Composite precise insulating layer structure

Abstract

The utility model belongs to the technical field of insulating layers, and particularly relates to a composite precise insulating layer structure, which adopts an atomic deposition system, a first layer adopts a precursor source and a metal source to form a high refractive index layer; the second layer adopts a precursor source and a metal source to form a low-refractive-index layer; the third layer to the N layer adopt precursor sources to alternately form a periodic refractive index gradient structure, the total layer number N is larger than or equal to 3, the single-layer thickness is lambda / (4n), lambda is the target regulation and control optical wavelength, and n is the film layer refractive index. According to the utility model, more than three layers are alternately stacked, so that films with high and low refractive indexes can be obtained through insulating layers formed by different precursor sources, and as a Bragg structure, the reflectivity is improved; in addition, the third layer starts to form a gradient structure with a periodic refractive index, and the regulation and control requirements of the light-emitting device on light overflow and light reflection are facilitated.

Description

Technical Field

[0001] This utility model belongs to the field of insulation layer technology, and specifically relates to a composite precision insulation layer structure. Background Technology

[0002] In the fields of materials science, semiconductor manufacturing, and electronic device manufacturing, alumina (Al2O3) thin films are crucial insulating materials due to their high dielectric constant and excellent insulating properties. They are widely used in the manufacturing process of electronic devices to effectively prevent current leakage and improve the reliability and stability of these devices. Traditionally, alumina (Al2O3) is prepared using atomic deposition (ALD) systems. A single precursor source, such as water-based H2O or ozone-based O3, reacts with trimethylaluminum (TMAl) to generate alumina (b) on top of the substrate (a). Figure 1 However, such methods have the following drawbacks:

[0003] 1. Insufficient insulation performance: Alumina films prepared with water-based precursors have poor density. Under positive low current drive, micropores or defects are easily formed inside the film, which leads to a decrease in voltage withstand capability, positive leakage current phenomenon, and reduced device reliability.

[0004] 2. Optical Performance Limitations: The refractive index of a single-layer alumina film is uniform and cannot meet the requirements of light-emitting devices for controlling the refraction or reflection of light. For example, alumina is one of the important insulating layers in LED chip fabrication. For products with light emanating from the electrode surface, a relatively low refractive index is required to facilitate the divergence of light from the quantum well. For products with light emanating from the substrate surface, a higher reflectivity is required. However, a single-layer film cannot achieve multi-layer progressive stacking of refractive indices to achieve maximum light extraction efficiency, nor can it achieve multi-layer interference effects similar to Bragg reflection.

[0005] 3. Mass production cost issues: Although the alumina film formed by ozone and trimethylaluminum effectively overcomes the above-mentioned problem of forward leakage, the preparation cost is high and an ozone generator is required to prepare the film, which is not conducive to mass production and promotion. Utility Model Content

[0006] This invention addresses the problems in the background art by providing a composite precision insulating layer structure to improve the insulation and optical performance of products.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A composite precision insulating layer structure is provided, which employs an atomic deposition system. The first layer uses a precursor source and a metal source to form a high refractive index layer; the second layer uses a precursor source and a metal source to form a low refractive index layer; the third to Nth layers use precursor sources to alternately form a periodic refractive index gradient structure, wherein the total number of layers N≧3, the thickness of a single layer is λ / (4n), where λ is the target modulation wavelength and n is the refractive index of the film layer.

[0009] Furthermore, the precursor source includes, but is not limited to, water-based (H2O), ozone-based (O3), or hydrogen peroxide-based (H2O2).

[0010] Preferably, the first layer uses an ozone-based precursor source, the second layer uses a water-based precursor source, and the third to N layers use ozone-based and water-based precursor sources alternately to form a periodic refractive index gradient structure.

[0011] Furthermore, the metal source includes, but is not limited to, trimethylaluminum (TMAl3) or tetramethylethylaminohafnium (TEMAH).

[0012] Furthermore, the high refractive index layer material is aluminum oxide (Al2O3), hafnium oxide (HfO2), or titanium oxide (TiO2), and the low refractive index layer material is combined with silicon dioxide (SiO2), magnesium fluoride (MgF2), or magnesium oxide (MgO).

[0013] Preferably, the periodic refractive index gradient structure has 5-20 alternating periods, and the total film thickness is 50-200 nm.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This invention employs three or more alternating stacks, enabling the formation of high and low refractive index films through insulating layers created by different precursor sources, thus creating a Bragg structure and improving reflectivity. Furthermore, the third layer onwards forms a periodic refractive index gradient structure, which facilitates the control of light leakage and light reflection by the light-emitting device. Attached Figure Description

[0016] Figure 1 This is a diagram of a traditional membrane structure.

[0017] Figure 2 This is a structural diagram of the membrane layer of this utility model.

[0018] Figure 3 This is a diagram illustrating the steps involved in the cavity growth process of this utility model.

[0019] Figure 4 This is a comparison chart of low-current drive voltages.

[0020] Figure 5 A comparison chart of reflectivity for different alumina stacking structures. Detailed Implementation

[0021] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0022] The specific implementation steps of the composite precision insulating layer structure of this utility model are as follows:

[0023] 1. For example Figure 1 The atomic deposition system (ALD) is used. The first layer uses an ozone precursor source and trimethylaluminum to form a high-refractive-index alumina layer. The second layer uses a water-based precursor source and trimethylaluminum to form a low-refractive-index alumina layer. The third to Nth layers use ozone and water-based precursor sources alternately to form a periodic refractive index gradient structure. The total number of layers N≧3, and the thickness of a single layer is λ / (4n), where λ is the target control wavelength and n is the refractive index of the film. The required reflectivity is set in the required light emission band of 380nm-700nm for film design using simulation tools such as Macleod or TFcalc.

[0024] 2. The periodic refractive index gradient structure consists of 5-20 alternating periods, with a total film thickness of 50-200 nm.

[0025] 3. The cavity growth procedure is as follows: Figure 3 :

[0026] 3.1) Purge the cavity with 1200 sccm of inert gas (nitrogen was used in this case) for 600-1200 seconds and preheat to 200°C;

[0027] 3.2) Trimethylaluminum was introduced through nitrogen carrier gas for 0.4 seconds, with the nitrogen flow rate set to 200 sccm;

[0028] 3.3) Purge with nitrogen for 9 seconds at a flow rate of 1200 sccm;

[0029] 3.4) The precursor ozone is introduced into the cavity through the carrier gas nitrogen for 6 seconds, and the nitrogen flow rate is set to 200 sccm.

[0030] 3.5) Purge with nitrogen for 9 seconds at a flow rate of 1200 sccm;

[0031] Steps 3.2) to 3.5) constitute the first cycle, completing the initial ozone-oxygenated alumina deposition. The summarized formula is as follows:

[0032]

[0033] 3.6) The precursor water-based material is introduced into the cavity through carrier nitrogen for 0.3 seconds, with a nitrogen flow rate of 200 sccm;

[0034] 3.7) Purge with nitrogen for 6 seconds at a flow rate of 1200 sccm;

[0035] 3.8) Trimethylaluminum was introduced through nitrogen carrier gas for 0.4 seconds, with the nitrogen flow rate set to 200 sccm;

[0036] 3.9) Purge with nitrogen for 6 seconds at a flow rate of 1200 sccm;

[0037] Steps 3.6) to 3.9) constitute the second cycle, completing the second layer of water-based alumina deposition. The summarized formula is as follows:

[0038]

[0039] 3.10) The first and second cycles are repeated 10 times to form the desired film properties and target thickness (120 nm in this case).

[0040]

[0041] In the above formula, t represents time and Q represents gas flow rate.

[0042] The alumina film invented in this invention can be used as a composite insulating layer in chip structures such as upright, flip, and vertical, taking into account both insulation properties and improved optical performance. For example, in this case, the starting voltage of the LED chip with three crystal strings can be 0.02-0.04V higher than that of the conventional structure under a small current of 1mA.

[0043] Experimental comparison:

[0044] Implementation Case 1: ALD Deposition of Water-Based Alumina Thin Films

[0045] Process parameters:

[0046] 1. Precursor combination: Trimethylaluminum (TMA) + deionized water (H2O);

[0047] 2. Reaction chamber temperature: 200℃;

[0048] 3. Purge gas: Nitrogen (N2);

[0049] Specific steps:

[0050] 1. Precursor source introduction: H2O vapor is introduced into the chamber through N2 carrier gas (flow rate 200 sccm) with a pulse duration of 0.3 seconds;

[0051] 2. First purging: Stop the H2O supply, maintain the N2 flow rate at 1200 sccm and purge for 9 seconds to thoroughly remove residual H2O and byproducts;

[0052] 3. Metal precursor introduction: Switch to TMA source and deliver TMA vapor through N2 carrier gas (flow rate 200 sccm) with a pulse time of 0.4 seconds;

[0053] 4. Second purging: Stop TMA supply, restore N2 flow rate to 1200 sccm and purge for 9 seconds to remove unreacted TMA and byproducts;

[0054] 5. Cyclic control: Repeat the above steps for 50-1000 cycles, with a film thickness range of 50-200 nm;

[0055] 6. Thin film characteristics: refractive index 1.63@633nm, film thickness 120nm, intra-film thickness uniformity <1%;

[0056] 7. Product electrical performance: Under a drive current of 1mA, the voltage performance of the 3-series products is 9.443V;

[0057] Implementation Case 2: Ozone-Oxide Alumina Thin Film ALD Deposition

[0058] Process parameters:

[0059] 1. Oxidizing agent replacement: Deionized water (H2O) → Ozone (O3, concentration 200g / m³) 3 );

[0060] 2. The remaining parameters are the same as in Case 1;

[0061] Specific steps:

[0062] 1. Introduction of metal precursor: The TMA source is introduced into the chamber through N2 carrier gas (flow rate 200 sccm) with a pulse duration of 0.4 seconds;

[0063] 2. First purging: Stop the TMA supply, maintain an N2 flow rate of 1200 sccm and purge for 9 seconds to remove unreacted TMA and byproducts;

[0064] 3. Precursor source introduction: Switch to O3 source, and deliver O3 vapor through N2 carrier gas (flow rate 200 sccm) for 6 seconds;

[0065] 4. Second purging: Stop the TMA supply, restore the N2 flow rate to 1200 sccm and purge for 9 seconds to thoroughly remove residues and byproducts;

[0066] 5. Cyclic control: Repeat the above steps for 50-1000 cycles, with a film thickness range of 50-200 nm;

[0067] 6. Thin film characteristics: refractive index 1.65@633nm, film thickness 120nm, intra-film thickness uniformity <1%;

[0068] 7. Product electrical performance: Under a drive current of 1mA, the voltage performance of the 3-series products is 9.462V;

[0069] Implementation Case 3: ALD deposition with a two-layer structure consisting of an ozone-based alumina layer and a water-based alumina layer.

[0070] Process parameters:

[0071] 1. Precursor assembly:

[0072] a) First layer: Trimethylaluminum (TMA) + ozone (O3);

[0073] b) Second layer: Trimethylaluminum (TMA) + deionized water (H2O);

[0074] 2. Reaction chamber temperature: 200℃

[0075] 3. Purge gas: Nitrogen (N2)

[0076] Specific steps:

[0077] 1. Introduction of metal precursor: TMA vapor is introduced into the chamber through N2 carrier gas (flow rate 200 sccm) with a pulse time of 0.4 seconds;

[0078] 2. First purging: Stop the TMA supply, maintain an N2 flow rate of 1200 sccm and purge for 9 seconds to remove unreacted TMA and byproducts;

[0079] 3. Precursor source introduction: Switch to ozone source, and deliver O3 vapor through N2 carrier gas (flow rate 200 sccm) for 6 seconds;

[0080] 4. Second purging: Stop the O3 supply, restore the N2 flow rate to 1200 sccm and purge for 9 seconds to thoroughly remove residual O3 and byproducts;

[0081] 5. Second precursor source introduction: H2O vapor is introduced into the chamber through N2 carrier gas (flow rate 200 sccm) with a pulse duration of 0.3 seconds;

[0082] 6. Third purging: Stop the H2O supply, maintain the N2 flow rate at 1200 sccm and purge for 9 seconds to thoroughly remove residual H2O and byproducts;

[0083] 7. Metal precursor introduction: Switch to TMA source and deliver TMA vapor through N2 carrier gas (flow rate 200 sccm) with a pulse time of 0.4 seconds;

[0084] 8. Fourth purging: Stop TMA supply, restore N2 flow rate of 1200 sccm and purge for 9 seconds to remove unreacted TMA and byproducts;

[0085] 9. Cyclic control: Repeat the above steps for 25-500 cycles, with a film thickness range of 50-200 nm;

[0086] 10. Thin film characteristics: film thickness 120nm, intra-wafer thickness uniformity <1%;

[0087] Compared to Implementation Case 1: The difference lies in the poor insulation properties of single-layer water-based alumina film, resulting in poor voltage performance of the light-emitting element under low current drive, and potential reliability issues caused by forward leakage. Figure 4 .

[0088] Comparison with Case Study 2: The difference lies in the stronger oxidizing power of ozone, resulting in better insulation properties of the prepared single-layer ozone-oxygenated alumina film, which helps improve the reliability of the light-emitting element. However, it has higher equipment hardware requirements, necessitating the addition of an ozone generator. Generating the required concentration of ozone consumes a large amount of oxygen, causing the price of single-wafer growth to increase by 80%, which is not conducive to industrial-scale production.

[0089] Comparison with Case Study 3: The difference lies in the fact that while the double-layer alumina structure balances insulation properties and mass production costs, when applied to light-emitting devices such as LEDs and lasers, it does not utilize a periodic stacking structure. Therefore, its reflectivity at the required emission wavelength is poor, which is detrimental to the optical performance of the light-emitting device. Reflectivity data is as follows... Figure 5 .

[0090] In summary, through comparison of the embodiments, this structure has the following characteristics:

[0091] 1. Improved electrical performance and component reliability: This invention uses a combination of ozone and trimethylaluminum in the first layer, which, compared to the preparation of the first layer based on pure water, effectively improves the voltage performance under forward low current drive, meaning a reduction in forward leakage current. The voltage performance of the product under low current is improved by 0.01-0.02V, and the yield is improved by 0.5-2%.

[0092] 2. Significant improvement in optical performance: This invention can obtain thin films with different refractive indices by reacting alumina with different precursors. Verified by ellipsometer testing, by adjusting the reaction temperature (200-400℃) and deposition rate (0.5-2 nm / s), the refractive index of the thin film at a wavelength of 550 nm can be precisely controlled within the range of 1.6±0.03 to 1.7±0.03. By designing the thickness of the multilayer film at the required emission wavelength through the difference between high and low refractive indices, the total internal reflection effect of the thin film can be improved, and the efficiency of light output can be improved by 0.3-0.5% for different light-emitting element product structures.

[0093] 3. Cost reduction: This invention uses a coating method that combines ozone and water-based materials, which balances reliability and reduces production costs. Compared with the consumption of ozone materials throughout the entire process, the cross-incorporation of water-based materials can effectively reduce input costs.

Claims

1. A composite precision insulating layer structure, employing an atomic deposition system, characterized by: The first layer uses a precursor source and a metal source to form a high refractive index layer; the second layer uses a precursor source and a metal source to form a low refractive index layer; the third layer to the Nth layer uses a precursor source to alternately form a periodic refractive index gradient structure, wherein the total number of layers N≧3, the thickness of a single layer is λ / (4n), λ is the target control wavelength, and n is the refractive index of the film layer.

2. A composite precision insulation layer structure as claimed in claim 1, characterized in that: The precursor source includes but is not limited to water-based, ozone-based or hydrogen peroxide-based.

3. A composite precision insulation layer structure as claimed in claim 2, characterized in that: The first layer uses an ozone-based precursor source, the second layer uses a water-based precursor source, and the third layer to the Nth layer uses an ozone-based and water-based precursor source to alternately form a periodic refractive index gradient structure.

4. A composite precision insulation layer structure as claimed in any one of claims 1 to 3, characterized in that: The metal source includes but is not limited to trimethylaluminum or tetramethyl ethylamine hafnium.

5. A composite precision insulation layer structure as claimed in claim 4, characterized in that: The high refractive index layer material is aluminum oxide, hafnium oxide, or titanium oxide, and the low refractive index layer material is combined with silicon dioxide, magnesium fluoride or magnesium oxide.

6. The composite precision insulation layer structure of claim 1, wherein: The periodic refractive index gradient structure is 5-20 alternating periods, and the total film thickness is 50-200 nm.

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