Method for manufacturing nano-scale periodic structured photonic crystals

Abstract

The invention discloses a method for manufacturing nano-scale periodic structured photonic crystals, which comprises the following steps: (1) coating a layer of photo-sensitive resists with a thickness of less than 150 nm on the surface of a sample; (2) vertically fixing a reflector and the sample on a sample platform; (3) selecting the wavelength lambda and incidence angle theta of a laser beam sent to the surface of the sample according to a formula 2dSin theta=n lambda; (4) carrying out first exposure on the sample; (5) carrying out 60-degree or 90-degree rotation on the sample platform on which the sample is fixed, then carrying out second exposure on the sample so as to obtain the pattern of a nano-scale periodic structured triangular lattice or square lattice photonic crystal; and (6) taking down the sample subjected to two exposures from the sample platform, then carrying out development, photographic fixing, baking, and etching standard process engineering on the sample until a nano-scale periodic structured photonic crystal is obtained on the surface of the sample. The method disclosed by the invention is simple and rapid; and by using the method, high-precision and high-contrast-ratio nano-scale periodic structured photonic crystals can be manufactured on the surfaces of various materials.

Description

technical field [0001] The invention relates to optoelectronic materials and devices, in particular to a method for preparing two-dimensional photonic crystals with nano-periodic structures on the surfaces of various materials by adopting a laser holographic interference method. Background technique [0002] Energy is the blood of economic operation. Semiconductor lighting technology based on high-efficiency white LEDs has been highly valued in my country's scientific research strategy due to its attractive energy-saving and environmental protection prospects. As a new type of high-efficiency energy-saving solid light source, high-efficiency white LEDs have an expected service life of more than 50,000 hours, which can save electricity 5-10 times compared to incandescent lamps, and can achieve the dual goals of saving resources and reducing environmental pollution. An epoch-making revolution in the field. The core material for realizing white LEDs is gallium nitride, which h...

AI Technical Summary

Problems solved by technology

[0004] Although theoretical and experimental studies in recent years have shown that by introducing photonic crystals with nano-periodic structures on the sapphire substrate, or on the surface or inside of GaN-based LEDs, the external quantum efficiency and luminescence of LEDs can be greatly improved (over 50%). Brightness, but the current preparation methods of photonic crystals with nano-periodic structures, such as electron beam drawing, are of high precision, but the equipment is expensive and the process is too long, which is only suitable for making photons on the surface of extremely small wafers in the laboratory. Crystal structure (Paper Jpn.J.Appl.Phys.Vol.43, 2004, pp.5809-5813)

Another relatively common nanoscale flat plate imprinting method, although the required equipment is relatively simple, it is easy to cause pollution to the wafer during the process, and the operation controllability is poor, which will inevitably lead to a decrease in product yield and increase in production costs. Not very suitable for industrialized production (Chinese published patents CN101487974 and CN101665234A; paper Jpn.J.Appl.Phys.Vol.43, 2004, pp.5809-5813)

The third type that has received a lot of attention recently is the laser holographic interferometry. In order to obtain two parallel laser beams, it is inevitable to use a laser collimator and a beam splitter. As a result, on the one hand, the processable wafer size will be reduced. Limited by the diameter of the collimator or beam splitter, on the other hand, the additional optical path difference caused by the propagation of the laser beam on the different optical mirror surfaces of the collimator and beam splitter will inevitably result in the required interference fringes Superimposing redundant irregular interference fringes on it can seriously affect the interference pattern, that is, the periodicity and contrast of the photonic crystal (paper Appl.Phys.Lett.Vol.92, 2008, pp.251110-1-3 and Cur. Appl.Phys.Vol.9, 2009, pp.633-635)

These essential defects make the current laser holographic interferometry unable to meet the needs of industrialized preparation of photonic crystals with nano-periodic structures

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