Quantum well material with light-emitting wavelength of 1178nm and preparation method thereof

Abstract

The invention relates to the technical field of optoelectronic materials, in particular to a quantum well material with the light-emitting wavelength of 1178nm and a preparation method of the quantum well material. Comprising the following steps: growing a gallium-arsenic-phosphorus (GaAsP) strain compensation barrier layer on a substrate; growing a GaAs spacer layer on the strain compensation barrier layer; growing a high In component (35-40%) InGaAs quantum well layer on the spacing layer by adopting a low-temperature process; growing a GaAs spacer layer on the quantum well layer; growing a GaAsP strain compensation barrier layer on the spacing layer; the process is repeated to complete the growth of the multi-quantum well luminescent material. The method has the advantages that the stress accumulation of the InGaAs quantum well material is reduced; mutual mixing of atoms between the barrier layer and the quantum well layer is avoided; by reducing the growth temperature and reducing the migration rate of atoms on an epitaxial surface, the critical thickness of the InGaAs multi-quantum well material is improved, the dislocation defect density is greatly reduced, and the growth quality of the InGaAs multi-quantum well material is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic materials technology, and in particular to a quantum well material with an emission wavelength of 1178 nm and its preparation method. Background Technology

[0002] A 589nm yellow light source can be obtained by frequency doubling a laser with a wavelength of 1178nm, which has wide and important applications in laser display, biomedicine, high-precision spectroscopy, and adaptive optics for atmospheric detection.

[0003] Based on the band structure of semiconductor materials, to obtain a light-emitting material with an emission wavelength of 1178 nm, a high In content needs to be introduced into the GaAs compound to form InGaAs material. This results in a large lattice mismatch and poor material growth quality. One approach is to introduce nitrogen elements with small atomic radii into the lattice to form InGaNAs to reduce strain. However, in typical arsenide metal-organic chemical vapor deposition (MOCVD) systems, nitrogen growth is difficult and introduces additional defects.

[0004] Directly growing high-In-content InGaAs quantum well materials on GaAs substrates is the optimal approach. However, to achieve 1178nm luminescence, the In content of the InGaAs material needs to be between 35% and 40%, with a maximum strain of 2.8%. Under typical epitaxial growth conditions, the critical thickness is only about 4nm, while the actual quantum well thickness usually needs to be 8-12nm, especially as strain accumulates further in the growth of multiple quantum wells. Therefore, under typical growth conditions, quantum well materials are prone to problems such as lattice relaxation and high mismatch defect density, resulting in very low luminescence efficiency or no luminescence in the active region of the quantum well. Obtaining high-quality InGaAs luminescent materials with low defects through structural design and growth research is the key technology.

[0005] Therefore, in order to overcome the above-mentioned technical defects, providing a method for growing and preparing InGaAs quantum well materials with an emission wavelength of 1178 nm has become an urgent problem to be solved in this field. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a quantum well material with an emission wavelength of 1178 nm and its preparation method.

[0007] The primary objective of this invention is to provide a method for preparing a quantum well material with an emission wavelength of 1178 nm, specifically comprising the following steps: S1. After deoxidizing the substrate, a buffer layer is grown on the substrate surface at 620~680℃; S2. Introduce an organometallic source and arsine to grow the first strain-compensated barrier layer on the surface of the buffer layer; S3. Grow a first spacer layer on the surface of the first strain-compensated barrier layer; S4. Turn off the metal-organic source, keep the arsine flowing in, lower the reaction chamber temperature to 480~540℃ and stabilize it for 1~3 min, then reintroduce the metal-organic source to grow the quantum well layer; S5. Turn off the organometallic source, keep the arsine flowing in, raise the temperature of the reaction chamber to 620~680℃ and stabilize it for 1~3 min, and grow the second spacer layer according to the process conditions of step S3; S6. Following the process conditions of step S2, a second strain-compensated barrier layer is grown on the surface of the second spacer layer to form a single-cycle symmetrical light-emitting active region structure.

[0008] Preferably, the process further includes: repeating steps S2 to S6 to prepare a symmetrical light-emitting active region with a period of N, forming a multi-quantum well material with a light emission wavelength of 1178 nm; N≥1.

[0009] Preferably, the organometal source includes trimethylgallium and / or trimethylindium; wherein, when growing the first strain-compensated barrier layer, the second strain-compensated barrier layer, the first spacer layer and the second spacer layer, the organometal source introduced is trimethylgallium; when growing the quantum well layer, the organometal source introduced is trimethylgallium and trimethylindium; The quantum well layer is In y Ga 1-y The As layer has a density of 0.35 ≤ y ≤ 0.42 and a thickness of 6~12 nm; the growth rate of the quantum well layer is 0.4~0.6 nm / s. Both the first strain-compensated barrier layer and the second strain-compensated barrier layer are made of GaAs. 1-x P x , where 0.15≤x≤0.25.

[0010] Preferably, phosphine is introduced during the growth of the first strain-compensated barrier layer and the second strain-compensated barrier layer; y=0.38; x=0.18.

[0011] Preferably, the buffer layer is made of a III-V compound semiconductor and has a thickness of 300~600nm; The first strain-compensated barrier layer and the second strain-compensated barrier layer are both made of tensile strain type III-V compound semiconductors with a thickness of 8~16nm; The first spacer layer and the second spacer layer are made of GaAs and have a thickness of 1~5nm.

[0012] Preferably, in step S1, the substrate undergoes surface deoxidation treatment at a constant temperature of 680~750℃ for 5~15 minutes; the substrate is a GaAs substrate. The first spacer layer and the second spacer layer are made of GaAs and have a thickness of 1~5nm; The buffer layer is made of GaAs and has a thickness of 400 nm. The thickness of the first strain-compensated barrier layer and the second strain-compensated barrier layer is 10 nm.

[0013] The second objective of this invention is to provide a quantum well material with an emission wavelength of 1178 nm, which is prepared by a method for preparing a quantum well material with an emission wavelength of 1178 nm, comprising a substrate, a buffer layer, and a symmetrical light-emitting active region with a period of N stacked from bottom to top; N≥1; The single-cycle symmetric light-emitting active region includes, from bottom to top, a first strain-compensated barrier layer, a first spacer layer, a quantum well layer, a second spacer layer, and a second strain-compensated barrier layer. Both the substrate and the buffer layer are made of group III-V compound semiconductors; Both the first and second strain-compensated barrier layers are tensile strain type III-V compound semiconductors. The quantum well layer is In y Ga 1-y For layer As, 0.35≤y≤0.42.

[0014] Preferably, both the first strain-compensated barrier layer and the second strain-compensated barrier layer are made of GaAs. 1- x P x Where 0.15≤x≤0.25; The thickness of the first strain-compensated barrier layer and the second strain-compensated barrier layer is 8~16nm.

[0015] Preferably, x=0.18; the thickness of the quantum well layer is 6~12nm, and y=0.38.

[0016] Preferably, both the substrate and the buffer layer are made of GaAs; the thickness of the buffer layer is 300~600nm; The first spacer layer and the second spacer layer are made of GaAs and have a thickness of 1~5nm.

[0017] Compared with the prior art, the present invention can achieve the following beneficial effects: This invention discloses a high-In-content InGaAs quantum well material with an emission wavelength of 1178 nm and its growth and preparation method. The process involves growing a gallium arsenide phosphide (GaAsP) tensile strain compensation layer on a substrate; growing a GaAs spacer layer on the GaAsP tensile strain compensation layer; growing a high-In-content (35-40%) InGaAs quantum well on the GaAs spacer layer using a low-temperature process; growing a GaAs spacer layer on the InGaAs quantum well; and growing a GaAsP tensile strain compensation layer on the GaAs spacer layer. Repeating this process allows for the growth of a multi-quantum-well luminescent material. This invention reduces stress accumulation in the InGaAs quantum well material by introducing a tensile strain compensation barrier layer; avoids atomic mixing between the barrier layer and the quantum well layer by introducing a spacer layer; and reduces the atomic migration rate on the epitaxial surface by lowering the growth temperature, thereby increasing the critical thickness and significantly reducing the dislocation defect density. Attached Figure Description

[0018] Figure 1 This is a flowchart of a method for preparing a quantum well material with an emission wavelength of 1178 nm according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of a quantum well material structure with an emission wavelength of 1178 nm provided according to an embodiment of the present invention.

[0020] Figure label: 1. Substrate; 2. Buffer layer; 3. The first strain-compensated barrier layer; 4. First spacer layer; 5. Quantum well layer; 6. Second spacer layer; 7. The second strain-compensated barrier layer. Detailed Implementation

[0021] In the following description, embodiments of the invention will be described with reference to the accompanying drawings. In the description below, the same modules are denoted by the same reference numerals. Where the same reference numerals are used, their names and functions are also the same. Therefore, their detailed description will not be repeated.

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0023] See Figures 1-2 The present invention provides a quantum well material with an emission wavelength of 1178 nm, comprising a substrate, a buffer layer, and a symmetrical light-emitting active region with a period of N stacked from bottom to top; N≥1; The single-cycle symmetric light-emitting active region includes, from bottom to top, a first strain-compensated barrier layer, a first spacer layer, a quantum well layer, a second spacer layer, and a second strain-compensated barrier layer. Both the substrate and the buffer layer are made of group III-V compound semiconductors; Both the first and second strain-compensated barrier layers are tensile strain type III-V compound semiconductors. The quantum well layer is In y Ga 1-y For layer As, 0.35≤y≤0.42.

[0024] Preferably, the thickness of the buffer layer is 300~600nm; Both the first and second strain-compensated barrier layers are made of GaAs. 1-x P x Where 0.15≤x≤0.25; the thickness of the first strain-compensated barrier layer and the second strain-compensated barrier layer is 8~16nm; The thickness of the quantum well layer is 6~12nm; Both the substrate and the buffer layer are made of GaAs. The first and second spacer layers are made of GaAs and have a thickness of 1~5nm. In a specific embodiment, x=0.18; y=0.38; the thickness of the buffer layer is 400nm; the thickness of the first strain compensation barrier layer and the second strain compensation barrier layer is 10nm; and the thickness of the first spacer layer is 2nm.

[0025] The preparation method specifically includes the following steps: S1. Substrate deoxidation and cleaning and buffer layer growth: Substrate 1 is placed in the LP-MOCVD reaction chamber, heated to 680~750℃ and held at the temperature for 5~15min to perform surface deoxidation treatment to obtain a clean substrate surface without an oxide layer; after deoxidation, the reaction chamber temperature is reduced to 620~680℃ to grow a buffer layer 2 with a thickness of 300~600nm. In a specific embodiment, the substrate 1 is a GaAs substrate with an orientation of (001) plane; the thickness of the buffer layer 2 is 400 nm.

[0026] S2. Growth of the first strain-compensated barrier layer 3: TMGa, AsH3, and PH3 are introduced to grow the first strain-compensated barrier layer 3 (GaAs) on the surface of buffer layer 2. 1-x P x Tensile strain compensation barrier layer material), wherein the P composition is between 0.15 and 0.25, and the thickness is 8 to 16 nm; the growth temperature of the first tensile strain compensation barrier layer 3 is the same as the growth temperature of the buffer layer 2; In InGaAs quantum well materials with a wavelength of 1178 nm, there is a compressive strain of up to 2.8%, which requires the introduction of tensile strain compensation barrier layer materials for (partial) compensation, especially in multi-quantum well structures. In a specific embodiment, the P component is 0.18, and the thickness of the first strain-compensated barrier layer 3 is 10 nm.

[0027] S3. Growth of the first spacer layer 4: TMGa and AsH3 are introduced to grow the first spacer layer 4 (material is GaAs) on the surface of the first strain-compensated barrier layer 3, with a thickness of 1~5nm. In a specific embodiment, the thickness of the first spacer layer 4 is 2 nm.

[0028] S4. Low-temperature growth of quantum well layer 5: After the first spacer layer 4 is grown, turn off the TMGa and TMIn sources (keep AsH3 flowing in to prevent material surface decomposition), cool the growth temperature of the reaction chamber to 480~540℃ and stabilize it for 1~3 min, and then turn on the TMGa and TMIn sources again to grow the quantum well layer 5. In a specific embodiment, the quantum well layer 5 is made of In. y Ga 1-y The As and In composition is 0.38, the thickness is 7.2 nm, and the growth rate is 0.5 nm / s.

[0029] S5. Growth of the second spacer layer 6: After the quantum well layer 5 is grown, turn off the TMI and TMGa sources (keep AsH3 flowing in), raise the temperature of the reaction chamber to 620~680℃ and stabilize it for 2 min; introduce TMGa and AsH3, and grow the second spacer layer 6 under the same process conditions as in step S3. In a specific embodiment, the thickness of the second spacer layer 6 is 2 nm.

[0030] S6. Growth of the second strain-compensated barrier layer 7: On the surface of the second spacer layer 6, the reaction chamber temperature is maintained at 620~680℃, and TMGa, AsH3 and PH3 are introduced. The second strain-compensated barrier layer 7 is grown according to the process conditions of step S2, and finally a symmetrical light-emitting active region structure is formed.

[0031] In a specific embodiment, the second strain-compensating barrier layer 7 is GaAs. 1-x P x P component x=0.18, thickness 10nm, growth rate 0.5nm / s.

[0032] Example 1 This embodiment provides a method for preparing an InGaAs quantum well luminescent material with an emission wavelength of 1178 nm. The flowchart is shown below. Figure 1Low-pressure metal-organic chemical vapor deposition (LP-MOCVD) was used to prepare InGaAs quantum well luminescent materials with an emission wavelength of 1178 nm using trimethylindium (TMIn), trimethylgallium (TMGa), arsine (AsH3), and phosphine (PH3) as source materials. The specific steps are as follows: S1. Substrate Deoxidation and Buffer Layer Growth: Substrate 1 is a GaAs substrate with an oriented (001) plane. It is placed in an LP-MOCVD reaction chamber, heated to 680~750℃ and held at that temperature for 10 min to perform surface deoxidation treatment to obtain a clean substrate surface without an oxide layer. In this step, if the holding temperature is too high, the surface of substrate 1 may decompose at high temperature; if the holding temperature is too low, the oxide layer cannot be removed; if the holding time is too long, the surface reconstruction complexity of substrate 1 increases, and excess arsenic will be consumed; if the holding time is too short, the oxide layer on the surface of substrate 1 cannot be effectively removed. After deoxidation, the reaction chamber temperature is reduced to 620~680℃ to grow a GaAs homoepitaxial buffer layer 2 with a thickness of 400nm. If the thickness of the buffer layer 2 is too large, it will be wasteful; if the thickness of the buffer layer 2 is too small, it may not be possible to form a high-quality buffer layer 2.

[0033] S2. Growth of the first strain-compensated barrier layer 3: TMGa, AsH3, and PH3 are introduced to grow GaAs on the surface of the buffer layer 2. 1-x P x The strain-compensated barrier layer material has a P component of x=0.18, a barrier layer thickness of 10nm, and a growth rate of 0.5nm / s, thus completing the growth of the first strain-compensated barrier layer 3; the growth temperature of the first strain-compensated barrier layer 3 is the same as the growth temperature of the buffer layer 2.

[0034] S3. Growth of the first spacer layer 4: TMGa and AsH3 are introduced to grow a first spacer layer 4 (made of GaAs) with a thickness of 2 nm on the surface of the first strain-compensated barrier layer 3. 1-x P x The growth of a strain-compensated barrier layer directly connected to an InGaAs quantum well may lead to the formation of an As / P compound within the quantum well, and atomic mixing at the interface will reduce its steepness; growing a GaAs spacer layer between the barrier and the well can effectively solve this problem.

[0035] S4. Low-temperature growth of quantum well layer 5: After the first spacer layer 4 is grown, the TMGa and TMIn sources are turned off (while AsH3 is continuously introduced to prevent material surface decomposition). The growth temperature of the reaction chamber is lowered to 520℃ and stabilized for 1-3 minutes. At this temperature, the TMGa and TMIn sources are reintroduced to grow quantum well layer 5. The material of quantum well layer 5 is In. y Ga 1-yThe As and In composition is 0.38, the thickness is 7.2 nm, and the growth rate is 0.5 nm / s.

[0036] S5. Growth of the second spacer layer 6: After the quantum well layer 5 is grown, turn off the TMIn and TMGa sources (keep AsH3 flowing in), raise the temperature of the reaction chamber to 620~680℃ and stabilize it for 2 min; introduce TMGa and AsH3, and grow the second spacer layer 6 with a thickness of 2nm under the same process conditions as in step S3.

[0037] S6. Growth of the second strain-compensated barrier layer 7: On the surface of the second spacer layer 6, the reaction chamber temperature is maintained at 650℃, and TMGa, AsH3 and PH3 are introduced. The second strain-compensated barrier layer 7 is grown according to the process conditions of step S2 (P composition x=0.18, thickness 10nm, growth rate 0.5nm / s), and finally a symmetrical light-emitting active region structure is formed.

[0038] Through the above steps, the high-In-content InGaAs quantum well luminescent material with an emission wavelength of 1178 nm is successfully grown and prepared. By repeating the growth cycle (S2-S6), InGaAs multi-quantum well materials with an emission wavelength of 1178 nm can be obtained. See the schematic diagram below. Figure 2 .

[0039] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0040] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for preparing a quantum well material having an emission wavelength of 1178 nm, characterized by: Specifically comprising the following steps: S1. After deoxidizing the substrate, grow a buffer layer on the surface of the substrate at 620-680℃; S2. Grow a first strain compensation barrier layer on the surface of the buffer layer by introducing an organic metal source and arsine; S3. Grow a first spacer layer on the surface of the first strain compensation barrier layer; S4. Turn off the metal organic source, keep the arsine flowing, reduce the temperature of the reaction chamber to 480-540℃ and stabilize for 1-3min, re-introduce the metal organic source to grow a quantum well layer; S5. Turn off the metal organic source, keep the arsine flowing, increase the temperature of the reaction chamber to 620-680℃ and stabilize for 1-3min, grow a second spacer layer according to the process conditions of step S3; S6. Grow a second strain compensation barrier layer on the surface of the second spacer layer according to the process conditions of step S2, forming a symmetric light-emitting active region structure.

2. The method of claim 1, wherein the quantum well material has an emission wavelength of 1178 nm. Also comprising: Repeat steps S2-S6 to prepare a symmetric light-emitting active region with a period of N, forming a multi-quantum well material with a light-emitting wavelength of 1178nm; N≥1.

3. The method of claim 1, wherein the quantum well material has an emission wavelength of 1178 nm. The organic metal source includes trimethylgallium or / and trimethylindium; wherein the organic metal source introduced when growing the first strain compensation barrier layer, the second strain compensation barrier layer, the first spacer layer and the second spacer layer is trimethylgallium; the organic metal source introduced when growing the quantum well layer is trimethylgallium and trimethylindium; The quantum well layer is In y Ga 1-y As layer, 0.35≤y≤0.42, with a thickness of 6-12 nm; the growth rate of the quantum well layer is 0.4-0.6 nm / s; The material of the first tensile strain compensation barrier layer and the second tensile strain compensation barrier layer is GaAs 1-x P x wherein 0.15≤x≤0.

25.

4. The method of claim 3, wherein the quantum well material has an emission wavelength of 1178 nm. When growing the first strain compensation barrier layer and the second strain compensation barrier layer, phosphine also needs to be introduced; y=0.38; x=0.

18.

5. The method of claim 1, wherein the quantum well material has an emission wavelength of 1178 nm. The material of the buffer layer is a group III-V compound semiconductor, and the thickness is 300-600nm; The materials of the first strain compensation barrier layer and the second strain compensation barrier layer are both tensile strain type group III-V compound semiconductors, and the thickness is 8-16nm; The materials of the first spacer layer and the second spacer layer are GaAs, and the thickness is 1-5nm.

6. The method of claim 1, wherein the quantum well material has an emission wavelength of 1178 nm. In step S1, the substrate is subjected to surface deoxidization treatment at 680-750℃ for 5-15min; the substrate is a GaAs substrate; The materials of the first spacer layer and the second spacer layer are GaAs, and the thickness is 1-5nm; The material of the buffer layer is GaAs, and the thickness is 400nm; The thickness of the first strain compensation barrier layer and the second strain compensation barrier layer is 10nm.

7. A quantum well material with a luminescence wavelength of 1178 nm, which is prepared by the method of claim 1. Comprising a substrate, a buffer layer and a symmetric light-emitting active region with a period of N stacked in order from bottom to top; N≥1; The symmetric light-emitting active region with a single period comprises a first strain compensation barrier layer, a first spacer layer, a quantum well layer, a second spacer layer and a second strain compensation barrier layer stacked in order from bottom to top; The materials of the substrate and the buffer layer are both group III-V compound semiconductors; The first strain compensation barrier layer and the second strain compensation barrier layer are both tensile strain type group III-V compound semiconductors; The quantum well layer is In y Ga 1-y As layer, 0.35 ≤ y ≤ 0.

42.

8. The quantum well material of claim 7, wherein the light emission wavelength is 1178 nm. The material of the first tensile strain compensation barrier layer and the second tensile strain compensation barrier layer is GaAs 1-x P x wherein 0.15≤x≤0.25; The thickness of the first strain compensation barrier layer and the second strain compensation barrier layer is 8-16nm.

9. The quantum well material of claim 8, wherein the light emission wavelength is 1178 nm. x=0.18; the thickness of the quantum well layer is 6-12nm, and y=0.

38.

10. The quantum well material of claim 7, wherein the light emission wavelength is 1178 nm. The material of the substrate and the buffer layer is GaAs; the thickness of the buffer layer is 300-600nm; The material of the first spacer layer and the second spacer layer is GaAs, and the thickness is 1-5nm.

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