Disclosure of Invention
The invention aims to provide a method for processing an ion-doped gadolinium gallium garnet wafer, which solves the problems mentioned in the background technology.
The purpose of the invention can be realized by the following technical scheme:
a processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
step one, mechanical grinding: placing the GGG coarse wafer in a cast iron disc at room temperature, adding grinding fluid, and mechanically grinding to obtain coarse-ground GGG wafer, wherein the grinding speed is controlled to be 60-65r/min, and the grinding pressure is controlled to be 105-2Grinding for 30-40min, wherein the grinding liquid is obtained by aluminum oxide (with particle size of 4-6 μm) and deionized water through ultrasonic oscillation for 20-30min, and the concentration of the aluminum oxide is 0.05-0.07 g/mL;
step two, mechanical polishing: using IC1000 polishing pad as polishing pad for mechanical polishing, dressing polishing pad, loading rough-ground GGG wafer, flowing mechanical polishing solution, and performing mechanical polishing at room temperature to obtain mechanically polished GGG wafer, wherein the polishing pressure is 125g/cm2The rotation speed of the polishing disc is 60r/min, the polishing time is 20-30min, the flow of mechanical polishing liquid is 4mL/min, the mechanical polishing liquid is obtained by ultrasonically oscillating alumina (the particle size is 1 mu m) and deionized water for 20-30min, and the concentration of the alumina is 0.08 g/mL;
step three, chemical mechanical polishing: adopting a flannelette polishing pad as a polishing pad for chemical mechanical polishing, trimming the flannelette polishing pad, adopting a silica sol polishing solution as a chemical mechanical polishing solution, loading a mechanically polished GGG wafer, then carrying out chemical mechanical polishing at room temperature to obtain an ion-doped gadolinium gallium garnet wafer, and controlling the polishing pressure to be 130g/cm2The rotation speed of the polishing disk is 70r/min, the polishing time is 40-70min, and the flow of the chemical mechanical polishing solution is 6 mL/min.
Further, the processing surface of the GGG wafer is a (111) crystal surface.
Further, the silica sol polishing solution in the third step is prepared by the following steps:
and (2) ultrasonically oscillating the silica sol, the auxiliary agent and deionized water for 15min at room temperature, then adding the abrasive cerium oxide and the auxiliary agent, continuing to ultrasonically oscillate for 30-40min, and finally adjusting the pH value of the solution to 8-8.5 by using citric acid to obtain the silica sol polishing solution.
Further, the adding mass ratio of the silica sol, the auxiliary agent, the deionized water and the cerium oxide is 10-25: 1.5-4.5: 95-115: 5.5-8, and the particle size of the cerium oxide is 0.03-0.06 mu m.
Further, the silica sol is alkaline nano silica sol, the pH value is 9.5-10, the concentration of silicon dioxide in the silica sol is 2-3%, and the particle size is 60-100 nm.
Further, the auxiliary agent is prepared by the following steps:
a1, uniformly mixing pyridine-4-formaldehyde, phenol and glacial acetic acid, slowly dropwise adding a mixed solution of concentrated sulfuric acid and glacial acetic acid while stirring in an ice water bath at 0 ℃, wherein the dropwise adding speed is 2 drops/second, continuously reacting at 0 ℃ and 200-400r/min for 48 hours after the dropwise adding is completed, then pouring ice water, stirring for 50 minutes, filtering, repeatedly washing and filtering a filter cake with the ice water until the filtrate is neutral, and then drying the filter cake in vacuum to constant weight to obtain the phenol derivative, wherein the dosage ratio of the mixed solution of pyridine-4-formaldehyde, phenol, glacial acetic acid, concentrated sulfuric acid and glacial acetic acid is 0.01 mol: 0.025 to 0.03 mol: 10-20 mL: 25-35mL of mixed solution of concentrated sulfuric acid and glacial acetic acid, wherein the mixed solution of the concentrated sulfuric acid and the glacial acetic acid with the mass fraction of 98% is prepared by mixing the concentrated sulfuric acid and the glacial acetic acid according to a volume ratio of 1: 4, mixing the components;
in the A1 reaction, the condensation reaction of para-active hydrogen in phenol and carbon-oxygen double bond of aldehyde group in pyridine-4-formaldehyde under the action of concentrated sulfuric acid is utilized to generate phenol derivative, and the molecular structural formula of the phenol derivative is shown as follows;
a2, adding pentaerythritol and glacial acetic acid into a three-neck flask with a stirrer and a reflux device, stirring uniformly, adding a sodium hydroxide solution to adjust the pH value of the solution to 10-11, then slowly dropwise adding epoxy chloropropane under the stirring state, wherein the dropwise adding speed is 2 drops/second, heating to 55 ℃, stirring for reaction for 6 hours, cooling to room temperature, washing to neutrality with deionized water, and finally drying in vacuum to constant weight to obtain an intermediate product, wherein the molar ratio of pentaerythritol to epoxy chloropropane is 1: 4; uniformly stirring the intermediate product, the phenol derivative and the glacial acetic acid, adding potassium hydroxide, heating to 86 ℃, reacting for 6 hours, stopping the reaction, cooling to 50 ℃, decompressing, steaming, and drying in vacuum to obtain the branched polyphenol, wherein the dosage ratio of the intermediate product, the phenol derivative, the glacial acetic acid and the potassium hydroxide is 0.1 mol: 0.45-0.5 mol: 100 and 250 mL: 6-10 g;
in the A2 reaction, firstly, the ether-forming reaction of chlorohydrocarbon and alcohol under alkaline condition is utilized to form an intermediate product, one mole of the intermediate product contains four moles of epoxy groups, and then the ring-opening reaction of the epoxy groups in the intermediate product and the phenolic hydroxyl groups in the phenol derivatives is utilized to obtain branched polyphenol, wherein the molecular structural formulas of the intermediate product and the branched polyphenol are respectively shown as follows;
intermediate product (2):
a3, uniformly mixing the branched polyphenol and the toluene, slowly dripping chlorohydrocarbon by using a constant-pressure dropping funnel at a dripping speed of 2 drops/second, heating and refluxing for 4 hours, stopping reaction, cooling to room temperature, adding distilled water, filtering, taking filtrate, distilling under reduced pressure, and drying in vacuum to obtain the pyridine quaternary ammonium salt, wherein the dosage ratio of the branched polyphenol to the chlorohydrocarbon is 0.01 mol: 0.045-0.050mol, wherein the chlorohydrocarbon is straight-chain alkane with 8-12 carbon atoms;
in the A3 reaction, the quaternary amination reaction of chlorohydrocarbon to pyridine is utilized to obtain pyridine quaternary ammonium salt, so that the pyridine quaternary ammonium salt has a molecular structural formula shown as follows;
a4, uniformly mixing pyridine quaternary ammonium salt, 3-glycidyl ether oxypropyl trimethoxysilane and a mixed solvent of isopropanol/water (the volume ratio of isopropanol to deionized water is 1.3: 1), adding potassium hydroxide, heating to 88 ℃, stirring for reaction for 6 hours, stopping the reaction, adjusting the solution to be neutral by using hydrochloric acid, adding acetone for precipitation and separation, dissolving and washing a precipitation product by using ethanol, precipitating and separating by using acetone again, and drying in vacuum to obtain an auxiliary agent, wherein the dosage ratio of the pyridine quaternary ammonium salt, the 3-glycidyl ether oxypropyl trimethoxysilane, the mixed solvent and the potassium hydroxide is 0.1 mol: 0.45-0.5 mol: 100 and 250 mL: 6-10 g.
In the A4 reaction, hydroxyl in the pyridine quaternary ammonium salt reacts with epoxy in 3-glycidyl ether oxypropyl trimethoxy silane to graft siloxane into the pyridine quaternary ammonium salt, so that the compatibility of the assistant and silica sol is promoted, and the silica sol polishing solution is dispersed more uniformly and stably.
The invention has the beneficial effects that:
aiming at the problems that the GGG wafer is easy to scratch and deform and difficult to ensure the flatness and the surface quality during grinding and polishing, the invention adopts the process steps of mechanical grinding, mechanical polishing and chemical mechanical polishing to process the GGG wafer, and the surface roughness Ra of the obtained GGG wafer is between 0.2 and 0.4nm and the flatness can reach 290-305nm through the combination of process parameters at each stage;
firstly, processing a GGG wafer by mechanical grinding and polishing, grinding a rough GGG wafer by adopting large-particle alumina in the mechanical grinding stage, utilizing the high speed of removing and finishing the defects on the surface of the wafer by mechanical grinding, shortening the whole process time, but controlling the time of the stage to be 30-40min, and preventing the grinding time from being overlong, and preventing the generation of a large amount of scratches on the surface of the wafer and the deformation and the breakage of the wafer caused by hard grinding materials;
secondly, polishing the rough ground GGG wafer by using mechanical polishing, wherein the ground rough ground GGG wafer is thinner and needs to be processed by more fine operation, but the efficiency problem is also considered, the invention selects mechanical polishing, and continuously processes the rough ground GGG wafer by using a hard abrasive alumina (with the grain diameter of 1 mu m) + IC1000 polishing pad, thereby utilizing the high speed of mechanical polishing, shortening the whole process time, but controlling the period of the stage to be 20-30min, preventing the overlong polishing time and preventing the generation of a large amount of scratches on the surface of the wafer caused by hard abrasive, and the deformation and the breakage of the wafer;
finally, the mechanically polished GGG wafer is processed by chemical mechanical polishing, and the low damage of the chemical mechanical polishing is utilized, so that the high flatness, low roughness and no damage of the surface of the wafer are realized; firstly, replacing a hard abrasive with a cerium oxide soft abrasive in chemical mechanical polishing to improve the low damage of the chemical mechanical polishing; secondly, the flannelette polishing pad is used as a polishing pad for chemical mechanical polishing, so that the low damage of the chemical mechanical polishing is further improved; thirdly, the silica sol polishing solution is used as the polishing solution, so that the use of strong acid or strong alkaline polishing solution is avoided, new defects such as corrosion pits are introduced on the surface of the wafer, and the silica sol polishing solution is used as the colloid polishing solution, so that the low damage of the chemical mechanical polishing is further improved; aiming at the problem that orange peel is caused by the fact that the silicon sol polishing solution has non-uniformity in corrosion on the surface of a GGG wafer in a slightly alkaline environment, the invention introduces an auxiliary agent into the silicon sol polishing solution, molecules of the auxiliary agent have high symmetry, and the molecular structure of the auxiliary agent has pyridine nitrogen, a siloxane chain, a pi bond and a quaternary ammonium salt structure, wherein the quaternary ammonium salt and the siloxane chain endow the silicon sol polishing solution with excellent surface activity, the quaternary ammonium salt has hydrophilicity, and the siloxane chain and the silicon sol have similar silicon-oxygen bond structures, so that the auxiliary agent has good compatibility with the silicon sol, further the silicon sol is promoted to be uniformly dispersed in water, the stability of the silicon sol polishing solution is improved, the chemical mechanical polishing effect is promoted to be stably exerted, and finally, the pyridine nitrogen and the pi bond can jointly act to form a protective film on the surface of the wafer (the formation and the damage of the protective film are a dynamic balance process in the polishing process, namely the protective film is formed on the surface of a crystal to protect abrasive material, the surface of the crystal is chemically corroded, namely a protective film is formed on the surface of the crystal), so that the effect of regulating the corrosion speed of the silica sol polishing solution on the surface of the GGG wafer is achieved, and the orange peel phenomenon is avoided.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
Preparation of an auxiliary agent:
a1, uniformly mixing 0.01mol of pyridine-4-formaldehyde, 0.025mol of phenol and 1mL of glacial acetic acid, slowly dropwise adding a 25mL mixed solution of concentrated sulfuric acid and glacial acetic acid while stirring in an ice water bath at 0 ℃, wherein the dropwise adding speed is 2 drops/second, reacting for 48 hours at 0 ℃ and 200r/min after the dropwise adding is completed, then pouring 50mL of ice water, stirring for 50 minutes, filtering, repeatedly washing and filtering a filter cake with 50mL of ice water until the filtrate is neutral, and then drying the filter cake in vacuum to constant weight to obtain a phenol derivative, wherein the mixed solution of concentrated sulfuric acid and glacial acetic acid is prepared by mixing concentrated sulfuric acid with 98% of mass fraction and glacial acetic acid according to a volume ratio of 1: 4, mixing the components;
a2, adding 0.1mol of pentaerythritol and 50mL of glacial acetic acid into a three-necked bottle with a stirrer and a reflux device, stirring uniformly, adding a sodium hydroxide solution to adjust the pH value of the solution to 10, then slowly dropwise adding 0.4mol of epoxy chloropropane under the stirring state, wherein the dropwise adding speed is 2 drops/second, heating to 55 ℃, stirring for reaction for 6 hours, cooling to room temperature, washing with 50mL of deionized water to be neutral, and finally vacuum-drying at 50 ℃ to constant weight to obtain an intermediate product; 0.1mol of the intermediate product, 0.45mol of phenol derivative and 100mL of glacial acetic acid are uniformly stirred, 6g of potassium hydroxide is added, the mixture is heated to 86 ℃ and reacted for 6 hours, the reaction is stopped, the temperature is reduced to 50 ℃, reduced pressure rotary evaporation is carried out, and vacuum drying is carried out at 50 ℃ to obtain branched polyphenol;
a3, uniformly mixing 0.01mol of branched polyphenol with 30mL of toluene, slowly dripping 0.045mol of chlorohydrocarbon by using a constant-pressure dropping funnel at a dripping speed of 2 drops/second, heating, refluxing for reaction for 4 hours, stopping the reaction, cooling to room temperature, adding distilled water, filtering, taking filtrate, distilling under reduced pressure, and drying in vacuum to obtain the pyridine type quaternary ammonium salt, wherein the chlorohydrocarbon is straight-chain alkane with the carbon atom number of 8;
a4, uniformly mixing 0.1mol of pyridine quaternary ammonium salt, 0.45mol of 3-glycidoxypropyltrimethoxysilane and 100mL of mixed solvent of isopropanol/water (the volume ratio of isopropanol to deionized water is 1.3: 1), adding 6g of potassium hydroxide, heating to 88 ℃, stirring for reacting for 6h, stopping the reaction, adjusting the solution to be neutral by using 0.1M hydrochloric acid, adding 50mL of acetone for precipitation and separation, dissolving and washing a precipitation product by using 50mL of ethanol, precipitating and separating by using 50mL of acetone again, and drying in vacuum to obtain the assistant.
Example 2
Preparation of an auxiliary agent:
a1, uniformly mixing 0.01mol of pyridine-4-formaldehyde, 0.03mol of phenol and 20mL of glacial acetic acid, slowly dropwise adding 35mL of mixed solution of concentrated sulfuric acid and glacial acetic acid while stirring in an ice water bath at 0 ℃, wherein the dropwise adding speed is 2 drops/second, reacting for 48 hours at 0 ℃ and 400r/min after the dropwise adding is completed, then pouring 50mL of ice water, stirring for 50 minutes, filtering, repeatedly washing and filtering a filter cake with 50mL of ice water until the filtrate is neutral, and then drying the filter cake at 50 ℃ in vacuum to constant weight to obtain a phenol derivative, wherein the mixed solution of concentrated sulfuric acid and glacial acetic acid is prepared by mixing 98% mass of concentrated sulfuric acid and glacial acetic acid according to a volume ratio of 1: 4, mixing the components;
a2, adding 0.1mol of pentaerythritol and 50mL of glacial acetic acid into a three-necked bottle with a stirrer and a reflux device, uniformly stirring, adding a sodium hydroxide solution to adjust the pH value of the solution to 11, slowly dropwise adding 0.4mol of epoxy chloropropane under the stirring state, heating to 55 ℃, stirring for reacting for 6 hours, cooling to room temperature, washing with 50mL of deionized water to be neutral, and finally vacuum-drying at 50 ℃ to constant weight to obtain an intermediate product; 0.1mol of the intermediate product, 0.5mol of phenol derivative and 250mL of glacial acetic acid are uniformly stirred, 10g of potassium hydroxide is added, the mixture is heated to 86 ℃ and reacted for 6 hours, the reaction is stopped, the temperature is reduced to 50 ℃, reduced pressure rotary evaporation is carried out, and vacuum drying is carried out at 50 ℃ to obtain branched polyphenol;
a3, uniformly mixing 0.01mol of branched polyphenol with 30mL of toluene, slowly dripping 0.050mol of chlorohydrocarbon by using a constant-pressure dropping funnel at a dripping speed of 2 drops/second, heating and refluxing for reaction for 4 hours, stopping the reaction, cooling to room temperature, adding 30mL of distilled water, filtering, distilling filtrate under reduced pressure, and drying in vacuum at 50 ℃ to obtain pyridine type quaternary ammonium salt, wherein the chlorohydrocarbon is straight-chain alkane with 12 carbon atoms;
a4, uniformly mixing 0.1mol of pyridine quaternary ammonium salt, 0.5mol of 3-glycidyl ether oxy propyl trimethoxy silane and 250mL of mixed solvent of isopropanol/water (the volume ratio of isopropanol to deionized water is 1.3: 1), adding 10g of potassium hydroxide, heating to 88 ℃, stirring for reacting for 6h, stopping the reaction, adjusting the solution to be neutral by using hydrochloric acid, adding 80mL of acetone for precipitation and separation, dissolving and washing a precipitation product by using 80mL of ethanol, precipitating and separating by using 80mL of acetone again, and drying in vacuum at 50 ℃ to obtain the assistant.
Example 3
Preparing a grinding fluid:
the grinding fluid is obtained by ultrasonic oscillation of alumina (with particle size of 4 μm) and deionized water for 20min, and the concentration of alumina is 0.05 g/mL.
Preparing a mechanical polishing solution:
the mechanical polishing solution is obtained by ultrasonic oscillation of alumina (with particle size of 1 μm) and deionized water for 20min, and the concentration of alumina is 0.08 g/mL.
Preparing a silica sol polishing solution:
at room temperature, ultrasonically oscillating silica sol, an auxiliary agent and deionized water for 15min, then adding abrasive cerium oxide and the auxiliary agent, then continuing to ultrasonically oscillate for 30min, and finally adjusting the pH value of the solution to 8 by using citric acid to obtain the silica sol polishing solution, wherein the adding mass ratio of the silica sol, the auxiliary agent, the deionized water and the cerium oxide is 10: 1.5: 95: 5.5, and the particle size of the cerium oxide is 0.03 mu m; the silica sol is alkaline nano silica sol, the pH value is 9.5-10, the concentration of silicon dioxide in the silica sol is 2%, and the particle size is 60-80 nm.
Example 4
Preparing a grinding fluid:
the grinding fluid is obtained by ultrasonic oscillation of alumina (with particle size of 5 μm) and deionized water for 25min, and the concentration of alumina is 0.06 g/mL.
Preparing a mechanical polishing solution:
the mechanical polishing solution is obtained by ultrasonic oscillation of alumina (with particle size of 1 μm) and deionized water for 25min, and the concentration of alumina is 0.08 g/mL.
Preparing a silica sol polishing solution:
at room temperature, ultrasonically oscillating silica sol, an auxiliary agent and deionized water for 15min, then adding abrasive cerium oxide and the auxiliary agent, then continuing to ultrasonically oscillate for 30min, and finally adjusting the pH value of the solution to 8 by using citric acid to obtain the silica sol polishing solution, wherein the adding mass ratio of the silica sol, the auxiliary agent, the deionized water and the cerium oxide is 16: 3: 105: 6, and the particle size of the cerium oxide is 0.04 mu m; the silica sol is alkaline nano silica sol, the pH value is 9.5-10, the concentration of silicon dioxide in the silica sol is 2%, and the particle size is 70-90 nm.
Example 5
The grinding fluid is obtained by ultrasonic oscillation of alumina (particle size is 6 μm) and deionized water for 30min, and the concentration of alumina is 0.07 g/mL.
Preparing a mechanical polishing solution:
the mechanical polishing solution is obtained by ultrasonic oscillation of alumina (with particle size of 1 μm) and deionized water for 30min, and the concentration of alumina is 0.08 g/mL.
Preparing a silica sol polishing solution:
ultrasonically oscillating silica sol, an auxiliary agent and deionized water for 15min at room temperature, then adding an abrasive cerium oxide and the auxiliary agent, continuing to ultrasonically oscillate for 40min, and finally adjusting the pH value of the solution to 8.5 by using citric acid to obtain the silica sol polishing solution; the adding mass ratio of the silica sol, the auxiliary agent, the deionized water and the cerium oxide is 25: 4.5: 115: 8, and the particle size of the cerium oxide is 0.06 mu m; the silica sol is alkaline nano silica sol, the pH value is 9.5-10, the concentration of silicon dioxide in the silica sol is 3%, and the particle size is 80-100 nm.
Example 6
A processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
step one, mechanical grinding: the coarse GGG wafers were placed in a cast iron pan at room temperature, and then the polishing slurry prepared in example 3 was added thereto to conduct mechanical polishing, to thereby obtain coarse GGG wafers, the polishing rate was controlled at 60r/min, and the polishing pressure was controlled at 105g/cm2Grinding for 30 min;
step two, mechanical polishing: using an IC1000 polishing pad as a polishing pad for mechanical polishing and a dresser polishing pad, the coarsely ground GGG wafer was loaded, the mechanical polishing liquid prepared in example 3 was flowed, and then the coarsely ground GGG wafer was mechanically polished at room temperature to obtain a mechanically polished GGG wafer, in which the polishing pressure was 125g/cm2The rotation speed of the polishing disc is 60r/min, the polishing time is 20min, and the flow of the mechanical polishing solution is 4 mL/min;
step three, chemical mechanical polishing: a flannelette polishing pad is adopted as a polishing pad for chemical mechanical polishing and is trimmed, the silica sol polishing solution prepared in the embodiment 3 is adopted as a chemical mechanical polishing solution, a mechanically polished GGG wafer is loaded, then the mechanically polished GGG wafer is subjected to chemical mechanical polishing at room temperature to obtain an ion-doped gadolinium gallium garnet wafer, and the polishing pressure is controlled to be 130g/cm2The rotation speed of the polishing disk is 70r/min, the polishing time is 50min, and the flow of the chemical mechanical polishing solutionThe amount was 6 mL/min.
Example 7
A processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
step one, mechanical grinding: the coarse GGG wafers were placed in a cast iron pan at room temperature, and then the polishing slurry prepared in example 4 was added thereto to conduct mechanical polishing, to thereby obtain coarse GGG wafers, the polishing rate was controlled at 63r/min, and the polishing pressure was controlled at 107g/cm2The grinding time is 35 min;
step two, mechanical polishing: using an IC1000 polishing pad as a polishing pad for mechanical polishing and a dresser polishing pad, the coarsely ground GGG wafer was loaded, the mechanical polishing liquid prepared in example 4 was flowed, and then the coarsely ground GGG wafer was mechanically polished at room temperature to obtain a mechanically polished GGG wafer, in which the polishing pressure was 125g/cm2The rotation speed of the polishing disc is 60r/min, the polishing time is 25min, and the flow of the mechanical polishing solution is 4 mL/min;
step three, chemical mechanical polishing: a flannelette polishing pad is adopted as a polishing pad for chemical mechanical polishing and is trimmed, the silica sol polishing solution prepared in the embodiment 4 is adopted as a chemical mechanical polishing solution, a mechanically polished GGG wafer is loaded, then the mechanically polished GGG wafer is subjected to chemical mechanical polishing at room temperature to obtain an ion-doped gadolinium gallium garnet wafer, and the polishing pressure is controlled to be 130g/cm2The rotation speed of the polishing disk is 70r/min, the polishing time is 50min, and the flow of the chemical mechanical polishing solution is 6 mL/min.
Example 8
A processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
step one, mechanical grinding: the coarse GGG wafers were placed in a cast iron pan at room temperature, and then the polishing slurry prepared in example 5 was added thereto to conduct mechanical polishing, to thereby obtain coarse GGG wafers, the polishing rate was controlled at 63r/min, and the polishing pressure was controlled at 108g/cm2The grinding time is 35 min;
step two, mechanical polishing: using an IC1000 polishing pad as a mechanical polishing pad and a dresser polishing pad, a coarse-ground GGG wafer was loaded and flowed as prepared in example 5Preparing mechanical polishing solution, and mechanically polishing the rough ground GGG wafer at room temperature to obtain a mechanically polished GGG wafer, wherein the polishing pressure is 125g/cm2The rotation speed of the polishing disc is 60r/min, the polishing time is 25min, and the flow of the mechanical polishing solution is 4 mL/min;
step three, chemical mechanical polishing: a flannelette polishing pad is adopted as a polishing pad for chemical mechanical polishing and is trimmed, the silica sol polishing solution prepared in the embodiment 5 is adopted as a chemical mechanical polishing solution, a mechanically polished GGG wafer is loaded, then the mechanically polished GGG wafer is subjected to chemical mechanical polishing at room temperature to obtain an ion-doped gadolinium gallium garnet wafer, and the polishing pressure is controlled to be 130g/cm2The rotation speed of the polishing disk is 70r/min, the polishing time is 70min, and the flow of the chemical mechanical polishing solution is 6 mL/min.
Comparative example 1
Preparing a silica sol polishing solution:
the auxiliary agent in the preparation of the silica sol polishing solution of example 3 was replaced with sodium lauryl sulfate as an emulsifier, and the rest was the same as the preparation of the silica sol polishing solution of comparative example 3.
Comparative example 2
A processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
compared with example 6, the silica sol polishing solution prepared in comparative example 1 was replaced with the silica sol polishing solution.
Comparative example 3
A processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
the mechanical milling operation was deleted compared to example 7, and the rest was the same.
Comparative example 4
A processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
the mechanical polishing operation was deleted compared to example 8, and the rest was the same.
Comparative example 5
A processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
the chemical mechanical polishing operation was deleted compared to example 6, and the rest was the same.
Comparative example 6
A processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
in comparison with example 7, the abrasives alumina in the mechanical grinding operation and the mechanical polishing operation were set to be the same, and alumina having a particle size of 4 μm was used, and the rest was the same, and it was found that the GGG wafer was broken in the mechanical polishing operation.
Comparative example 7
A processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
in comparison with example 8, the abrasives alumina in the mechanical grinding operation and the mechanical polishing operation were set to be the same, and alumina having a particle diameter of 1 μm was used for each, and the rest was the same.
Comparative example 8
A processing method of an ion-doped gadolinium gallium garnet wafer comprises the following steps:
in comparison with example 6, the abrasives in the silica sol polishing solution in the chemical mechanical polishing operation were replaced with 1 μm alumina, and the rest was the same.
Example 9
GGG wafers obtained in examples 6 to 8 and comparative examples 2 to 5 and 7 to 8 were subjected to surface roughness and flatness tests, and the obtained data are shown in Table 1.
TABLE 1
As can be seen from the above table, the GGG wafer obtained by the processing method provided by the invention has the surface roughness Ra of 0.2-0.4nm, the flatness of 290-305nm, and the processing effect is better than that of the processing methods of comparative examples 2-5 and 7-8.
The GGG wafers obtained in comparative example 6 were subjected to AFM testing, and the results are shown in FIG. 1.
The scratches on the GGG wafer obtained in comparative example 7 are shown in fig. 2, with the middle fold for the scale and the inside of the coil for the scratches.
In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The foregoing is merely exemplary and illustrative of the principles of the present invention and various modifications, additions and substitutions of the specific embodiments described herein may be made by those skilled in the art without departing from the principles of the present invention or exceeding the scope of the claims set forth herein.