Preparation method of regular and ordered quantum dot or line material

Abstract

The invention discloses a preparation method of a regular and ordered quantum dot or line material. The preparation method comprises the following steps: (1) cleaning a GaAs substrate; (2) attaching nano microspheres; (3) etching the substrate; (4) cleaning and removing residual nano microspheres; and (5) growth of quantum dots / quantum lines: putting the processed substrate with the regular and ordered circular truncated cone structure into molecular beam epitaxy equipment for growth of the quantum dots / quantum lines. The method is simple in preparation process, low in cost, wide in application range and high in repeatability, and the quantum dots / quantum lines which are uniform in size distribution, high in density and good in spatial orderliness can be prepared; meanwhile, the size and the distribution condition of the wells can be regulated and controlled by regulating and controlling the size of the nano-microspheres and a plasma etching process, so that the size and the density of the prepared quantum dots / quantum wires are regulated and controlled.

Description

Technical Field

[0001] The present application relates to a method for preparing a regular and ordered quantum dot or wire material, and belongs to the field of semiconductor materials. Background Art

[0002] Low-dimensional semiconductor materials mainly include two-dimensional superlattices, quantum wells, one-dimensional quantum wires, and zero-dimensional quantum dots. Low-dimensional semiconductor materials can be artificially tailored in physical dimensions through nano-fabrication and processing technology, thus having excellent optoelectronic properties that are completely different from traditional bulk semiconductor materials. Because semiconductor materials are restricted in different dimensions in real space, the degree to which their band structures deviate from bulk materials is also different. With the reduction of material dimensions and the reduction of the characteristic dimensions of material structures, quantum size effects, quantum tunneling effects, Coulomb blockade effects, quantum interference effects, and surface and interface effects will become more and more prominent. The new phenomena and high performance brought about by this have become the basis of a new generation of optoelectronic devices. Various new devices using low-dimensional semiconductor materials as working areas have also sprung up like mushrooms after rain, which has had a significant impact on the development of the world's economy and society today.

[0003] Semiconductor quantum dots, with their unique quantum confinement structure and novel physical properties, occupy an important position in low-dimensional semiconductor materials. The special three-dimensional quantum confinement structure of quantum dots makes their electronic system have an energy state similar to the atomic energy level, so they are also called "artificial atoms". Compared with other low-dimensional semiconductor materials, the electronic state density distribution of quantum dots is more concentrated, the exciton binding energy is larger, the exciton resonance is stronger, and the interaction between light and matter is more effective. Therefore, semiconductor quantum dots are widely used in the development of optoelectronic devices such as lasers, detectors, and optical modulators.

[0004] Although semiconductor quantum dots are considered to be the most suitable nanostructures for developing next-generation optoelectronic devices, the current preparation process is unable to obtain high-quality quantum dot materials with highly consistent morphology and size, precisely controllable surface density, and smooth and completely defect-free interface with the potential barrier. This makes the actual performance of quantum dot devices still quite different from theoretical expectations.

[0005] Molecular beam epitaxy is a crystal material growth technology under ultra-high vacuum conditions. It can flexibly control and tailor the growth of various in-phase and heterogeneous semiconductor materials at the atomic scale. It is the core technology of the modern nano-semiconductor industry revolution. As soon as this technology appeared, it changed the design concept of microelectronics and optoelectronic devices with a new concept, making it possible for the design and manufacture of semiconductor devices to develop from "impurity engineering" to "band engineering", thus entering the era of a new generation of semiconductor devices with quantum effects and low-dimensional structural characteristics.

[0006] CN103050574A discloses a method for growing silicon-based ordered quantum dots using polystyrene nanospheres as templates. On a silicon wafer covered with a dense passivation layer, a single layer of ordered and closely arranged polystyrene nanospheres is prepared as a template to grow quantum dots. After high-temperature annealing, the polystyrene nanosphere template is removed to obtain quantum dots with orderly arrangement and uniform size.

[0007] CN101404246A discloses a method for epitaxial growth of large-sized InGaSb quantum dots, wherein the epitaxial structure comprises a substrate (1), a buffer layer (2), a seed quantum dot (3), a short-period superlattice (4), a GaSb cap layer (5) and large-sized quantum dots (6). The method is significantly enhanced and improved in terms of the size, uniformity, and shape controllability of the quantum dots, and is helpful to improve the overall performance of the laser. Summary of the invention

[0008] The present invention attaches polystyrene nano-microspheres to the front of the substrate and processes it by plasma etching, processes the substrate surface into a regular and orderly truncated cone structure, forms a well structure (depression) with uniform size and regular morphology, and then promotes the preparation of quantum dots and quantum wires. Its advantages are simple preparation process, low cost, wide application range, high repeatability, and can prepare quantum dots / quantum wires with uniform size distribution, high density, and good spatial order; the size and distribution of the well can be regulated by regulating the size of the nano-microspheres and the plasma etching process, and then the size and density of the prepared quantum dots / quantum wires can be regulated.

[0009] A method for preparing a regular and ordered quantum dot or wire material comprises the following steps:

[0010] (1) Cleaning the GaAs substrate;

[0011] (2) Attachment of nanoparticles;

[0012] (3) Substrate etching;

[0013] (4) cleaning and removing residual nanospheres;

[0014] (5) Growth of quantum dots / quantum wires: placing the processed substrate with a regular and orderly truncated cone structure into a molecular beam epitaxy device for growth of quantum dots / quantum wires.

[0015] The cleaning and treatment in step (1) includes cleaning with deionized water and an organic solvent.

[0016] The attachment in step (2) is carried out by liquid / air interface transfer method, the nanospheres are polystyrene nanospheres, preferably single-layer polystyrene nanospheres; the average particle size of the polystyrene nanospheres is 20nm-100nm, more preferably 40-70nm.

[0017] The etching in step (3) is preferably performed using an inductively coupled plasma etching device to remove 20-50 nm of the GaAs substrate.

[0018] In step (4), the residual polystyrene nanoparticles are removed by high temperature annealing or plasma etching. When high temperature annealing is used, the temperature is 500-650° C. and the time is 20-30 min. The plasma etching process gas is oxygen.

[0019] The growth temperature of the quantum dots / quantum wires in step (5) is 200-800° C., and the growth time is 1-120 min.

[0020] The prepared regular and ordered quantum dot / quantum wire materials also include group IIIA and VA compounds.

[0021] The prepared regular and ordered quantum dot / quantum wire material is one of AlAs, GaAs, InAs, GaN, InN, AlN or a multi-element alloy compound composed of multiple thereof.

[0022] Regular and ordered quantum dot / quantum wire material prepared by the method of the present invention.

[0023] The purpose of using the regular and ordered quantum dot / quantum wire material to prepare a laser.

[0024] The beneficial technical effects of the present application are as follows: First, the preparation process is simple, the cost is low, the application range is wide, and the repeatability is high, and quantum dots / quantum wires with uniform size distribution, high density, and good spatial order can be prepared; second, the size and distribution of the wells can be controlled by regulating the size of the nano-microspheres and the plasma etching process, thereby regulating the size and density of the prepared quantum dots / quantum wires. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 : The substrate with attached nano-microspheres prepared by the liquid / air interface transfer method described in the present invention.

[0026] Figure 2 : Scanning electron microscope image of the substrate having a regular and orderly truncated cone structure after processing according to the present invention. DETAILED DESCRIPTION

[0027] Example:

[0028] A method for preparing a regularly ordered InAs quantum dot material comprises the following steps:

[0029] (1): Cleaning the GaAs substrate;

[0030] (2): Attaching nanoparticles, wherein the average particle size of the nanoparticles is 50 nm;

[0031] (3): Substrate etching, using inductively coupled plasma etching equipment to remove 30nm GaAs substrate, etching process gases and their flow rates are: N2 4sccm, BCl3 8sccm, Cl2 10sccm, table RF 35W, ICP RF 200W;

[0032] (4): cleaning and removing the residual polystyrene nanospheres, and removing the polystyrene nanospheres by high temperature annealing at a temperature of 550°C for 20 min;

[0033] (5): Growth of InAs quantum dots. The processed substrate with a regular and orderly truncated cone structure is placed in a molecular beam epitaxy device to grow InAs quantum dots. The growth temperature is 500-530°C and the growth time is 1 min.

[0034] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, they shall all fall within the protection scope of the present invention.

Claims

1. A method for preparing a regular and ordered quantum dot or wire material, comprising the following steps: (1) Cleaning the GaAs substrate; (2) Attachment of nanoparticles; (3) Substrate etching; (4) cleaning and removing residual nanospheres; (5) Growth of quantum dots / quantum wires: placing the processed substrate with a regular and orderly truncated cone structure into a molecular beam epitaxy device for growth of quantum dots / quantum wires.

2. The method according to claim 1, characterized in that The cleaning and treatment in step (1) includes cleaning with deionized water and an organic solvent.

3. The method according to claim 1, characterized in that The attachment in step (2) is carried out by liquid / air interface transfer method, the nanospheres are polystyrene nanospheres, preferably single-layer polystyrene nanospheres; the average particle size of the polystyrene nanospheres is 20-100 nm, more preferably 40-70 nm.

4. The method according to claim 1, characterized in that The etching in step (3) preferably uses an inductively coupled plasma etching device to remove 20-50 nm of the GaAs substrate.

5. The method according to claim 1, characterized in that In step (4), the residual polystyrene nanoparticles are removed by high temperature annealing or plasma etching. When high temperature annealing is used, the temperature is 500-650° C. and the time is 20-30 min. The plasma etching process gas is oxygen.

6. The method according to any one of claims 1 to 5, characterized in that The prepared regular and ordered quantum dot / quantum wire materials also include group IIIA and VA compounds.

7. The method according to any one of claims 1 to 5, characterized in that The prepared regular and ordered quantum dot / quantum wire material is one of AlAs, GaAs, InAs, GaN, InN, AlN or a multi-element alloy compound composed of multiple thereof.

8. The method according to any one of claims 1 to 5, characterized in that The growth temperature of the regularly ordered quantum dot / quantum wire material prepared in step (5) is 200-800° C., and the growth time is 1-120 min.

9. Regularly ordered quantum dot / quantum wire material prepared according to the method according to any one of claims 1 to 8.

10. Use of the regularly ordered quantum dot / quantum wire material prepared by the method according to any one of claims 1 to 8 in a laser.

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