TWI830295B - Nanocolloidal particles, preparation methods, cleaning agents and cleaning methods containing the same - Google Patents

Abstract

The invention provides a nano-colloid particle, a preparation method, an application, a cleaning agent containing the nano-colloid particle, a preparation method, a cleaning method, etc. The nano-colloid particle includes nano-silica, a colloidal stabilizer and silica adsorbent, and the cleaning agent includes the nanocolloidal particles, pH adjuster, surfactant, wetting agent and ultrapure water. The nanocolloidal particles have excellent stability and cleaning effect, and are particularly suitable for cleaning hard and brittle material surfaces such as silicon wafers, sapphire substrate wafers, optical grade glass, gallium arsenide substrate wafers, precision ceramics, etc., and have broad applications. Prospects and replacement potential.

Description

Nanocolloidal particles, preparation methods, cleaning agents and cleaning methods containing the same

The present invention relates to a supramolecular system formed by inorganic compounds and organic compounds and its preparation method and application. More particularly, it relates to a nano-colloid particle formed from nano-silica and a hydrophilic polymer compound and its preparation method. It also relates to The nano-colloid particles are used for surface cleaning of a variety of hard and brittle materials, and further relate to a cleaning agent containing the nano-colloid particles and a cleaning method using the cleaning agent, which belongs to the field of new cleaning agents and the field of surface treatment technology for hard and brittle materials.

Hard and brittle materials such as sapphire are crystal materials with good thermal conductivity and light transmittance. They have excellent dielectric properties, high wear resistance, and good stability at high temperatures. They can be used as GaN-based materials and various Substrate materials for electronic components can be used in the manufacturing process of LED chips. In addition, hard and brittle materials such as silicon wafers are the basic material of chips. Sapphire crystals are also commonly used as guidance windows and laser devices in military precision-guided weapons. In the field of precision instruments, they are used as precision optical devices, lenses, dials, etc., while arsenic Gallium substrates can be used in high-frequency communications, wireless networks and optoelectronics. Optical grade glass can be used in optical communications, precision guided weapons and other fields. Precision ceramics can be used to make circuit substrates, rocket nose cones, high-voltage insulating porcelain, etc. In short, hard and brittle materials have very wide applications in many high-tech fields.

These hard and brittle materials, such as sapphire substrates, silicon wafers, gallium arsenide substrates, etc., require cutting, grinding, polishing and other processes during precision processing. Suspending agents, diamond liquid, etc. are required during the grinding process. A variety of fine chemicals and many different types of polishing fluids are used in the polishing process. Therefore, ground powder particles, metal impurities from the grinding disc, residual polishing fluid, and inorganic and/or organic pollution will remain on the surface and fine grooves of hard and brittle materials after thinning, surface polishing and other processes. These substances are mixed together to produce pollutants after polishing. In addition, other organic dirt will be introduced during the processing, such as glove marks, fingerprints, etc.

With the development of the industry, the performance requirements for the luminous performance of LED chips and other chips such as circuit chips are also constantly increasing, and the surface quality requirements for various substrates are becoming increasingly stringent. In the existing technology, traditional cleaning methods such as SPM, SC1 or SC2 are mainly used to clean these substrates. The main chemicals involved are mainly prepared from inorganic strong acids (such as concentrated sulfuric acid, HF or HCl) or ammonia and hydrogen peroxide. Taking the cleaning of sapphire substrates as an example, there are the following existing technologies:

CN102632055A discloses a method for cleaning sapphire substrates, in which the cleaning liquid used is a mixture of ammonia, hydrogen peroxide and water; or a mixture of hydrochloric acid, hydrogen peroxide and water, or a mixture of sulfuric acid and phosphoric acid.

CN103111434A discloses a final cleaning process for sapphire processing (i.e. SPM process). In the cleaning process, phosphoric acid, hydrofluoric acid and ammonia are used for cleaning, and the steps are very cumbersome (see Figure 1).

However, in the SPM cleaning method, although the cleaning agent composed of a mixture of concentrated sulfuric acid and hydrogen peroxide has strong oxidizing and corrosive properties on various types of organic pollutants on the surface of solid materials, it also has a good cleaning effect; at the same time With ultrasonic cleaning technology, most particles, dust and other inorganic attachments on the surface of the material can be removed, but the cleaning effect still needs to be improved. In addition, what is more serious is that this type of cleaning method causes serious environmental pollution due to the use of strong acids and oxidants. As a result, the cost of treating the waste liquid generated by the SPM cleaning process is much higher than the application value of the SPM cleaning agent itself. In addition, it also poses considerable security threats to the operator's personal safety, which also leads to an increase in the cost of safety equipment and a more complicated operation protection process.

In addition to the above cleaning agents and cleaning methods, scientific researchers have also developed various other types of cleaning fluids and/or cleaning methods, such as:

CN103343060A discloses a sapphire substrate wafer cleaning liquid. The cleaning liquid includes amine oxide surfactant, fluorine-containing surfactant, organic sulfonate, fatty alcohol polyoxyethylene polyoxypropylene ether, alkali, complexing agent, particle capture Agent and pure water, which has excellent cleaning ability for sapphire substrate wafers, can completely remove pollutants, and improve the cleanliness of electronic components; in addition, the cleaning solution has many advantages such as simple preparation, low cost, and environmental friendliness. It has broad research value and industrial application prospects.

CN104772313A discloses a method for cleaning coated sapphire wafers, which uses a flat-panel cleaning machine containing an assembly line, a spray device and a roller brush device to clean it. The cleaning steps include step A, detergent roller brush spray cleaning, and step B. , high-temperature pure water spray washing, step C, low-temperature pure water spray washing, step D, air knife blow-drying. It solves the problem in the existing technology that sapphire coating can only be cleaned manually and is difficult to clean. This method improves the cleanliness and production efficiency of sapphire wafer products and avoids the waste of time caused by wiping actions and the effects of organic solvents. pungent smell.

CN106391548A discloses an alkaline cleaning process for sapphire windows. First, the sapphire workpiece is made into a double-sided polished sapphire sheet through cutting, grinding, and polishing, and then the double-sided polished sapphire sheet is finally cleaned. The steps are simple, the preparation is convenient, and the entire cleaning is The process includes two times of weak alkaline environmentally friendly cleaning agent and five times of ultrapure water cleaning. Compared with the original cleaning process, the alkaline cleaning process is more environmentally friendly, has good wafer cleanliness, and is highly safe. The cost is lower, safe and environmentally friendly.

CN110591837A discloses a cleaning agent for sapphire wafers, which includes the following components in parts by weight: 10-18 parts of modified starch, 3-5 parts of potassium carbonate, 9-12 parts of surfactant, and 15-15 parts of sodium citrate. 20 parts, 10-15 parts of metatartaric acid, 25-35 parts of methyl acetate, 1-3 parts of polyethylene glycol, 0.3-0.8 parts of stabilizer, 30-50 parts of borax, 5-10 parts of dibutyl phosphate, remove 30-40 parts of ionized water; the modified starch is composed of starch, methylhydroxypropyl cellulose and nanographene according to a molar ratio of 25-38:1:4-8. The cleaning agent has simple components and low cost. It can clean the residues of various liquids during processing and can effectively reduce the reflection on the sapphire surface. As mentioned above, a variety of sapphire cleaning solutions and cleaning methods are disclosed in the prior art. However, these cleaning solutions and/or cleaning methods still have some defects, such as the components are too complex, which brings great difficulties to the subsequent waste liquid treatment. The cost is high, and the cleaning method is cumbersome and the process is long.

Therefore, the current sapphire cleaning solutions and cleaning methods in the prior art have various defects and are difficult to meet the increasingly demanding cleaning and process requirements. Moreover, with the technological development of the LED industry and the precision processing of sapphire substrate wafers, more stringent and diverse requirements have been put forward for cleaning fluids. The main development requirements and trends are as follows: 1. Achieve a cleaner surface of the wafer with a simpler process High cleanliness cleaning. 2. Improve cleaning efficiency, shorten processing time, and improve production efficiency. 3. It is environmentally friendly, has less waste liquid, and achieves green processing.

Therefore, the development of new hard and brittle materials such as sapphire substrate cleaning agents is currently a technical difficulty and hot spot in this field. The starting point of the present invention is to provide a brand-new cleaning agent that can meet the above technical requirements and trends. The focus and technical innovation points are mainly concentrated on a new type of nano-colloid particles. Through the use of the nano-colloid particles, many achievements have been achieved. Excellent technical effects, breakthrough progress in the field, and good industrialization value.

In order to solve the above-mentioned problems existing in the existing sapphire wafer cleaning technology, comply with the requirements and trends of current technological development, and in order to develop new environmentally friendly cleaning fluids, preparation methods and cleaning processes, the purpose of the present invention is to provide a cleaning solution for hard and brittle material surfaces such as Nano-colloidal particles for sapphire wafer cleaning and their preparation methods and uses, as well as many technical solutions including cleaning compositions and cleaning methods containing the nano-colloidal particles. The cleaning compositions and cleaning methods have the characteristics of high cleaning efficiency, green environmental protection, and large-scale use. It has many excellent effects such as significantly reducing the amount of pollution caused by cleaning waste liquid.

It should be noted that in the present invention, unless otherwise specified, the specific meaning of "including" when it comes to constitutive limitations and descriptions includes both open-ended "includes", "includes", etc. and similar meanings, as well as Closed forms of "consisting of", "consisting of", etc. and similar meanings. Specifically, the present invention specifically includes the following technical solutions.

[First technical solution]

In a first aspect, a technical solution of the present invention is to provide a nanocolloidal particle.

In the nanocolloidal particles of the present invention, the nanocolloidal particles include nanosilica, a silica adsorbent (hereinafter sometimes also referred to as "adsorbent") and a colloidal stabilizer.

In the nanocolloidal particles of the present invention, the particle size of the nanosilica is 1-100 nm, for example, it can be 1 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm The range formed by any two values among , 60 nm, 70 nm, 80 nm, 90 nm, and 100 nm can be, for example, 5-90 nm, 10-80 nm, 20-70 nm, 30-60 nm, etc. , preferably 20-60 nm. In the nanocolloidal particles of the present invention, the colloidal stabilizer is an oligomer of the following formula (1):

in:

R1 is each independently selected from H, -CH ₂ CH ₂ OH or -CH(CH ₃ )OH;

n is the degree of polymerization, which is an integer selected from 10-60.

Among them, for R ₁ "independently selected from" means that each R ₁ in formula (1 can be independently selected from its definition range, and it does not mean that all or multiple R ₁ must be the same.

In the colloidal stabilizer of the above formula (1), the colloidal stabilizer is a known compound, which can be various cellulose compounds, for example, when R ₁ is -H (in this case, formula 1 is a cellulose fragment) , -CH ₂ CH ₂ OH (in this case, Formula 1 is the hydroxyethylcellulose fragment) or -C(CH ₃ )OH (in this case, Formula 1 is the hydroxypropylcellulose fragment). In the nanocolloidal particles of the present invention, the silica adsorbent is any one or a mixture of polyacrylic acid, polymaleic acid, acrylic acid-maleic acid copolymer or acrylic acid-styrene copolymer. .

Wherein, the molecular weight of the silica adsorbent is not strictly limited, for example, it can be (that is, selected from) 2000-20000, and further can be (that is, selected from) 2000, 3000, 4000, 5000, 6000, 7000 , 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, 20000. The range formed by any two numerical values may be, for example, 2000-20000, 5000-15000, 8000-12000, etc. Of course, a narrower or wider molecular weight range can also be obtained by controlling the degree of polymerization. This is a conventional technical means for polymerization reactions in the field of polymers and will not be described in detail here.

As an illustrative example, the structure of the nanocolloidal particles is shown in the following formula (2):

In the formula (2), the colloidal stabilizer is the oligomer of formula (1), and the silica adsorbent is polyacrylic acid. The dashes at both ends of the colloidal stabilizer refer to the repeating units in the colloidal stabilizer. The connection position, n, has the same definition as above.

It should be noted that in formula (2), the dotted lines represent ionic bonds. Among them, when R ₁ is H, then the carboxyl oxygen anion in polyacrylic acid (i.e., O- in -C(O)O-, the same below) is the same as R ₁ (i.e., H) in OR ₁ (i.e., -OH). connected by ionic bonds; and when R1 is -CH ₂ CH ₂ OH or -CH(CH ₃ )OH, the O- in polyacrylic acid is connected with the terminal hydroxyl group of OR ₁ at this time (that is, the terminal - of -OCH ₂ CH ₂ OH The H in OH or -OCH(CH ₃ )OH terminal -OH) are connected by ionic bonds. That is, the oxygen anion (O-) in polyacrylic acid is connected to the H in the terminal hydroxyl group of the colloidal stabilizer in the form of ionic bonds.

Of course, it should be noted that the colloidal stabilizer in the above formula (2) is only an exemplary case, and is not necessarily the case, because in cellulose compounds, hydroxyl, hydroxyethyl or hydroxypropyl groups are present in the sugar base. The distribution may not be like this, but may be different in substitution positions. The above is just one specific example, and it does not mean that it is inevitable and can only be the case. The nanocolloidal particles have good colloidal stability, and when used for cleaning the surface of hard and brittle materials, they have very excellent cleaning effects and can be used in many technical fields such as silicon wafers, sapphire substrate wafers, arsenic wafers, etc. It has good application prospects in the surface cleaning of gallium substrates, optical grade glass and precision ceramics.

[Second technical solution]

In a second aspect, a technical solution of the present invention is to provide the use of the above-mentioned nanocolloidal particles for surface cleaning of hard and brittle materials. Due to their unique structure and cleaning mechanism, the nanocolloidal particles can be used in surface cleaning of hard and brittle material surfaces such as silicon wafers, sapphire substrate wafers, gallium arsenide substrate wafers, optical grade glass and precision ceramics.

[The third technical solution]

In a third aspect, a technical solution of the present invention is to provide a method for preparing the above-mentioned nanocolloidal particles.

The preparation method includes the following steps:

A. Weigh 5-15 parts of nanosilica, 0.01-1 part of colloidal stabilizer, 0.5-4 parts of silica adsorbent and 70-90 parts of ultrapure water in parts by mass, and add the Divide ultrapure water into two equal parts for later use;

B. Add the nano-silica to the first portion of ultrapure water with stirring, then add the silica adsorbent with stirring, continue stirring for 30-60 minutes, and set aside as agent I;

C. Add the colloidal stabilizer to the second portion of ultrapure water under stirring, and keep stirring until the colloidal stabilizer is fully swollen, and set aside as agent II;

D. At a temperature of 25°C, while stirring Agent I, slowly add Agent II, continue stirring until fully uniform, and let stand for 5-10 hours to obtain the nanocolloidal particles. In the preparation method of nanocolloidal particles, the nanosilica, colloidal stabilizer, and silica adsorbent in step A are the corresponding nanosilica described in the first technical solution. , colloidal stabilizer and silica adsorbent. For example, in the preparation method of nanocolloidal particles, the particle size of the nanosilica is 1-100 nm, for example, it can be 1 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, The range formed by any two values of 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, and 100 nm can be, for example, 5-90 nm, 10-80 nm, 20-70 nm, 30-60 nm, etc., preferably 20-60 nm.

For another example, the colloidal stabilizer and silica adsorbent are also described in the first technical solution. For the sake of simplicity, the description will not be repeated. For specific descriptions and various limitations, please refer to the first technical solution. , which will not be described in detail here. In the preparation method of nanocolloidal particles, in step A, the nanosilica is 5-15 parts by mass, for example, it can be 5 parts, 7 parts, 9 parts, 11 parts, 13 parts servings or 15 servings.

In the preparation method of nanocolloidal particles, in step A, the colloidal stabilizer is 0.01-1 part by mass, for example, it can be 0.01 part, 0.02 part, 0.05 part, 0.1 part, 0.2 part, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts or 1 part.

In the preparation method of nanocolloidal particles, in step A, the silica adsorbent is 0.5-4 parts by mass, for example, it can be 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts servings, 3 servings, 3.5 servings or 4 servings.

In the preparation method of nanocolloidal particles, in step A, the ultrapure water is 70-90 parts by mass, for example, it can be 70 parts, 75 parts, 80 parts, 85 parts or 90 parts.

The ultrapure water is deionized water with a resistance of ≥ 18 MΩ. In the preparation method of the present invention, the stirring speed in step B is not particularly strictly limited, as long as the nanosilica and the silica adsorbent can be fully mixed evenly, for example, it can be 40-150 rpm. , further for example, it can be 40 rpm, 50 rpm, 60 rpm, 70 rpm, 80 rpm, 90 rpm, 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm or 150 rpm.

In the preparation method of the present invention, the stirring speed in step C is not particularly strictly limited, as long as the colloidal stabilizer can be fully stirred in ultrapure water to completely swell, for example, it can be 40-150 rpm , further for example, may be 40 rpm, 50 rpm, 60 rpm, 70 rpm, 80 rpm, 90 rpm, 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm or 150 rpm. The stirring time is determined according to the complete swelling. As long as the colloidal stabilizer is fully swollen, the stirring can be stopped or the stirring can be continued for 5-10 minutes. Those skilled in the art can make appropriate selections and determinations after reading this preparation method. , which will not be described in detail here.

In the preparation method of the present invention, the stirring speed in step D is not particularly strictly limited, as long as the agent I and agent II can be fully stirred evenly, for example, it can be 40-150 rpm, and further, it can be 40 rpm. rpm, 50 rpm, 60 rpm, 70 rpm, 80 rpm, 90 rpm, 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm or 150 rpm. The stirring time is not particularly strictly limited, as long as Agent I and Agent II can be fully stirred evenly. Those skilled in the art can make appropriate selections and determinations after reading this preparation method, and will not be described in detail here.

[The fourth technical solution]

In a fourth aspect, a technical solution of the present invention is to provide a cleaning agent for surface cleaning of hard and brittle materials, and a preparation method of the cleaning agent. Among them, the hard and brittle materials can be, for example, silicon wafers, sapphire substrate wafers (sometimes also called "sapphire wafers"), gallium arsenide substrate wafers, optical grade glass, precision ceramics, etc. These materials are usually used in the chip field. High-tech fields such as precision optics (such as missile optical seekers) have extremely high technical requirements and demands for surface cleanliness. Among them, the cleaning agent can be used in the cleaning process after grinding or polishing the above-mentioned hard and brittle materials to remove surface particles and contaminants such as oil, dust, fingerprints, etc.

According to the cleaning agent for surface cleaning of hard and brittle materials of the present invention, the cleaning agent contains the above-mentioned nanocolloidal particles.

According to the cleaning agent for surface cleaning of hard and brittle materials of the present invention, in addition to the nanocolloidal particles, the cleaning agent also contains a pH regulator, a surfactant, a wetting agent and ultrapure water. The cleaning agent used for surface cleaning of hard and brittle materials according to the present invention, as an example, in terms of parts by mass, the cleaning agent includes 2-10 parts of nanocolloidal particles, 5-15 parts of pH regulator, surface 0.1-0.5 parts of active agent, 2-12 parts of wetting agent and 70-90 parts of ultrapure water.

Furthermore, in terms of parts by mass, the nanocolloidal particles are 2-10 parts, for example, they can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts .

Furthermore, in terms of parts by mass, the pH adjuster is 5-15 parts, for example, it can be 5 parts, 7 parts, 9 parts, 11 parts, 13 parts or 15 parts. Furthermore, in terms of parts by mass, the surfactant is 0.1-0.5 parts, for example, it can be 0.1 part, 0.2 part, 0.3 part, 0.4 part or 0.5 part.

Furthermore, in terms of parts by mass, the wetting agent is 2-12 parts, for example, it can be 2 parts, 4 parts, 6 parts, 8 parts, 10 parts or 12 parts.

Furthermore, in terms of parts by mass, the ultrapure water is 70-90 parts, for example, it can be 70 parts, 75 parts, 80 parts, 85 parts or 90 parts.

Wherein, the pH adjuster can be any one of sodium carbonate, potassium carbonate, sodium bicarbonate, KOH, NaOH, tetramethylammonium hydroxide, potassium bicarbonate or a mixture of any more. Wherein, the surfactant can be any one of sodium fatty alcohol polyoxyethylene ether carboxylate (i.e. AEC), sodium fatty alcohol polyoxyethylene ether sulfate (i.e. AES), amine oxide, and acetylene glycol surfactants. .

Among them, sodium fatty alcohol polyoxyethylene ether carboxylate (AEC), fatty alcohol polyoxyethylene ether sodium sulfate (AES) and amine oxide are all very well-known surfactants and can be purchased through a variety of commercial channels. Here A detailed description will not be given.

Among them, acetylenic diol surfactants are also very well-known surfactants, such as dimethylhexynediol (i.e., 2,5-dimethyl-3-hexyne-2,5-diol). , 1-hexyne-1,3-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, etc., which can be easily purchased through a variety of commercial channels. A detailed description will not be given here. Wherein, the wetting agent is a small molecule polyol or a polyether alcohol. For example, the small molecule polyol can be glycerin, neopentyl glycol, diethylene glycol, triethylene glycol, ethylene glycol, isoprene glycol, Any one or any combination of propylene glycol; for example, polyether alcohol can be polyethylene glycol (such as polyethylene glycol 400, polyethylene glycol 600, etc.), polyethylene glycol monomethyl ether (such as polyethylene glycol Alcohol monomethyl ether 2000, etc.) or a combination of the two. Wherein, the ultrapure water is deionized water with a resistance of ≥ 18 MΩ.

According to the preparation method of the cleaning agent for surface cleaning of hard and brittle materials of the present invention, the preparation method includes the following steps:

A1: Weigh the respective mass parts of nanocolloidal particles, pH regulator, surfactant, wetting agent and ultrapure water;

B1: Add each component into the container and stir at room temperature at a stirring speed of 300-1000 rpm for 1-2 hours to obtain the cleaning agent.

Among them, each component in step A1 is as described above and will not be described in detail here.

Wherein, the stirring speed in step B1 is 300-1000 rpm, for example, it can be 300 rpm, 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm or 1000 rpm.

Wherein, the stirring time in step B1 is 1-2 hours, for example, it can be 1 hour, 1.5 hours or 2 hours. According to the cleaning agent for surface cleaning of hard and brittle materials of the present invention, the cleaning agent contains the above-mentioned unique nano-colloidal particles, so it has excellent surface cleaning effect and performance, and is especially suitable for hard and brittle material surfaces such as It is used for surface cleaning of silicon wafers, sapphire substrate wafers, gallium arsenide substrate wafers, optical grade glass and precision ceramics. The cleaning steps are simple and the amount of waste liquid is very small. It achieves green and environmentally friendly cleaning processing and has good industrial application potential and value.

[The fifth technical solution]

In a fifth aspect, a technical solution of the present invention is to provide a surface cleaning method for hard and brittle materials.

According to the surface cleaning method of hard and brittle materials, the surface cleaning method uses the above-mentioned cleaning agent, and its components, content, etc. are as described in the above [Fourth Technical Solution], and will not be repeatedly cited and described here. .

According to the surface cleaning method of the hard and brittle material, the surface cleaning method includes the following steps:

S1: Add the cleaning agent into the cleaning tank, and then put the hard and brittle materials to be cleaned into the cleaning tank;

S2: Turn on the ultrasound and perform ultrasonic cleaning; preferably, the ultrasonic current during ultrasonic cleaning is 1.5-2.5 A, and the ultrasonic cleaning time is 5-10 minutes;

S3: Take out the hard and brittle materials from the cleaning tank, clean them 2-3 times with ultrapure water, and finally vacuum dry them to complete the cleaning method.

According to the surface cleaning method of hard and brittle materials, the hard and brittle material in step S1 is as mentioned above, and can be silicon wafers, sapphire substrate wafers, gallium arsenide substrate wafers, optical grade glass or precision ceramics, etc.

According to the surface cleaning method of hard and brittle materials, the preferred ultrasonic current during cleaning in step S2 is 1.5-2.5 A, for example, it can be 1.5 A, 2 A, or 2.5 A; the preferred ultrasonic cleaning time is 5-10 minutes, for example, it can be be 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes. Of course, the ultrasonic current can also be appropriately increased or reduced, and the cleaning time can be extended or shortened according to the actual situation (such as serious dirt on the surface of hard and brittle materials).

According to the surface cleaning method of hard and brittle materials, the ultrapure water in step S3 is deionized water with a resistance of ≥ 18 MΩ. In the cleaning method of the present invention, excellent cleaning effects are achieved due to the use of a cleaning agent containing the unique nanocolloidal particles. The details can be seen in the subsequent cleaning test, which will not be described in detail here. As mentioned above, the present invention provides a nano-colloidal particle, its preparation method and use, as well as a cleaning agent containing the nano-colloidal particle, a preparation method of the cleaning agent and a method of using the cleaning agent to clean the surface of hard and brittle materials. Cleaning methods, etc., these technical solutions have the following principles and advantages:

1. The pioneering use of nano-silica, silica adsorbent and colloidal stabilizer resulted in the unique structure of the nano-colloidal particles, which are amphiphilic supramolecular systems and can be used in a variety of cleaning environments ( Such as acidic, neutral or alkaline) and maintains excellent stability, it can be used for surface cleaning of a variety of hard and brittle materials, and can achieve excellent surface cleaning effects with ultra-high cleanliness.

2. The nanocolloidal particles of the present invention can be used for surface cleaning of various hard and brittle materials such as silicon wafers, sapphire substrate wafers, gallium arsenide substrate wafers, optical glass, precision ceramics, etc., and can be used with the traditionally used strong acid/strong alkali hydrogen peroxide. Compared with the cleaning process, it can not only eliminate the use of strong acids and alkalis that are highly corrosive, highly polluting, and produce a large amount of waste acid and waste alkali water, thereby eliminating the use of highly polluting and harmful chemicals, and is environmentally friendly and waste-free. The amount of liquid produced is very small, which greatly reduces the cost of waste liquid treatment; it also helps to reduce the use process. The cleaning process is very simple, significantly shortening the operating time and reducing the complexity of the operation, thereby significantly improving the cleaning efficiency and cleaning effect. Excellent.

3. The nanocolloidal particles of the present invention do not contain metal ions and traditional chelating agents. When used, the colloidal stabilizer and silica adsorbent will react with the pH regulator, surfactant, wetting agent and water molecules. Dynamic equilibrium changes occur under the action of comprehensive dilution. The modified nanosilica can be exposed from the colloidal particles and directly contact the surface of the cleaning material, thereby contacting particles and organic dirt adsorbed on the surface of the hard and brittle material. The friction effect of weak van der Waals force causes the pollutants on the surface of the material to quickly and fully combine with the silica molecules, thereby breaking away from the surface of the material, achieving the effect of eluting particles and organic dirt from the surface of the material. In addition, since the molecular structure of the silica adsorbent used contains a large number of carboxylic acid groups, it also has an efficient chelating effect on metal ions. Without the need to add additional chelating agents, it can achieve all kinds of chelating effects on the surface of hard and brittle materials. Complexation of attached impurity metal ions. Moreover, the nanocolloidal ions have good water solubility and strong chelating ability, and have a good cleaning effect regardless of whether they are hard and brittle materials with serious surface metal contamination or materials that require extremely low metal residue after cleaning. .

Therefore, the nanocolloidal particles of the present invention and the cleaning liquid containing them have excellent cleaning effects in many technical fields, especially the field of surface cleaning of hard and brittle materials, and are more environmentally friendly and have very little environmental pressure. The operator's operating requirements and operating environment are also more friendly, and it has good large-scale industrial application value.

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail through specific examples below. However, the use and purpose of these exemplary embodiments are only to illustrate the present invention and are not intended to limit the actual protection scope of the present invention in any form, let alone The scope of protection of the present invention is limited to this.

Among them, in all the preparation examples below, the ultrapure water used is deionized water with a resistance of ≥ 18MΩ.

Preparation Example 1 of Nano Colloidal Particles: Preparation of Nano Colloidal Particles A. In terms of parts by mass, weigh 10 parts of nanosilica (particle size: 20-60 nm) and 0.5 parts of colloidal stabilizer hydroxyethyl cellulose. , 2.25 parts of silica adsorbent polyacrylic acid (molecular weight 5000-12000) and 80 parts of ultrapure water, and divide the ultrapure water into two equal parts (ie, each part is 40 parts by mass) for use;

B. Add the nanosilica to the first portion of ultrapure water with stirring, then add the silica adsorbent with stirring at 100 rpm, and continue stirring for 45 minutes to obtain Agent I, which is ready for use;

C. Add the colloidal stabilizer to the second portion of ultrapure water under stirring, and stir at 100 rpm until the colloidal stabilizer is fully swollen to obtain Agent II, which is ready for use;

D. At a temperature of 25°C, while stirring Agent I at 100 rpm, slowly add Agent II, continue stirring until fully uniform, and let stand for 7.5 hours to obtain the nanocolloidal particles, which are named N1.

Preparation Example 2 of Nanocolloidal Particles: Preparation of Nanocolloidal Particles

A. In terms of parts by mass, weigh 5 parts of nanosilica (particle size: 20-60 nm), 1 part of colloidal stabilizer cellulose, and 0.5 part of silica adsorbent polymaleic acid (molecular weight: 15000- 20000) and 90 parts of ultrapure water, and divide the ultrapure water into two equal parts (ie, each part is 45 parts by mass) for later use;

B. Add the nanosilica to the first portion of ultrapure water with stirring, then add the silica adsorbent with stirring at 100 rpm, and continue stirring for 30 minutes to obtain Agent I, which is ready for use;

C. Add the colloidal stabilizer to the second portion of ultrapure water under stirring, and stir at 100 rpm until the colloidal stabilizer is fully swollen to obtain Agent II, which is ready for use;

D. At a temperature of 25°C, while stirring Agent I at 100 rpm, slowly add Agent II, continue stirring until fully uniform, and let stand for 10 hours to obtain the nanocolloidal particles, which are named N2.

Preparation Example 3 of Nanocolloidal Particles: Preparation of Nanocolloidal Particles

A. In terms of parts by mass, weigh 15 parts of nanosilica (particle size: 20-60 nm), 0.1 part of colloidal stabilizer hydroxypropyl cellulose, and 4 parts of silica adsorbent acrylic acid-maleic acid copolymer (molecular weight is 3000-8000) and 70 parts of ultrapure water, and the ultrapure water is divided into two equal parts (ie, each part is 35 parts by mass) for use;

B. Add the nanosilica to the first portion of ultrapure water with stirring, then add the silica adsorbent with stirring at 100 rpm, and continue stirring for 60 minutes to obtain Agent I, which is ready for use;

C. Add the colloidal stabilizer to the second portion of ultrapure water under stirring, and stir at 100 rpm until the colloidal stabilizer is fully swollen to obtain Agent II, which is ready for use;

D. At a temperature of 25°C, while stirring Agent I at 100 rpm, slowly add Agent II, continue stirring until fully uniform, and let stand for 7.5 hours to obtain the nanocolloidal particles, which are named N3.

Cleaning agent preparation example 1: Preparation of cleaning agent

A1: Weigh the following components separately by mass: 6 parts of nanocolloidal particles N1, 10 parts of pH regulator potassium carbonate, 0.3 parts of surfactant amine oxide, 7 parts of wetting agent glycerol and 80 parts of ultrapure water;

B1: Add each component into the container and stir at room temperature at a stirring speed of 650 rpm for 1.5 hours to obtain a cleaning agent, which is named Q1.

Cleaning agent preparation example 2: Preparation of cleaning agent

A1: Weigh the following components separately by mass: 2 parts of nanocolloidal particles N2, 15 parts of pH adjuster sodium carbonate, 0.1 part of surfactant 2,5-dimethyl-3-hexyne-2,5 -Glycol, 12 parts of wetting agent triethylene glycol and 70 parts of ultrapure water;

B1: Add each component into the container and stir at room temperature at a stirring speed of 300 rpm for 2 hours to obtain a cleaning agent, which is named Q2.

Cleaning agent preparation example 3: Preparation of cleaning agent

A1: Weigh the following components separately by mass: 10 parts of nanocolloidal particles N3, 5 parts of pH regulator tetramethylammonium hydroxide, 0.5 parts of surfactant fatty alcohol polyoxyethylene ether sodium sulfate, 2 parts of moisturizer Wetting agent polyethylene glycol 400 and 90 parts ultrapure water;

B1: Add each component into the container and stir at room temperature at a stirring speed of 1000 rpm for 1 hour to obtain a cleaning agent, which is named Q3.

Spectral characterization, stability testing and cleaning performance testing of nanocolloidal particles

I. Infrared spectrum characterization

Characterization test objects: Nano-silica powder in Step A of Nano-colloidal Particle Preparation Example 1 (its infrared spectrum is a), the composite of the obtained nano-colloidal particles and silica adsorbent polypropylene ( That is, Agent I, whose infrared spectrum is b) and the finally obtained nanocolloidal particle N1 (its infrared spectrum is c). The results are shown in Figure 3:

1. The strong absorption peak near 3421 cm-1 in the b spectrum is the stretching vibration peak of -OH and OH in the associated state on nano-SiO2, but there is no such peak in the a spectrum of nano-SiO ₂ powder, indicating that after In the step B treatment of the adsorbent polyacrylic acid, the silica powder is hydrated to form Si-OH bonds, which is the beginning of the formation of the nanocolloidal particle structure. And the peak intensity in the b spectrum is significantly stronger than the peak intensity in the c spectrum. This is because after being treated with the colloidal stabilizer in step C, Si-OH is wrapped in the overall structure of the particles by the polyacrylic acid backbone and the colloidal stabilizer, thus weakening the peak intensity of Si-OH in the c spectrum.

2. The weak absorption peak near 803 cm ^-1 in the a spectrum is the stretching vibration peak of Si-O, but there is no such peak in b and c. This is due to the combination between SiO ₂ and the adsorbent polyacrylic acid, thus It is caused by the change of the dipole moment of Si-O in SiO ₂ , which proves the recombination between SiO ₂ and the colloidal adsorbent polyacrylic acid.

3. The absorption peak at 1607 cm ^-1 in the b spectrum is the OH bending vibration peak of the silica adsorbent polyacrylic acid after adsorbing trace amounts of water. In comparison, the absorption peak at 1607 cm ^-1 in the c spectrum is significantly weakened. This is because after treatment with a colloidal stabilizer, the OH bending vibration peak of polyacrylic acid is wrapped in the overall structure of the particles by the colloidal stabilizer, which weakens the intensity of the OH peak in the c spectrum.

The I agent formed by nanosilica, silica adsorbent (polymaleic acid and acrylic acid-maleic acid copolymer respectively) and nanosilica used in Preparation Example 2-3 of Nanocolloidal Particles The obtained final corresponding nanocolloidal particles were subjected to infrared spectrum testing. The changes and trends of the corresponding spectral peaks also proved the same results as in 1-3 above, so they will not be listed again.

II. Stability test of nanocolloidal particles

Figure 4 is the TEM micromorphology of the composite (i.e. Agent I) obtained in Step B of Nanocolloidal Particle Preparation Example 1 and the finally obtained Nanocolloidal Particles N1 after standing for 1 day and 30 days, where: 4( 1) is the morphology of the complex and the nanocolloidal particle N1 after standing for 1 day (because the two are highly similar, only one is listed), 4(2) is the morphology of the complex after standing TEM micromorphology after 30 days, 4(3) is the TEM micromorphology of nanocolloidal particles N1 after standing for 30 days.

It can be seen that the colloidal particles of Agent I and nanocolloidal particles N1 after standing for 1 day are spherical, uniformly distributed, without agglomeration, and have an obvious shell-core structure. However, as the storage time increases, at 30 days, Agent I, which has not been treated with the colloidal stabilizer in Step C, has undergone very obvious polymerization. It can be seen that the colloidal particles have significantly agglomerated and no longer appear in a uniformly distributed spherical shape. structure. In contrast, after step C, in which the colloidal stabilizer hydroxyethyl cellulose was added, the microscopic morphology of the nanocolloidal particles N1 remained stable even if it was left standing for 30 days, and no obvious changes occurred. Despite the agglomeration phenomenon, the particles are still uniformly spherical, which shows that the addition of colloidal stabilizer can greatly improve the long-term stability of nanocolloidal particles.

The corresponding I agent and N2 and N3 obtained in Nanocolloidal Particle Preparation Example 2-3 were subjected to the same stability test. The TEM micromorphology is highly similar to Figure 4, so it will not be listed again.

III. Cleaning performance test of nanocolloidal particles

1. Clean the polished sapphire substrate. There is an obvious fingerprint mark remaining on the substrate sheet (see the oval in Figure 5(1)). Use two substrate sheets with fingerprint marks at the same position for testing. , because the two are highly similar, only one is listed). The cleaning method uses SPM cleaning and the cleaning agent Q1 of the present invention for cleaning. Among them: SPM cleaning is carried out in accordance with the sequence of paragraphs 0018-0027 of the prior art CN103111434A specification (see also Figure 2) and its process parameters, and the cleaning method using the cleaning agent Q1 of the present invention includes the following steps:

S1: Add cleaning agent Q1 into the cleaning tank, and then put the sapphire substrate to be cleaned into the cleaning tank;

S2: Turn on the ultrasound, set the ultrasonic current to 2 A, and perform ultrasonic cleaning for 8 minutes;

S3: Take out the sapphire substrate from the cleaning tank and use ultrapure water (resistance ≥ 18 MΩ)

Wash 3 times and finally vacuum dry to complete the cleaning.

It can be seen from Figure 5 that when using SPM cleaning, the process steps are complicated, a large number of materials are used, and a variety of strong acids are used which are highly corrosive, polluting and can produce a large amount of waste liquid. However, the cleaning effect is not satisfactory, which is specifically reflected in the lining. The fingerprint marks on the negative film cannot be completely removed (see Figure 5(2)). When using the cleaning agent Q1 of the present invention for cleaning, not only the process steps are very few, but also only ultrapure water is used, there is no need to use a large amount of acid and alkali, almost no waste liquid is produced, and the time is short and the process is efficient. What is even more remarkable is that the cleaning effect is very excellent, with no fingerprint residue on the substrate (see Figure 5(3)), and ultra-high surface cleanliness is achieved.

When cleaning agents Q2-Q3 are used for cleaning tests, excellent cleaning results with no residue on the surface and ultra-high cleanliness can also be achieved. The results are exactly the same as in Figure 5(3), so they will not be listed again.

2. Clean the polished sapphire substrate. After AOI inspection, it is found that there is a large amount of organic dirt and particles remaining on the substrate at this time (see the multiple ovals in Figure 6(1)); AOI inspection It is an optical detection. The detection process is: by scanning the substrate with light of different wavelengths, substances that are not part of the substrate itself will be displayed in a red pattern, which are inorganic particles and/or metals on the surface of the substrate material. Particulate and/or organic dirt.

Among them, the cleaning method also uses the SPM cleaning in the prior art and the cleaning agent Q1 of the present invention for cleaning, and the SPM cleaning and the cleaning operations of the present invention are exactly the same as the above-mentioned cleaning of fingerprint marks, and will not be repeated here.

It can be seen from Figure 6: There is a large amount of organic dirt and particles on the polished sapphire substrate in Figure 6(1). When SPM is used to clean it, not only the above-mentioned defects also exist (see the above-mentioned cleaning of fingerprint marks for details) (described), and the organic dirt and particles have not been completely removed, and there are still residues (see the two ovals in Figure 6(2)). But surprisingly, when the cleaning agent Q1 of the present invention is used for cleaning, not only does it have many of the advantages of cleaning fingerprint marks mentioned above, but the cleaning effect is very thorough and excellent, and there is no organic dirt or various particle residues on the substrate (see figure) 6(3)), resulting in ultra-high surface cleanliness.

When cleaning agents Q2-Q3 are used for cleaning tests, excellent cleaning results with no residue on the surface and ultra-high cleanliness can also be achieved. The results are exactly the same as in Figure 6(3), so they will not be listed again.

As mentioned above, the present invention provides a nano-colloidal particle, its preparation method and use, as well as a cleaning agent containing the nano-colloidal particle, a preparation method of the cleaning agent and a method of using the cleaning agent to clean the surface of hard and brittle materials. Cleaning methods, etc., the nano-colloid particles are formed by nano-silica, silica adsorbent and colloidal stabilizer to form nano-colloid particles with a unique structure, which have excellent stability, and due to the unique structure, Dynamic changes can occur during cleaning, which can achieve a balance and combination of hydrophilicity and lipophilicity with the surface to be cleaned and various impurities, and then efficiently remove impurities such as particles from the surface, with excellent cleaning effects, especially suitable for hard and brittle surfaces. Surface cleaning of materials such as silicon wafers, sapphire substrates, gallium arsenide substrates, optical glass, precision ceramics, etc.

It should be understood that the purpose of these examples is only to illustrate the present invention and is not intended to limit the scope of the present invention. In addition, it should also be understood that after reading the technical content of the present invention, those skilled in the art can make various changes, modifications and/or variations to the present invention, and all these equivalent forms also fall within the scope of the claims attached to this application. within the limited scope of protection.

The above are only the best possible embodiments of the present invention. Any equivalent changes made by applying the description and patent scope of the present invention should be included in the patent scope of the present invention.

without

Figure 1 is a schematic diagram of the formation principle of the nanocolloidal particles of the present invention. The specific formation principle is as follows: The first stage: The silica nanopowder (shown as a ball in Figure 1) combines with the hydrophobic groups in the silica adsorbent to form a micelle structure in which the silica nanopowder is wrapped inside. : The hydrophilic groups in the adsorbent face outward, causing the silica molecules that are insoluble in water to be dispersed in the water in the form of micelles (see the large ball pointed by the first arrow, whose outer layer is the hydrophilic group facing outward, and The inner layer is a hydrophobic group combined with silica). Second stage: After adding the colloidal stabilizer, due to the very high density of hydroxyl groups in the molecular structure of the colloidal stabilizer, it can further combine with the outward-facing hydrophilic groups on the micelle surface around the micelle, thereby forming a spatial network structure, thus avoiding The agglomeration (i.e. aggregation) or destruction of micelles due to molecular motion ensures the stability of nanocolloidal particles. Figure 2 is the traditional cleaning process flow of sapphire substrate. Figure 3 is the infrared spectrum of the nano-silica powder in the nano-colloidal particle preparation example 1, the composite obtained after the nano-silica and polyacrylic acid are combined, and the final nano-colloidal particle N1, where: a is The infrared spectrum of nano-silica powder, b is the infrared spectrum of the composite obtained after combining nano-silica and polyacrylic acid, and c is the infrared spectrum of the final nano-colloidal particle N1. Among them, the composite of nanosilica and polyacrylic acid (i.e. b) is the composite obtained in step B in nanocolloidal particle preparation example 1 (i.e. agent I). Figure 4 is the TEM micromorphology of the composite (i.e. agent I) obtained in Step B of Nanocolloidal Particle Preparation Example 1 and the final nanocolloidal particle N1 after standing for 1 day and 30 days, where: 4(1) is the morphology of the composite or the nanocolloidal particle N1 after standing for 1 day (because the two are highly similar, only one is listed), 4(2) is the morphology of the complex after standing for 30 days The TEM micromorphology after 4(3) is the TEM micromorphology of the nanocolloidal particle N1 after standing for 30 days. Figure 5 is a diagram showing the fingerprint mark residue detection after cleaning the sapphire substrate using the existing SPM process and the cleaning method of the present invention respectively. Among them, 5(1) is before cleaning, 5(2) is after cleaning with SPM, and 5(3) is after cleaning with cleaning agent Q1 of the present invention. Figure 6 is a detection chart of AOI particles/organic dirt residue after cleaning the sapphire substrate using the existing SPM process and the cleaning method of the present invention respectively. Among them, 6(1) is before cleaning, 6(2) is after cleaning with SPM, and 6(3) is after cleaning with cleaning agent Q1 of the present invention.

Claims (9)

A kind of nano-colloidal particles, the nano-colloidal particles include nano-silica, a colloidal stabilizer and a silica adsorbent; the colloidal stabilizer is an oligomer of the following formula (1):

Wherein: R1 is each independently selected from H, -CH ₂ CH ₂ OH or -CH(CH ₃ )OH; n is the degree of polymerization, which is an integer selected from 10-60; the silica adsorbent is polyacrylic acid, Any one or a mixture of polymaleic acid, acrylic acid-maleic acid copolymer, and acrylic acid-styrene copolymer. The nano-colloidal particles according to claim 1, characterized in that: the particle size of the nano-silica is 1-100 nm. The nano-colloidal particles according to claim 1, characterized in that: the particle size of the nano-silica is 20-60 nm. The nanocolloidal particles described in any one of claims 1 to 3 are used for surface cleaning of hard and brittle materials. A method for preparing nanocolloidal particles as described in any one of claims 1 to 3, the preparation method comprising the following steps: A. Weigh 5-15 parts of nanosilica, 0.01-1 part of colloidal stabilizer, 0.5-4 parts of silica adsorbent and 70-90 parts of ultrapure water in parts by mass, and add the Divide ultrapure water into two equal parts for use; B. Add the nano-silica to the first part of ultrapure water with stirring, then add the silica adsorbent with stirring, and continue stirring for 30-60 minutes , as the I agent for use; C. Add the colloidal stabilizer to the second portion of ultrapure water under stirring, and keep stirring until the colloidal stabilizer is fully swollen, and as the II agent for use; D. at 25°C , during the process of stirring Agent I, slowly add Agent II, then continue stirring until fully uniform, and let stand for 5-10 hours to obtain the nanocolloidal particles. A cleaning agent for surface cleaning of hard and brittle materials, the cleaning agent includes the nanocolloidal particles described in any one of claims 1-4. A preparation method of a cleaning agent as described in claim 6, which preparation method includes the following steps: A1: Weigh respective mass parts of nanocolloidal particles, pH regulator, surfactant, wetting agent and ultrapure water ; B1: Add each component into the container and stir at room temperature at a stirring speed of 300-1000 rpm for 1-2 hours to obtain the cleaning agent. A method for surface cleaning of hard and brittle materials based on the cleaning agent described in claim 6. The surface cleaning method includes the following steps: S1: Add the cleaning agent into the cleaning tank, and then put the hard and brittle materials to be cleaned into the cleaning tank. In the tank; S2: Turn on the ultrasound, set the ultrasonic current to 1.5-2.5A, and perform ultrasonic cleaning for 5-10 minutes; S3: Take out the hard and brittle materials from the cleaning tank, clean them 2-3 times with ultrapure water, and finally vacuum dry them Once dry, the cleaning method is completed. The surface cleaning method according to claim 8, characterized in that: the hard and brittle material in step S1 is silicon wafer, sapphire substrate wafer, gallium arsenide substrate wafer, optical grade glass or precision ceramics.

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