CN112366263B - Light emitting diode and preparation method thereof - Google Patents
Light emitting diode and preparation method thereof Download PDFInfo
- Publication number
- CN112366263B CN112366263B CN202010703012.6A CN202010703012A CN112366263B CN 112366263 B CN112366263 B CN 112366263B CN 202010703012 A CN202010703012 A CN 202010703012A CN 112366263 B CN112366263 B CN 112366263B
- Authority
- CN
- China
- Prior art keywords
- layer
- defect
- growth
- dimensional
- dimensional growth
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000002360 preparation method Methods 0.000 title abstract description 4
- 230000007547 defect Effects 0.000 claims abstract description 81
- 239000000758 substrate Substances 0.000 claims abstract description 38
- 239000004065 semiconductor Substances 0.000 claims abstract description 28
- 239000010410 layer Substances 0.000 claims description 292
- 238000000034 method Methods 0.000 claims description 28
- 229910002704 AlGaN Inorganic materials 0.000 claims description 14
- 239000000463 material Substances 0.000 claims description 12
- 238000002488 metal-organic chemical vapour deposition Methods 0.000 claims description 11
- 238000003780 insertion Methods 0.000 claims description 6
- 230000037431 insertion Effects 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- 230000007423 decrease Effects 0.000 claims description 5
- 238000005240 physical vapour deposition Methods 0.000 claims description 5
- 239000002356 single layer Substances 0.000 claims description 5
- 150000001875 compounds Chemical class 0.000 claims description 4
- 238000010030 laminating Methods 0.000 claims description 4
- 238000000059 patterning Methods 0.000 claims description 3
- 238000000151 deposition Methods 0.000 claims 1
- 230000006798 recombination Effects 0.000 abstract description 6
- 238000005215 recombination Methods 0.000 abstract description 5
- 229910002601 GaN Inorganic materials 0.000 description 32
- 229910052594 sapphire Inorganic materials 0.000 description 11
- 239000010980 sapphire Substances 0.000 description 11
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 239000012535 impurity Substances 0.000 description 5
- 238000012546 transfer Methods 0.000 description 5
- 230000003111 delayed effect Effects 0.000 description 4
- 230000004888 barrier function Effects 0.000 description 3
- 230000009643 growth defect Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000000407 epitaxy Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/20—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a particular shape, e.g. curved or truncated substrate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/005—Processes
- H01L33/0062—Processes for devices with an active region comprising only III-V compounds
- H01L33/0075—Processes for devices with an active region comprising only III-V compounds comprising nitride compounds
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/04—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/04—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction
- H01L33/06—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction within the light emitting region, e.g. quantum confinement structure or tunnel barrier
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/12—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a stress relaxation structure, e.g. buffer layer
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/20—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a particular shape, e.g. curved or truncated substrate
- H01L33/22—Roughened surfaces, e.g. at the interface between epitaxial layers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/26—Materials of the light emitting region
- H01L33/30—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table
- H01L33/32—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table containing nitrogen
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Led Devices (AREA)
Abstract
The invention belongs to the technical field of semiconductors, and particularly relates to a light-emitting diode and a preparation method thereof, wherein the light-emitting diode comprises a patterned substrate, a buffer layer, a three-dimensional growth layer, a two-dimensional growth layer, an N-type semiconductor layer, a light-emitting layer and a P-type semiconductor layer, wherein a defect turning layer is grown between the three-dimensional growth layer and the two-dimensional growth layer, and can block the defect extension of the top of a projection of the patterned substrate and enable the two-dimensional growth layer not to be transversely combined at the top of the projection but to be transversely combined near two sides of the top of the projection, so that dislocation is reduced, non-radiative recombination is reduced, and the light-emitting efficiency is improved.
Description
Technical Field
The invention belongs to the technical field of semiconductors, and particularly relates to a light-emitting diode with a buffer layer and a preparation method thereof.
Background
Referring to fig. 1, a conventional gallium nitride epitaxial layer includes a patterned sapphire substrate, a GaN buffer layer, three-dimensional GaN, two-dimensional GaN, an N-type GaN layer, a light emitting layer, and a P-type GaN layer.
Wherein GaN grown directly on sapphire results in more defects due to the lattice mismatch between the sapphire substrate and GaN. In order to reduce the generation of defects, three-dimensional GaN growth is usually performed, and then two-dimensional GaN growth is performed.
In order to enhance the three-dimensional GaN growth at the bottom and improve the light extraction problem, the sapphire substrate is usually patterned to form a series of protrusions on the surface of the substrate. When the two-dimensional GaN grows, the two-dimensional GaN extends to two sides along the three-dimensional GaN pattern, and the two-dimensional GaN meets at the top end of the bulge to form a defect. This defect extends into the light-emitting layer and becomes a non-radiative recombination center, which exacerbates the Droop effect and affects brightness.
Disclosure of Invention
In one embodiment, the present invention provides a light emitting diode, comprising: a substrate having opposing first and second surfaces, the first surface having a series of protrusions; the buffer layer, the three-dimensional growth layer, the two-dimensional growth layer, the N-type semiconductor layer, the light emitting layer and the P-type semiconductor layer are sequentially deposited on the first surface; the method is characterized in that: and a defect turning layer is arranged between the three-dimensional growing layer and the two-dimensional growing layer, covers the surface of the protrusion and the surface of the three-dimensional growing layer, forms a recess at the junction of the two side surfaces, and covers the defect turning layer and fills the recess.
Further, the starting growth position of the defect turning layer is the position where the longitudinal growth of the three-dimensional growth layer is highest.
Furthermore, the thickness of the defect turning layer is 20-1000 angstroms.
Further, the defect turning layer is a material layer containing Al, and the defects at the top ends of the barrier protrusions extend in the vertical direction. The Al-containing material layer includes a compound represented by the formula AlxGa1-xN, wherein 0 < x ≦ 1. Preferably, the Al component range in the Al-containing material layer is 5-15%.
Further, the Al composition of the defect turn layer is fixed or gradually decreases along the growth direction.
Further, the defect diverting layer has a single-layer structure or a multi-layer structure. Wherein the superlattice structure is a structure formed by alternately laminating AlGaN and AlN or a structure formed by alternately laminating AlGaN and GaN.
Further, a GaN insertion layer is also included in the defect turning layer of the superlattice structure. Preferably, the thickness of the GaN insertion layer is 1000-8000A.
In another aspect of the present invention, a method for manufacturing the light emitting diode is provided, which includes the following steps:
(1) providing a substrate, wherein the substrate is provided with a first surface and a second surface which are opposite to each other, and the first surface is subjected to patterning treatment to form a series of bulges;
(2) growing a buffer layer on the first surface;
(3) growing a three-dimensional growth layer on the buffer layer;
(4) growing a side growth layer on the protrusion and the three-dimensional growth layer, wherein the defect turning layer covers the surface of the protrusion and the three-dimensional growth layer, and a recess is formed at the junction of the protrusion and the side of the three-dimensional growth layer;
(5) growing a two-dimensional growth layer on the lateral growth layer, wherein the two-dimensional growth layer fills and levels the depression;
(6) and sequentially growing an N-type semiconductor layer, a light emitting layer and a P-type semiconductor layer on the two-dimensional growing layer.
The defect turning layer is grown by adopting an MOCVD method or a PVD method, and the growth temperature of the side growth layer is higher than that of the three-dimensional growth layer and lower than that of the two-dimensional growth layer. The growth temperature of the defect turning layer is 1030-1100 ℃. The growth pressure of the side growth layer is 100 to 300 Torr.
The invention has the beneficial effects that: according to the invention, the defect turning layer is arranged between the three-dimensional growth layer and the two-dimensional growth layer, and covers the protrusion and the surface of the three-dimensional growth layer, so that the defect at the top end of the protrusion can be prevented from extending along the vertical direction, and the defect can be turned transversely, thereby the transverse combination position of the subsequent two-dimensional growth layer is shifted, the defect generation is reduced, and the brightness is improved.
Drawings
FIG. 1 is a cross-sectional view of a prior art LED.
Fig. 2 is a partially enlarged view of the led shown in fig. 1 during the growth process.
Fig. 3 is a cross-sectional view of a light emitting diode according to an embodiment of the invention.
FIG. 4 is a partially enlarged view of the LED shown in FIG. 3 according to the present invention during the growing process.
Detailed Description
The invention is described in detail below with reference to the figures and specific examples. It is to be noted that the drawings of the present invention are provided in a very simplified and non-precise scale for convenience and clarity in order to facilitate the description of the present invention.
With continued reference to fig. 1, in the light emitting diode 10 of the prior art, a buffer layer 12, a three-dimensionally grown layer 13, a two-dimensionally grown layer 14, an N-type layer 15, a light emitting layer 16, and a P-type layer 17 are sequentially grown on a patterned substrate 11. Wherein the patterned substrate 11 is formed by a periodic arrangement of a series of protrusions 111. The three-dimensionally grown layer 13 is longitudinally grown in an island shape between the adjacent projections 111, and then the two-dimensionally grown layer 14 is laterally grown on the surface of the three-dimensionally grown layer 13.
Referring to fig. 2, fig. 2 is an enlarged partial view of a dashed circle in fig. 1. During the lateral growth, the two-dimensional growth layer 14 is firstly deposited on the surface of the three-dimensional growth layer 13 to form a sheet structure, then the sheet structures are gradually combined laterally at the top end of the protrusion 111, and finally the two-dimensional growth layer 14 with a flat surface is formed. When the segments of the two-dimensional growth layer 14 are laterally combined at the top end of the protrusion 111, the screw dislocation generated at the top end of the protrusion 111 extends upwards to the light-emitting layer along the lateral combination position, so that non-radiative recombination of electrons and holes is caused, and the final light-emitting brightness of the LED is reduced.
Referring to fig. 3, in order to transfer the screw dislocations at the top end of the protrusion 211 to the vicinity of the top end of the protrusion 211 and to be dispersed and weakened by the transfer, the present invention grows a defect turning layer 28 between the two-dimensional growth layer 24 and the three-dimensional growth layer 23, the defect turning layer 28 blocks the extension of dislocations at the top end of the protrusion 211 and laterally transfers the dislocations, thereby shifting the lateral merging position of the two-dimensional growth layer 24 from the top end of the protrusion 211 to both sides of the top end of the protrusion 211, thereby weakening the continuation of dislocations.
With continued reference to fig. 3, in one embodiment, the light emitting diode of the present invention comprises at least: a substrate 21, a buffer layer, a three-dimensional growth layer 23, a defect-turning layer 28, a two-dimensional growth layer 24, an N-type semiconductor layer 25, a light-emitting layer 26, and a P-type semiconductor layer 27.
The substrate 21 has a first surface and a second surface opposite to each other, wherein the first surface has a series of protrusions 211, and the patterned substrate 21 is formed, so that the direction of light rays emitted to the substrate 21 can be changed, the light loss can be reduced, and the light emitting efficiency of the light emitting diode can be improved. The substrate 21 may be made of sapphire, silicon nitride, silicon carbide, or the like. Since a semiconductor material such as GaN has a very high melting point and a nitrogen equilibrium vapor pressure, it is difficult to manufacture a bulk single crystal GaN substrate 21 of high quality and large area. The conventionally adopted GaN growth method is to grow sapphire (Al)2O3) The substrate 21 serves as an underlying substrate 21 on which a buffer layer is formed to reduce lattice mismatch with GaN. Therefore, the present embodiment prefers a conventional patterned sapphire substrate 21 and performs epitaxial growth on the C-plane thereof. Since the epitaxial layer is grown on the foreign substrate 21, screw dislocations are easily generated at the top ends of the protrusions 211 and extend into the subsequent epitaxial layer, and non-radiative recombination of electrons and holes easily occurs at the dislocation D positions, reducing the light emitting efficiency. Therefore, it is necessary to block the extension of the dislocations D and make the dislocations transfer positions to reduce the occurrence of non-radiative recombination.
Referring to fig. 4, fig. 4 is a partially enlarged portion of fig. 3 at the dashed circle. The buffer layer 22 is deposited on the first surface of the substrate 21, so that lattice mismatch between the substrate 21 and a subsequent epitaxial layer can be reduced, and the subsequent epitaxial layer with better growth quality is facilitated. The buffer layer 22 is typically grown under low temperature conditions using metal organic chemical vapor deposition (hereinafter referred to as "MOCVD") or PVD, and is a group III nitride semiconductor layer, and the material includes Alx1Ga1-x1N, where 0. ltoreq. x 1. ltoreq.1. For example, the buffer layer 22 may be AlN grown by PVD method or GaN grown by MOCVD method, and in this embodiment, the buffer layer 22 preferably includes AlN and GaN on the surface of AlN. The AlN or GaN buffer layer 22 grown under a low temperature condition covers the protrusions 211 of the substrate 21 and the surface of the substrate 21 between the adjacent protrusions 211 with a fine crystal in the form of particles, and then grows the subsequent epitaxial layer using the fine crystal as a nucleus, thereby improving the crystal quality of the growth of the epitaxial layer. The buffer layer 22 is formed on the patterned substrate 21 having the protrusions 211, and has a wave shape as a whole in conformity with the shape of the substrate 21, and the buffer layer 22 has a thickness of 100 to 500 angstroms.
The three-dimensionally grown layer 23 is deposited on the buffer layer 22, and is deposited mainly between adjacent protrusions 211 and on the buffer layer 22 at the bottoms of the protrusions 211. There may be an extremely small amount of three-dimensionally grown layer 23 deposited on top of the protrusions 211. The three-dimensionally grown layer 23 is formed by longitudinal growth and is a high-quality crystal having a low dislocation D density. The three-dimensionally grown layer 23 has an island shape between adjacent projections 211, and a concave region 231 is formed at a junction between a side surface thereof and a side surface of the projection 211. The material of the three-dimensionally grown layer 23 includes gallium nitride. The three-dimensionally grown layer 23 may be doped to accelerate the three-dimensional growth. For example doped with Si impurities. The thickness of the three-dimensional growth layer 23 is a height from the flat surface of the substrate 21 between the adjacent protrusions 211 to the top surface of the three-dimensional growth layer 23, and is smaller than the height H of the protrusions 211, and the thickness of the three-dimensional growth layer 23 is preferably 60% to 90% (ratio) of the height of the protrusions 211. Within this range, the concentration of the dislocations D is suppressed, and the effect of improving the crystallinity can be sufficiently obtained.
And the defect turning layer 28 is deposited and covers the top of the protrusion 211 and the surface of the three-dimensional growing layer 23, and the depression 281 is formed in the three-dimensional growing layer 23 and the depression area 231 on the side surface of the protrusion 211, and the defect turning layer 28 is enabled to be waved as the protrusion 211 fluctuates due to the fact that the defect turning layer 28 covers the surfaces of the protrusion 211 and the three-dimensional growing layer 23. The three-dimensional growth layer 23 has a recessed region 231 at the intersection of the side surface and the protrusion 211, the cross section of the recessed 281 is at an angle a, the angle a is in the range of 40-90 °, and the defect turning layer 28 forms a recess 281 above the recessed 281, the cross section of the recess 281 is at an angle b, because the defect turning layer 28 can perform a certain lateral growth, resulting in b > a. The range of the angle b is 60-120 degrees.
Applicants conducted comparative analyses of the brightness of the light emitting diode obtained from the prior art, an embodiment thereof, and the delayed growth defect diversion layer 28. In the prior art, the two-dimensional growth layer 24 is directly grown on the three-dimensional growth layer 23, in one embodiment, the AlGaN defect turning layer 28 starts to grow immediately after the three-dimensional growth layer 23 grows to the highest point, and the delayed growth defect turning layer 28 is the AlGaN defect turning layer 28 delayed from growing and the two-dimensional growth layer 24 is regrown after the three-dimensional growth layer 23 grows to the highest point.
Through comparative experiments, the brightness of the light-emitting secondary obtained by starting to grow the defect turning layer 28 after the longitudinal growth of the three-dimensional growth layer 23 reaches the maximum is found to be 241.6mv, which is improved by 0.35% compared with the brightness (240.9 mv) of the light-emitting diode in the prior art. And the delayed growth defect diverting layer 28 achieves a minimum (230.1 mv) brightness of the led, even lower than prior art leds.
Therefore, in mass production, it is necessary to strictly control the time for starting the growth of the defect inversion layer 28, that is, to select the time for starting the growth of the defect inversion layer 28 immediately after the growth of the three-dimensional growth layer 23 reaches the maximum point, and to control the growth conditions so as to grow the defect inversion layer 28 with a thickness of 20 to 1000 angstroms, and then to grow the two-dimensional growth layer 24. By growing in this way, a higher brightness light emitting diode can be obtained.
Since the longitudinal growth of the three-dimensional growth layer 23 reaches the highest point and the defect inversion layer 28 starts to grow, the dislocation D can be transferred and dispersed, the dislocation D can be reduced, and the luminance can be improved by 0.35%. If the defect-diverting layer 28 starts to grow when the three-dimensional growth layer is not fully grown, more dislocations D are generated, reducing the brightness of the LED. Meanwhile, if the defect turn layer 28 starts to grow after the two-dimensional growth layer 24 grows or after the two-dimensional growth layer 24 grows for a certain period of time, more defects are generated, and the brightness of the LED is lowered.
And it is necessary to control the growth end time of the defect diverting layer 28, the defect diverting layer 28 cannot be grown too thick nor too thin. Preferably, the defect-diverting layer 28 is grown to a thickness of 20-1000 angstroms. An excessively thick defect-diverting layer 28 may fill in the valleys 281 between the three-dimensional growth layer 23 and the protrusions 211, making the subsequent two-dimensional growth layer 24 unable to grow. Too thin a defect-turning layer 28 does not serve to block and turn the extension of dislocations D at the top of the protrusions 211.
The substrate 21 is a sapphire substrate 21 comprising Al, while on top of the protrusions 211 of the substrate 21 little buffer layer 22 is deposited, even hardly buffer layer 22. Therefore, in order to perform a lattice transition function for the substrate 21 and the subsequent two-dimensional growth layer 24, the defect-diverting layer 28 is preferably an Al-containing material, which can be represented by the formula AlxGa1-xN, where 0 < x.ltoreq.1, for example, the defect-diverting layer 28 is composed of AlGaN or AlN, where the Al component is 5% to 15%, and the Al component is constant or variable along the growth direction.
Further, since the substrate 21 is made of sapphire containing Al, it is designed that the Al composition of the defect turn layer 28 is gradually decreased along the growth direction of the defect turn layer 28, so that the Al composition of the defect turn layer 28 is higher on the side near the projections 211 and lower on the side near the two-dimensional growth layer 24. The defect turn layer 28 having a higher Al composition near the side of the protrusion 211 may block the dislocations D at the top of the protrusion 211 from extending in the vertical direction and dispersing them to the recess 281 in the horizontal direction. At the same time, the lattice difference between the defect turn layer 28 and the protrusion 211 is made smaller, reducing the generation of the dislocation D. Similarly, the lower Al content near the side of the two-dimensionally grown layer 24 may cause defects to be diverted from the layer 28 and reduce the lattice difference between the two-dimensionally grown layer 24. Preferably, the Al composition of the defect turning layer 28 gradually decreases from 15% to 5% along the growth direction.
The defect turning layer 28 may be a single layer structure or a superlattice structure. The single-layer structure comprises a single-layer AlGaN layer, wherein the Al component is constant or gradually reduced along the growth direction, and preferably 5% -15% of the Al component. The superlattice structure includes a structure in which AlGaN and AlN are alternately stacked, or a structure in which AlGaN and GaN are alternately stacked. The Al of each AlGaN layer in the superlattice structure may be the same or may gradually decrease along the growth direction of the defect steering layer 28, and preferably the Al of the AlGaN layer decreases from 15% to 5%. Further, in order to reduce the lattice difference between AlGaN and AlN, a GaN insertion layer is inserted into any layer between at least one pair of AlGaN layer and AlN layer, and the thickness of the GaN insertion layer is 1000 to 8000 ANGSTROM.
Continuing with FIG. 4, the two-dimensionally grown layer 24 is deposited on the surface of the defect-diverting layer 28, and along the growth direction, the two-dimensionally grown layer 24 first forms a structure similar to the shape of the three-dimensionally grown layer 23 on both sides of the vertical line of the recess 281 of the defect-diverting layer 28 and merges laterally on the vertical line of the recess 281, the two-dimensionally grown layer 24 now having a wave shape and being lowest on the vertical line of the recess 281. Subsequently, the two-dimensionally grown layer 24 gradually connects on the vertical lines of the recess 281 and gradually fills up the recess 281 to form a flat surface. The two-dimensional growth layer 24 having a flat surface may facilitate higher quality epitaxy for subsequent epitaxial layer growth. The two-dimensional growth layer 24 is transversely combined at the position of the recess 281 of the defect turning layer 28, so that the transverse combination position of the two-dimensional growth layer 24 is transferred to the vicinity of two sides of the protrusion 211 from the top of the protrusion 211, turning and dispersion of defects are realized, the defects after turning and dispersion become smaller and weaker, in the subsequent epitaxial growth process, a part of the defects cannot extend to the light-emitting layer 26, the quality of the light-emitting layer 26 is improved, and the light-emitting efficiency is improved.
In the conventional epitaxial underlayer, there is no defect-free turning layer 28 between the three-dimensional growth layer 23 and the two-dimensional growth layer 24, and after the two-dimensional growth layer 24 is laterally grown on the surface of the three-dimensional growth layer 23, lateral combination is performed at the top position of the protrusion 211, and defects are easily generated at the combined position. In the present invention, the defect deflecting layer 28 is grown between the three-dimensional growth layer 23 and the two-dimensional growth layer 24 to a certain thickness, and the defect deflecting layer 28 covers the top end of the protrusion 211, so that the top end dislocations D are prevented from extending in the vertical direction, and the dislocations D are deflected in the lateral direction while being dispersed. Specifically, the dislocation D is diverted to the position of the recess 281, which is small, and cannot extend upward into the light-emitting layer 26 during the subsequent epitaxial layer growth process, so that non-radiative recombination is correspondingly reduced, and the brightness of the LED is prevented from being reduced.
The N-type semiconductor layer 25 is deposited on the two-dimensional growth layer 24 for providing electrons, and the doping impurity is preferably Si, but other impurities are also possible, and the embodiment is not limited thereto. The N-type semiconductor layer 25 may have a plurality of layers and be formed of a gallium nitride-based compound semiconductor material.
The light emitting layer 26 is deposited on the N-type semiconductor layer 25, and is generally formed of an In material, and has a single quantum well or multiple quantum well structure formed by alternately stacking quantum wells and quantum barriers, and the energy gap of the quantum well is lower than that of the quantum barrier, so that electrons and holes are radiatively recombined In the light emitting layer 26 to emit light.
The P-type semiconductor layer 27 is deposited on the light emitting layer 26 for providing holes, and the doping impurity thereof is preferably Mg, but other impurities are also possible, and the embodiment is not limited thereto.
In another embodiment, the present invention provides a method for manufacturing the light emitting diode, including the following steps:
1) providing a substrate 21 having a first surface and a second surface opposite to the first surface, and patterning the first surface to form a series of protrusions 211; the substrate 21 is preferably a patterned sapphire substrate 21, the first surface being the C-plane of sapphire.
2) Growing a buffer layer 22 on the first surface; the buffer layer 22 is formed by growing AlN using a PVD method and then growing GaN using an MOCVD method.
3) Growing a three-dimensional growth layer 23 on the buffer layer 22; the three-dimensional growth layer 23 is grown by MOCVD, and three-dimensional growth is preferably GaN.
4) Growing a defect turning layer 28 on the protrusion 211 and the three-dimensionally grown layer 23, wherein the defect turning layer 28 covers the surface of the protrusion 211 and the three-dimensionally grown layer 23, and a recess 281 is formed at the boundary of the protrusion 211 and the three-dimensionally grown layer 23; when the three-dimensional growth layer 23 grows to the highest point longitudinally, a MOCVD method is adopted to grow the defect turning layer 28 with the thickness of 20-1000 angstroms, and the growth temperature of the defect turning layer 28 is higher than that of the three-dimensional growth layer 23 and lower than that of the subsequent two-dimensional growth layer 24. The specific growth temperature is 1030-1100 ℃, and the growth pressure is 100-300 Torr.
5) Growing a two-dimensional growth layer 24 on the defect-turning layer 28, the two-dimensional growth layer 24 filling the recess 281; the two-dimensional growth layer 24 is grown by the MOCVD method so that the upper surface of the two-dimensional growth layer 24 is flat.
6) The N-type semiconductor layer 25, the light-emitting layer 26, and the P-type semiconductor layer 27 are sequentially grown on the two-dimensional growth layer 24, and the N-type semiconductor layer 25, the light-emitting layer 26, and the P-type semiconductor layer 27 are sequentially grown by the MOCVD method, and the N-type semiconductor layer 25, the light-emitting layer 26, and the P-type semiconductor layer 27 are all gallium nitride-based compound semiconductor layers.
The growth method of the defect growth layer 28 in the invention is consistent with that of the three-dimensional growth layer 23, the two-dimensional growth layer 24 and the subsequent epitaxial layers, and the defect growth layer 28 can be grown by adopting an MOCVD method, so that the epitaxial wafer does not need to be taken out of an MOCVD machine and then grown additionally during the growth of the defect turning layer 28, and the intermediate transfer process is reduced, therefore, the growth quality of the epitaxial wafer is higher, the growth process and the growth time are less, and the purpose of mass production can be realized.
It should be understood that the above-mentioned embodiments are preferred examples of the present invention, and the scope of the present invention is not limited to these examples, and any modifications made according to the present invention are within the scope of the present invention.
Claims (16)
1. A light emitting diode comprising at least: a substrate having opposing first and second surfaces, the first surface having a series of protrusions; the buffer layer, the three-dimensional growth layer, the two-dimensional growth layer, the N-type semiconductor layer, the light emitting layer and the P-type semiconductor layer are sequentially deposited on the first surface; the method is characterized in that: depositing a defect diverting layer between the three-dimensional growth layer and the two-dimensional growth layer, the defect diverting layer covering the surface of the protrusion and the three-dimensional growth layer and forming a recess at the interface of the protrusion and the three-dimensional growth layer, the two-dimensional growth layer covering the defect diverting layer and filling up the recess.
2. The led of claim 1, wherein: and the starting growth position of the defect turning layer is the position of the highest longitudinal growth position of the three-dimensional growth layer.
3. The led of claim 1, wherein: the thickness of the defect turning layer is 20-1000 angstroms.
4. The led of claim 1, wherein: the defect turning layer is a material layer containing Al, and blocks the extension of the defect at the top end of the bulge along the vertical direction and turns the defect transversely.
5. The light-emitting diode according to claim 4, wherein: the Al-containing material layer includes a compound represented by the formula AlxGa1-xN, wherein 0 < x ≦ 1.
6. The light-emitting diode according to claim 5, wherein: the Al component range in the Al-containing material layer is 5-15%.
7. The led of claim 1, wherein: the Al composition of the defect turning layer is fixed or gradually decreases along the growth direction.
8. The led of claim 1, wherein: the defect turning layer is of a single-layer structure or a superlattice structure.
9. The led of claim 8, wherein: the superlattice structure is formed by alternately laminating AlGaN and AlN or formed by alternately laminating AlGaN and GaN.
10. The led of claim 8, wherein: and a GaN insertion layer is also arranged in the defect turning layer of the superlattice structure.
11. The led of claim 10, wherein: the thickness of the GaN insertion layer is 1000-8000A.
12. The manufacturing method of the light-emitting diode comprises the following steps:
providing a substrate, wherein the substrate is provided with a first surface and a second surface which are opposite to each other, and the first surface is subjected to patterning treatment to form a series of bulges;
growing a buffer layer on the first surface;
growing a three-dimensional growth layer on the buffer layer;
growing a defect turning layer on the protrusion and the three-dimensional growing layer, wherein the defect turning layer covers the surface of the protrusion and the three-dimensional growing layer, and a recess is formed at the junction of the protrusion and the three-dimensional growing layer;
growing a two-dimensional growth layer on the defect turning layer, wherein the two-dimensional growth layer fills and levels a recess;
and sequentially growing an N-type semiconductor layer, a light emitting layer and a P-type semiconductor layer on the two-dimensional growing layer.
13. The method of claim 12, wherein: the growth temperature of the defect turning layer is higher than that of the three-dimensional growth layer and lower than that of the two-dimensional growth layer.
14. The method of claim 12, wherein: the defect turning layer is grown by adopting an MOCVD method or a PVD method.
15. The method of claim 13, wherein: the growth temperature of the defect turning layer is 1030-1100 ℃.
16. The method of claim 12, wherein: the growth pressure of the defect turning layer is 100-300 Torr.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010703012.6A CN112366263B (en) | 2020-07-21 | 2020-07-21 | Light emitting diode and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010703012.6A CN112366263B (en) | 2020-07-21 | 2020-07-21 | Light emitting diode and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112366263A CN112366263A (en) | 2021-02-12 |
| CN112366263B true CN112366263B (en) | 2022-07-08 |
Family
ID=74516643
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010703012.6A Active CN112366263B (en) | 2020-07-21 | 2020-07-21 | Light emitting diode and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112366263B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114122210B (en) * | 2021-11-23 | 2023-04-18 | 聚灿光电科技（宿迁）有限公司 | Composite substrate LED epitaxial structure and preparation method thereof |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1649090A (en) * | 2004-01-29 | 2005-08-03 | Lg电子有限公司 | Nitride semiconductor thin film and method for growing the same |
| CN101069290A (en) * | 2004-12-23 | 2007-11-07 | Lg伊诺特有限公司 | Nitride semiconductor light emitting device and fabrication method thereof |
| CN103296151A (en) * | 2012-03-01 | 2013-09-11 | 上海蓝光科技有限公司 | Method for reducing warping stress of LED epitaxy |
| CN104025260A (en) * | 2012-08-03 | 2014-09-03 | 夏普株式会社 | Nitride semiconductor element structure and method for producing same |
| CN105742428A (en) * | 2016-02-03 | 2016-07-06 | 华灿光电(苏州）有限公司 | Light-emitting diode epitaxial wafer and preparation method thereof |
| CN106229388A (en) * | 2016-07-29 | 2016-12-14 | 华灿光电（浙江）有限公司 | A kind of preparation method of the epitaxial wafer of gallium nitride based light emitting diode |
| CN106887495A (en) * | 2017-03-22 | 2017-06-23 | 湘能华磊光电股份有限公司 | Epitaxial wafer of light emitting diode and preparation method thereof |
| CN109390440A (en) * | 2018-09-03 | 2019-02-26 | 淮安澳洋顺昌光电技术有限公司 | A kind of epitaxial wafer and preparation method of light emitting diode |
| CN109728144A (en) * | 2017-10-26 | 2019-05-07 | 丰田合成株式会社 | Template substrate and its manufacturing method and luminescent device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2579297B1 (en) * | 2010-06-07 | 2020-12-16 | Soko Kagaku Co., Ltd. | Method of producing template for epitaxial growth and nitride semiconductor device |
-
2020
- 2020-07-21 CN CN202010703012.6A patent/CN112366263B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1649090A (en) * | 2004-01-29 | 2005-08-03 | Lg电子有限公司 | Nitride semiconductor thin film and method for growing the same |
| CN101069290A (en) * | 2004-12-23 | 2007-11-07 | Lg伊诺特有限公司 | Nitride semiconductor light emitting device and fabrication method thereof |
| CN103296151A (en) * | 2012-03-01 | 2013-09-11 | 上海蓝光科技有限公司 | Method for reducing warping stress of LED epitaxy |
| CN104025260A (en) * | 2012-08-03 | 2014-09-03 | 夏普株式会社 | Nitride semiconductor element structure and method for producing same |
| CN105742428A (en) * | 2016-02-03 | 2016-07-06 | 华灿光电(苏州）有限公司 | Light-emitting diode epitaxial wafer and preparation method thereof |
| CN106229388A (en) * | 2016-07-29 | 2016-12-14 | 华灿光电（浙江）有限公司 | A kind of preparation method of the epitaxial wafer of gallium nitride based light emitting diode |
| CN106887495A (en) * | 2017-03-22 | 2017-06-23 | 湘能华磊光电股份有限公司 | Epitaxial wafer of light emitting diode and preparation method thereof |
| CN109728144A (en) * | 2017-10-26 | 2019-05-07 | 丰田合成株式会社 | Template substrate and its manufacturing method and luminescent device |
| CN109390440A (en) * | 2018-09-03 | 2019-02-26 | 淮安澳洋顺昌光电技术有限公司 | A kind of epitaxial wafer and preparation method of light emitting diode |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112366263A (en) | 2021-02-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11049995B2 (en) | High-efficiency long-wavelength light-emitting device | |
| JP4432180B2 (en) | Group III nitride compound semiconductor manufacturing method, group III nitride compound semiconductor device, and group III nitride compound semiconductor | |
| US9397281B2 (en) | Carrier for a semiconductor layer | |
| KR100448662B1 (en) | Nitride semiconductor device and method for manufacturing the same | |
| EP2747220B1 (en) | Nitride semiconductor ultraviolet light emitting element | |
| EP2843714B1 (en) | Semiconductor light emitting device including hole injection layer and method of fabricating the same. | |
| JP4332720B2 (en) | Method for manufacturing plate-like substrate for forming semiconductor element | |
| US7629619B2 (en) | Group III nitride-based compound semiconductor light-emitting device and method for producing the same | |
| US20020171091A1 (en) | Indium gallium nitride smoothing structures for iii-nitride devices | |
| US20110163295A1 (en) | Semiconductor with low dislocation | |
| KR20060050798A (en) | Sapphire substrate, epitaxial substrate and semiconductor device | |
| CN110112273A (en) | A kind of deep ultraviolet LED epitaxial structure and preparation method thereof and deep ultraviolet LED | |
| US20230006092A1 (en) | Light-emitting structure, method for producing the light-emitting structure, and light-emitting device | |
| KR100809229B1 (en) | Nitride semiconductor light emitting device and manufacturing method of the same | |
| WO2017076116A1 (en) | Led epitaxial structure and manufacturing method | |
| WO2014061692A1 (en) | Nitride semiconductor light emitting element | |
| US6844246B2 (en) | Production method of III nitride compound semiconductor, and III nitride compound semiconductor element based on it | |
| CN112366263B (en) | Light emitting diode and preparation method thereof | |
| US20120241753A1 (en) | Semiconductor device and method for manufacturing same | |
| JP2009049179A (en) | Manufacturing method for group iii nitride compound semiconductor, and light-emitting element | |
| JP4051892B2 (en) | Group III nitride compound semiconductor manufacturing method and group III nitride compound semiconductor device | |
| KR20220012337A (en) | Light emitting diode precursor comprising a passivation layer | |
| US20090166669A1 (en) | Nitride semiconductor light emitting device and method of manufacturing the same | |
| CN101483212A (en) | Group III nitride compound semiconductor LED and method for manufacturing the same | |
| KR101669638B1 (en) | METHOD OF GROWING n-TYPE NITRIDE SEMICONDUCTOR, LIGHT EMITTING DIODE AND METHOD OF FABRICATING THE SAME |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |