transition layer 111 of the first transition unit 21 is located on the first transition layer 110, and the fourth transition layer 113 of the second transition unit 22 is located on the third transition layer 112 of the first transition unit 21. Figure 2 As shown, the group III nitride transition region 2 includes a first transition layer 110, a first transition unit 21, and a second transition unit 22. The first transition unit 21 includes a second transition layer 111 and a third transition layer 112. The second transition unit 22 includes a fourth transition layer 113 and a fifth transition layer 114. The first transition layer 110, the second transition layer 111, the third transition layer 112, the fourth transition layer 113, and the fifth transition layer 114 are stacked sequentially in the vertical direction.

[0067] The content of Group III elements in the first transition layer 110 is x. 110 The content of Group III elements in the second transition layer 111 is x. 111 The content of Group III elements in the third transition layer 112 is x. 112 The content of Group III elements in the fourth transition layer 113 is x.113 The content of Group III elements in the fifth transition layer 114 is x. 114 x 110 Greater than x 111 x 111 Greater than x 112 x 113 Greater than x 114 x 111 Greater than x 113 x 112 Greater than x 114 .

[0068] 35% x 110 -x 111 45%, preferred, 37.5% x 110 -x 111 42.5%.

[0069] 35% x 111 -x 112 45%, preferred, 37.5% x 111 -x 112 42.5%.

[0070] 35% x 113 -x 114 45%, preferred, 37.5% x 113 -x 114 42.5%.

[0071] For example, 57.5% x 111 62.5%, 20% x 112 25%, 37.5% x 113 42.5%, 0 x 114 2.5%.

[0072] In some embodiments, M 2. N=0, M first transition units 21 are stacked on the first transition layer 110. For example, in... Figure 3In this embodiment, M=2, N=0. For example... Figure 3 As shown, the group III nitride transition region 2 includes a first transition layer 110, a first transition unit 211, and a first transition unit 212. The first transition unit 211 includes a second transition layer 1111 and a third transition layer 1121. The first transition unit 212 includes a second transition layer 1112 and a third transition layer 1122.

[0073] The content of Group III elements in the first transition layer 110 is x. 110 The content of Group III elements in the second transition layer 1111 is x 1111 The content of Group III elements in the third transition layer 1121 is x. 1121 The content of Group III elements in the second transition layer 1112 is x. 1112 The content of Group III elements in the third transition layer 1122 is x. 1122 x 110 Greater than x 1111 x 1111 Greater than x 1121 x 1112 Greater than x 1122 .

[0074] 35% x 110 -x 1111 45%, preferred, 37.5% x 110 -x 1111 42.5%.

[0075] 35% x 1111 -x 1121 45%, preferred, 37.5% x 1111 -x 1121 42.5%.

[0076] 35% x 1112 -x 1122 45%, preferred, 37.5% x 1112 -x 1122 42.5%.

[0077] For example, 57.5% x 1111 62.5%, 20% x 1121 25%, 57.5% x 1112 62.5%, 20% x 1122 25%.

[0078] In some embodiments, x 1111 Greater than x 1112 x 1121 Greater than x 1122 That is, the overall content of Group II III elements in the first transition unit located below is greater than that in the first transition unit located above.

[0079] like Figure 3 As shown, the Group III nitride transition region 2 also includes a transition layer 115. A channel layer 140 is formed on the transition layer 115, and the content of Group II III elements in the transition layer 115 is less than or equal to 5%. The channel layer 140 is a binary compound composed of nitrogen and Group I III elements. Therefore, a Group II III element content of less than or equal to 5% in the uppermost transition layer of the Group III nitride transition region 2 (i.e., the transition layer in contact with the channel layer 140) is beneficial for forming a high-quality channel layer 140.

[0080] The first transition unit has a high content of Group III elements. The high content of Group III elements in the transition layer can significantly increase the bandgap of the transition layer, giving it a higher critical breakdown field and better insulation resistance characteristics. By setting two or more first transition units in the Group III nitride transition region 2, it is equivalent to constructing a thicker barrier layer with a higher energy barrier, which can effectively suppress the tunneling effect and vertical leakage current of charge carriers in the vertical direction, and can also withstand a stronger vertical electric field distribution. This greatly improves the vertical high voltage withstand capability of the overall semiconductor device, enabling it to fully meet the stringent application requirements of high-voltage power components (such as HEMTs with a withstand voltage of 650V or even higher).

[0081] In some embodiments, M=0, N 2. N second transition units 22 are stacked on the first transition layer 110. Figure 4 In this embodiment, M=0, N=2. For example... Figure 4As shown, the group III nitride transition region 2 includes a first transition layer 110, a second transition unit 221, and a second transition unit 222. The second transition unit 221 includes a fourth transition layer 1131 and a fifth transition layer 1141. The second transition unit 222 includes a fourth transition layer 1132 and a fifth transition layer 1142.

[0082] The content of Group III elements in the first transition layer 110 is x. 110 The content of Group III elements in the fourth transition layer 1131 is x. 1131 The content of Group III elements in the fifth transition layer 1141 is x. 1141 The content of Group III elements in the fourth transition layer 1132 is x. 1132 The content of Group III elements in the fifth transition layer 1142 is x. 1142 x 110 Greater than x 1131 x 1131 Greater than x 1141 x 1132 Greater than x 1142 .

[0083] 35% x 1131 -x 1141 45%, preferred, 37.5% x 1131 -x 1141 42.5%.

[0084] 35% x 1132 -x 1142 45%, preferred, 37.5% x 1132 -x 1142 42.5%.

[0085] For example, 37.5% x 1131 42.5%, 0 x 1141 2.5%, 37.5% x 1132 42.5%, 0 x 1142 2.5%.

[0086] In some embodiments, x 1131 Greater than x1132 x 1141 Greater than x 1142 .

[0087] In some embodiments, the group III nitride transition region 2 further includes a transition layer located between the first transition layer 110 and the fourth transition layer 1131. This transition layer includes nitrogen, a first group III element, and a second group III element. The content of the second group III element in this transition layer is x. 116 The content of Group III elements greater than 1131 in the fourth transition layer x 1131 The content of Group III elements less than 110 in the first transition layer is x. 110 35% x 116 -x 1131 45%, preferred, 37.5% x 116 -x 1131 42.5%.

[0088] The second transition unit has a lower content of Group III elements compared to the first transition unit. When epitaxially growing a transition layer with a high content of Group III elements, a lower growth rate is usually necessary to suppress the strong parasitic reactions between the Group III element-containing precursor (such as TMAl) and ammonia (NH3) and to ensure good surface morphology and crystal quality. Moderately reducing the Group III element content can effectively slow down the pre-reaction of the precursor in the gas phase, improve the surface mobility and bonding efficiency of Group III atoms, and thus significantly increase the growth rate of the epitaxial layer.

[0089] Compared to Figure 3 and Figure 4 Group III nitride transition region 2, Figure 2 The group III nitride transition region 2 includes both a first transition unit 21 located at the lower part of the transition region and a second transition unit 22 located at the upper part of the transition region. The first transition unit 21, with a high content of group III elements, establishes a high barrier and insulating barrier layer. The second transition unit 22, with a low content of group III elements, can accelerate the growth rate of the epitaxial layer while maintaining the vertical high voltage withstand capability of the semiconductor device (such as meeting the leakage current specifications for HEMT applications). This balances the electrical reliability of the semiconductor device, effectively shortens the total cycle time of a single epitaxial operation, and improves the overall epitaxial throughput.

[0090] exist Figure 2In the middle, the second transition layer 111, the third transition layer 112, and the fifth transition layer 114 all include island structures and flat structures. Figure 3 In the embodiments, the second transition layer 1111 and the third transition layers 1121 and 1122 each include island structures and flat structures. Figure 4 In the embodiments, the fourth transition layer 1131 and the fifth transition layers 1141 and 1142 each include island structures and flat structures. All of the above transition layers are formed on a transition layer with a high content of Group II III elements, creating a transition layer with a low content of Group II III elements. The island structures are formed on the underlying transition layer with a high content of Group II III elements, and the flat structures cover the island structures. In the process of forming the transition layer with a low content of Group II III elements on the transition layer with a high content of Group II III elements, the island structures are formed first, followed by the flat structures. In some embodiments, the thickness of the island structures is less than or equal to 30% of the overall thickness of the transition layer corresponding to the island structures.

[0091] Figure 1 The method for manufacturing the semiconductor device shown includes the following steps: forming a nucleation layer 200 on a substrate layer 100; forming a group III nitride transition region 2 on the nucleation layer 200; forming a channel layer 140 on the group III nitride transition region; forming a barrier layer 150 on the channel layer 140; and forming a gate structure 160.

[0092] This application also provides a method for manufacturing a group III nitride epitaxial layer, the method comprising the following steps: epitaxially forming a nucleation layer 200 on a substrate layer 100; and epitaxially forming a group III nitride transition region 2 on the nucleation layer 200. The group III nitride transition region 2 includes a first transition layer 110, M first transition units 21, and N second transition units 22.

[0093] The first transition unit includes a second transition layer and a third transition layer. Both the second and third transition layers include elements from Group I III and Group II III. The content of Group II III elements in the second transition layer is greater than that in the third transition layer. The difference in the content of Group II III elements between the second and third transition layers is greater than or equal to 35% and less than or equal to 45%, preferably greater than or equal to 37.5% and less than or equal to 42.5%.

[0094] The second transition unit includes a fourth transition layer and a fifth transition layer. Both the fourth and fifth transition layers include elements from Group I III and Group II III. The content of Group II III elements in the fourth transition layer is greater than that in the fifth transition layer. The difference in the content of Group II III elements between the fourth and fifth transition layers is greater than or equal to 35% and less than or equal to 45%, preferably greater than or equal to 37.5% and less than or equal to 42.5%.

[0095] For example, the content of Group III elements in the second transition layer is greater than or equal to 57.5% and less than or equal to 62.5%; the content of Group III elements in the third transition layer is greater than or equal to 20% and less than or equal to 25%; the content of Group III elements in the fourth transition layer is greater than or equal to 37.5% and less than or equal to 42.5%; and the content of Group III elements in the fifth transition layer is greater than 0 and less than or equal to 2.5%. The content of Group III elements in the first transition layer is greater than or equal to 99%.

[0096] For example, the thickness of the group III nitride transition region 2 is greater than or equal to 240 nm and less than or equal to 7200 nm.

[0097] In some embodiments, the manufacturing method further includes epitaxially forming a channel layer and a barrier layer, wherein the channel layer is located on a group III nitride transition region and the barrier layer is located on the channel layer.

[0098] In some embodiments, a method for forming a nucleation layer 200 on a substrate 100 includes: controlling the temperature of an epitaxial reaction chamber within a first temperature range, and controlling the ratio of the intake volume of a gas containing nitrogen (N) to a gas containing a Group III element within the epitaxial reaction chamber within a first interval, to form the nucleation layer 200. The pressure within the epitaxial reaction chamber is, for example, 40 mbar to 200 mbar. The gas containing nitrogen is, for example, ammonia (NH3), and the gas containing a Group III element is, for example, trimethylaluminum (TMAL). The nucleation layer 200 is an aluminum nitride layer. The first temperature range is, for example, 800°C. 920℃.

[0099] In some embodiments, the method of forming a first transition layer 110 of a group III nitride transition region 2 on the nucleation layer 200 includes: controlling the temperature of the epitaxial reaction chamber within a second temperature range, and controlling the ratio of the intake volume of a gas containing nitrogen to a gas containing a second group III element in the epitaxial reaction chamber within a first range to form the first transition layer. The second temperature range is higher than the first temperature range. The second temperature range is, for example, 1020°C. 1100℃.

[0100] In some embodiments, the method for forming the second and third transition layers of the first transition unit 21 includes: maintaining the temperature of the epitaxial reaction chamber within a second temperature range; controlling the introduction of a gas including nitrogen, a gas including a group II III element, and a gas including a group I III element into the epitaxial reaction chamber such that the ratio of the intake volume of the gas including the group II III element and the gas including the group I III element is within a second interval, to form the second transition layer; maintaining the temperature of the epitaxial reaction chamber within the second temperature range; and adjusting the ratio of the intake volume of the gas including the group II III element and the gas including the group I III element to a third interval, to form the third transition layer. The value of the third interval is less than the value of the second interval.

[0101] In some embodiments, forming the fourth and fifth transition layers of the second transition unit 22 includes: maintaining the temperature of the epitaxial reaction chamber within a second temperature range; controlling the introduction of a gas including nitrogen, a gas including a group II element, and a gas including a group I element into the epitaxial reaction chamber; and adjusting the ratio of the intake amounts of the gas including the group II element and the gas including the group I element within a fourth interval to form the fourth transition layer; maintaining the temperature of the epitaxial reaction chamber within the second temperature range; and adjusting the ratio of the intake amounts of the gas including the group II element and the gas including the group I element within a fifth interval to form the fifth transition layer. The value of the fourth interval is greater than the value of the fifth interval.

[0102] The first transition unit 21 and the second transition unit 22 are ternary compounds composed of nitrogen, a Group I III element, and a Group II III element. The reaction gas (precursor) in the epitaxial reaction chamber includes: a gas containing nitrogen, a gas containing a Group I III element, and a gas containing a Group II III element. For example, the gas containing nitrogen is ammonia (NH3), the gas containing a Group I III element is trimethylgallium (TMGa), and the gas containing a Group II III element is trimethylaluminum (TMAL). The carrier gas for the reaction gas is, for example, hydrogen.

[0103] In the method for manufacturing a group III nitride epitaxial layer of this application, a second transition layer is epitaxially formed on the first transition layer 110. Figure 2 and Figure 3 A fourth transition layer is formed epitaxially on the first transition layer 110. Figure 4 The formation of the second, third, fourth, and fifth transition layers involves epitaxially forming a third transition layer on top of a second transition layer, and an epitaxially forming a fifth transition layer on top of a fourth transition layer. These processes involve forming layers with low group III element content on top of layers with high group III element content. The method for forming the second, third, fourth, and fifth transition layers includes the following steps.

[0104] like Figure 5As shown, island structures 2001 are formed on a high Group II III element content layer 1000. Island structures 2001 grow on the upper surface A of the high Group II III element content layer 1000. Due to lattice mismatch, epitaxially grown low Group II III element content layers tend to form island structures on surface A. In island structures 2001, dislocations mainly grow vertically. Figure 6 As shown, a flat structure 2002 is formed covering the island structure 2001. Some dislocations in the island structure 2001 grow laterally to connect with dislocations in adjacent island structures 2001, while some dislocations bend downwards to grow, thus reducing the number of vertically growing dislocations and lowering the number of defects on the upper surface of the low group III element content layer.

[0105] Figure 5 and Figure 6 The high group III element content layer 1000 is, for example, the first transition layer 110, the second transition layer and the fourth transition layer, and the low group III element content layer is, for example, the second transition layer, the third transition layer and the fifth transition layer.

[0106] In some embodiments, the thickness of the island structure is less than or equal to 30% of the overall thickness of the corresponding transition layer (low content of group III elements).

[0107] In some embodiments, island structures 2001 are epitaxially formed on a layer 1000 with a high content of Group II III elements using the Volmer-Weber mode, and flat structures 2002 are epitaxially formed using the Frank-van der Merwe mode. The temperature of the epitaxial reaction chamber in the Volmer-Weber mode is lower than that in the Frank-van der Merwe mode, and the ratio of nitrogen-containing gas to Group II III-containing gas in the Volmer-Weber mode is higher than that in the Frank-van der Merwe mode. The Volmer-Weber mode is favorable for nucleation but limits the migration rate of surface atoms, thus promoting the formation of 3D island structures and helping to release the strong tensile stress on both sides of the heterojunction. In the Frank-van der Merwe mode, by increasing the temperature of the epitaxial reaction chamber and reducing the ratio of nitrogen-containing gas to gas containing Group III elements, the diffusion length of Ga (a Group III element) atoms is enhanced, causing these island structures to gradually merge into a thin film through lateral growth. During the coalescence process of the 3D island structures, adjacent through-dislocations have a certain probability of meeting to form a half-loop and canceling each other out. This switching of the micro-growth mechanism, combined with the aforementioned design of the first and second transition units, can significantly reduce the dislocation density on the surface of the transition layer with low Group III element content, greatly improving the overall crystal quality of the epitaxial layer.

[0108] In this embodiment, the dislocation growth direction is changed through kinetic control. The Volmer-Weber mode and the Frank-van der Merwe mode are achieved using metal-organic chemical vapor deposition (MOCVD).

[0109] by Figure 2 Taking the group III nitride epitaxial layer shown as an example, the manufacturing method includes the following steps. In the following steps, the first group III element is Ga, and the second group III element is Al.

[0110] A nucleation layer 200 is epitaxially formed on the substrate layer 100. The temperature of the epitaxial reaction chamber is controlled within a first temperature range (800°C). (920℃), the reaction gases are ammonia and trimethylaluminum. The substrate layer 100 is, for example, a sapphire substrate, a silicon substrate, or a silicon carbide substrate. The nucleation layer 200 is an AlN layer.

[0111] A first transition layer 110 is epitaxially formed on the nucleation layer 200. The temperature of the epitaxial reaction chamber is controlled within a second temperature range, which is greater than or equal to 1020°C. The reaction gases are ammonia and trimethylaluminum, and the carrier gas is hydrogen. The first transition layer 110 is an AlN layer.

[0112] A second transition layer 111 is formed on the first transition layer 110. The temperature of the epitaxial reaction chamber is controlled to be maintained within a second temperature range. The reaction gases are ammonia, trimethylaluminum, and trimethylgallium, and the carrier gas is hydrogen. The second transition layer 111 is an AlGaN layer with an Al content greater than or equal to 57.5% and less than or equal to 62.5%.

[0113] A third transition layer 112 is formed on the second transition layer 111. The temperature of the epitaxial reaction chamber is controlled to remain within a second temperature range. The reaction gases are ammonia, trimethylaluminum, and trimethylgallium, and the carrier gas is hydrogen. The third transition layer 112 is an AlGaN layer with an Al content greater than or equal to 20% and less than or equal to 25%. The Al content of the third transition layer 112 is less than the Al content of the second transition layer 111. The third transition layer 112 with a lower Al content is achieved by reducing the amount of trimethylaluminum entering the epitaxial reaction chamber.

[0114] A fourth transition layer 113 is formed on the third transition layer 112. The temperature of the epitaxial reaction chamber is controlled to remain within a second temperature range. The reaction gases are ammonia, trimethylaluminum, and trimethylgallium, and the carrier gas is hydrogen. The fourth transition layer 113 is an AlGaN layer with an Al content greater than or equal to 37.5% and less than or equal to 42.5%. A fourth transition layer 113 with a higher Al content is achieved by increasing the amount of trimethylaluminum entering the epitaxial reaction chamber.

[0115] A fifth transition layer 114 is formed on the fourth transition layer 113. The temperature of the epitaxial reaction chamber is controlled to remain within a second temperature range. The reaction gases are ammonia, trimethylaluminum, and trimethylgallium, and the carrier gas is hydrogen. The fifth transition layer 114 is an AlGaN layer with an Al content greater than 0 and less than or equal to 2.5%.

[0116] The manufacturing method includes: epitaxially forming a channel layer 140 on a fifth transition layer 114. The reactant gases are ammonia and trimethylgallium. The channel layer 140 is an intrinsic GaN layer.

[0117] The epitaxial growth of the second transition layer 111, the third transition layer 112, and the fourth transition layer 113 all involve two stages. First, island-like structures are formed, and then these island-like structures are merged to form a planar structure. Both stages are completed in situ within the epitaxial reaction chamber. The temperature of the epitaxial reaction chamber during island-like structure formation is lower than that during planar structure formation. The ratio of ammonia to group III reactant gases during island-like structure formation is greater than that during planar structure formation. The island-like structures help reduce tensile stress and improve the performance of the transition layers. The island-like structures cause some dislocation growth directions to deflect at large angles, which, combined with the growth conditions of the planar structure, can reduce dislocation density.

[0118] This application provides a group III nitride epitaxial layer, a method for manufacturing the same, and a semiconductor device. The group III nitride epitaxial layer includes a substrate layer, a nucleation layer, and a group III nitride transition region located on the nucleation layer. The group III nitride transition region includes a first transition layer, M first transition units, and N second transition units. Each first transition unit includes a second transition layer and a third transition layer, and each second transition unit includes a fourth transition layer and a fifth transition layer. The difference in the content of group III elements between the second and third transition layers, and between the fourth and fifth transition layers, is greater than or equal to 35% and less than or equal to 45%. The interface between the first and second transition units has a large difference in the content of group III elements, reducing dislocation density and decreasing the overall thickness of the epitaxial layer. When forming the third and fifth transition layers, island structures are first formed using the Volmer-Weber mode, and then the island structures are merged and a frit structure is formed using the Frank-van der Merwe mode, further reducing dislocation density.

[0119] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A group III nitride epitaxial layer, characterized in that, include: Substrate layer; The nucleation layer located on the substrate layer includes a Group III element and nitrogen. as well as Located on the nucleation layer, the group III nitride transition region, The group III nitride transition region includes a first transition layer, M first transition units, and N second transition units, where M and N are integers. 0, N 0, M+N 2, The first transition unit includes a second transition layer and a third transition layer, with the third transition layer located above the second transition layer. Both the second and third transition layers include Group III elements and Group III elements. The content of Group III elements in the second transition layer is greater than the content of Group III elements in the third transition layer. The difference in the content of Group III elements in the second and third transition layers is greater than or equal to 35% and less than or equal to 45%. The second transition unit includes a fourth transition layer and a fifth transition layer. The fifth transition layer is located above the fourth transition layer. The fourth and fifth transition layers include a first group III element and a second group III element. The content of the second group III element in the fourth transition layer is greater than the content of the second group III element in the fifth transition layer. The difference between the content of the second group III element in the fourth and fifth transition layers is greater than or equal to 35% and less than or equal to 45%.

2. The group III nitride epitaxial layer according to claim 1, characterized in that, The content of Group III elements in the second transition layer is greater than or equal to 57.5% and less than or equal to 62.5%, and the content of Group III elements in the third transition layer is greater than or equal to 20% and less than or equal to 25%.

3. The group III nitride epitaxial layer according to claim 1, characterized in that, The content of Group III elements in the fourth transition layer is greater than or equal to 37.5% and less than or equal to 42.5%, and the content of Group III elements in the fifth transition layer is greater than 0 and less than or equal to 2.5%.

4. The group III nitride epitaxial layer according to claim 1, characterized in that, The difference in the content of Group III elements between the second and third transition layers is greater than or equal to 37.5% and less than or equal to 42.5%. The difference in the content of the second group III elements between the fourth and fifth transition layers is greater than or equal to 37.5% and less than or equal to 42.5%.

5. The group III nitride epitaxial layer according to claim 1, characterized in that, The first transition layer is formed directly on the nucleation layer, and the content of the second group III element in the first transition layer is greater than or equal to 99%.

6. The group III nitride epitaxial layer according to claim 1, characterized in that, M=1, N=1, the second transition layer of the first transition unit is located on the first transition layer, and the fourth transition layer of the second transition unit is located on the third transition layer of the first transition unit.

7. The group III nitride epitaxial layer according to claim 1, characterized in that, M 2, N=0, the M first transition units are stacked on the first transition layer.

8. The group III nitride epitaxial layer according to claim 1, characterized in that, M=0, N 2. The N second transition units are stacked on the first transition layer.

9. The group III nitride epitaxial layer according to claim 1, characterized in that, M 1, N 1, N M, wherein the M first transition units are stacked on the first transition layer, and the N second transition units are stacked on the M first transition units.

10. The group III nitride epitaxial layer according to claim 1, characterized in that, The group III nitride epitaxial layer further includes a channel layer and a barrier layer, wherein the channel layer is located on the group III nitride transition region and the barrier layer is located on the channel layer.

11. The group III nitride epitaxial layer according to claim 1, characterized in that, The thickness of the group III nitride transition region is greater than or equal to 240 nm and less than or equal to 7200 nm.

12. The group III nitride epitaxial layer according to claim 1, characterized in that, Each of the second transition layer, the third transition layer, and the fifth transition layer includes: an island structure and a flat structure, the flat structure covering the island structure.

13. The group III nitride epitaxial layer according to claim 12, characterized in that, The thickness of the island structure is less than or equal to 30% of the total thickness of the transition layer corresponding to the island structure.

14. The group III nitride epitaxial layer according to claim 1, characterized in that, The first group III element is Ga, and the second group III element is Al.

15. A semiconductor device, characterized in that, Includes a group III nitride epitaxial layer according to any one of claims 1-14.

16. A method for manufacturing a group III nitride epitaxial layer, characterized in that, include: A nucleation layer is formed on a substrate, the nucleation layer comprising a Group III element and nitrogen. as well as A group III nitride transition region is formed on the nucleation layer. The group III nitride transition region includes a first transition layer, M first transition units, and N second transition units, where M and N are integers. 0, N 0, M+N 2, The first transition unit includes a second transition layer and a third transition layer, with the third transition layer located above the second transition layer. Both the second and third transition layers include Group III elements and Group III elements. The content of Group III elements in the second transition layer is greater than the content of Group III elements in the third transition layer. The difference in the content of Group III elements in the second and third transition layers is greater than or equal to 35% and less than or equal to 45%. The second transition unit includes a fourth transition layer and a fifth transition layer. The fifth transition layer is located above the fourth transition layer. The fourth and fifth transition layers include a first group III element and a second group III element. The content of the second group III element in the fourth transition layer is greater than the content of the second group III element in the fifth transition layer. The difference between the content of the second group III element in the fourth and fifth transition layers is greater than or equal to 35% and less than or equal to 45%.

17. The manufacturing method according to claim 16, characterized in that, The content of Group III elements in the second transition layer is greater than or equal to 57.5% and less than or equal to 62.5%, and the content of Group III elements in the third transition layer is greater than or equal to 20% and less than or equal to 25%.

18. The manufacturing method according to claim 16, characterized in that, The content of Group III elements in the fourth transition layer is greater than or equal to 37.5% and less than or equal to 42.5%, and the content of Group III elements in the fifth transition layer is greater than 0 and less than or equal to 2.5%.

19. The manufacturing method according to claim 16, characterized in that, The difference in the content of Group III elements between the second and third transition layers is greater than or equal to 37.5% and less than or equal to 42.5%. The difference in the content of Group III elements between the fourth and fifth transition layers is greater than or equal to 37.5% and less than or equal to 42.5%.

20. The manufacturing method according to claim 16, characterized in that, The first transition layer is formed directly on the nucleation layer, and the content of the second group III element in the first transition layer is greater than or equal to 99%.

21. The manufacturing method according to claim 16, characterized in that, M=1, N=1, the second transition layer of the first transition unit is located on the first transition layer, and the fourth transition layer of the second transition unit is located on the third transition layer of the first transition unit.

22. The manufacturing method according to claim 16, characterized in that, M 2, N=0, the M first transition units are stacked on the first transition layer.

23. The manufacturing method according to claim 16, characterized in that, M=0, N 2. The N second transition units are stacked on the first transition layer.

24. The manufacturing method according to claim 16, characterized in that, M 1, N 1, N M, wherein the M first transition units are stacked on the first transition layer, and the N second transition units are stacked on the M first transition units.

25. The manufacturing method according to claim 16, characterized in that, The manufacturing method further includes forming a channel layer and a barrier layer, wherein the channel layer is located on the group III nitride transition region and the barrier layer is located on the channel layer.

26. The manufacturing method according to claim 16, characterized in that, The thickness of the group III nitride transition region is greater than or equal to 240 nm and less than or equal to 7200 nm.

27. The manufacturing method according to claim 16, characterized in that, The method for forming a nucleation layer on the substrate includes: The temperature of the epitaxial reaction chamber is controlled within a first temperature range, and the ratio of the gas containing nitrogen to the gas containing group III elements in the epitaxial reaction chamber is controlled within a first interval to form the nucleation layer.

28. The manufacturing method according to claim 27, characterized in that, The method for forming a first transition layer of the group III nitride transition region on the nucleation layer includes: controlling the temperature of the epitaxial reaction chamber in a second temperature range, and controlling the ratio of the intake volume of gas including nitrogen element to gas including a second group III element in the epitaxial reaction chamber in a first range to form the first transition layer, wherein the value of the second temperature range is greater than the value of the first temperature range.

29. The manufacturing method according to claim 28, characterized in that, The second and third transition layers forming the first transition unit include: The temperature of the epitaxial reaction chamber is controlled within a second temperature range, and the intake flow rates of the gas containing the nitrogen element, the gas containing the first group III element, and the gas containing the second group III element in the epitaxial reaction chamber are adaptively controlled to form the second transition layer. The temperature of the epitaxial reaction chamber is maintained within the second temperature range, and the intake amounts of the gas containing nitrogen, the gas containing the first group III element, and the gas containing the second group III element in the epitaxial reaction chamber are adaptively adjusted to form the third transition layer.

30. The manufacturing method according to claim 28, characterized in that, The fourth and fifth transition layers forming the second transition unit include: The temperature of the epitaxial reaction chamber is maintained within a second temperature range, and the intake amounts of the gas containing nitrogen, the gas containing the first group III element, and the gas containing the second group III element in the epitaxial reaction chamber are adaptively adjusted to form the fourth transition layer. The temperature of the epitaxial reaction chamber is maintained within the second temperature range, and the gas containing nitrogen, the gas containing the first group III element, and the gas containing the second group III element in the epitaxial reaction chamber are adaptively adjusted to form the fifth transition layer.

31. The manufacturing method according to claim 21, characterized in that, The methods for forming the second transition layer, the third transition layer, and the fifth transition layer all include: Forming an island-like structure; and A flat structure is formed that covers the island-like structure.

32. The manufacturing method according to claim 31, characterized in that, The thickness of the island structure is less than or equal to 30% of the overall thickness of the transition layer corresponding to the island structure.

33. The manufacturing method according to claim 31, characterized in that, The island-shaped structure is formed by epitaxy on the first transition layer using the Volmer-Weber pattern, and the flat structure is formed by epitaxy using the Frank-VanderMerwe pattern.

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