CN113437187B - Supercritical processing method for light-emitting diode - Google Patents
Supercritical processing method for light-emitting diode Download PDFInfo
- Publication number
- CN113437187B CN113437187B CN202110984706.6A CN202110984706A CN113437187B CN 113437187 B CN113437187 B CN 113437187B CN 202110984706 A CN202110984706 A CN 202110984706A CN 113437187 B CN113437187 B CN 113437187B
- Authority
- CN
- China
- Prior art keywords
- substance
- supercritical
- emitting diode
- processing method
- light emitting
- 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
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier 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
Abstract
According to the supercritical processing method of the light-emitting diode, a second substance is selected according to a first element of a semiconductor structure of the light-emitting diode; acquiring a second substance in a supercritical state; and carrying out crystal defect repair on the semiconductor structure through the second substance in the supercritical state. Therefore, the permeability and the fluidity of the second material in the supercritical state are utilized, and the crystal defect repair is carried out on the semiconductor structure of the light-emitting diode through the elements of the second material in the supercritical state, so that the semiconductor structure of the light-emitting diode tends to an ideal crystal structure, the optical performance of the light-emitting diode is closer to an ideal model, and the electro-optic conversion of the light-emitting diode and the generated light-emitting spectrum are more in line with the ideal model.
Description
Technical Field
The invention relates to the technical field of light emitting diodes, in particular to a supercritical processing method of a light emitting diode.
Background
Light Emitting Diodes (LEDs) have the unique advantages of high brightness, high light emitting efficiency, low power consumption, fast response speed, long lifetime, etc., wherein micro LEDs are one of the key development targets of next generation displays. Although LED is gaining attention, it still faces many difficulties.
The existing LED generates non-interband recombination and generates leakage current due to unexpected defects, and directly causes the wave crest of actually emitted light wave to shift the required wave band.
Particularly, when the size of the light emitting diode is reduced to the micrometer scale, the defect rate becomes a key factor affecting the display quality.
Disclosure of Invention
The invention mainly solves the technical problem that the existing light-emitting diode has defects to cause the light-emitting spectrum to shift from the ideal spectrum.
According to a first aspect, an embodiment provides a supercritical processing method for a light emitting diode, including:
providing a light emitting diode and a first substance;
selecting a second substance according to a first element of a semiconductor structure of the light-emitting diode;
performing supercritical treatment on the first substance to obtain a supercritical first substance, wherein the treatment temperature T is T1-T, the treatment pressure P is P1-P, T1 is the critical temperature of the first substance, and P1 is the critical pressure of the first substance;
processing the second substance through the first substance in the supercritical state to obtain the second substance in the supercritical state;
and carrying out crystal defect repair on the semiconductor structure through the second substance in the supercritical state.
According to a second aspect, an embodiment provides a supercritical processing method for a light emitting diode, including:
providing a light emitting diode;
selecting a second substance according to a first element of a semiconductor structure of the light-emitting diode;
acquiring a second substance in a supercritical state;
and carrying out crystal defect repair on the semiconductor structure through the second substance in the supercritical state.
According to the supercritical processing method of the light emitting diode of the embodiment, the second substance is selected according to the first element of the semiconductor structure of the light emitting diode; acquiring a second substance in a supercritical state; and carrying out crystal defect repair on the semiconductor structure through the second substance in the supercritical state. Therefore, the permeability and the fluidity of the second material in the supercritical state are utilized, and the crystal defect repair is carried out on the semiconductor structure of the light-emitting diode through the elements of the second material in the supercritical state, so that the semiconductor structure of the light-emitting diode tends to an ideal crystal structure, the optical performance of the light-emitting diode is closer to an ideal model, and the electro-optic conversion of the light-emitting diode and the generated light-emitting spectrum are more in line with the ideal model.
Drawings
Fig. 1 is a schematic flowchart of a supercritical processing method for a light emitting diode according to an embodiment;
fig. 2 is a schematic flowchart of a supercritical processing method for light emitting diodes according to another embodiment;
FIG. 3 is a schematic structural diagram of a semiconductor device supercritical processing apparatus according to an embodiment;
FIG. 4 is a schematic diagram showing the comparison of electrical characteristics of GaN deep ultraviolet light-emitting diodes before and after processing;
FIGS. 5a to 5c are schematic diagrams of the light emission characteristics of GaN deep ultraviolet light-emitting diodes before and after processing, and comparative schematic diagrams;
FIG. 6 is a comparison graph of Fourier transform infrared absorption spectrum analysis before and after GaN deep ultraviolet light emitting diode treatment.
Reference numerals: 100-a carbon dioxide supply source; 200-pneumatic pump; 300-a valve; 400-a reaction chamber; 401-a temperature regulating assembly; 500-gallium nitride deep ultraviolet light emitting diode.
Detailed Description
The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.
Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.
The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).
Example one
The semiconductor device comprises a plurality of semiconductor structure layers and insulating medium layers, wherein certain crystal defects exist in the semiconductor structure (in this case, a single crystal structure) in the preparation process, and the crystal defects can influence the electrical characteristics of the semiconductor structure.
The light emitting diode emits light by the recombination of electrons and holes, and the forbidden band width Eg can be changed by adjusting the components of the semiconductor material, so that the light emitting color of the light emitting diode is changed. Conventional emission colors include blue, green, yellow, red, infrared, and ultraviolet, and common compound semiconductor materials include group iii and group v elements such as indium, gallium, aluminum, arsenic, phosphorus, and nitrogen. In the preparation process of each semiconductor structure in the light-emitting diode, a certain amount of crystal defects (such as point defects and line defects) exist, and when the light-emitting diode works, the defects can generate non-interband recombination and generate leakage current, so that the wave crest of actually generated light is directly deviated from a required wave band. For example, the required wavelength band of the GaN deep ultraviolet light emitting diode is 100nm to 280nm, and the wavelength band of the existing GaN deep ultraviolet light emitting diode is concentrated in 300nm to 400 nm.
Supercritical technology is gradually applied to traditional industrial production, such as extraction, particle manufacturing, environmental management, chemical reaction, energy conservation and the like. Taking supercritical extraction technology as an example, the extraction process mainly adopts supercritical carbon dioxide as an extraction solvent, and organic compounds can be extracted from plant seeds, fruits, leaves and other parts by utilizing the unique physical properties of supercritical fluid. The application field of the supercritical fluid technology is wide, but the supercritical fluid principle is not thoroughly researched, the operating pressure of the supercritical fluid is high, and the requirement on equipment is high. Meanwhile, the semiconductor process manufacturing threshold is high, and practitioners of the supercritical technology are aware of the problems of profession and industry, so that the application of the supercritical technology in the semiconductor integrated circuit industry is always very limited.
As shown in fig. 1, the present invention provides a supercritical processing method for light emitting diodes, comprising:
step 1: a light emitting diode is provided.
The light emitting diode may be a light emitting diode that is manufactured by any process from the preparation of the active layer to the end of the packaging, that is, a semi-finished product in the manufacturing process or a finished product after the packaging.
Step 2: the second material is selected according to the first element of the semiconductor structure of the light emitting diode.
The second material is selected according to the first element of the semiconductor structure of the light emitting diode, wherein the first element is preferably a non-metal element. The second substance is fluid at normal temperature and pressure.
Further, the second material may have the first element, or the second material may have an element that is in the same or adjacent group as the first element. For example, when the material of the semiconductor structure is gallium nitride, the second substance may be a simple substance or a compound having an iv-group or v-group element such as a nitrogen element or a carbon element.
And step 3: and acquiring the second substance in the supercritical state.
And 4, step 4: and carrying out crystal defect repair on the semiconductor structure through the second substance in the supercritical state.
And placing the light-emitting diode in the second material in the supercritical state, and processing the semiconductor structure of the light-emitting diode by using the second material in the supercritical state.
More specifically, by utilizing the permeability and the fluidity of the second substance in the supercritical state, the element of the second substance in the supercritical state can permeate into the semiconductor structure of the light emitting diode. Since the second material is selected based on the first element in the semiconductor structure, a bond may be formed between the element of the second material and the first element. Therefore, the second substance or the element in the second substance is bonded to a dangling bond generated by a crystal defect in the semiconductor structure, thereby realizing crystal defect repair. Therefore, the semiconductor structure tends to an ideal crystal structure, crystal defects are reduced, the influence caused by the defects is also reduced, the optical performance of the semiconductor structure is closer to an ideal model, and therefore the electro-optic conversion of the light emitting diode and the generated light emitting spectrum are more consistent with the ideal model.
In practical applications, the semiconductor structures that affect the electrical characteristics and the light emission spectrum of the led include, but are not limited to, the substrate, the confinement layer, and the active layer, wherein the active layer is a structure in which carriers of the led recombine to generate photons, and therefore, the influence of crystal defects in the active layer on the light emission spectrum is theoretically the greatest. Therefore, the above semiconductor structure may be an active layer of a light emitting diode in which the crystal defects are point defects (mainly vacancy defects) or line defects. The crystal defects mostly cause a large number of dangling bonds in the crystal, and the second substance in a supercritical state can be bonded with the dangling bonds, so that the influence caused by the dangling bonds is reduced.
Based on the above explanation, the light emitting diodes have many light emitting colors, the adopted materials are correspondingly different, the preparation process of the light emitting diodes with most colors is more perfect, and the corresponding semiconductor structure has fewer crystal defects. The ultraviolet light emitting diode is mainly made of gallium nitride or gallium aluminum nitride, and particularly in a deep ultraviolet light emitting diode (UVC-LED), the light spectrum deviation degree is more serious due to crystal defects, generally, the wave peak is required to be between 100nm and 280nm, and the actual wave peak is concentrated between 300nm and 400 nm.
In a practical application, for the deep ultraviolet light emitting diode, the active layer of the light emitting diode is made of gallium nitride or gallium aluminum nitride, and the second substance is a pure substance containing nitrogen. At this time, after the second material in the supercritical state permeates into the active layer, the nitrogen element of the second material is bonded with the dangling bond of the gallium element in the active layer, so that the existence of the dangling bond is reduced. For the sake of convenience of distinction, the nitrogen element of the second substance is denoted as N1, and the nitrogen element in the semiconductor structure is denoted as N2.
Meanwhile, Fourier transform infrared absorption spectrum analysis of the deep ultraviolet light-emitting diode shows that more N-H bonds (nitrogen-hydrogen bonds) exist in the existing active layer, because the gallium element or the nitrogen element with the crystal defects has dangling bonds, and the dangling bonds of the nitrogen element are easy to bond with the hydrogen element in the preparation process.
Therefore, the crystal defects of the deep ultraviolet light emitting diode not only comprise a dangling bond, but also comprise an N-H bond, and hydrogen elements in the N-H bond can be classified as impurity defects in point defects.
In a practical application, the supercritical processing method of the light emitting diode provided by the invention aims at the problem that when the crystal defects of the gallium nitride/gallium aluminum nitride UVC-LED are repaired, the second substance adopts nitride. The nitrogen element N1 in the second material in the supercritical state preferentially bonds with dangling bonds of the gallium element in the semiconductor structure (e.g., active layer), and also bonds with the hydrogen element bonded with the nitrogen element N2 in the semiconductor structure, so that the hydrogen element is removed from the semiconductor structure. Therefore, the second substance in the supercritical state repairs the dangling bonds on one hand, reduces the N-H bonds on the other hand, and repairs the crystal defects of the semiconductor structure on two sides. Finally, the light-emitting spectrum of the UVC-LED tends to an ideal spectrum, and particularly, the peak energy is concentrated between 100nm and 280 nm.
For example, the second substance may be ammonia or nitrogen. The preparation process of the ammonia and the nitrogen is simple and is easy to realize supercritical treatment.
Example two
The existing substance supercritical method adopts a single means of temperature rise and pressure rise, and the realization of supercritical needs substances to meet the conditions of high concentration and even pure substances. Many substances (such as acetylene, ethylene and hydrogen sulfide) are combustible or toxic in nature, the combustible gas is easily exploded at high concentration, and the substances also have the problem of difficulty in preparation and storage. It is seen that these materials are difficult to perform supercritical processing and have high risk factors, and therefore, the need to perform supercritical processing of these materials is limited in various aspects. Meanwhile, supercritical substances need to satisfy the conditions of temperature and pressure, and energy needs to be consumed to maintain the conditions of temperature and pressure, for example, the critical pressure of water is 21.76MPa, the critical temperature is 374.2 ℃, the critical pressure of carbon dioxide is 7.38MPa, and the critical temperature is 31.06 ℃.
Therefore, the existing supercritical technology has the following defects:
1. the supercritical method is single; 2. safety issues such as supercritical treatment of flammable or toxic fluids; 3. high energy consumption is needed for supercritical treatment of substances such as water, ammonia and the like; 4. supercritical material processing requires that it be highly concentrated or pure.
In the embodiment of the present invention, on the basis of the first embodiment, a method for realizing supercritical processing of a second substance by using a first substance in a supercritical state is provided, and the method is applied to the supercritical processing method of the light emitting diode provided by the present invention. Wherein, the supercritical treatment of the single second substance has at least one of the disadvantages of the prior supercritical technology. By adopting the method provided by the embodiment of the invention, at least one problem can be solved. The supercritical processing method of the light-emitting diode provided by the invention has more advantages.
For example, the critical pressure of ammonia is 11.25MPa and the critical temperature is 132.4 ℃. Ammonia with low concentration can cause people to feel pungent taste and irritate burning feeling on eyes, nasopharynx and other places; the higher the concentration of ammonia, the more harmful it is to the human body. In the prior art, the supercritical treatment of the substance requires the heating and pressurizing of the substance with high concentration (even pure). Therefore, the supercritical treatment with ammonia and other nitrides has many limitations.
For example, when the second substance is flammable and explosive gas, the second substance with high concentration (even pure) needs to be heated and pressurized to realize supercritical state, which is very dangerous, easy to explode and difficult to operate.
In order to avoid the above limitations and achieve supercritical processing of substances such as ammonia under lower temperature and pressure and safer conditions for repairing crystal defects of leds, the present invention provides a supercritical processing method for leds, which may include:
step 10: a light emitting diode and a first material are provided.
Step 20: the second material is selected according to the first element of the semiconductor structure of the light emitting diode.
Step 30: and performing supercritical treatment on the first substance to obtain the first substance in a supercritical state, wherein the treatment temperature T is T1-T, the treatment pressure P is P1-P, T1 is the critical temperature of the first substance, and P1 is the critical pressure of the first substance.
The processing temperature T and the processing pressure P may be temperatures and pressures at which the semiconductor device is subsequently processed. Under this temperature and pressure condition, the first substance is supercritical.
Step 40: and processing the second substance through the first substance in the supercritical state to obtain the second substance in the supercritical state.
Specifically, the second substance and the first substance in the supercritical state are introduced into one reaction chamber, wherein the order of introducing the second substance and the first substance in the supercritical state into the reaction chamber is not limited, and after standing for a certain time, the second substance is dissolved in the first substance in the supercritical state based on the fact that the supercritical fluid has high solubility and high permeability, and the second substance is subjected to supercritical processing.
Step 50: and carrying out crystal defect repair on the semiconductor structure through the second substance in the supercritical state.
Here, the second substance in a supercritical state refers to the second substance dissolved in the first substance in a supercritical state. For example, when the light emitting diode is placed in the reaction chamber, the second substance and the supercritical first substance are introduced, and after the second substance is subjected to supercritical treatment, the second substance in the supercritical state and the supercritical first substance exist in the reaction chamber at the same time, so that only the supercritical second substance performs crystal repair on the semiconductor structure, and the supercritical first substance can play a role of a solvent or a protective gas. It is not excluded that there is a possibility that both the first and second species may act to crystallographically repair the semiconductor structure.
Therefore, the present embodiment is further improved on the basis of the first embodiment, and various technical solutions mentioned in the first embodiment can be adopted, for example, the selection standard of the second substance has the following technical effects in addition to the technical effects mentioned in the first embodiment:
by the LED supercritical processing method, the second substance can be supercritical under the condition of lower temperature and pressure, and meanwhile, the second substance with lower concentration can be supercritical. When the second substance is inflammable, explosive and toxic fluid, the safety of the second substance with low concentration in actual operation can be guaranteed.
Since the first substance needs to be supercritical at a high concentration, in some application environments, the first substance is required to be non-flammable or even non-toxic. At the same time, the supercritical is preferably achieved at relatively low temperature and pressure conditions, and therefore the first substance is preferably a gas.
In practical applications, the first substance may be a saturated bond compound containing a carbon element. The saturated bond compound containing carbon has high chemical stability, is not easy to react with a second substance, and is not easy to cause adverse effect on the light-emitting diode.
For example, the first substance may be carbon dioxide or carbon tetrafluoride. The critical pressure of the carbon dioxide is 7.38MPa, and the critical pressure is 31.06 ℃; the critical pressure of the carbon tetrafluoride is 3.74MPa, and the critical temperature is-45.67 ℃. It can be seen that both substances can be supercritical (compared with ammonia) at a lower temperature and pressure, and are non-flammable and non-toxic gases.
In another practical application, on the premise of not considering the safety of the first substance and the second substance, the supercritical state of the second substance is realized for lower energy consumption, and in this case, the first substance may be selected as follows: t1 < T2, and/or P1 < P2, T2 being the critical temperature of the second substance and P2 being the critical pressure of the second substance. That is, when the second substance is supercritical, if one process condition of temperature or pressure is difficult to realize, the second substance may be supercritical by the above method.
In one possible implementation, the mass fraction or volume fraction of the second substance in the reaction chamber is 100% when the second substance alone is subjected to supercritical treatment. In the method provided by this embodiment, the second substance is dissolved in the first substance in the supercritical state, and the closer the processing condition in the reaction chamber is to the critical condition of the second substance, the higher the solubility of the second substance in the first substance in the supercritical state, that is, the higher the mass fraction or volume fraction of the second substance. For a second substance with high concentration, which may be explosive or toxic or corrosive, a low concentration is required, and the concentration of the second substance is also low under low temperature and low pressure conditions, for example, the mass fraction of the second substance may be less than or equal to 5%, or the integral number of the second substance may be less than or equal to 5%.
In summary, in practice, the specific implementation manner of the first substance needs to be selected according to the second substance to be supercritical. That is, in an ideal state (without considering the problems of toxicity, flammability, etc.), the first substance may be water, a gaseous inorganic substance, a gaseous organic substance, or a liquid organic substance under normal temperature and pressure conditions.
In one implementation, the first substance may be a gaseous non-metallic inorganic substance. For example, the first substance may be a gaseous elemental nonmetal such as nitrogen or an inert gas, or a gaseous nonmetallic compound such as carbon dioxide or ammonia. The decrease in the critical temperature and pressure of the gaseous non-metallic inorganic substance may correspond to the use of a second substance having a higher critical temperature and pressure, for example, when the second substance is water. For example, when the first material is an inert gas, the inert gas is chemically stable and inactive, and does not react with the second material or with a device to be processed.
In one implementation, the first substance may be an organic substance of the fluid. For example, the first substance may be an alkane, alkene, or alkyne. Wherein the critical temperature of methane is-82.6 deg.C, and the critical pressure is 4.59 MPa. Such materials have a lower critical pressure (as compared to carbon dioxide) and some materials (e.g., methane, ethylene) have a lower critical temperature than carbon dioxide. In this case, when the second substance is carbon dioxide, the second substance can be supercritical by using such a substance as the first substance.
As another example, the first substance may be a saturated halogenated hydrocarbon of the fluid. Wherein the first substance can be carbon tetrafluoride, the critical pressure of the carbon tetrafluoride is 3.74MPa, the critical temperature is-45.67 ℃, and the first substance is an incombustible and nontoxic substance. The method has the characteristics of easy supercritical treatment, no toxicity, no flammability, high safety and the like.
For example, the first substance may be an alcohol organic substance, an aldehyde organic substance, an ester organic substance, a ketone organic substance, a phenol organic substance, an ether organic substance, an acyl organic substance, or a carboxylic acid organic substance, and the first substance may be a fluid. The organic material preferably contains 1-2 carbon atoms, such as ethanol, and the critical temperature and pressure are relatively low. Meanwhile, the substances are mutually soluble with water and can be used as first substances to realize the supercritical treatment of water.
EXAMPLE III
The following further describes the supercritical processing method for the light emitting diode provided by the present invention by taking the application of the gallium nitride deep ultraviolet light emitting diode (GaN UVC-LED) as an example, but the supercritical processing method for the light emitting diode provided by the present invention is not limited to the application example. The second substance is ammonia and the first substance is carbon dioxide.
Firstly, testing the characteristics of the gallium nitride deep ultraviolet light-emitting diode before treatment.
For example, basic electrical characteristics and light emission characteristics including, but not limited to, turn-on voltage, current level, and light emission band are tested.
And secondly, processing the gallium nitride deep ultraviolet light-emitting diode by adopting supercritical ammonia to repair crystal defects. The supercritical processing method of the light emitting diode provided in the first embodiment or the second embodiment can be adopted.
For example, the semiconductor device supercritical processing apparatus shown in fig. 3 is used for processing, and the following processing procedures are adopted:
1. the required carbon dioxide gas is charged into the pneumatic pump 200 through the carbon dioxide supply source 100, and then the pneumatic pump is closed through the valve 300, and the carbon dioxide is warmed and pressurized above the critical condition. Wherein, the temperature can be raised firstly or the pressure can be increased firstly, and the sequence is not strictly required. Or directly pressurizing without heating, and heating in the next step.
2. A proper amount of magnesium nitride, distilled water and gallium nitride deep ultraviolet light emitting diode 500 are placed in the reaction chamber 400, wherein the amount of magnesium nitride is variable and has no strict range requirement, the proportion ratio is based on the amount of generated ammonia, and the temperature is raised to be higher than the critical temperature of carbon dioxide through the temperature adjusting assembly 401.
3. After a sufficient period of time for the reaction to occur, the magnesium nitride reacts with the distilled water to produce the desired ammonia. Of course, ammonia may be introduced directly into the reaction chamber 400.
4. And introducing carbon dioxide gas of a pneumatic pump into the reaction chamber 400, wherein the reaction chamber is a closed chamber, and the carbon dioxide in the chamber reaches the required temperature and pressure, so that the carbon dioxide enters a supercritical state. Subsequently, the ammonia enters the supercritical state by the action of carbon dioxide in the supercritical state.
5. After being placed in the environment of the supercritical fluid of carbon dioxide and ammonia for a period of time, the supercritical treatment is completed, and the reaction chamber 400 is cooled and decompressed to complete the supercritical treatment of the gallium nitride deep ultraviolet light emitting diode 500.
And thirdly, performing characteristic test and analysis on the processed gallium nitride deep ultraviolet light-emitting diode.
For example, characteristics such as a turn-on voltage, a current level, and a light emission band are tested. And then comparing the characteristics with the characteristics of the gallium nitride deep ultraviolet light-emitting diode before treatment.
As shown in fig. 4, it can be seen that the processed gan deep uv led has a larger on-current at the same on-voltage.
As shown in fig. 5a to 5c, it can be seen that, as shown in fig. 5a, the gan deep uv led before treatment emits light with a longer wavelength and a wider wavelength range, and concentrates on emission at the tail. As shown in fig. 5b, the processed gan deep ultraviolet led has a shorter overall wavelength, emits closer to the band gap, and has a sharper peak, which indicates that the band-tail and deep level electron hole recombination luminescence is reduced, i.e., the band-tail effect and deep level defect are suppressed, and a part of the crystal defects of the active layer are repaired. As shown in fig. 5c, the intensity of deep level emission of the processed gan deep uv led is significantly reduced.
The active layer of the ideal gallium nitride deep ultraviolet light-emitting diode is a perfect single crystal, and N-H bonds do not exist. However, the defects are inevitably introduced in the actual manufacturing process, and more dangling bonds and N-H bonds exist. As shown in fig. 6, it can be seen that the content of N-H bonds in the active layer of the processed gan deep ultraviolet led is reduced, indicating that the supercritical fluid nitridation process causes a portion of N-H bonds in the active layer to be eliminated.
As shown in the table below, it can be seen that the relative content of nitrogen element in the active layer of the treated gan deep ultraviolet led is increased, indicating that ammonia in a super-critical state enters the active layer of the led and bonds with the dangling bond.
In conclusion, the GaN UVC-LED is treated by supercritical ammonia, so that nitrogen elements successfully enter the active layer of the device and react with dangling bonds, and the content of the relative nitrogen elements is increased. The adjacent N-H bonds react to remove hydrogen elements, so that the content of the N-H bonds in the active layer is reduced, dangling bonds are reduced, and the concentration of crystal defects is reduced. Therefore, when the carrier of the active layer of the GaN UVC-LED emits light according to the ideal model, the wavelength of the generated light is more consistent with the ideal model, and the wave band requirement (100 nm-280 nm) of the UVC-LED is met.
Meanwhile, the conduction current is improved under the condition that the starting voltage and the doping state are not changed, the light-emitting wavelength is shorter, the light-emitting wavelength is closer to the band gap for emission, the wave peak is sharper, and the influence of a band-tail effect and deep energy level defects is inhibited. The GaN UVC-LED is processed by supercritical ammonia, so that defects can be effectively repaired, on-state current is improved, and emitted wavelength is concentrated in a required short wave band.
By combining the three embodiments, it can be seen that the supercritical processing method for the light emitting diode provided by the invention at least has the following technical effects:
1. compatibility: taking gallium nitride deep ultraviolet light emitting diode as an example, supercritical processing can be performed in the middle and at the end of the process flow because of the unique physical properties of the supercritical fluid and the high permeability and solubility. That is, the light emitting diode may be a light emitting diode that is manufactured by performing any process from the preparation of the active layer to the end of the package, that is, a semi-finished product in the manufacturing process or a finished product after the package is completed.
2. The universality is as follows: according to the light emitting diode which needs to be treated actually, the types of the fluids selected by the first substance and the second substance can be adjusted, and during actual treatment, a plurality of additions such as treatment temperature, pressure, time, fluid flow and the like can be adjusted, so that the optimal treatment condition parameters can be obtained through a plurality of experiments.
3. Safety: when the supercritical processing method of the light emitting diode provided by the second embodiment is adopted, the supercritical processing of the second substance can be realized under the safe and controllable condition.
4. Repairing action: the method proves that the method can effectively repair the crystal defects in the light-emitting diode and reduce non-interband recombination, thereby leading the emitted wavelength to be concentrated in the required short wave band.
The present invention has been described in terms of specific examples, which are provided to aid understanding of the invention and are not intended to be limiting. For a person skilled in the art to which the invention pertains, several simple deductions, modifications or substitutions may be made according to the idea of the invention.
Claims (9)
1. A supercritical processing method for a Light Emitting Diode (LED) is characterized by comprising the following steps:
providing a light emitting diode and a first substance;
selecting a second substance according to the first element of the semiconductor structure of the light-emitting diode;
performing supercritical treatment on the first substance to obtain a supercritical first substance, wherein the treatment temperature T is T1-T, the treatment pressure P is P1-P, T1 is the critical temperature of the first substance, and P1 is the critical pressure of the first substance;
processing the second substance through the first substance in the supercritical state to obtain the second substance in the supercritical state;
and carrying out crystal defect repair on the semiconductor structure through the second substance in the supercritical state.
2. The supercritical processing method for led according to claim 1, wherein the first material is gaseous inorganic substance, gaseous organic substance or liquid organic substance at normal temperature and pressure.
3. The supercritical processing method for light emitting diode according to claim 1, wherein the first substance is alkane, alkene, alkyne, saturated halogenated hydrocarbon, alcohol organic substance, aldehyde organic substance, ester organic substance, ketone organic substance, phenol organic substance, ether organic substance, acyl organic substance or carboxylic acid organic substance, and the first substance is fluid.
4. The supercritical processing method for led as recited in claim 1 wherein the first material is carbon dioxide, carbon tetrafluoride, water, nitrogen, ammonia or inert gas.
5. The supercritical processing method according to claim 1 wherein the second material has the first element or the second material has an element that is in the same or adjacent group as the first element.
6. The supercritical processing method for light emitting diode according to claim 5, wherein the semiconductor structure is an active layer of the light emitting diode, and the crystal defect is a point defect or a line defect.
7. The supercritical processing method for processing led as claimed in claim 6, wherein the material of the active layer is gan or gan-al, the second substance is pure substance containing nitrogen element, and the second substance is fluid.
8. The supercritical processing method of claim 7 wherein the second material is ammonia or nitrogen.
9. The supercritical processing method for led according to claim 1 wherein the mass fraction of the second substance is less than or equal to 5% or the integral number of the second substance is less than or equal to 5%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110984706.6A CN113437187B (en) | 2021-08-26 | 2021-08-26 | Supercritical processing method for light-emitting diode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110984706.6A CN113437187B (en) | 2021-08-26 | 2021-08-26 | Supercritical processing method for light-emitting diode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113437187A CN113437187A (en) | 2021-09-24 |
| CN113437187B true CN113437187B (en) | 2022-01-25 |
Family
ID=77797868
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110984706.6A Active CN113437187B (en) | 2021-08-26 | 2021-08-26 | Supercritical processing method for light-emitting diode |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113437187B (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6087191A (en) * | 1998-01-22 | 2000-07-11 | International Business Machines Corporation | Method for repairing surface defects |
| KR100679377B1 (en) * | 2001-10-26 | 2007-02-05 | 암모노 에스피. 제트오. 오. | Lighting Emitting Device Structure Using Nitride Bulk Single Crystal layer |
| US7175704B2 (en) * | 2002-06-27 | 2007-02-13 | Diamond Innovations, Inc. | Method for reducing defect concentrations in crystals |
| TWI674629B (en) * | 2017-01-12 | 2019-10-11 | 國立中山大學 | Method for processing electronic components by supercritical fluid |
| CN113113314A (en) * | 2021-04-07 | 2021-07-13 | 湖北大学 | Method for processing MOS (Metal oxide semiconductor) tube based on supercritical carbon dioxide fluid |
-
2021
- 2021-08-26 CN CN202110984706.6A patent/CN113437187B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113437187A (en) | 2021-09-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Creason et al. | Rb2CuX3 (X= Cl, Br): 1D all‐inorganic copper halides with ultrabright blue emission and up‐conversion photoluminescence | |
| Yuan et al. | Carbon quantum dots: an emerging material for optoelectronic applications | |
| Zhang et al. | Multicolour nitrogen-doped carbon dots: tunable photoluminescence and sandwich fluorescent glass-based light-emitting diodes | |
| Song et al. | Highly efficient light‐emitting diode of graphene quantum dots fabricated from graphite intercalation compounds | |
| Jain et al. | High performance electron blocking layer-free InGaN/GaN nanowire white-light-emitting diodes | |
| Do et al. | Soft-template synthesis of nitrogen-doped carbon nanodots: tunable visible-light photoluminescence and phosphor-based light-emitting diodes | |
| Wang et al. | White light emitting diodes realized by using an active packaging method with CdSe/ZnS quantum dots dispersed in photosensitive epoxy resins | |
| CN108641716B (en) | Preparation method of fluorescence-adjustable p-phenylenediamine carbon dots | |
| Wickramaratne et al. | Electrical and optical properties of iron in GaN, AlN, and InN | |
| Xiang et al. | Efficient white and red light emission from GaN/tris-(8-hydroxyquinolato) aluminum/platinum (II) meso-tetrakis (pentafluorophenyl) porphyrin hybrid light-emitting diodes | |
| CN113437187B (en) | Supercritical processing method for light-emitting diode | |
| Lu et al. | Study of ultraviolet emission spectra in ZnO thin films | |
| Bui et al. | High-performance nanowire ultraviolet light-emitting diodes with potassium hydroxide and ammonium sulfide surface passivation | |
| Ni et al. | Random lasing carbon dot fibers for multilevel anti-counterfeiting | |
| Li et al. | Improved optical property and lasing of ZnO nanowires by Ar plasma treatment | |
| Kůsová | Silicon nanocrystals: From indirect to direct bandgap | |
| CN102213362A (en) | Pollution-free filling method for high purity ammonia | |
| CN107200321A (en) | A kind of method of regulation and control graphene quantum dot luminescence generated by light | |
| Li et al. | Wide-bandgap organic nanocrystals with high mobility and tunable lasing emission | |
| Kumar et al. | Single-crystalline ZnO/graphene quantum dots phosphors-converted white light-emitting diodes | |
| Yu et al. | White light emission from blue InGaN LED precoated with conjugated copolymer/quantum dots as hybrid phosphor | |
| WO2023024001A1 (en) | Substance supercritical treatment method and device, and semiconductor device treatment method | |
| WO2016056371A1 (en) | Photochemical reaction device, photochemical reaction method using same, and lactone production method using said method | |
| Sato et al. | Three primary color luminescence from natively and thermally oxidized nanocrystalline silicon | |
| Canham | Progress towards understanding and exploiting the luminescent properties of highly porous silicon |
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 |