阅读说明：本技术 一种半球谐振子溅射镀膜均匀性评价装置及评价方法 (Evaluation device and evaluation method for sputtering coating uniformity of hemispherical harmonic oscillator ) 是由 黄帅 王建青 何晓霞 党建军 张培新 柳凯 于 2021-08-03 设计创作，主要内容包括：本发明涉及一种半球谐振子溅射镀膜均匀性评价装置及评价方法,其目的是解决现有半球谐振子溅射镀膜均匀性评价中存在若采用硅片膜层均匀性评价结果来衡量谐振子的膜层均匀性,硅片膜层均匀性无法代表谐振子膜层均匀性,若随批抽取一件谐振子进行破坏,来得到谐振子膜层厚度均匀性,则成本高、效率低,不适合批量化生产的技术问题。该评价装置包括平行镀膜工装和(M×N)个硅片；平行镀膜工装的外形尺寸与待镀半球谐振子的外形尺寸相同,包括中心杆和固连于中心杆上的半球壳体；半球壳体上沿其经线方向均布有M列台阶孔组,每列台阶孔组均布有N个台阶孔；硅片的尺寸与台阶孔的大端尺寸相等；所有硅片分别粘接于各台阶孔内。(The invention relates to a device and a method for evaluating the sputtering coating uniformity of a hemispherical harmonic oscillator, and aims to solve the technical problems that in the existing evaluation of the sputtering coating uniformity of the hemispherical harmonic oscillator, if the film uniformity of the harmonic oscillator is measured by using a silicon wafer film uniformity evaluation result, the film uniformity of the silicon wafer cannot represent the film uniformity of the harmonic oscillator, and if one harmonic oscillator is extracted in batches to be damaged to obtain the film thickness uniformity of the harmonic oscillator, the cost is high, the efficiency is low, and the method is not suitable for batch production. The evaluation device comprises a parallel coating tool and (M multiplied by N) silicon chips; the parallel coating tool has the same overall dimension as that of the hemispherical harmonic oscillator to be coated, and comprises a central rod and a hemispherical shell fixedly connected to the central rod; m rows of step hole groups are uniformly distributed on the hemispherical shell along the meridian direction, and N step holes are uniformly distributed on each row of step hole groups; the size of the silicon chip is equal to the size of the big end of the step hole; all the silicon chips are respectively adhered in the step holes.)

1. The utility model provides a hemisphere harmonic oscillator sputter coating homogeneity evaluation device which characterized in that:

comprises a parallel coating tool (1) and (M multiplied by N) silicon wafers (2); wherein M is more than or equal to 2, and N is more than or equal to 2;

the parallel coating tool (1) is used as a parallel test piece of the semi-spherical harmonic oscillator to be coated, has the same external dimension as that of the semi-spherical harmonic oscillator to be coated, and comprises a central rod and a semi-spherical shell fixedly connected to the central rod;

m rows of step hole groups are uniformly distributed on the hemispherical shell along the meridian direction, N step holes are uniformly distributed on each row of step hole groups, and (M multiplied by N) step holes are formed on the hemispherical shell;

the size of the silicon wafer (2) is equal to that of the big end of the step hole;

the (M multiplied by N) silicon chips (2) are respectively adhered in the (M multiplied by N) step holes.

2. The apparatus for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator according to claim 1, wherein:

the mask is characterized by also comprising 2(M multiplied by N) silicon chip masks (3) which are respectively stuck on the front and back surfaces of the (M multiplied by N) silicon chips (2);

l hollow stripes are uniformly distributed on each silicon chip mask (3); l is more than or equal to 2.

3. The apparatus for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator according to claim 2, wherein:

the front surface and the back surface of the silicon wafer (2) are flat.

4. The apparatus for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator according to claim 3, wherein:

the parallel coating tool (1) is made of metal alloy;

the silicon wafer (2) is pure silicon;

the silicon wafer mask (3) adopts a high-temperature-resistant and non-volatile adhesive tape.

5. The apparatus for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator according to claim 4, wherein:

the parallel coating tool (1) is made of stainless steel.

6. The apparatus for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator according to claim 5, wherein:

the silicon wafer mask (3) adopts a polyimide film adhesive tape.

7. The device for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator according to any one of claims 2 to 6, wherein the value ranges of M, N and L are respectively as follows:

3≤M≤6；3≤N≤5；3≤L≤5。

8. the device for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator according to claim 7, wherein the values of M, N and L are respectively as follows:

M＝4；N＝4；L＝3。

9. a method for evaluating the sputtering coating uniformity of a hemispherical resonator, which is characterized in that the apparatus for evaluating the sputtering coating uniformity of a hemispherical resonator based on any one of claims 1 to 8 comprises the following steps:

1) cleaning all the silicon wafers (2) by adopting an organic solvent to ensure that the surfaces of the silicon wafers (2) are clean and pollution-free;

2) bonding all the cleaned silicon wafers (2) in the step holes of the parallel coating tool (1) by using an adhesive to complete the assembly of the hemispherical harmonic oscillator sputtering coating uniformity evaluation device;

3) taking the hemisphere harmonic oscillator sputtering coating uniformity evaluation device as a parallel test piece, and finishing coating in the same furnace with the hemisphere harmonic oscillator to be coated according to the same installation mode, installation position, spatial motion rule and coating time length as the hemisphere harmonic oscillator to be coated;

4) taking down the silicon wafers (2) which are subjected to film coating, numbering the silicon wafers according to positions in sequence, wherein the numbering is 1#, 2#, 3# … and (MxN) #, and marking the front side and the back side of each silicon wafer (2) at the same time;

5) cleaning all silicon wafers (2) by adopting an organic solvent, and removing residual adhesive to obtain the silicon wafers (2) plated with the film layers;

6) measuring the film thickness of the front and back sides of each silicon wafer (2) obtained in the step 5) by using a step meter, and obtaining and recording film thickness data Xi, i-1, 2,3 …, (M multiplied by N) of the front side of all the silicon wafers (2) and film thickness data Yi, i-1, 2,3 …, (M multiplied by N) of the back side of all the silicon wafers (2);

7) respectively calculating the uniformity value A of the thickness of the whole outer spherical surface film layer of the hemispherical resonator and the uniformity value B of the thickness of the whole inner spherical surface film layer of the hemispherical resonator by the following formulas:

A＝(maxXi-minXi)/(maxXi+minXi)；

B＝(maxYi-minYi)/(maxYi+minYi)；

wherein, max Xi and mix Xi represent the maximum value and the minimum value of the film thickness data Xi respectively; max Yi and mix Yi represent the maximum value and the minimum value of the film thickness data Yi respectively;

8) selecting film thickness data of the front and back surfaces of all the silicon wafers (2) on the same meridian, and evaluating the film uniformity of the inner and outer spherical surfaces of the hemispherical harmonic oscillator along the meridian direction;

selecting film thickness data of the front and back surfaces of all the silicon wafers (2) on the same weft, and evaluating the film uniformity of the inner and outer spherical surfaces of the hemispherical harmonic oscillator along the weft direction;

all the silicon wafers (2) on the same weft refer to all the silicon wafers (2) which are positioned in different rows in the radial direction and are positioned at the same position in the circumferential direction.

10. The method for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator according to claim 9, wherein:

step 2) specifically, adhering silicon wafer masks (3) to the front and back surfaces of all cleaned silicon wafers (2), and adhering all the silicon wafers (2) adhered with the silicon wafer masks (3) to step holes of a parallel coating tool (1) by using an adhesive to complete the assembly of the hemispherical harmonic oscillator sputtering coating uniformity evaluation device;

step 5), specifically, sequentially tearing off the silicon wafer masks (3) on the front and back surfaces of each silicon wafer (2), then cleaning the silicon wafers (2) by adopting an organic solvent, and removing residual adhesive to obtain the silicon wafers (2) plated with the film layers at the positions of the hollow stripes;

and 6) specifically, measuring the thicknesses of the film layers on the front side and the back side of each silicon wafer (2) obtained in the step 5) by using a step meter, calculating the average value of the thicknesses of all the film layers on the front side of each silicon wafer (2), obtaining and recording film layer thickness data Xi, i being 1,2,3 …, (M multiplied by N) of all the front sides of the silicon wafers (2), and calculating the average value of the thicknesses of all the film layers on the back side of each silicon wafer (2), obtaining and recording film layer thickness data Yi, i being 1,2,3 …, (M multiplied by N) of all the back sides of the silicon wafers (2).

Technical Field

The invention relates to a hemispherical harmonic oscillator, in particular to a device and a method for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator.

Background

The hemispherical resonator gyroscope has the characteristics of high precision, high reliability, long service life, small volume, irradiation resistance and the like, and becomes a research hotspot in the field of inertial instruments. The fused quartz harmonic oscillator is a core part of a hemispherical resonator gyroscope, is generally of a psi type, and is mainly characterized in that the harmonic oscillator comprises a hemispherical shell and a central anchor rod. In order to ensure the electrostatic excitation efficiency of the harmonic oscillator, the surface of the hemispherical resonator is metallized. The film coating is mainly carried out on the surface of the whole harmonic oscillator except the hemispherical lip edge, and the lip edge is positioned between the inner surface and the outer surface of the harmonic oscillator to play an insulating role. Generally, a sputtering coating technology is adopted to coat the hemispherical harmonic oscillator, and the coating technology has the advantages of high film forming uniformity, strong film-substrate binding force, compact film layer, small internal stress and the like, and is a coating technology with high technical maturity and wide application.

The frequency cracking value (frequency difference) is a key index for measuring the performance of the harmonic oscillator and directly influences the drift precision of the hemispherical resonant gyroscope. When the harmonic oscillator is in vibration with frequency of about several kilohertz in a working state, after the harmonic oscillator is metalized (metallized and plated), the nonuniformity of a metal film layer can cause the axial asymmetry of the mass of the harmonic oscillator, thereby increasing the frequency difference and the loss. Therefore, the harmonic oscillator metallization coating process should keep the early-stage characteristic of the harmonic oscillator, namely low frequency difference, as much as possible, which requires that the coating process should ensure that the film layer has high uniformity.

The harmonic oscillator belongs to a hemispherical thin-wall part, the coating thickness is about hundreds of nanometers, the film thickness of the harmonic oscillator needs to be directly measured without damaging the part, the difficulty is high, and how to realize accurate evaluation of the sputtering coating uniformity of the harmonic oscillator becomes the key work of research in the field.

At present, there are two main methods for evaluating the uniformity of harmonic oscillator sputter coating:

one method is that during the process of coating the harmonic oscillator, a plane silicon wafer is placed in the same furnace, after coating is finished, the thickness and the uniformity of the film of the silicon wafer are evaluated, and the film uniformity of the harmonic oscillator is measured according to the evaluation result of the film uniformity of the silicon wafer. This method has a drawback that the evaluation result is particularly inaccurate. As the harmonic oscillator belongs to a special-shaped part and has a more complex structure than a silicon wafer, the difference between the motion tracks, sputtering distances and the like of each coating part of the silicon wafer and the harmonic oscillator in the coating process is large, so that the difference between the film state of the silicon wafer and the film state of the harmonic oscillator exists, and finally, the uniformity of the film layer of the silicon wafer cannot represent the uniformity of the film layer of the harmonic oscillator.

And the other method is that after the harmonic oscillators finish film coating, one harmonic oscillator is randomly inspected in batch to be damaged, the film coating part of the harmonic oscillator to be evaluated is selected, a section is cut out by using a focused ion beam, and the thickness of a film layer of the section is tested by matching with a scanning electron microscope, so that the uniformity of the film layer of the harmonic oscillator is obtained. The method needs to destroy one harmonic oscillator in each batch, needs to cut a plurality of sections by using a focused ion beam, can accurately evaluate the uniformity of the harmonic oscillator film layer, but has high cost and low efficiency, and is not suitable for batch production.

Disclosure of Invention

The invention aims to solve the technical problems that in the existing evaluation of the sputtering coating uniformity of hemispherical harmonic oscillators, if the film uniformity of harmonic oscillators is measured by using a silicon wafer film uniformity evaluation result, the film uniformity of the silicon wafer cannot represent the film uniformity of the harmonic oscillators, and if one harmonic oscillator is extracted in batches to be damaged, the film thickness uniformity of the harmonic oscillators is obtained, the cost is high, the efficiency is low, and the evaluation device and the evaluation method are not suitable for batch production.

The invention conception is as follows:

by designing a parallel coating tool with the same overall dimension as that of the harmonic oscillator to be coated and arranging a certain number of silicon wafers on the parallel coating tool, coating thickness data of different parts of the harmonic oscillator are correspondingly obtained by testing the coating thicknesses of the silicon wafers distributed at different positions on the parallel coating tool, and accurate evaluation of the uniformity of the surface film layer of the harmonic oscillator is realized at low cost.

In order to solve the technical problems, the technical solution provided by the invention is as follows:

a hemisphere harmonic oscillator sputtering coating uniformity evaluation device is characterized in that:

comprises a parallel coating tool and (M multiplied by N) silicon chips; wherein M is more than or equal to 2, and N is more than or equal to 2;

the parallel coating tool is used as a parallel test piece of the hemispherical harmonic oscillator to be coated, has the same external dimension as that of the hemispherical harmonic oscillator to be coated, and comprises a central rod and a hemispherical shell fixedly connected to the central rod;

m rows of step hole groups are uniformly distributed on the hemispherical shell along the meridian direction, N step holes are uniformly distributed on each row of step hole groups, and (M multiplied by N) step holes are formed on the hemispherical shell;

the size of the silicon wafer is equal to that of the big end of the step hole;

the (M multiplied by N) silicon chips are respectively adhered in the (M multiplied by N) step holes.

Furthermore, the mask also comprises 2(M multiplied by N) silicon chip masks which are respectively stuck on the front and back surfaces of the (M multiplied by N) silicon chips;

l hollow stripes are uniformly distributed on each silicon chip mask; l is more than or equal to 2.

Furthermore, the front surface and the back surface of the silicon wafer are flat.

Further, the parallel coating tool is made of metal alloy;

the silicon wafer is pure silicon;

the silicon chip mask adopts a high-temperature resistant and non-volatile adhesive tape.

Further, the parallel coating tool is made of stainless steel.

Further, the silicon wafer mask adopts a polyimide film adhesive tape.

Further, the value ranges of M, N and L are respectively:

3≤M≤6；3≤N≤5；3≤L≤5。

further, the values of M, N and L are respectively:

M＝4；N＝4；L＝3。

meanwhile, the invention also provides a method for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator, which is characterized in that the device for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator comprises the following steps:

1) cleaning all silicon wafers by adopting an organic solvent to ensure that the surfaces of the silicon wafers are clean and pollution-free;

2) bonding all the cleaned silicon wafers in each step hole of the parallel coating tool by using an adhesive to complete the assembly of the hemispherical harmonic oscillator sputtering coating uniformity evaluation device;

3) taking the hemisphere harmonic oscillator sputtering coating uniformity evaluation device as a parallel test piece, and finishing coating in the same furnace with the hemisphere harmonic oscillator to be coated according to the same installation mode, installation position, spatial motion rule and coating time length as the hemisphere harmonic oscillator to be coated;

4) taking down the silicon wafers after film coating, numbering the silicon wafers according to positions in sequence, wherein the numbers are 1#, 2#, 3# … and (MxN) #, and marking the front side and the back side of each silicon wafer;

5) cleaning all silicon wafers by using an organic solvent, and removing residual adhesive to obtain the silicon wafers plated with the film layers;

6) measuring the film thickness of the front and back sides of each silicon wafer obtained in the step 5) by using a step profiler, and obtaining and recording film thickness data Xi, i of the front sides of all the silicon wafers is 1,2,3 …, (M multiplied by N), and film thickness data Yi, i of the back sides of all the silicon wafers is 1,2,3 …, (M multiplied by N);

7) respectively calculating the uniformity value A of the thickness of the whole outer spherical surface film layer of the hemispherical resonator and the uniformity value B of the thickness of the whole inner spherical surface film layer of the hemispherical resonator by the following formulas:

A＝(max Xi-min Xi)/(max Xi+min Xi)；

B＝(max Yi-min Yi)/(max Yi+min Yi)；

wherein, max Xi and mix Xi represent the maximum value and the minimum value of the film thickness data Xi respectively;

max Yi and mix Yi represent the maximum value and the minimum value of the film thickness data Yi respectively;

8) selecting film thickness data of the front and back surfaces of all silicon wafers on the same warp, and evaluating the film uniformity of the inner and outer spherical surfaces of the hemispherical harmonic oscillator along the warp direction;

selecting film thickness data of the front and back surfaces of all silicon wafers on the same weft, and evaluating the film uniformity of the inner and outer spherical surfaces of the hemispherical harmonic oscillator along the weft direction;

all the silicon wafers on the same weft refer to all the silicon wafers which are positioned in different rows in the radial direction but are positioned at the same position in the circumferential direction.

Further, the step 2) specifically comprises the steps of adhering silicon wafer masks to the front and back surfaces of all cleaned silicon wafers, adhering all the silicon wafers adhered with the silicon wafer masks to step holes of a parallel coating tool by using an adhesive, and completing the assembly of the hemispherical harmonic oscillator sputtering coating uniformity evaluation device;

step 5) specifically, sequentially tearing off silicon wafer masks on the front side and the back side of each silicon wafer, cleaning the silicon wafers by adopting an organic solvent, and removing residual adhesive to obtain the silicon wafers plated with the film layers at the positions of the hollow stripes;

step 6) specifically, measuring the thicknesses of the film layers on the front and back surfaces of each silicon wafer obtained in the step 5) by using a step profiler, calculating the average value of the thicknesses of all the film layers on the front surface of each silicon wafer to obtain and record film layer thickness data Xi, i being 1,2,3 …, (M × N) of all the front surfaces of the silicon wafers, and calculating the average value of the thicknesses of all the film layers on the back surface of each silicon wafer to obtain and record film layer thickness data Yi, i being 1,2,3 …, (M × N) of all the back surfaces of the silicon wafers.

Compared with the prior art, the invention has the following beneficial effects:

1. compared with the existing evaluation method for the uniformity of the film layers of the plane silicon wafers placed in the same furnace and the harmonic oscillators in the same batch, the evaluation device and the evaluation method for the sputtering film coating uniformity of the hemispherical harmonic oscillators provided by the invention have the advantages that a certain number of silicon wafers are distributed on the parallel film coating tool, the film coating thickness data of different parts on the front side and the back side of the harmonic oscillator are obtained by measuring the film coating thickness of the silicon wafers distributed on different positions of the parallel film coating tool, the accurate measurement of the harmonic oscillator film layers is indirectly realized, the evaluation precision of the sputtering film coating uniformity of the inner surface and the outer surface of the hemispherical harmonic oscillator is further improved, the evaluation cost is reduced, the parallel film coating tool can be repeatedly used, only the silicon wafers need to be replaced when the hemispherical harmonic oscillator is reused, the operation method is simple, the cost is further reduced, and the efficiency is improved.

2. The method for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator provided by the invention utilizes the step profiler to carry out high-precision measurement on the thickness of the film layer, has small measurement error, realizes accurate evaluation on the uniformity of the film layer, and can be widely applied to evaluation on the coating uniformity of special-shaped parts in the fields of aerospace and the like.

3. According to the device and the method for evaluating the sputtering coating uniformity of the hemispherical harmonic oscillator, a mask method is adopted, hollow stripes are distributed on a silicon wafer mask, coating of partial areas of the silicon wafer is achieved, coating of partial areas is not achieved, the purposes that a plurality of data are obtained through one-time testing, and the average value of the plurality of data is obtained to reflect the thickness of the film more accurately are achieved.

Drawings

FIG. 1 is a top view of a parallel plating tool in an embodiment of the invention;

FIG. 2 is a cross-sectional view of a parallel plating tool in an embodiment of the invention;

FIG. 3 is a schematic structural diagram of a silicon wafer mask according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a silicon wafer with silicon wafer masks adhered to both sides thereof according to an embodiment of the present invention;

FIG. 5 is a cross-sectional view of the parallel coating tool after a silicon wafer is mounted thereon, wherein a silicon wafer mask is attached to the silicon wafer;

FIG. 6 is a schematic structural diagram of a silicon wafer with a plated film on the front surface according to an embodiment of the present invention;

description of reference numerals:

1-parallel coating tool; 2-a silicon wafer; 3-silicon wafer mask.

Detailed Description

The invention is further described below with reference to the figures and examples.

A device for evaluating the sputtering coating uniformity of a hemispherical harmonic oscillator comprises 1 and 16 (M multiplied by N can be (M multiplied by N) parallel coating tools, wherein M is more than or equal to 2, N is more than or equal to 2, preferably, M is more than or equal to 3 and less than or equal to 6, N is more than or equal to 3 and less than or equal to 5) round silicon wafers 2 and 32 (2 (M multiplied by N) silicon wafer masks 3 (in a round grid shape), as shown in figures 1 to 6. Wherein, the silicon chip 2 is made of pure silicon, has a standard circular shape, and has flat front and back surfaces; the silicon wafer masks 3 are made of high-temperature-resistant and non-volatile adhesive tapes such as polyimide film adhesive tapes, and 32 silicon wafer masks 3 are respectively adhered to the front and back surfaces of 16 silicon wafers 2; each silicon wafer mask 3 is uniformly distributed with 3 (more than 2, such as 3-5, preferably 3) hollow stripes.

The parallel coating tool 1 is used as a parallel test piece of the hemispherical harmonic oscillator to be coated, has the same external dimension as that of the hemispherical harmonic oscillator to be coated, comprises a central rod and a hemispherical shell fixedly connected to the central rod, is made of a material different from quartz glass of the harmonic oscillator, can be made of metal alloy which is easy to process, such as stainless steel, and is fixed on a sputtering coating equipment clamp through the central rod during coating.

The hemisphere casing is gone up along its warp direction equipartition and is had 4 rows of step punch combination (distribute in 0 °, 90 °, 180 °, 270 four longitude line positions on hemisphere casing sphere), and every row of step punch combination equipartition has 4 step holes, forms 16 circular shape step holes on the hemisphere casing, and the primary action in step hole is: the front side and the back side of the silicon wafer 2 after film coating are effectively distinguished through the film coating area of the silicon wafer 2; the size of the silicon wafer 2 is equal to that of the big end of the step hole; and 16 silicon wafers 2 are respectively adhered in the 16 step holes.

A method for evaluating the sputtering coating uniformity of a hemispherical harmonic oscillator comprises the following steps of:

1) cleaning all the silicon wafers 2 by using an organic solvent to ensure that the surfaces of the silicon wafers 2 are clean and pollution-free;

2) the front and back surfaces of all the cleaned silicon wafers 2 are pasted with silicon wafer masks 3 to ensure reliable adhesion, the silicon wafer masks 3 are used for shielding the silicon wafers 2, after film coating, partial area film coating and partial area film non-coating of the silicon wafers 2 are realized, and a film layer thickness step is formed, so that the film layer thickness is accurately measured by a step instrument; then, all the silicon wafers 2 adhered with the silicon wafer masks 3 are adhered to the step holes of the parallel coating tool 1 by using an adhesive, and the assembly of the hemispherical harmonic oscillator sputtering coating uniformity evaluation device is completed;

3) the method comprises the following steps of taking a hemisphere harmonic oscillator sputtering coating uniformity evaluation device as a parallel test piece, placing the parallel test piece in sputtering coating equipment, ensuring that the coating parameters of the parallel test piece and a hemisphere harmonic oscillator to be coated are completely consistent in the coating process, wherein the parameters comprise the same installation mode, installation position, spatial motion rule, coating duration and the like, and the hemisphere harmonic oscillator to be coated and the same batch of hemisphere harmonic oscillator to be coated are coated in the same furnace;

4) taking down the silicon wafers 2 after film coating, numbering the silicon wafers according to positions in sequence, wherein the numbering is 1#, 2#, 3# … and 16#, and marking the front and back surfaces of each silicon wafer 2;

5) sequentially tearing off the silicon wafer masks 3 on the front side and the back side of each silicon wafer 2, cleaning the silicon wafers 2 by using an organic solvent, and removing residual adhesives, wherein the step can effectively eliminate the influence of the residual on the measurement precision of the silicon wafer 2 surface, reduce the film thickness measurement error, and obtain the silicon wafer 2 plated with the film layer at the hollow stripe position;

6) measuring the thicknesses of 3 film layers on the front side and the back side of each silicon wafer 2 obtained in the step 5) by using a step profiler, calculating the average value of the thicknesses of 3 film layers on the front side of each silicon wafer 2 to obtain and record film layer thickness data Xi, i is 1,2,3 …, (M × N) on the front side of all the silicon wafers 2, calculating the average value of the thicknesses of 3 film layers on the back side of each silicon wafer 2 to obtain and record film layer thickness data Yi, i is 1,2,3 …, (M × N) on the back side of all the silicon wafers 2, and reducing measurement errors and improving evaluation accuracy by taking the average value as a film thickness data to record;

7) calculating the uniformity value A of the thickness of the whole external spherical surface film layer of the hemispherical harmonic oscillator by the following formula:

A＝(max Xi-min Xi)/(max Xi+min Xi)；

wherein, max Xi and mix Xi represent the maximum value and the minimum value of the film thickness data Xi respectively;

calculating the uniformity value B of the thickness of the whole inner spherical surface film layer of the hemispherical harmonic oscillator by the following formula:

B＝(max Yi-min Yi)/(max Yi+min Yi)；

wherein max Yi and mix Yi represent the maximum value and the minimum value of the film thickness data Yi respectively;

8) selecting film thickness data of the front and back surfaces of all silicon wafers 2 (for example, 1#, 2#, 3#, 4# silicon wafers) on the same meridian, and evaluating the film uniformity of the inner and outer spherical surfaces of the hemispherical harmonic oscillator along the meridian direction;

selecting film thickness data of the front and back surfaces of all silicon wafers 2 (for example, 4#, 8#, 12# and 16# silicon wafers) on the same weft, and evaluating the film uniformity of the inner and outer spherical surfaces of the hemispherical harmonic oscillator along the weft direction;

all the silicon wafers 2 on the same weft refer to all the silicon wafers 2 which are located in different rows in the radial direction but are located at the same position in the circumferential direction.

Of course, the silicon wafer mask 3 is not needed, accordingly, after film coating, the front side and the back side of the silicon wafer are provided with a complete film layer, one film layer thickness data can be measured through a step profiler and used for the step 7), and the operation of averaging is not needed.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, and it is obvious for a person skilled in the art to modify the specific technical solutions described in the foregoing embodiments or to substitute part of the technical features, and these modifications or substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions protected by the present invention.