CN216528935U - Composite patterned substrate, epitaxial wafer containing substrate and light-emitting diode - Google Patents

Abstract

The utility model discloses a composite patterned substrate, an epitaxial wafer containing the substrate and a light-emitting diode; the substrate is divided into a plurality of concentric annular areas by taking the center as the circle center, the bottom width of the graphs in the same annular area is the same as the distance between the graphs, and the heights of the graphs in different annular areas are sequentially increased or decreased from inside to outside; when the warping degree of the substrate is a positive value, the heights of the graphs in different annular areas are sequentially increased from inside to outside; and when the warping degree of the substrate is a negative value, the heights of the graphs in different annular regions are sequentially decreased from inside to outside. The utility model utilizes the height of the patterns in different annular regions to increase or decrease from inside to outside in sequence, improves the warping phenomenon of the substrate after epitaxial growth and ensures the wavelength uniformity.

Description

Composite patterned substrate, epitaxial wafer containing substrate and light-emitting diode

Technical Field

The utility model relates to the technical field of semiconductors, in particular to a composite patterned substrate, an epitaxial wafer containing the substrate and a light emitting diode.

Background

LEDs are widely used as a new generation of light source in the fields of illumination, display, backlight, and optical communication. The substrate is an important component of LED products, which is a clean single crystal wafer with specific crystal planes and appropriate electrical, optical and mechanical properties for growing epitaxial layers, and it serves not only as an electrical but also as a mechanical support.

In the prior art, the substrate takes the center as the center of a circle, the bottom width and the height of the patterns in each area and the distance between the patterns are the same, and the warping degree is larger after epitaxial growth, so that the wavelength uniformity is poorer.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a composite patterned substrate, an epitaxial wafer containing the substrate and a light-emitting diode, which are used for improving the warping phenomenon of the substrate after epitaxial growth and ensuring the wavelength uniformity so as to solve the problems in the background technology.

In order to achieve the purpose, the utility model provides the following technical scheme:

a composite graphical substrate is characterized in that the substrate is divided into a plurality of concentric annular areas by taking the center as the circle center, the bottom width of graphs in the same annular area is the same as the distance between the graphs, and the heights of the graphs in different annular areas are sequentially increased or decreased from inside to outside.

According to a further improvement of the utility model, when the warpage of the substrate is a positive value, the heights of the patterns in different annular regions are sequentially increased from inside to outside.

According to a further improvement of the utility model, when the warpage of the substrate is a negative value, the heights of the patterns in different annular regions are sequentially decreased from inside to outside.

The utility model has the further improvement scheme that the number of the concentric annular areas is 2-5.

The utility model has the further improvement that the reference height of the annular area pattern at the center of the substrate is 1.5-3.0 um.

The utility model has the further improvement that the bottom width of the annular area pattern at the center of the substrate is 2.5-3.5 um.

The utility model has the further improvement scheme that the substrate is a sapphire substrate, a sapphire and silicon dioxide composite base substrate, a silicon-based substrate or a gallium nitride base substrate.

An epitaxial wafer comprises a substrate, and further comprises a buffer layer, an N-type layer, a multi-quantum well layer and a P-type layer which are sequentially arranged on the substrate.

A light emitting diode includes a composite patterned substrate.

The utility model has the beneficial effects that:

the substrate is divided into a plurality of concentric annular areas by taking the center as the circle center, the bottom width of the graph in the same annular area is the same as the distance between the graphs, the heights of the graphs in different annular areas are sequentially increased or decreased from inside to outside, the warping phenomenon of the substrate after epitaxial growth is improved, and the wavelength uniformity is ensured.

Drawings

FIG. 1 is a schematic structural diagram of a substrate patterned with a positive BOW value in example 1.

FIG. 2 is a schematic cross-sectional view of a substrate patterned with a positive BOW value in example 1.

Fig. 3 is a schematic structural view of an epitaxial wafer in example 1.

FIG. 4 is a schematic structural diagram of a negative BOW value patterned substrate in example 2.

FIG. 5 is a schematic cross-sectional view of a negative BOW value patterned substrate of example 2.

Fig. 6 is a schematic structural view of an epitaxial wafer in example 2.

FIG. 7 is a schematic structural diagram of a substrate patterned with a positive BOW value in example 3.

FIG. 8 is a schematic view of the structure of a negative BOW value patterned substrate in example 4.

Detailed Description

The utility model is further elucidated with reference to the drawings and the embodiments.

A compound patterned substrate, the said substrate 10 regards centre as the centre of a circle, divide into a plurality of concentric ring regions, the bottom width of the figure in the same ring region is the same with interval between the figures, the height of the figure in different ring regions increases progressively or decreases progressively from inside to outside sequentially; when the warpage (BOW value) of the substrate 10 is a positive value, the heights of the patterns in different annular regions are sequentially increased from inside to outside; when the warpage of the substrate 10 is a negative value, the heights of the patterns in different annular regions are sequentially decreased from inside to outside; the number of the concentric annular areas is 2-5; the reference height of the annular area figure at the center of the substrate 10 is 1.5-3.0 um; the bottom width of the annular area pattern at the center of the substrate 10 is 2.5-3.5 um; the substrate 10 is a sapphire substrate, a sapphire and silicon dioxide composite base substrate, a silicon-based substrate or a gallium nitride base substrate.

As shown in table one, in the following embodiments, the sapphire flat substrate 10 is taken as an example, and a PSS pattern is processed on the sapphire flat substrate 10 for use in epitaxial growth; however, the BOW value of the sapphire flat substrate 10 seriously affects the BOW value after epitaxial growth, and the large or small BOW value of the epitaxial wafer can cause poor wavelength uniformity of the epitaxial wafer; therefore, the pattern heights of the PSS pattern in different areas on the substrate 10 are adjusted according to the BOW value of the substrate 10 to adapt to the warping degree of the flat substrate 10, so that the optimal warping degree is obtained during epitaxial growth, and the wavelength uniformity of the epitaxial wafer after growth is improved; the BOW values of the epitaxy corresponding to different pattern heights are different, and generally speaking, the higher the PSS pattern is, the lower the BOW value of the epitaxial wafer after growth is easy to be; the wavelength uniformity of the epitaxial wafer is deteriorated when the BOW value of the epitaxial wafer is small or large.

BOW value for flat sheet substrate	PSS pattern height variation direction	PSS pattern height variation amplitude
			Positive BOW value: 0-5	Increasing from inside to outside	Increasing by 0-0.05
Positive BOW value: 5-10	Increasing from inside to outside	Increasing by 0.05-0.1
			Positive BOW value: 10-15	Increasing from inside to outside	Increasing by 0.1-0.15
Negative BOW value: 0-5	Decreasing from inside to outside	Decreasing by 0-0.05
			Negative BOW value: 5-10	Decreasing from inside to outside	Decreasing by 0.05-0.1
Negative BOW value: 10-15	Decreasing from inside to outside	Decreasing by 0.1-0.15

Table one: BOW value of sapphire plain film substrate and PSS pattern height correspondence (unit: um)

Example 1: dividing the substrate 10 into a plurality of concentric annular regions from the center to the edge according to the BOW value, wherein the more the BOW value is, the more the division is; as shown in fig. 1, the substrate 10 is divided into three concentric annular regions, a central region 110, a middle region 120, and an outer ring region 130.

The patterns 111, 121 and 131 in each area are uniformly distributed, and the bottom widths and the intervals of the patterns 111, 121 and 131 are the same among different areas; the height of the patterns 111, 121, 131 increases from the central region 110, the middle region 120, to the outer band region 130.

As shown in fig. 2, the C-plane of the sapphire substrate 10 with a positive BOW value is a convex surface, and the C-plane is an epitaxial growth plane; wherein the height of the patterns 111, 121, 131 increases in a gradient from the central region 110 to the outer band region 130, with increasing magnitudes as indicated in table one.

Fig. 3 shows an epitaxial wafer, which includes a substrate 10, and further includes a buffer layer 20, an N-type layer 30, a mqw layer 40, and a P-type layer 50 sequentially disposed on the substrate 10.

Example 2: as shown in fig. 4, this embodiment is different from embodiment 1 in that the BOW value of the substrate 10 in this embodiment is negative, and the heights of the patterns 111, 121, 131 on the substrate 10 with negative BOW value gradually decrease from the central region 110, the middle region 120, to the outer ring region 130, and the decreasing gradient is shown in table one.

As shown in fig. 5, the C-plane of the sapphire substrate 10 with a negative BOW value is a concave surface, and the C-plane is an epitaxial growth plane; wherein the height of the patterns 111, 121, 131 decreases in a gradient from the central region 110 to the outer band region 130 by an amount represented in table one.

Fig. 6 shows an epitaxial wafer, which includes a substrate 10, and further includes a buffer layer 20, an N-type layer 30, a mqw layer 40, and a P-type layer 50, which are sequentially disposed on the substrate 10.

Example 3: as shown in fig. 7, this embodiment is substantially the same as embodiment 1, except that the patterns 111, 121, 131 are uniformly distributed in each region, but the pitches of the patterns 111, 121, 131 in adjacent regions are different, that is, the densities of the patterns 111, 121, 131 are different, and the densities gradually decrease from the central region 110 to the outer ring region 130.

Example 4: as shown in fig. 8, the present embodiment is different from embodiment 2 in that the patterns 111, 121, 131 are uniformly distributed in each region, but the pitches of the patterns 111, 121, 131 in adjacent regions are different, that is, the densities of the patterns 111, 121, 131 are different, and the densities gradually decrease from the central region 110 to the outer ring region 130.

Example 5: the present embodiment provides a light emitting diode comprising the composite patterned substrate 10 of any one of embodiments 1, 2, 3, and 4.

The above embodiments are only for illustrating the technical idea and features of the present invention, and the purpose of the embodiments is to enable those skilled in the art to understand the content of the present invention and implement the present invention, and not to limit the protection scope of the present invention by this means. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims (9)

1. A composite patterned substrate characterized by: the substrate (10) is divided into a plurality of concentric annular areas by taking the center as the circle center, the bottom width of the graphs in the same annular area is the same as the distance between the graphs, and the heights of the graphs in different annular areas are sequentially increased or decreased from inside to outside.

2. A composite patterned substrate according to claim 1 wherein: when the warpage of the substrate (10) is a positive value, the heights of the patterns in different annular regions are sequentially increased from inside to outside.

3. A composite patterned substrate according to claim 1 wherein: when the warping degree of the substrate (10) is a negative value, the heights of the graphs in different annular areas are sequentially decreased from inside to outside.

4. A composite patterned substrate according to claim 1 wherein: the number of the concentric annular regions is 2-5.

5. A composite patterned substrate according to claim 2 or 3 wherein: the reference height of the annular area figure at the center of the substrate (10) is 1.5-3.0 um.

6. A composite patterned substrate according to claim 2 or 3 wherein: the bottom width of the annular region figure at the center of the substrate (10) is 2.5-3.5 um.

7. A composite patterned substrate according to claim 1 wherein: the substrate (10) is a sapphire substrate, a sapphire and silicon dioxide composite base substrate, a silicon-based substrate or a gallium nitride base substrate.

8. An epitaxial wafer, characterized in that: comprising a composite patterned substrate (10) according to any of claims 1 to 7, a buffer layer (20), an N-type layer (30), a MQW layer (40) and a P-type layer (50) being provided in this order on the substrate (10).

9. A light emitting diode, characterized by: comprising a composite patterned substrate (10) according to any of claims 1 to 7.

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