CN112255717A - Method for correcting reticle errors caused by surface type errors of grating blanks - Google Patents

Method for correcting reticle errors caused by surface type errors of grating blanks Download PDF

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CN112255717A
CN112255717A CN202011137813.7A CN202011137813A CN112255717A CN 112255717 A CN112255717 A CN 112255717A CN 202011137813 A CN202011137813 A CN 202011137813A CN 112255717 A CN112255717 A CN 112255717A
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grating
error
blank
scribing
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CN112255717B (en
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糜小涛
张善文
齐向东
江思博
林雨
周敬萱
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Changchun Institute of Optics Fine Mechanics and Physics of CAS
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    • G02B5/1852Manufacturing methods using mechanical means, e.g. ruling with diamond tool, moulding

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Abstract

本发明提供了一种光栅毛坯的面型误差引起的刻线误差的校正方法,属于衍射光栅的制备技术领域,本发明的校正方法首先测量出待刻光栅毛坯的面型误差,然后求得光栅毛坯面型所引起的刻线误差矩阵,并将之写入光栅刻划程序中,最后在光栅刻划时通过微定位控制来校正光栅毛坯的面型误差引起的刻线误差。本发明的光栅毛坯的面型误差引起的刻线误差的校正方法,对光栅基底的加工质量和镀膜机的尺寸、镀膜机自身均匀性的要求不高,大大降低了光栅刻划毛坯的制作难度和对镀膜机的要求,不受光栅基底的加工水平和镀膜工艺水平的限制,尤其是对于大尺寸光栅而言,更容易获得较高的波前质量。

Figure 202011137813

The invention provides a method for calibrating the scribe line error caused by the surface error of the grating blank, which belongs to the technical field of diffraction grating preparation. The grating error matrix caused by the surface shape of the blank is written into the grating scribing program, and finally the grating blank is corrected by the micro-positioning control during grating scribing. The method for correcting the scribe line error caused by the surface error of the grating blank of the present invention does not have high requirements on the processing quality of the grating substrate, the size of the coating machine, and the uniformity of the coating machine itself, and greatly reduces the difficulty of making the grating scribe blank. And the requirements for the coating machine are not limited by the processing level of the grating substrate and the coating technology level, especially for large-sized gratings, it is easier to obtain higher wavefront quality.

Figure 202011137813

Description

Method for correcting reticle errors caused by surface type errors of grating blanks
Technical Field
The invention relates to the technical field of diffraction grating preparation, in particular to a method for correcting a scribing error caused by a surface type error of a grating blank.
Background
The mechanical etching method is one of the main methods for manufacturing a grating master plate, and gratings with deep groove depth, high diffraction efficiency and strict groove requirements, such as infrared gratings and most echelle gratings, are generally manufactured by the mechanical etching method. The surface shape error of the grating blank directly affects the position error of grating lines and further affects the diffraction wavefront quality of the grating, and the measurement, correction and control are required.
Factors influencing the surface shape error of the grating blank mainly comprise the processing quality of the surface shape of the grating substrate and the uniformity of the film layer. In the prior art, the processing quality of the surface type of the grating substrate is mainly ensured by optical processing, the processing cost and difficulty are higher when the size is larger, and the surface type of the grating substrate with the diameter larger than 500mm is difficult to be processed to be better than lambda/6 (@632.8 nm). In addition, the uniformity of the grating film layer is mainly ensured by adjusting the parameters of a film coating machine, especially the coating of the large-size echelle grating film layer, the grating size is large, the film layer is 10 microns or more, large-size coating equipment is needed, the required cost is high, the parameters of the film coating machine need to be repeatedly adjusted in order to obtain the optimal value of the film coating uniformity, however, for the film layer with the size larger than 500mm and the film layer thickness larger than 10 microns, the uniformity of the film coating machine hardly reaches the index requirement superior to 0.5%.
Therefore, a new method for correcting the scribing error caused by the processing quality of the grating substrate surface type and the uniformity of the film layer is needed to solve the above problems.
Disclosure of Invention
The invention aims to provide a method for correcting a scribing error caused by a surface type error of a grating blank, aiming at the defects in the prior art, and solving the problems of high cost, high difficulty, difficulty in reaching a higher level and the like in the correction method in the prior art.
The object of the invention can be achieved by the following technical measures:
the invention provides a method for correcting a scribing error caused by a surface type error of a grating blank, which comprises the following steps of:
step S1: coating a film layer on the grating substrate by using a coating machine to prepare a grating blank;
step S2: measuring the wave front error value of the surface to be scribed of the grating blank;
step S3: collecting the wavefront error values and establishing a zero-order wavefront error matrix deltanm
Figure RE-GDA0002824457380000021
Wherein the rows represent different positions of the same reticle, the columns represent different reticles, δnmThe wave front error value of the nth position of the mth reticle is indicated, m and n are natural numbers, and m and n are more than or equal to 2;
step S4: on the basis of the zero-order wavefront error matrix, a reticle error matrix xi caused by the surface type error of the grating blank is obtained by using the scalar theory of geometric optics and grating diffractionnm
Figure RE-GDA0002824457380000022
Wherein alpha is an incident angle and beta is a diffraction angle;
step S5: mounting the grating blank on a workbench of a ruling machine, adjusting the position of the grating blank on the workbench, and positioning;
step S6: determining zero positions and scribing areas of the grating blank in the scribing direction and the indexing direction;
step S7: writing the scribed line error matrix in the scribed area into an operation program of a scribing machine;
step S8: and during grating ruling, measuring the position of the grating ruling tool relative to the grating blank, correcting the ruling error caused by the face shape error of the grating blank in real time through a ruling machine micro-positioning system according to the ruling error matrix, and completing the ruling of the grating.
Furthermore, the grating blank positioning device further comprises a scribing limiting block and an indexing limiting block which are respectively arranged in the scribing and indexing directions of the grating blank, and the positioning of the grating blank is realized through the scribing limiting block and the indexing limiting block.
Further, the step S6 is specifically:
step S61: adjusting the workbench to move to the initial position of grating ruling;
step S62: adjusting the running stroke of the nicking tool to ensure the length of the grating groove;
step S63: operating a ruling machine to carve a single grating groove by a falling knife;
step S64: taking out the grating blank, measuring the position relation of the single grating groove relative to the edge of the grating blank, and determining the corresponding relation between the position of the single grating groove and the zero-order wavefront error matrix;
step S65: and positioning and putting the grating blank back to the original position through the arranged limiting block.
Furthermore, the wavefront error value is measured by an interferometer and is determined by the processing precision and the coating uniformity of the grating substrate.
Further, the processing precision of the grating substrate is less than 1 times of lambda, wherein lambda is 632.8 nm.
Further, the uniformity requirement of the film layer of the grating blank is as follows: the diameter of the grating substrate is more than 500mm, and when the thickness of the film layer is more than 10um, the uniformity is better than 10%.
Further, the measurement of the position of the grating ruling tool relative to the grating blank is realized through a laser interferometer or a grating interferometer.
The method for correcting the groove error caused by the surface type error of the grating blank corrects the groove error caused by the surface type error of the carved grating blank through micro-positioning control, has low requirements on the processing quality of a grating substrate, the size of a film coating machine and the uniformity of the film coating machine, greatly reduces the manufacturing difficulty of the grating blank and the requirements on the film coating machine, is not limited by the processing level and the film coating process level of the grating substrate, and is more easy to obtain higher wavefront quality especially for large-size gratings.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic flow chart of the method for correcting the reticle error caused by the face shape error of the grating blank according to the present invention;
fig. 2 is a detailed flowchart of step S6;
FIG. 3 is a schematic structural diagram of a grating blank, a limiting block and a single reticle;
description of reference numerals: 1-scribing a limit block; 2-indexing a limiting block; 3-grating blank; 4-single score line.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
In order to make the description of the present disclosure more complete and complete, the following description is given for illustrative purposes with respect to the embodiments and examples of the present invention; it is not intended to be the only form in which the embodiments of the invention may be practiced or utilized. The embodiments are intended to cover the features of the various embodiments as well as the method steps and sequences for constructing and operating the embodiments. However, other embodiments may be utilized to achieve the same or equivalent functions and step sequences.
As shown in fig. 1 to 3, the present invention provides a method for correcting a reticle error caused by a face shape error of a grating blank, comprising the following steps:
step S1: coating a film layer on the grating substrate by using a coating machine to prepare a grating blank 3;
step S2: measuring the wave front error value of the surface to be scribed of the grating blank 3;
step S3: collecting the wavefront error values and establishing a zero-order wavefront error matrix deltanm
Figure RE-GDA0002824457380000051
Wherein the rows represent different positions of the same reticle, the columns represent different reticles, δnmThe wave front error value of the nth position of the mth reticle is indicated, m and n are natural numbers, and m and n are more than or equal to 2;
step S4: on the basis of the zero-order wavefront error matrix, a scale error matrix xi caused by the surface type error of the grating blank 3 is obtained by using the scalar theory of geometric optics and grating diffractionnm
Figure RE-GDA0002824457380000052
Wherein alpha is an incident angle and beta is a diffraction angle;
step S5: installing the grating blank 3 on a workbench of a ruling machine, adjusting the position of the grating blank 3 on the workbench, and positioning;
step S6: determining zero positions and scribing areas of the grating blank 3 in the scribing direction and the indexing direction;
step S7: writing the scribed line error matrix in the scribed area into an operation program of a scribing machine;
step S8: and during grating ruling, measuring the position of the grating ruling tool relative to the grating blank 3, correcting a ruling error caused by a face shape error of the grating blank 3 in real time through a ruling machine micro-positioning system according to a ruling error matrix, and completing the ruling of the grating.
The grating blank positioning device is characterized by further comprising a scribing limiting block 1 and an indexing limiting block 2 which are respectively arranged in the scribing and indexing directions of the grating blank 3, and the positioning of the grating blank 3 is realized through the scribing limiting block 1 and the indexing limiting block 3.
Wherein, the step S6 specifically includes:
step S61: adjusting the workbench to move to the initial position of grating ruling;
step S62: adjusting the running stroke of the nicking tool to ensure the length of the grating groove;
step S63: a single grating scribed line 4 is scribed by operating a scribing machine;
step S64: taking out the grating blank 3, measuring the position relation of the single grating groove 4 relative to the edge of the grating blank 3, and determining the corresponding relation between the position of the single grating groove and the zero-order wavefront error matrix;
step S65: positioning and replacing the grating blank 3 by the arranged limit blocks (the scribing limit block 1 and the indexing limit block 2).
The wavefront error value is measured by an interferometer, preferably a Zygo interferometer, and is determined by the processing precision and the coating uniformity of the grating substrate. In step S1, the requirement for the processing accuracy of the grating substrate is greatly reduced, and the processing accuracy may be greater than λ or less than 1 time λ, where λ is 632.8 nm. The size of the film plating machine used in step S2 is required to meet the requirement of the grating size, but there is no high requirement for the uniformity of the film plating, and the requirement for the uniformity of the film layer of the grating blank 3 is as follows: when the diameter of the grating substrate is more than 500mm and the thickness of the film layer is more than 10um, the uniformity is better than 10 percent. The step S8 of measuring the position of the grating ruling tool relative to the grating blank may be implemented by a laser interferometer or a grating interferometer, etc.
The method for correcting the groove error caused by the surface type error of the grating blank corrects the groove error caused by the surface type error of the carved grating blank through micro-positioning control, has low requirements on the processing quality of a grating substrate, the size of a film coating machine and the uniformity of the film coating machine, greatly reduces the manufacturing difficulty of the grating blank and the requirements on the film coating machine, is not limited by the processing level and the film coating process level of the grating substrate, and is more easy to obtain higher wavefront quality especially for large-size gratings.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (7)

1.一种光栅毛坯的面型误差引起的刻线误差的校正方法,其特征在于,包括以下步骤:1. the correction method of the reticle error that the surface error of a grating blank causes, is characterized in that, comprises the following steps: 步骤S1:采用镀膜机在光栅基底上镀制膜层,制备光栅毛坯;Step S1: using a coating machine to coat a film layer on the grating substrate to prepare a grating blank; 步骤S2:测量所述光栅毛坯的待刻划面的波前误差值;Step S2: measuring the wavefront error value of the to-be-scribed surface of the grating blank; 步骤S3:采集所述波前误差值,并建立零级波前误差矩阵δnmStep S3: collecting the wavefront error value, and establishing a zero-order wavefront error matrix δ nm ,
Figure FDA0002737312400000011
Figure FDA0002737312400000011
其中,行代表同一刻线的不同位置,列代表不同刻线,δnm指第m条刻线的第n个位置的波前误差值,m、n均为自然数,且m、n≥2;Among them, rows represent different positions of the same reticle, columns represent different reticles, δ nm refers to the wavefront error value of the nth position of the mth reticle, m and n are both natural numbers, and m, n≥2; 步骤S4:在所述零级波前误差矩阵的基础上,运用几何光学和光栅衍射的标量理论求得光栅毛坯的面型误差引起的刻线误差矩阵ξnmStep S4: On the basis of the zero-order wavefront error matrix, the scalar theory of geometrical optics and grating diffraction is used to obtain the grating error matrix ξ nm caused by the surface error of the grating blank,
Figure FDA0002737312400000012
Figure FDA0002737312400000012
其中,α为入射角,β为衍射角;where α is the incident angle and β is the diffraction angle; 步骤S5:将所述光栅毛坯安装在刻划机的工作台上,调整所述光栅毛坯在工作台上的位置,并进行定位;Step S5: installing the grating blank on the worktable of the scribing machine, adjusting the position of the grating blank on the worktable, and positioning; 步骤S6:确定所述光栅毛坯在刻划方向和分度方向的零位以及刻划区域;Step S6: determining the zero position of the grating blank in the scribing direction and the indexing direction and the scribing area; 步骤S7:将所述刻划区域内的刻线误差矩阵写入刻划机的运行程序中;Step S7: write the scribing error matrix in the scribing area into the running program of the scribing machine; 步骤S8:在光栅刻划时,测量光栅刻刀相对于所述光栅毛坯之间的位置,根据刻线误差矩阵通过刻划机微定位系统实时校正所述光栅毛坯的面型误差引起的刻线误差,并完成光栅的刻划。Step S8: during grating scribing, measure the position of the grating scribe relative to the grating blank, and correct the scribe line caused by the surface error of the grating blank in real time through the scriber micro-positioning system according to the scribe line error matrix error, and complete the scribing of the grating.
2.根据权利要求1所述的光栅毛坯的面型误差引起的刻线误差的校正方法,其特征在于,还包括在所述光栅毛坯的刻划、分度两个方向上分别设置刻划限位块和分度限位块,所述光栅毛坯的定位通过所述刻划限位块和分度限位块实现。2 . The method for correcting the scribe line error caused by the surface shape error of the grating blank according to claim 1 , further comprising setting scribe limits in two directions of scribing and indexing of the grating blank, respectively. 3 . A bit block and an indexing limit block, the positioning of the grating blank is realized by the scribing limit block and the indexing limit block. 3.根据权利要求2所述的光栅毛坯的面型误差引起的刻线误差的校正方法,其特征在于,所述步骤S6具体为:3. the method for correcting the reticle error caused by the surface error of the grating blank according to claim 2, is characterized in that, described step S6 is specifically: 步骤S61:调整工作台运行至光栅刻划的起始位置;Step S61: adjust the worktable to run to the starting position of grating scribing; 步骤S62:调整刻刀的运行行程,保证光栅刻线的长度;Step S62: adjusting the running stroke of the engraving knife to ensure the length of the grating engraving line; 步骤S63:运行刻划机落刀刻划单一光栅刻线;Step S63: run the scriber to drop the knife to scribe a single grating scribe line; 步骤S64:取出所述光栅毛坯,测量所述单一光栅刻线相对于所述光栅毛坯边缘的位置关系,并确定其位置与所述零级波前误差矩阵间的对应关系;Step S64: taking out the grating blank, measuring the positional relationship of the single grating scribe line relative to the edge of the grating blank, and determining the corresponding relationship between its position and the zero-order wavefront error matrix; 步骤S65:通过已设置的限位块定位并将所述光栅毛坯放回原处。Step S65: Positioning and returning the grating blank to the original position through the set limit block. 4.根据权利要求1所述的光栅毛坯的面型误差引起的刻线误差的校正方法,其特征在于,所述波前误差值通过干涉仪测得,由所述光栅基底的加工精度和镀膜均匀性共同决定。4. The method for correcting the grating line error caused by the surface error of the grating blank according to claim 1, wherein the wavefront error value is measured by an interferometer, and is determined by the machining accuracy of the grating substrate and the coating film. Uniformity is determined jointly. 5.根据权利要求1所述的光栅毛坯的面型误差引起的刻线误差的校正方法,其特征在于,所述光栅基底的加工精度小于1倍的λ,其中λ=632.8nm。5 . The method for calibrating the grating line error caused by the surface error of the grating blank according to claim 1 , wherein the machining accuracy of the grating substrate is less than 1 times λ, where λ=632.8 nm. 6 . 6.根据权利要求1所述的光栅毛坯的面型误差引起的刻线误差的校正方法,其特征在于,所述光栅毛坯的膜层的均匀性要求为:所述光栅基底直径大于500mm、所述膜层厚度大于10um时,均匀性优于10%。6 . The method for correcting the grating line error caused by the surface error of the grating blank according to claim 1 , wherein the uniformity requirements of the film layer of the grating blank are: the diameter of the grating base is greater than 500mm, the When the thickness of the film layer is greater than 10um, the uniformity is better than 10%. 7.根据权利要求1所述的光栅毛坯的面型误差引起的刻线误差的校正方法,其特征在于,测量光栅刻刀相对于所述光栅毛坯之间的位置通过激光干涉仪或者光栅干涉仪实现。7 . The method for calibrating the grating line error caused by the surface error of the grating blank according to claim 1 , wherein the measurement of the position of the grating knife relative to the grating blank is performed by a laser interferometer or a grating interferometer. 8 . accomplish.
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