Chemical corrosive agent for preparing micro-nano pattern on surface of single crystal diamond and corrosion method

Abstract

The invention discloses a chemical corrosive agent for preparing a micro-nano pattern on the surface of a single crystal diamond and a corrosion method. Comprising the following steps: performing surface treatment on the monocrystal diamond, and performing rough polishing and fine polishing by adopting mechanical polishing; preparing a chemical corrosive agent, wherein the chemical corrosive agent comprises rare earth oxide, a solvent, a dispersing agent and an oxidizing agent; the polished sample is placed in a corrosive agent, and machining conditions are set; and the corroded sample is subjected to ultrasonic cleaning and drying, and the monocrystal diamond containing the surface micro-nano pattern is obtained. The chemical corrosion process disclosed by the invention has the advantages of high selectivity, high uniformity and no mechanical damage, accurate regulation and control on the surface appearance of the monocrystal diamond can be realized, and a reliable preparation means is provided for the fields of high-performance optoelectronic devices, quantum chips, micro-nano sensors and the like. The method is simple and convenient in process, controllable in cost, suitable for efficient preparation of the single crystal diamond micro-nano structure and wide in application prospect.

Description

Technical Field

[0001] The present invention relates to a chemical etchant and an etching method for preparing micro-nano patterns on the surface of single-crystal diamond, belonging to the technical field of diamond processing. Background Art

[0002] Single-crystal diamond has wide applications in the fields of micro-nano optics, quantum computing, microelectronic devices, and high-end sensors due to its extremely high hardness, excellent thermal conductivity, wide bandgap, high chemical stability, and low friction coefficient. However, its extremely high physical and chemical stability also makes the processing of surface micro-nano structures extremely difficult. Traditional mechanical processing methods are prone to introducing damage and difficult to achieve high-precision patterning, which limits the application of diamond in high-end fields such as microelectromechanical systems (MEMS).

[0003] Currently, diamond micro-nano processing technologies mainly include laser etching, reactive ion etching (RIE), and chemical etching methods. Although laser etching can achieve high-resolution patterns, the equipment cost is high and the thermal effect is prone to cause material phase change or cracks; the RIE technology relies on complex masks and vacuum environments, the process steps are cumbersome, and the requirements for equipment are strict. In contrast, the chemical etching method has attracted much attention due to its advantages such as low cost and large-area processing. However, its core challenges are as follows: 1. Insufficient adaptability of the etchant: Traditional etchants have significant differences in the etching rates of different crystal planes of diamond, resulting in poor pattern uniformity, and high-temperature (>200°C) or high-pressure conditions are required, and the process is complex; 2. The contradiction between precision and efficiency: Existing etchants are difficult to balance the etching rate and selectivity. The efficiency is low at low concentrations, and over-etching is easily caused at high concentrations, affecting the edge clarity of micro-nano structures; 3. Environmental and operation limitations: Strong acid systems produce toxic by-products, and the waste liquid treatment is complex, which does not conform to the trend of green manufacturing. To address the above problems, developing a new type of chemical etchant and supporting methods that can achieve high-precision and isotropic controllable etching on the diamond surface under mild conditions, while taking into account environmental protection and process compatibility, has become the key to breaking through the bottleneck of diamond micro-nano processing. The present invention optimizes the etchant components and process parameters, significantly improving the patterning efficiency and quality, and providing technical support for the large-scale preparation of diamond devices. Summary of the Invention

[0004] In view of the above problems, the present invention provides a chemical etchant for preparing micro-nano patterns on the surface of single-crystal diamond, which includes rare earth oxides, a solvent, a dispersant, and an oxidant; the concentration of rare earth oxides is 5 - 15 g / L, the concentration of the dispersant is 5 - 15 ml / L or 0.5 - 3 g / L, and the concentration of the oxidant is 0.05 - 0.5 mol / L.

[0005] The etching method using the chemical etchant for preparing micro-nano patterns on the surface of single-crystal diamond includes the following steps: Step 1: Select a single-crystal diamond sample, fix the crystal plane to be processed, and perform rough polishing and fine polishing on the single-crystal diamond by mechanical polishing; Step 2: Prepare a chemical etchant; Step 3: Place the polished sample in the chemical etchant and maintain magnetic stirring; Step 4: Ultrasonically clean the sample, place it in a drying oven for drying treatment, and micro-nano patterns can be formed on the surface of the sample; In Step 1, the abrasive used for rough polishing during the mechanical polishing process is diamond micropowder with a particle size of 10 - 30 μm, and the rotational speed of the polishing disc is 2000 - 3000 r / min; the abrasive used for fine polishing is diamond micropowder with a particle size of 0.5 - 3 μm, and the rotational speed of the polishing disc is 200 - 2000 r / min.

[0006] In Step 2, the rare earth oxide used to prepare the chemical etchant is one or several of cerium oxide, erbium oxide, ytterbium oxide, and lanthanum oxide, with a particle size of 50 - 500 nm.

[0007] In Step 2, the solvent used to prepare the chemical etchant is deionized water.

[0008] In Step 2, the dispersant used to prepare the chemical etchant is sodium dodecyl sulfate (SDS), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), sodium hexametaphosphate, water glass, or a combination thereof.

[0009] In Step 2, the oxidant used to prepare the chemical etchant is Fenton's reagent (H 2 O 2 +FeSO 4 ), H 2 O 2 KNO 3 K 2 FeO 4 KMNO 4 K 2 Cr 2 O 7 One of them.

[0010] The rotational speed of magnetic stirring in Step 3 is 100 - 500 r / min, and the time is 1 - 3 h.

[0011] In Step 4, the reagents for cleaning the sample are 0.5 - 5 mol / L dilute hydrochloric acid, absolute ethanol, and deionized water in sequence. Description of the Drawings

[0012] In order to make the content of the present invention easier to be clearly understood, the present invention will be further described in detail below according to specific embodiments in conjunction with the drawings, where: The present invention is further described in detail as follows: Figure 1This is the SEM image of the original single crystal diamond surface; Figure 2 This is the SEM image of the chemically etched single crystal diamond (110) surface of the present invention. DETAILED DESCRIPTION

[0013] The technical solution of the present invention is further specifically described below through specific embodiments, but the present invention is not limited to these embodiments. Example

[0014] This embodiment provides a chemical etchant and an etching method for preparing a micro-nano pattern on the surface of a single crystal diamond, comprising the following steps: A single crystal diamond sample was selected, the (100) crystal plane of the surface to be processed was fixed, and mechanical polishing equipment was used for rough polishing and fine polishing. During rough polishing, the rotation speed of the polishing disk was 2500 r / min, and the abrasive was 10 μm diamond powder; during fine polishing, the rotation speed of the polishing disk was 500 r / min, and the abrasive was 1.5 μm diamond powder.

[0015] Prepare chemical etchant. Take 395 ml of deionized water, add 5 ml of polyethylene glycol dispersant, mix well, add 3 g of cerium oxide, the average particle size of cerium oxide is 100 nm, mix well, add 50 ml of 30% H 2 O 2 and 50ml of 0.5mol / L FeSO 4 , maintain magnetic stirring during the preparation process to obtain the chemical corrosive agent.

[0016] The polished single crystal diamond was placed in a chemical corrosive agent, stirred at a magnetic stirring speed of 200 r / min for 2 h for corrosion treatment.

[0017] The chemically etched samples were cleaned with 1 mol / L dilute hydrochloric acid, anhydrous ethanol, and deionized water ultrasonically in sequence. The cleaned samples were placed in a drying oven to dry, and single crystal diamonds with micro-nano patterns on the surface were obtained. Figure 2 .

[0018] Embodiment 1

[0019] This embodiment provides a chemical etchant and an etching method for preparing a micro-nano pattern on the surface of a single crystal diamond, comprising the following steps: A single crystal diamond sample was selected, and the (110) crystal plane of the surface to be processed was fixed. Mechanical polishing equipment was used for rough polishing and fine polishing. During rough polishing, the rotation speed of the polishing disk was 2000 r / min, and the abrasive was 8 μm diamond micropowder; during fine polishing, the rotation speed of the polishing disk was 1000 r / min, and the abrasive was 1 μm diamond micropowder.

[0020] Prepare a chemical etchant. Take 395 ml of deionized water, add 1 g of sodium hexametaphosphate, mix well and then add 3 g of ytterbium oxide with an average particle size of 100 nm. After thorough mixing, add 50 ml of 30% H 2 O 2 and 50 ml of FeSO with a concentration of 0.5 mol / L. Keep magnetic stirring during the preparation process to obtain the chemical etchant. 4 Put the polished single-crystal diamond into the chemical etchant, stir magnetically at a speed of 200 r / min for 2 h for etching treatment.

[0021] Ultrasonically clean the chemically etched sample successively with 1 mol / L dilute hydrochloric acid, absolute ethanol, and deionized water. Place the cleaned sample in a drying oven to dry, and a single-crystal diamond with micro-nano patterns on its surface can be obtained.

[0022] Example 2

[0023] This example provides a chemical etchant and an etching method for preparing micro-nano patterns on the surface of single-crystal diamond, including the following steps:

[0024] Select a single-crystal diamond sample, fix the (111) crystal plane of the surface to be processed, and perform rough polishing and fine polishing using a mechanical polishing device. During rough polishing, the rotation speed of the polishing disc is 3000 r / min, and the abrasive is diamond micropowder with a particle size of 10 μm; during fine polishing, the rotation speed of the polishing disc is 1500 r / min, and the abrasive is diamond micropowder with a particle size of 2 μm. Prepare a chemical etchant. Take 500 ml of deionized water, add 1 g of sodium hexametaphosphate, mix well and then add 5 g of erbium oxide with an average particle size of 80 nm. After thorough mixing, keep magnetic stirring during the preparation process to obtain the chemical etchant.

[0025] Put the polished single-crystal diamond into the chemical etchant, stir magnetically at a speed of 200 r / min for 2 h for etching treatment.

[0026] Ultrasonically clean the chemically etched sample successively with 1 mol / L dilute hydrochloric acid, absolute ethanol, and deionized water. Place the cleaned sample in a drying oven to dry, and a single-crystal diamond with micro-nano patterns on its surface can be obtained.

[0027] ​

Claims

1. A chemical etchant for preparing micro-nano patterns on the surface of single crystal diamond, characterized in that The chemical corrosive agent comprises rare earth oxide, solvent, dispersant and oxidant; the concentration of the rare earth oxide is 5-15 g / L, the concentration of the dispersant is 5-15 ml / L or 0.5-3 g / L, and the concentration of the oxidant is 0.05-0.5 mol / L.

2. A method for etching a single crystal diamond surface micro-nano pattern using a chemical etchant as claimed in claim 1, characterized in that: The following steps are involved: Step 1, selecting a single crystal diamond sample, fixing the crystal surface to be processed, and performing rough polishing and fine polishing on the single crystal diamond by mechanical polishing; Step 2, preparing a chemical etchant; Step 3, placing the polished sample in a chemical etchant and maintaining magnetic stirring; Step 4, ultrasonically clean the sample and place it in a drying oven for drying, so as to form a micro-nano pattern on the surface of the sample.

3. The etching method according to claim 2, characterized in that: In step 1, the abrasive used for rough polishing in the mechanical polishing process is 10~30μm diamond powder, and the polishing disk speed is 2000~3000r / min; the abrasive used for fine polishing is 0.5~3μm diamond powder, and the polishing disk speed is 200~2000r / min.

4. The etching method according to claim 2, characterized in that: In step 2, the rare earth oxide used in preparing the chemical etchant is one or more of cerium oxide, erbium oxide, ytterbium oxide and lanthanum oxide, and the particle size is 50-500 nm.

5. The etching method according to claim 2, characterized in that: In step 2, the solvent used to prepare the chemical etchant is deionized water.

6. The etching method according to claim 2, characterized in that: In step 2, the dispersant used in preparing the chemical etchant is sodium dodecyl sulfate (SDS), polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG), sodium hexametaphosphate, water glass or a combination thereof.

7. The etching method according to claim 2, characterized in that: In step 2, the oxidant used in preparing the chemical etchant is one of Fenton's reagent (H2O2+FeSO4), H2O2, KNO3, K2FeO4, KMNO4, and K2Cr2O7.

8. The etching method according to claim 2, characterized in that: The magnetic stirring speed in step 3 is 100~500r / min, and the time is 1~3h.

9. The etching method according to claim 2, characterized in that: The reagents for cleaning the sample in step 4 are 0.5-5 mol / L dilute hydrochloric acid, anhydrous ethanol, and deionized water, respectively.

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