CN100549667C - Polarization analysis apparatus and polarization analysis method - Google Patents

Abstract

No drive division, small-sized and polarization analysis apparatus and ellipsometers at a high speed are provided, wherein, the wave plate array that a polarizer array of a plurality of polarizers zone strip configuration that optical axis direction is mutually different and a plurality of wave plates zone strips certain and that optical axis direction is different mutually that will lag behind dispose, make striped cross one another ground overlapping, and the configuration photodetector array, can be individually to measure light intensity by rectangular cross section.As the analytical approach of the two-dimensional intensity distribution pattern of the photodetector array of this polarization analysis apparatus observation, adopt the match of pattern form mathematics or carry out asking the method for incident polarization ripple with the coupling of database; Perhaps pattern form is made Fourier transform, ask one of method side of incident polarization ripple or two sides' algorithm by frequency component.In addition as required, adopt the signal processing method of removing from the signal in the photo detector zone of accepting unwanted scattered light or diffraction light, can do more high-precision polarized wave analysis.

Description

Polarization analysis apparatus and polarization analysis method

Technical field

The present invention relates to the polarisation of light light analytical equipment and utilize this polarization analysis apparatus to measure the optical constant of film and the ellipsometers of thickness.

Background technology

As the typical method of the membranous or thickness of analysed film, can enumerate well-known in the past method is the analysis of polarized light determination method.The analysis of polarized light determination method refers to the light to film test portion incident specific polarization light state, by the reflectivity R of mensuration electric field from the light of test portion reflection component (p polarized wave) parallel with the plane of incidence _pReflectivity R with the electric field component (s polarized wave) vertical with the plane of incidence _sRatio ρ, obtain the method for test portion thickness or refractive index.Here, general ρ is a plural number, can be expressed as ρ=R _p/ R _s=tan (Ψ) * exp (j Δ).Ψ and Δ are the parameters that the polarized light state of light (reflected light) is measured in expression, are called oval symmetric angle.This ρ is by optical constant of film test portion (n) and the definite value of thickness (d), as long as therefore can obtain polarization of reflected light light state (Ψ, Δ) with ellipsometers, just can oppositely calculate the optical constant and the thickness of test portion.

In the ellipsometers, as the method for carrying out obtaining from the polarization of reflected light light analysis of test portion Ψ and Δ, (applied physics association compiles, nineteen ninety can to adopt the applied physics guide, ball is kind, pp.20-22) waits the light extinction method of publicity in the document or rotates analyzer method etc.In the light extinction method, make reflected light (being generally elliptically polarized wave) pass through quarter wave plate, the polarizer successively, accept,, read the anglec of rotation of light intensity minimum, thereby obtain Ψ and Δ quarter wave plate and polarizer rotation independently respectively by light-receiving device from test portion.But, find out minimum value with two variablees in this method, only once measure the shortcoming of also spending the long period even if therefore exist.And rotation analyzer method is not use quarter wave plate and the method for only carrying out analysis of polarized light with analyzer.The variation that is subjected to light intensity when mensuration rotates a circle the polarizer in the rotation analyzer method, if the function with angle obtains being subjected to light intensity, then can obtain Ψ and Δ by calculating, be difficult for difference phase difference and (2 π-Δ) but exist, promptly be difficult to distinguish the right-handed elliptical polarization ripple or the unfavorable condition of left-handed elliptically polarized wave.For fear of this situation, need the plug quarter wave plate to wait 1 point measurement is carried out mensuration more than 2 times, it is very big therefore to become complicated with mensuration and measure the required time, and this compares with light extinction method before almost and does not change.

In recent years, along with the marked improvement of semiconductor technology, in the process of high performance that carries out various devices and miniaturization, permissible accuracy is very strict in the processing film such as CVD or sputter, for example, requires to make with the precision of 0.1nm the film of number nm thickness.Now, in order to realize this high-precision film forming (or film formation device), earnestly hope can online mode be measured test portion thickness and membranous high precision thickness/membranous monitor in the process.But though the thickness of analysis of polarized light determination method high-precision measuring film, membranous and be suitable for the mode of this film forming monitor, but traditional ellipsometers adopts the assay method of above-mentioned such complexity, therefore general finding speed is slow, in addition, because this device is large-scale and very expensive, is difficult to import processing unit (plant).

Polarization analysis apparatus as no drive division, after proposition branches into 4 bundles with the light beam of measuring, respectively by the polarizer or the wave plate and the polarizer, by measuring 4 methods (Japanese kokai publication hei 5-113371 communique) of restrainting the light intensity analysis polarized wave state of different polarization light components.The analysis of polarized light of the easy and suitable high speed of this polarized light determinator, its measuring principle are illustrated in crystal optics, and (applied physics association support is talked and can be compiled, and nineteen ninety, publish in gloomy north, pp.139-140) waits document, is well-known.But, realize this polarization analysis apparatus, need beam splitter, polarising beam splitter and quarter wave plate or the polarizer, also need to be called numerous optical elements of photo detector in addition, be difficult to reach equipment miniaturization.Because the very difficult high precision assembling of accomplishing each product, it is relatively poor that the result causes measuring precision, therefore is not suitable for requiring the optical constant of high-precision measuring film or the ellipsometers of thickness.

As mentioned above, propose to be fit to high speed that analysis of polarized light measures and small-sized and do not have the polarization analysis apparatus of drive division so far as yet, and to adopt this device the polarization of incident light light state to be carried out the method for high accuracy analysis.

Summary of the invention

The invention provides by combination have the mutually different a plurality of zones of optical axis direction polarizer array, have optical axis direction or hysteresis (phase differential) the wave plate array in different a plurality of zones and the polarization analysis apparatus or the ellipsometers of the no drive division that photodetector array constitutes mutually, and the polarization analysis method that adopts them.As polarizer array and wave plate array, can realize device fully small-sized and that reliability is high by adopting the artificial optical material that constitutes by the multidimensional periodic structure that is called photonic crystal (photonic crystal).

At first, just the polarizer and the wave plate that is made of photonic crystal describes.Forming on the transparent material substrate 101 that periodically groove is listed as shown in Figure 1, Yi Bian make the medium 102 of transparent and high index of refraction and the medium 103 of low-refraction preserve interface shape, Yi Bian interaction cascading.Each layer has periodically in the x direction, but can be same on the y direction, also can have periodicity or the aperiodic structure bigger than x direction of principal axis.This meticulous periodic structure (photonic crystal) can be called mode (Japanese kokai publication hei 10-335758 communique) from the convex surface process technology by employing, and high repeatability and high uniformity ground make.On the periodic structure body that makes like this from relative xy face vertical or vergence direction incident do not have polarized light or elliptically polarized light, be the y polarized wave and the x polarized wave of quadrature with it then, produce the light of TE mould and TM mould in periodic structure body inside respectively for the parallel polarized wave of groove row.The propagation constant of TE mould and TM mould can be selected in wide scope according to the material refractive index that constitutes periodic structure, the cycle of xy face, stacked cycle.

Fig. 2 is that an example adopts Si, adopts SiO as low-index material as high-index material ₂The time the dispersion curve of two-dimensionally periodic structure.The longitudinal axis is with the stacked period L of the inverse of wavelength X _zValue after the standardization, transverse axis are with the phase changing capacity k of propagation during one-period _zL _z(k _zBe the propagation constant of z direction) with the value after the π standardization.Bai Yuan represents TE ripple, black circle expression TM ripple.L _xThe cycle of direction is established L here in the presentation surface _z/ L _x=1.If the incident light frequency in the middle of band gap, then can not be propagated in the periodic structure body with this pattern, incident light reflection or diffraction.On the other hand, in being with, then light can see through in the periodic structure body as if light frequency.In frequency field 201, the TE ripple becomes band gap and reflects, and the TM ripple is because of seeing through in propagation zone, thereby can be used as polarization separating element (TOHKEMY 2001-83321 communique) work.In frequency field 202, see through and the polarizer work of TM wave reflection as the TE ripple.On the other hand, in frequency field 203, TE ripple and TM ripple all are in propagation zone and see through.But at this moment two curves stagger, so each propagation constant difference, as the wave plate work that two patterns is brought phase differential.The pattern by suitably being designed for substrate or material and the stacked cycle or the stacked number of film forming can be designed the wave plate that random phase difference is provided, and for example make phase differential become pi/2, just can be used as quarter wave plate work.In addition, because independent cycle or direction that changes groove in each zone that can be in a substrate, can be by the characteristic of each area change photonic crystal.It is called multiple pattern photonic crystal.For example, if the polarizer then can be by each area change optical axis direction, in addition, the occasion changeable optical axis direction or the phase differential of wave plate.

As the low-refraction medium that constitutes photonic crystal, the most frequently used material is with SiO ₂Be major component, the wide and chemical in its transparent wavelength zone, hot, mechanicalness is also stable, film forming is also carried out easily.In addition, can adopt other optical glass, for example MgF as the low-refraction medium ₂Such lower material of refractive index.As high-index material, can adopt semiconductor or Ta such as Si, Ge ₂O ₅, TiO ₂, Nb ₂O ₅, HfO ₂, Si ₃N ₄On oxide or nitride.Because the refractive index of semiconductor material is bigger, has the advantage that can access than large band gap, but utilizes wavelength zone to be defined as near infrared.On the other hand, the transparent wavelength scope of oxide or nitride is wider, therefore also can use in the visible region.

When making the photonic crystal polarizer or wave plate from the convex surface processing method, the such periodicity groove of substrate 101 as shown in Figure 1 before at first on substrate, being produced on by el and dry ecthing.The formation of channel patterns can be adopted other photoetch or interfere the stamping technology of exposure, metal pattern.In addition, the cross sectional shape of groove is a rectangle among the figure, but can be other shapes such as triangle.Substrate can use Si or quartz glass, other optical glass etc.Concavo-convex pitch is about half of lambda1-wavelength, and for example the light time of 0.8 μ m is about 0.4 μ m, and the degree of depth of groove is about 0.2 μ m.On this substrate, use Ta ₂O ₅And SiO ₂Deng target, combination sputtering deposit and biasing sputter interaction cascading multilayer film.At this moment, it is important suitably setting bias condition on the x of each layer direction of principal axis retention cycle concaveconvex shape ground.One of condition is for example following: at Ta ₂O ₅In the film forming of layer, air pressure be 2mTorr, target to apply high frequency power be 300W, at SiO ₂In the film forming of layer, air pressure be 6mTorr, target to apply high frequency power be 300W, sputter is at SiO ₂Layer carries out after the film forming, and air pressure is that to apply high frequency power be 90W for 2mTorr, substrate.

Then, describe with regard to polarization analysis apparatus of the present invention.Fig. 3 illustrates the typical example of the polarization analysis apparatus of the no drive division that adopts wave plate array and polarizer array.A plurality of zones row M row that wave plate array 301 is different with optical axis direction make each regional hysteresis certain (being desirably quarter wave plate) through design.In addition, a plurality of zones row N row that polarizer array 302 is different with the direction of polarized light of transmitted light make each regional polarized wave extinction ratio fully high through design.Such wave plate array and polarizer array mutually orthogonal ground are pasted, dispose the photodetector array 303 of the light in M * N zone can accepting individually to make at its rear, thereby can realize polarization analysis apparatus by superimposed wave chip arrays and polarizer array.As polarizer array and wave plate array, can use the above-mentioned photonic crystal polarizer, can carry out miniaturization, the high precision int of device thus.

When light incided polarization analysis apparatus as described above, by behind each domain transformation polarized wave state, only the specific polarization wave component of being determined by each regional direction of principal axis of polarizer array just saw through incident light by the wave plate array.Thereby each photo detector of photodetector array detects and sees through the wave plate of different angles and the light of the polarizer separately, i.e. the light intensity of different polarization wave component separately.Therefore, by analyzing the light intensity that each photo detector detects, can hold the polarization of incident light light state by two-dimensional approach.For example, in polarization analysis apparatus as described above, the phase differential of wave plate array is made as pi/2 (1/4 wavelength), and the number of cutting apart of wave plate array and polarizer array was made as 16 o'clock, and the analog result of the detector array sensitization intensity distributions of an example 256 elements is shown at Fig. 4.Here illustrating till making each regional main shaft angle of quarter wave plate array from 0 ° to 180 ° per 12 ° changes and y direction is arranged, each regional main shaft angle of polarizer array (the polarized wave angle that sees through) too, from 0 ° till 180 ° per 12 ° change and the analog result of X direction when arranging.The result learns thus, and the light intensity distributions shape that photo detector observes changes according to the polarization of incident light light state, therefore by analyzing this intensity distributions pattern, can oppositely obtain the polarization of incident light light state.

Here, the intensity distributions pattern that observes with regard to polarization analysis apparatus of the present invention carries out logic (mathematics) analysis.If will go into the polarisation of light light state of injection device is that Ψ and Δ are represented with oval symmetric angle, then the Jones vector by the light behind the wave plate and the polarizer can be expressed as:

$\stackrel{\→}{u}=\left(\begin{array}{cc}1& 0\\ 0& 0\end{array}\right)\left(\begin{array}{cc}\cos \mathrm{\φ}& \sin \mathrm{\φ}\\ -\sin \mathrm{\φ}& \cos \mathrm{\φ}\end{array}\right)\left(\begin{array}{cc}\cos \mathrm{\θ}& -\sin \mathrm{\θ}\\ \sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right)\left(\begin{array}{cc}{e}^{\mathrm{j\α}}& 0\\ 0& 1\end{array}\right)\left(\begin{array}{cc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\\ -\sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right)\left(\begin{array}{c}1\\ \tan \mathrm{\Ψ}\·e^{\mathrm{j\Δ}}\end{array}\right)$ (formula 1)

In this formula, θ represents the main shaft angle of wave plate, and α represents the hysteresis (phase differential) of wave plate, and φ represents the main shaft angle of the polarizer in addition.As shown in Figure 5, compare with the performance of oval symmetric angle, the polarization of incident light light state is during by the ellipticity (ε) of elliptically polarized wave and slope (γ) expression, easier image of catching polarized light state.The polarization of incident light light state can be replaced as follows thus:

$\left(\begin{array}{c}1\\ \tan \mathrm{\Ψ}\·e^{\mathrm{j\Δ}}\end{array}\right)=\left(\begin{array}{cc}\cos \mathrm{\γ}& -\sin \mathrm{\γ}\\ \sin \mathrm{\γ}& \cos \mathrm{\γ}\end{array}\right)\left(\begin{array}{c}1\\ \mathrm{j\ϵ}\end{array}\right)$ (formula 2)

Thereby the wavy attitude of polarisation of light that arrives photodetector array finally can show as:

$\stackrel{\→}{u}=\left(\begin{array}{cc}1& 0\\ 0& 0\end{array}\right)\left(\begin{array}{cc}\cos (\mathrm{\φ}-\mathrm{\θ})& \sin (\mathrm{\φ}-\mathrm{\θ})\\ -\sin (\mathrm{\φ}-\mathrm{\θ})& \cos (\mathrm{\φ}-\mathrm{\θ})\end{array}\right)\left(\begin{array}{cc}{e}^{\mathrm{j\α}}& 0\\ 0& 1\end{array}\right)\left(\begin{array}{cc}\cos (\mathrm{\θ}-\mathrm{\γ})& \sin (\mathrm{\θ}-\mathrm{\γ})\\ -\sin (\mathrm{\θ}-\mathrm{\γ})& \cos (\mathrm{\θ}-\mathrm{\γ})\end{array}\right)\left(\begin{array}{c}1\\ \mathrm{j\ϵ}\end{array}\right)$ (formula 3)

The light intensity that observes can be obtained by following formula.

${\left|\stackrel{\→}{u}\right|}^2={\stackrel{\→}{u}}^{*}\·\stackrel{\→}{u}$ (formula 4)

That is, the intensity distributions that photodetector array observes by the wavy attitude of incident polarization (ε, γ) and the function of wave plate angle (θ) and polarizer angle (φ) performance.Because θ and φ are the known values that relies on device, the shape of the light intensity distributions that observes by analysis can clearly accurately be obtained the polarization of incident light light state from the logic view point.

As the simplest method of analytical approach of intensity distributions pattern is the method for position that detects the minimum value of determined pattern.This is corresponding with light extinction method in traditional ellipsometers of preceding explanation.In the light extinction method, the wave plate in the time of can making incident light fully by delustring with the rotation polarizer by the wave plate angle and the angle of the polarizer are directly obtained the ellipticity and the slope of incident polarized light.On the other hand, in the occasion of the new polarization analysis apparatus that adopts wave plate array of the present invention and polarizer array also according to identical principle, the position of the dim spot that produces on the specific two-dimensional intensity distribution pattern (minimum value, zero point), be the main shaft angle of the wave plate and the polarizer, thereby but moment obtain the polarization of incident light light state.But this method is not utilized a greater part of two-dimensional signal that is measured to, the not talkative advantage of giving full play to new polarization analysis apparatus.In addition, for example the wave plate phase differential is not strict when being 1/4 wavelength, exists dim spot to depart from ideal position, therefore can not carry out the situation that high-precision polarized wave is analyzed.

Therefore, as utilizing multi-site data more to analyze the shape of pattern, and wave plate is departed from the pattern analysis method that also can do to proofread and correct, the present invention proposes the Fourier analysis method of two-dimensional pattern and near the shape fitting process the dim spot.In the Fourier analysis method, utilize intensity distributions pattern that polarization analysis apparatus observes situation, by judging the incident polarization light state by the amplitude of each frequency component that the pattern form Fourier transform is tried to achieve and the value of phase place with the simple frequency representation in components.And near the shape fitting process the dim spot, obtain near the light intensity minimum value pattern form by approximate treatment, calculate dim spot position accurately., can carry out at a high speed and noise resistance and the high analysis of polarized light of precision with these two kinds of analytical approachs by also.

Above-mentioned polarization analysis apparatus of the present invention or utilize the ellipsometers of this device, by utilizing photonic crystal (multiple pattern photonic crystal), very high precision is made.In addition, can adopt existing imageing sensors such as CCD as photodetector array.Thereby, to compare with conventional articles, ellipsometers of the present invention not only can realize very small-sized and device at a low price, and the reliability of device is also high.Therefore, can expect to import processing film device inside, as to thickness, membranous real-time monitor use etc., in the almost irrealizable new using method of traditional ellipsometers.Following simple declaration various schemes of the present invention.

The polarization analysis apparatus of the present invention the 1st aspect is characterized in that comprising: the polarizer array that is provided with the different a plurality of zones of the polarized wave direction that sees through; And the wave plate array that is provided with a plurality of zones that the phase differential that brings transmitted light is certain and optical axis direction is different, make each polarizer configuration overlappingly respectively of each wave plate of described wave plate array and described polarizer array, and disposed the photodetector array that individually to accept by the light that only makes the zone that the specific polarization wave component sees through of the wave plate and the polarizer.Here, wave plate array, polarizer array and photodetector array can come integrated by direct stickup, but can dispose relay lens between each array, make through the imaging on next array of the picture behind each array.In addition, realize high-precision polarized wave analysis on the whole polarized wave state in order to be implemented in, preferably each regional phase differential of wave plate array is 1/4 wavelength (a pi/2 radian), and the optical axis direction of the optical axis direction of wave plate array and polarizer array comprises at least from 0 ° to 180 ° scope.In addition, many mensuration precision is just high more more for the number of cutting apart in the zone of polarizer array and wave plate array.

The polarization analysis apparatus of the present invention the 2nd aspect is characterized in that comprising: the polarizer array that is provided with at least 2 different above strip regions of the polarized wave direction that sees through; And the wave plate array that is provided with at least 2 above strip regions that the phase differential that brings transmitted light is certain and optical axis direction is different, described wave plate array and described polarizer array striped are separately disposed across, and configuration can be accepted the photodetector array by the light of each intersection region individually.Same with the occasion of the present invention the 1st aspect, wave plate array, polarizer array and photodetector array also can directly be pasted and be integrated, but also can dispose relay lens between each array, make through the picture behind each array to image on the next array.In addition, in order on whole polarized wave state, to realize high-precision polarized wave analysis, preferably each regional phase differential of wave plate array is 1/4 wavelength (a pi/2 radian), and the optical axis direction of the optical axis direction of wave plate array and polarizer array comprises at least from 0 ° to 180 ° scope.In addition, many mensuration precision is just high more more for the quantity of the strip region of polarizer array and wave plate array.

The polarization analysis apparatus of the present invention the 3rd aspect, it is characterized in that: in the polarization analysis apparatus aspect the above-mentioned the 1st or 2, described polarizer array and described wave plate array are made of the dielectric multilayer film that has in stacked direction upper strata shape periodically and each layer shape has a periodicity concaveconvex shape of repetition on direction in the face of determining by each zone.

The polarization analysis apparatus of the present invention the 4th aspect is characterized in that comprising: the polarizer array that is provided with the different a plurality of zones of the polarized wave direction that sees through; And the wave plate array that is provided with the same and a plurality of zones that phase differential transmitted light is different of optical axis direction, described wave plate array and described polarizer array are disposed with overlapping each other, and the optical component array by the light that only makes the zone that the specific polarization wave component sees through of wave plate array and polarizer array can be individually accepted in configuration.Here, wave plate array, polarizer array and photodetector array can come integrated by direct stickup, but can dispose relay lens between each array, make through the imaging on next array of the picture behind each array.In addition, in order to realize high-precision polarized wave analysis on whole polarized wave state, preferably each regional phase differential of wave plate array comprises from 0 ° to 360 ° scope, and the main shaft angle of polarizer array comprises from 0 ° to 180 ° scope.In addition, many mensuration precision is just high more more for the number of cutting apart in the zone of polarizer array and wave plate array.

The polarization analysis apparatus of the present invention the 5th aspect is characterized in that comprising: the polarizer array that is provided with at least 2 different above strip regions of the polarized wave direction that sees through; And the wave plate array that is provided with the same and at least 2 the above strip regions that phase differential transmitted light is different of optical axis direction, described wave plate array and described polarizer array striped are separately disposed across, and configuration can be accepted the optical component array by the light of each cross section individually.Same with the occasion of the present invention the 4th aspect, wave plate array, polarizer array and photodetector array also can directly be pasted and be integrated, but also can dispose relay lens between each array, make through the picture behind each array to image on the next array.In addition, in order to realize high-precision polarized wave analysis on whole polarized wave state, preferably each regional phase differential of wave plate array comprises from 0 ° to 360 ° scope, and the main shaft angle of polarizer array comprises from 0 ° to 180 ° scope.In addition, many mensuration precision is just high more more for the number of cutting apart in the zone of polarizer array and wave plate array.

The polarization analysis apparatus of the present invention the 6th aspect, it is characterized in that: aspect the above-mentioned the 4th or 5 in the described polarization analysis apparatus, described polarizer array by have in the stacked direction shape periodically and face that each layer shape determined by each zone in have the periodicity concaveconvex shape of repetition on direction the dielectric multilayer film constitute, the dielectric multilayer film of concaveconvex shape constitutes described wave plate array by having periodically and have repetition period of determining by each zone in shape on the stacked direction and having periodically on a common direction.

The polarization analysis apparatus of the present invention the 7th aspect is characterized in that: have the polarization analysis apparatus of above-mentioned the 1st, 2 or 3 aspects and the polarization analysis apparatus of above-mentioned the 4th, 5 or 6 aspects simultaneously, make the light beam difference incident polarization light analytical equipment of measurement.

The polarization analysis apparatus of the present invention the 8th aspect, it is characterized in that: in aspect the above-mentioned the 1st to the 7th in the polarization analysis apparatus of arbitrary scheme, between described wave plate array and described polarizer array, or a certain side between described polarizer array and the described photodetector array or two sides are provided with the layer of light absorption, perhaps on described wave plate array and described polarizer array or described photodetector array at least 1, by on each zone boundary of described array, forming transparent region or zone of opacity, make unwanted multipath reflection optical attenuation.

The polarization analysis apparatus of the present invention the 9th aspect, it is characterized in that: in aspect the above-mentioned the 1st to the 8th in the polarization analysis apparatus of arbitrary scheme, the peripheral part of described wave plate array and described polarizer array is provided with the isotropic transparent region of relative incident polarized light, perhaps on the part of each zone boundary part of the part of described each zone boundary part of wave plate array and described polarizer array, the isotropic transparent region of relative incident polarized light is set, and make up with photodetector array, thereby passing through of will wanting originally to measure light intensity distributions after the polarizer and the wave plate distributes with incident intensity or the transmission loss of polarizer array and wave plate array distributes mensuration simultaneously and correcting determination result.

The polarization analysis apparatus of the present invention the 10th aspect, it is characterized in that: in aspect the above-mentioned the 1st to the 9th in the polarization analysis apparatus of arbitrary scheme, in order to suppress from the diffraction light of each zone boundary part of described wave plate array and described polarizer array and the influence of scattered light, each zone boundary part at described wave plate array and described polarizer array is provided with lightproof area, perhaps in the regional shading with the photodetector array of correspondence of the boundary member of described wave plate array and described polarizer array.Obviously, can carry out the shading of described wave plate array and described polarizer array boundary part and the shading of the corresponding region of photodetector array simultaneously.

The polarization analysis apparatus of the present invention the 11st aspect is characterized in that: the polarization analysis apparatus of arbitrary scheme in aspect configuration a plurality of the above-mentioned the 1st to the 10th in face, the error at measurment that the shift in position of avoidance incident beam causes.

The optical measurement instrument of the present invention the 12nd aspect or photo measure mode is characterized in that: the polarization analysis apparatus that adopts arbitrary scheme in above-mentioned the 1st to the 11st aspect.

The ellipsometers of the present invention the 13rd aspect, it is characterized in that: the polarized light that makes specific wavelength is to measuring test portion incident at a predetermined angle, and will import the polarization analysis apparatus of arbitrary scheme in above-mentioned the 1st to the 11st aspect from the reflected light of measuring test portion, obtain the amplitude reflectivity ratio of P polarized light component and S polarized light component by the light intensity distributions of photodetector array acquisition.At this moment for removing from the light beyond the reflected light of test portion and improving and measure precision, can before described polarization analysis apparatus, insert the optical wavelength filter plate corresponding with lambda1-wavelength.

The ellipsometers of the present invention the 14th aspect, it is characterized in that: form in the device at vacuum film, substrate surface in thin-film deposition makes the light of specific wavelength and specific polarization light state by predetermined angular incident, and will import the polarization analysis apparatus of arbitrary scheme in above-mentioned the 1st to the 11st aspect from the reflected light of substrate surface, the light intensity distributions that is obtained by photodetector array is obtained the amplitude reflectivity ratio of P polarized light component and S polarized light component.At this moment for removing, be preferably in the preceding insertion of the described polarization analysis apparatus optical wavelength filter plate corresponding with lambda1-wavelength from radiating light or scattered light in the film formation device beyond the reflected light of test portion.

The thickness of the present invention the 15th aspect and membranous control device is characterized in that: the thickness and the membranous information that will be obtained by the ellipsometers of the above-mentioned the 13rd or the 14th aspect feed back to the control device of film forming speed or film formation time.

The thickness of the present invention the 16th aspect and membranous control device, it is characterized in that: be provided with more than 2 the above-mentioned the 13rd or the ellipsometers of the 14th aspect at least, thickness and the membranous information that obtains by the position measurement with the substrate diverse location feed back to thickness and membranous distribution correction control apparatus.

The polarization analysis method of the present invention the 17th aspect or analysis of polarized light system, it is characterized in that: the polarizer array that makes the wave plate array that is provided with a plurality of zones that phase differential is certain and optical axis direction the is different a plurality of zones different with being provided with the polarized wave direction that sees through, on the direction of light incident, make described wave plate array in front, described polarizer array is overlay configuration in the back, and can accept individually by wave plate a certain zone and with the polarization analysis apparatus of the photodetector array two-dimensional arrangement of the light in the zone of the polarizer of this region overlapping in, the two-dimensional intensity distribution pattern that utilization observes by described photodetector array is obtained the polarization of incident light light state only by DC (discrete cosine) component and maximum three features that frequency component is represented.

The polarization analysis method of the present invention the 18th aspect or analysis of polarized light system, it is characterized in that: in polarization analysis method aspect the above-mentioned the 17th or the analysis of polarized light system, the maximum point of the intensity distributions pattern that utilization is observed by photodetector array or near the pattern form feature the smallest point, with sampling value match or interpolation, obtain the extinction point of oval symmetry or the smallest point of light quantity, and obtain the polarization of incident light light state.

The polarization analysis method of the present invention the 19th aspect or analysis of polarized light system, it is characterized in that: in polarization analysis method aspect the above-mentioned the 17th and the analysis of polarized light system, as the shape analysis method of the intensity distributions pattern of observing, adopt Fourier transform.

The polarization analysis method of the present invention the 20th aspect or analysis of polarized light system is characterized in that: also with the polarization analysis method of above-mentioned the 18th aspect and the polarization analysis method of above-mentioned the 19th aspect.

The polarization analysis method of the present invention the 21st aspect or analysis of polarized light system, it is characterized in that: in aspect the above-mentioned the 17th to the 20th in the polarization analysis method or analysis of polarized light system of either side, the shape of the intensity distributions pattern that observes by analysis, detect the value of the wave plate array phase difference of using in the described polarization analysis apparatus, the deviation between self-correcting and the design load.

The signal processing method of the present invention the 22nd aspect, it is characterized in that: in aspect the above-mentioned the 17th to the 21st in the polarization analysis method or analysis of polarized light system of arbitrary scheme, in order to remove from the scattered light of each zone boundary part of wave plate array or polarizer array and the influence of diffraction light, and from the signal of photodetector array output, remove signal from the zone of accepting described scattered light and diffraction light.

Description of drawings

Fig. 1 is the polarizer that is made of photonic crystal or the concept map of wave plate.

Fig. 2 is the band figure of the propagation characteristic of expression photonic crystal shown in Figure 1.

Fig. 3 constitutes " angle change type " polarization analysis apparatus with photonic crystal.

Fig. 4 is the light intensity distributions that an example is observed when adopting polarization analysis apparatus shown in Figure 3.

Fig. 5 is the concept map of the method for performance polarisation of light light state.

Fig. 6 constitutes " phase differential variation type " polarization analysis apparatus with photonic crystal.

Fig. 7 is the light intensity distributions that an example is observed when adopting polarization analysis apparatus shown in Figure 6.

Fig. 8 is that an example is according to counting wave plate and cutting apart of the polarizer different intensity distributions patterns.

Fig. 9 is the relation of intensity distributions after a routine intensity distributions pattern of measuring and the interpolation.

Figure 10 is the slope of expression incident polarization ripple and the concept map of the relation of the intensity distributions pattern that observes.

Figure 11 is the intensity distributions pattern (with the relation of incident polarization ripple ellipticity) of an example observation.

Figure 12 is the intensity distributions pattern (with the relation of incident polarization ripple slope) of an example observation.

Figure 13 is the structure example of the analysis of polarized light system of analytic intensity distribution patterns.

Figure 14 is near the contour nemaline diagrammatic sketch of dim spot of the intensity distributions pattern of observation.

Figure 15 is the concept map with pattern form and database polarization analysis method relatively.

Figure 16 is a diagrammatic sketch of removing the signal processing mode of array boundary influence partly.

Figure 17 is the analog result (its 1) of the Fourier analysis of intensity distributions pattern.

Figure 18 is the analog result (its 2) of the Fourier analysis of intensity distributions pattern.

Figure 19 is an example and the pattern analysis algorithm that detects method with Fourier analysis and dim spot.

Figure 20 is the concept map of expression wave plate array and the incorporate method of polarizer array.

Figure 21 is the concept map of wave plate array and incorporate second method of polarizer array.

Figure 22 is the concept map with the incorporate polarization analysis apparatus of polarization analysis apparatus of Fig. 3 and Fig. 6.

Figure 23 is the concept map that suppresses the method for the multipath reflection of light in the polarization analysis apparatus.

Figure 24 is the concept map that suppresses second method of the multipath reflection of light in the polarization analysis apparatus.

Figure 25 is the structure example (its 1) of proofreading and correct the polarization analysis apparatus of incident intensity distribution or loss distribution.

Figure 26 is the structure example (its 2) of proofreading and correct the polarization analysis apparatus of incident intensity distribution or loss distribution.

Figure 27 is the structure example by the polarization analysis apparatus of the influence of lightproof area avoidance scattering/diffraction light.

Figure 28 is the structure example in order to the polarization analysis apparatus of the influence of avoiding the incident light position change.

Figure 29 is the concept map that utilizes the structure of ellipsometers of the present invention.

Figure 30 utilizes the concept map of the structure of beam split ellipsometers of the present invention.

Figure 31 is the concept map of the online thickness/membranous monitor in the processing film.

Figure 32 is the online thickness/membranous in the processing film and the concept map of distribution monitor.

Figure 33 is thickness in the routine sputtering unit/membranous and the control method (its 1) that distributes.

Figure 34 is thickness in the routine sputtering unit/membranous and the control method (its 2) that distributes.

Figure 35 is thickness in the routine sputtering unit/membranous and the control method (its 3) that distributes.

Figure 36 is thickness in the routine vacuum deposition apparatus/membranous and the control method that distributes.

Figure 37 is the first embodiment diagrammatic sketch of proofreading and correct the method for wave plate array phase difference skew.

Figure 38 is the second embodiment diagrammatic sketch of proofreading and correct the method for wave plate array phase difference skew.

Embodiment

At first, just describe by polarizer array that constitutes from convex surface processing type photonic crystal and the same polarization analysis apparatus that constitutes by the combination of wave plate array that constitutes from convex surface processing type photonic crystal and photodetector array.As described above, the photonic crystal polarizer and photonic crystal wave plate are made of the structure of Fig. 1, make from convex surface processing growth by make two kinds of inorganic material 102 and 103 on the substrate 101 that forms the two-dimensional groove pattern.At this moment, the cycle by being controlled at the groove that makes on the substrate 101, film forming can freely be designed the refractive index of light, the various characteristicses such as frequency band of photon band gap (PBG) with cycle of material, each layer etc.Utilize this feature, suitably select design parameter, thereby, not only can make and make in a certain special wavelength light, one side's polarized wave (TM: the polarized wave vertical) see through with substrate pattern, and the opposing party's polarized wave (TE: the polarized wave parallel with substrate pattern) by the polarizer (polarization separating element) that interdicted, and can make to bring between paired 2 polarized waves the wave plate of random phase difference.

The structure example of " wave plate angle change type " polarization analysis apparatus of realizing the use photonic crystal represented aspect the present invention the 3rd is shown at Fig. 3.Wave plate array 301 and polarizer array 302 use from convex surface processing type photonic crystal and constitute, and the such labyrinth of diagram can be made of time processing respectively.Photonic crystal wave plate array 301 is arranged M the zone that each groove direction (direction of wave plate optical axis) is changed a little, makes each regional hysteresis (phase differential of TM light and TE light) certain through design.Equally, photonic crystal polarizer array 302 is also arranged N the zone that each groove direction (the polarized wave direction of blocking) is changed a little, makes each regional polarized wave extinction ratio fully high through design.Establishing the x direction of principal axis among the figure is horizontal direction, and the y direction of principal axis is a vertical direction, and the angle of the axle of the wave plate and the polarizer is that benchmark gradually changes from 0 ° to 180 ° with the x axle, but gets the method for reference axis or the scope of angle is arbitrarily.In addition, zone that crystallographic axis is different among the figure, in polarizer array 302, angle is arranged with gradually changing in wave plate array 301 upper edge x directions (laterally) along y direction (vertically), if but the wave plate and the orientation of the polarizer are intersected, orientation or put in order just to arbitrarily.This wave plate array and polarizer array mutually orthogonal ground are pasted,, and individually measured the light intensity that sees through M * N the zone that makes by the overlapping of wave plate array and polarizer array at its rear configuration photodetector array 303.As the light-receiving device array, can adopt existing elements such as CCD, can realize fully small-sized device.

Incident light is with than the fully big spot definition incident of above-mentioned polarization analysis apparatus.By behind each domain transformation polarized wave state, only order is seen through by the specific polarization wave component of each regional direction of principal axis regulation of the polarizer array incident light by the wave plate array.Thereby each photo detector in the photodetector array detects the wave plate that sees through different angles separately, the light of the polarizer, and analyzes the light intensity that each photo detector detects, and can hold the polarization of incident light light state two-dimensionally.

Fig. 4 illustrates an example in this wave plate angle change type polarization analysis apparatus, if the phase differential of wave plate array is pi/2 (1/4 wavelength), and with wave plate array and polarizer array cut apart the number be made as the analog result of the intensity distributions of the detector array sensitization of 256 elements at 16 o'clock.Here illustrate with each regional main shaft angle of quarter wave plate array till from 0 ° to 180 ° per 12 ° change and y direction is arranged, each regional main shaft angle (angle of the polarized wave that sees through) of polarizer array too, from 0 ° till 180 ° per 12 ° change and the analog result of X direction when arranging.The result is as can be known according to the polarization of incident light light state thus, and therefore the light intensity distributions change of shape that detector detects by analyzing the intensity distributions pattern that is obtained, can distinguish the polarization of incident light light state.This ellipsometers with the extinction type that adopts the traditional rotation quarter wave plate or the rotation polarizer is compared, and can expect the cripetura of the miniaturization of device or minute and measure numerous effects such as precision raising.

The structure example of " wave plate phase differential variation type " polarization analysis apparatus of the employing photonic crystal shown in realizing aspect the present invention the 6th then, is shown at Fig. 6.Wave plate array 601 and polarizer array 602 can realize illustrating the structure of such complexity easily by forming from convex surface processing type photonic crystal.Polarizer array 602 is same with the Fig. 3 (the present invention the 3rd aspect) that has stated, arranges N zone that changes groove direction (the polarized wave direction of blocking) gradually, and it is fully high to be designed to each regional polarized wave extinction ratio.On the other hand, in the wave plate array 601 on the All Ranges groove direction (optical axis direction) identical, each regional hysteresis is changed M time.Among the figure, make the relative x axle of optical axis (horizontal direction) of wave plate array become 45 °, but it is arbitrarily angled to be set at 0 ° or 90 ° etc.In addition, same with the occasion of wave plate angle change type (Fig. 3), get method, the array of reference axis orientation, put in order, the scope of the phase differential of the angular range of the main shaft of polarizer array and wave plate array is arbitrarily.Such wave plate array and polarizer array mutually orthogonal ground are pasted,, individually measured the light intensity that sees through respectively by wave plate array and the overlapping respectively M * N that makes of polarizer array zone at its rear configuration photodetector array 603.The occasion of this wave plate phase differential variation type polarization analysis apparatus, also same with the occasion of above-mentioned wave plate angle change type, by the light intensity that each photo detector of analyzing photodetector array is accepted, can two dimension hold the polarization of incident light light state.

Fig. 7 illustrates an example in phase differential variation type polarized wave analytical equipment, the number of cutting apart of wave plate array and polarizer array is made as 16 respectively, the main shaft that makes polarizer array from 0 ° to 180 ° till per 12 ° of variations, and the hysteresis that makes the wave plate array is from the intensity distributions of 0 ° of per 24 ° of photodetector array sensitization when changing till 360 °.With same in preceding Fig. 4 occasion, transverse axis is got the main shaft angle (the polarized wave direction that sees through) of the polarizer, and the longitudinal axis is got the hysteresis of wave plate, obtains the light intensity of the light-receiving device sensitization of 256 elements by analog form.At this moment corresponding polarization of incident light light state, the light intensity distributions that detector detects changes, and therefore by analyzing the intensity distributions pattern that is obtained, can differentiate the polarization of incident light light state.This compares with the rotation analyzing type ellipsometers that adopts traditional phase-modulator, can expect the miniaturization of device, the cripetura of minute and numerous effects such as raising of mensuration precision.

Polarization analysis method when then, adopting the polarization analysis apparatus of these wave plate angle change types and wave plate phase differential variation type describes.The shape of the intensity distributions pattern that observes in polarization analysis apparatus of the present invention as mentioned above, depends on the polarization of incident light light state.Thereby, by analyzing the intensity distributions pattern of observation, can oppositely judge the polarization of incident light light state.As this pattern analysis method, the most simple method of following simple declaration promptly detects the maximal value (bright spot) of intensity distributions pattern or the method for minimum value (dim spot, zero point).

Polarization analysis apparatus about wave plate angle change type, the arbitrary occasion of wave plate phase differential variation type, if suitably select the angular range of wave plate array and polarizer array, must have bright spot and dim spot on the intensity distributions pattern that observes, its position depends on the incident polarization ripple.Thereby, if can detect this bright spot position or dim spot position, but with regard to the specific polarization light state.In fact the beam distribution by considering occasion that the incident light intensity changes in time or incident light is in the array gamut and uneven occasion, can learn that detecting bright spot with it is more prone to not as detecting dim spot, therefore the following occasion that detects method with regard to dim spot is described, set up but the occasion that bright spot detects, its theory are also same fully.

The number of cutting apart with wave plate array and polarizer array infinitely increases ideally, then can accurately learn the dim spot position of the intensity distributions pattern that observes, but it is limited to cut apart number in the actual array, and therefore the dim spot position that is obtained exists corresponding array to cut apart several errors.As an example, Fig. 8 is illustrated in the wave plate angle change type polarized wave analytical equipment, with the main shaft angle of wave plate array and polarizer array from 0 ° till 180 ° per 12 ° when changing when (16 cut apart) and per 1 ° of variation under two kinds of situations of (181 cut apart), the analog result of the intensity distributions during the linearly polarized wave incident of horizontal direction.181 two dim spots when cutting apart (white point and arrow are represented) are obtained with ± 1 ° precision as known in the figure, but 16 slightly are difficult to accurately know the dim spot position owing to cutting apart when cutting apart.In order to improve the resolution of dim spot position, array to cut apart number many more just good more, but consider actual manufacturing and cost, preferably realize with few number of cutting apart of trying one's best.

Obtain the dim spot position in order to count the high precision of trying one's best with less cutting apart, its effective ways are that the intensity distributions that at every turn observes is carried out interpolation, and obtain the method for continuous intensity distributions by calculating.As an example, can consider in wave plate phase differential variation type polarized wave analytical equipment, if the relative horizontal direction of main shaft angle of wave plate array is 45 °, per 24 ° of variations (16 cut apart) till making phase differential from 0 ° to 360 °, and the main shaft angle that makes polarizer array from 0 ° to 180 ° till the occasion of per 12 ° of variations (16 cut apart).When Fig. 9 has illustrated to this polarization analysis apparatus incident right-hand circularly polarized wave, the intensity distributions that observes and the result who is obtained is carried out the analog result of the continuous intensity distributions behind the spline interpolation.As seen from the figure by intensity distributions is carried out interpolation, can access not and be inferior to increases array and cuts apart continuous intensity distributions when several.Because can be based on the data after this interpolation, obtain the point (representing) of intensity minimum through approximate treatment with white point, also can accurately judge the polarized wave state cutting apart under the less situations of number.The dim spot positional precision of trying to achieve through interpolation is several relevant with cutting apart of array, therefore based on the precision of matching requirements, determines that the number of cutting apart of array gets final product.

As mentioned above, but dim spot detects the relative intensity distribution moment differentiation polarized light state of the light that detects based on photodetector array in the method, does not therefore need the information of relevant light intensity absolute value.For example have when incident light has intensity distributions, or light intensity when change etc. arranged, can carry out the feature of analysis of polarized light with degree of precision.But it is not omnipotent that this dim spot detects method, and as mentioned above, for example in that the wave plate hysteresis is not strict when being 1/4 wavelength, depart from from ideal position the dim spot position, therefore measures deterioration in accuracy.In order to solve this unfavorable condition, provide " Fourier analysis method " and " pattern form fitting process " two kinds as the polarized wave analytical approach among the present invention.

Before each pattern form analytical approach is described, the feature of the pattern form that the simple declaration photodetector array observes.The light intensity distributions that the polarization analysis apparatus that the present invention uses observes such as the formula 3 of key diagram 5 and formula 4 expressions can be represented by the function of the slope (γ) of the ellipticity (ε) of incident light and ellipse.Here, oval slope (γ) defines a certain direction of principal axis (horizontal direction at this moment) as benchmark, but the direction of reference axis is an any direction.Thereby, the change of oval slope (γ), the method that is equivalent to get reference axis promptly changes the situation about putting in order in each zone of wave plate array and polarizer array.For example, as shown in figure 10, if it is the ellipticity of incident polarized light certain (ε value is any), when when then oval slope is 0 ° the intensity distributions of polarization analysis apparatus 1001 horizontal arrangement acquisition being 45 ° with oval slope that identical polarization analysis apparatus 1002 is identical with the result that the occasion of 45 ° of configurations observes.The measurement result that polarization analysis apparatus 1002 obtains is identical with the measurement result that polarization analysis apparatus 1003 obtains, and this is equivalent to change the occasion that puts in order of the wave plate array and the polarizer array of polarization analysis apparatus 1001.Hence one can see that when changing the slope of polarization of incident light ripple, and the intensity distributions pattern that observes moves horizontally in face, and its pattern concaveconvex shape does not change itself.As an example, the ellipticity that Figure 11 illustrates incident light is made as necessarily (ε=0.5), the light intensity distributions that observe when oval angle (γ) is changed by 0 °, 45 °, 90 °.

The situation that pattern form changed when on the other hand, the ellipticity that can expect incident light easily changed.As an example, Figure 12 illustrates slope with incident light and is made as γ=0 ° and certain, makes under the situation that ellipticity ε changes by 0 (rectilinearly polarized light), 0.2,0.5,1 (right-circularly polarized light) light intensity distributions that observes.When incident light was rectilinearly polarized light, pattern became the cycle shape of " hull bottom shape ", and along with the increase of ellipticity, pattern form is stretched, and becomes the straight line cycle shape of the oval limit that is infinitely stretched when circularly polarized light.Thus, the concaveconvex shape of the light intensity distributions pattern that can be observed by photodetector array is obtained the ellipticity (ε) of incident polarized light, is obtained the slope (γ) of incident polarized light as can be known by pattern relative position (coordinate) planar.Figure 13 illustrates in order to implement the apparatus structure example of polarization analysis method of the present invention or analysis of polarized light system.Receive the light intensity distributions 1302 that observes by the polarization analysis apparatus 1301 that utilizes wave plate array and polarizer array at CPU1303, analyze its two-dimensional pattern shape.Below, describe with regard to each polarization analysis method.

At first, as the polarized wave analytic approach based on the match of light intensity distributions shown in a routine the present invention the 18th aspect, the contour nemaline analysis of polarized light algorithm of just analyzing the intensity distributions pattern that observes describes.The level line shape of intensity distributions can simply be obtained by extracting the equal point of intensity from the intensity distribution data that observes.At this moment, if wave plate array and polarizer array to cut apart number less, then for obtaining level line shape more accurately, its effective ways are by The Fitting Calculation the value that at every turn observes to be carried out interpolation, calculate contour nemaline method after obtaining smooth intensity distributions.Level line such as Figure 11 and shown in Figure 12 can obtain the intensity distributions pattern Zone Full that observes, and also can show near the best bright point or obtain near the dim spot pattern characteristics.If can analyze the level line shape and the position of trying to achieve like this, just can obtain the polarization of incident light light state as described above.Here, as the example of isocontour shape analysis method, near contour nemaline slope and the method for position and the method that compares with pre-prepd pattern database the pattern dim spot (minimum value) analyzed in simple declaration.

At first, describe with regard to the method that detects isocontour slope and position.As an example, before Figure 14 has compiled when Fig. 4 and incident light shown in Figure 11 are rectilinearly polarized light (ε=0) and when right-hand circular polarization light time (ε=1) and right-handed elliptical polarization light (ε=0.5), near the isocontour result the intensity distributions pattern dim spot of only describing to observe.The main shaft angular range of general wave plate array and polarizer array is from 0 ° to 180 ° occasion, and there are two places in dim spot in face, for fear of confusion, only show near the level line of dim spot of representative among Figure 14.Near the dim spot level line shape is roughly ellipse as known in the figure, and its shape can show as:

A (φ-φ _o) ²+ B (φ-φ _o) (θ-θ ₀)+C (θ-θ ₀) ²+ D=0 (formula 5)

Wherein, A, B, C and D are constant.The position of this dim spot is present on the particular line of being determined by ellipticity in ellipticity (ε) timing of incident polarization ripple as can be known.For example, dim spot is present on the straight line P-p during rectilinearly polarized light (ε=1), right-hand circular polarization light time dim spot be present in that straight line Q-q goes up or Q '-q ' on, and the dim spot position of the elliptic polarization light time of ε=0.5 is present in that straight line R-r goes up or R '-r ' on.In addition, though not shown in the diagram, symmetry when dim spot position during left circularly polarized light incident and dextrorotation is present on straight line S-s or S '-s '.When the slope (γ) of incident polarized light changed, moved on the above-mentioned straight line definite by ellipticity (ε) the dim spot position as can be known.

In addition, near the oval slope that obtains in the level line mode the dim spot changes with the ellipticity of incident light as can be known.Level line when circularly polarized light becomes that oval the slope of the track of minimum value is 1 by the unlimited elongated and rectilinear form that reaches capacity, and along with reducing of ellipticity, isocontour oval slope diminishes.Utilize this feature, can obtain the polarization of incident light light state.In a word, if the level line shape match of the intensity distributions pattern that can polarization analysis apparatus be observed by above-mentioned formula 5 just can accurately be obtained its slope or position, therefore can accurately obtain polarization of incident light light state (ε and γ).

As another example of isocontour shape analysis method, Figure 15 illustrates the method that the pattern form of will try to achieve and database compare.At this moment, in advance with the pattern form data base system of the various polarized wave states of correspondence, the intensity distributions pattern that polarization analysis apparatus 1501 is observed, transform to contour line data by CPU1502, carry out with database 1503 in the comparison of pattern form of storage, the data that retrieval is consistent, thus obtain the polarization of incident light light state.Obviously, the method that can detect by the isocontour position stated simultaneously and slope and with database method relatively, carry out analysis of polarized light more accurately.

Then, illustrate that the present invention the 19th aspect represents with after the intensity distributions pattern Fourier transform that observes, ask the analysis of polarized light algorithm (Fourier analysis method) of its frequency component.The formula (formula 3, formula 4) of the light intensity distributions that the polarization analysis apparatus that the present invention is used observes is described below once more:

$\stackrel{\→}{u}=\left(\begin{array}{cc}1& 0\\ 0& 0\end{array}\right)\left(\begin{array}{cc}\cos (\mathrm{\φ}-\mathrm{\θ})& \sin (\mathrm{\φ}-\mathrm{\θ})\\ -\sin (\mathrm{\φ}-\mathrm{\θ})& \cos (\mathrm{\φ}-\mathrm{\θ})\end{array}\right)\left(\begin{array}{cc}{e}^{\mathrm{j\α}}& 0\\ 0& 1\end{array}\right)\left(\begin{array}{cc}\cos (\mathrm{\θ}-\mathrm{\γ})& \sin (\mathrm{\θ}-\mathrm{\γ})\\ -\sin (\mathrm{\θ}-\mathrm{\γ})& \cos (\mathrm{\θ}-\mathrm{\γ})\end{array}\right)\left(\begin{array}{c}1\\ \mathrm{j\ϵ}\end{array}\right)$ (formula 6)

${\left|\stackrel{\→}{u}\right|}^2={\stackrel{\→}{u}}^{*}\·\stackrel{\→}{u}$ (formula 7)

If this formula of distortion is also used the incident intensity standardization, then obtain

${\left|\stackrel{\→}{u}\right|}^2\·\frac{1}{1+{\mathrm{\ϵ}}^2}=\frac{1}{2}$ The DC component

$+\frac{1}{4}\·\frac{1-{\mathrm{\ϵ}}^2}{1+{\mathrm{\ϵ}}^2}(1+\cos \mathrm{\α})\·\cos (\mathrm{\Φ}-2\mathrm{\γ})---X$

$+\frac{1}{4}\·\frac{1-{\mathrm{\ϵ}}^2}{1+{\mathrm{\ϵ}}^2}(1-\cos \mathrm{\α})\·\cos (2\mathrm{\Θ}-\mathrm{\Φ}-2\mathrm{\γ})---Y$

$+\frac{\mathrm{\ϵ}}{1+{\mathrm{\ϵ}}^2}\sin \mathrm{\α}\·\sin (\mathrm{\Θ}-\mathrm{\Φ})---Z$ (formula 8)

Here, 2 φ=Φ, 2 θ=Θ ground displacement for simplicity.The two-dimensional intensity distribution that formula 8 expressions observe is made of three frequency components of Φ, 2 Θ-Φ, Θ-Φ.As shown in Equation 8, when each frequency component is placed X, Y, Z, as can be known if incident light is then Z=0 of rectilinearly polarized light (ε=0), if rectilinearly polarized light (ε=1) X=Y=0 then.In addition, the slope of incident polarized light (γ) is by the performance of the phase place of X and Y, the therefore shape invariance of the amplitude intensity distributions of each frequency component when γ changes as can be known, and this is consistent with the result who has stated.

If can calculate its vector by the intensity distributions Fourier transform that polarization analysis apparatus is observed as can be known, and obtain the amplitude and the phase place of each frequency component, just can accurately obtain the polarization of incident light light state by formula 8.In other words, when the value of known each frequency component X, Y, Z, the slope of incident polarized light (γ) as the formula (9):

γ=(phase place of X)/2 or γ=(phase place of Y)/2 (formula 9)

Can be tried to achieve by 1/2 of the phase value of X or Y, the ellipticity of incident light (ε) can be tried to achieve by the amplitude of Z is following.

(formula 10)

Example as the analysis of polarized light of Fourier transform, the ellipticity that Figure 17 and Figure 18 are illustrated in the incident polarization ripple changes and the occasion (Figure 11, Figure 12) of slope variation, the intensity distributions that is observed by photodetector array, the result after this intensity distributions Fourier transform is reached the seize back confiscated property result of incident polarization light state of each frequency component of trying to achieve by Fourier transform.The result of figure represents that the wave plate array of polarization analysis apparatus and polarizer array are made as 64 to be cut apart, to (to mention 177.1875 ° exactly) till 180 ° per that 2.8125 ° of intensity distributions when changing are analyzed from 0 ° with the main shaft angle.In addition, each frequency component incident intensity standardization that will try to achieve through Fourier transform.Consistent from the polarized light state that the value of each frequency component of obtaining is seized back confiscated property as can be known by the result with incident polarized light.

But, in actual polarization analysis apparatus, except stray light from the outside, because of various electrical noises noise on the intensity distributions that observes overlapping.In addition, exist during the light of photodetector array is replied when non-linear, just can not get correct intensity distributions.Thereby only by above-mentioned The Fitting Calculation or Fourier analysis, the error of the polarized light state of being tried to achieve may be bigger.In this case, shown in the present invention the 20th aspect,, can realize more high-precision analysis of polarized light by also using two kinds of level line analytic approach and Fourier analysis methods.For example, by the Fourier analysis result of the intensity distributions pattern that comprises noise, ask near 1 approximate value of the relevant pattern form of pattern dim spot, if can utilize this approximate value with the sampling value match, try to achieve level line shape accurately, then can high precision obtain the polarization of incident light light state.

In addition, as the noise countermeasure of polarization analysis apparatus, and use the method for method (light extinction method) of minimum value (dim spot) position that polarization analysis method and traditional polarization analysis based on level line analysis or Fourier analysis method promptly detect pattern also effective.Such as already described, light extinction method is very simple polarized wave analytical approach, can obtain the state of incident polarized light from coordinate information moment of 1 point (for example smallest point) in the intensity distributions pattern.Utilize this method, for example as (c) of Figure 19 with (d), if can utilize 1 the approximate position by the intensity distributions pattern that observes all being carried out dim spot that Fourier analysis obtains and near the information of 2 curve shapes of the intensity distributions the dim spot, with near intensity distributions pattern the dim spot and the accurate match of sampling value that observes, and high precision is obtained the 2nd approximate value of relevant dim spot position, then with as (b) not any information of tool and the occasion of carrying out the match of sampling spot compare, can make very high-precision analysis of polarized light.(in fact determination data is a two-dimensional signal, but the occasion of one dimension is shown for simplification among Figure 19).In addition, when analyzing all shape of pattern, photodetector array is also unsaturated when considering maximal value, determines light intensity and minute (gating time), because it is peaked saturated that emphasis need not to consider, can obtain the S/N higher data by the long time when minimum value (dim spot).By this method, can carry out more high-precision match, can improve the analysis precision of the wavy attitude of incident polarization near the shape the dim spot.

Below, describe with regard to embodiments of the invention.

(embodiment 1)

In the polarization analysis apparatus aspect Figure 20 illustrates the present invention the 1st to the 6th, wave plate array and the incorporate example of polarizer array.On substrate 2004, form channel patterns, and make polarizer array by stacked multilayer film 2003.The final layer 2002 of this polarizer array layer is stacked thick slightly, force sputter etching simultaneously, then, can make smooth surface by the concavo-convex disappearance that is processed to form from convex surface.Surface smoothing employing mechanical lapping also there is no special problem.Then, make new wave plate pattern between line and line by photoetching process again, and, make the wave plate array by process stacked multilayer film 2001 from convex surface.On the pattern of polarizer array and the wave plate array location, in the part of substrate the location is set in advance and gets final product with mark.Like this, if can polarizer array and wave plate array is integrally formed, then can realize littler polarization analysis apparatus by making up with photodetector array 2005.

(embodiment 2)

In the polarization analysis apparatus aspect Figure 21 illustrates the present invention the 1st to the 6th, with wave plate array and incorporate another example of polarizer array.This occasion forms channel patterns on substrate 2102 surfaces respectively with the back side, and realizes integrated for 2103 layers by be processed to form wave plate array layer 2101 and polarizer array from convex surface.For the location of pattern, substrate 2102 can adopt SiO ₂Deng transparency carrier, and have the location mark.Combination by this integrated wave plate/polarizer array and photodetector array 2104 can realize the small polarization light analytical equipment.

(embodiment 3)

As can be known on any polarization analysis apparatus of wave plate angle change type and wave plate phase differential variation type, intensity becomes zero position and does not show as and a little show as line when a certain specific polarization ripple incident by Fig. 4 and Fig. 7.For example, in the occasion of angle change type (Fig. 4), the light time of incident dextrorotation, left-handed circularly polarized wave, intensity distributions is wire, and the occasion of phase differential variation type (Fig. 7), when the main shaft angle equidirectional of incident and wave plate or the rectilinearly polarized light of orthogonal directions, intensity distributions is wire.When the polarized wave analytical algorithm adopts dim spot to detect method,,, be difficult to do the judgement of polarized light state because bottom position (or peak position) is not decided to be a bit at these abnormity point and near the polarized light state it.

So as the embodiment of the present invention the 7th aspect, Figure 22 illustrates the method that combination wave plate angle change type polarization analysis apparatus and wave plate phase differential variation type polarization analysis apparatus complementally use.Main shaft angle change type quarter wave plate array 2201 and hysteresis (phase differential) change type wave plate array 2202 are formed on the same substrate, and make up, and distribute by optical detector array 2204 measured light intensity with polarizer array 2203.Make various patterns in available same processing on convex surface processing type photonic crystal, therefore also can make the such complex pattern of diagram easily.Among the figure each zone is arranged along the y direction of principal axis, but each regional allocation position or order are any.At this moment,, on the opposing party zone, also can accurately obtain null position, so the judgement of all polarized wave states is out of question even intensity distributions becomes wire and is difficult to differentiate polarized light state on the side zone.The invention has the advantages that: even if so complicated structure, can be fully small-sized and by using photonic crystal with simple processing realization.

(embodiment 4)

The polarization analysis apparatus of the present invention the 1st to the 7th aspect constitutes by making up polarizer array and wave plate array and these three planar devices of photodetector array, and therefore the multipath reflection of light may throw into question between the polarizer and wave plate and photo detector.As the method for the influence of avoiding this multipath reflection, Figure 23 illustrates an embodiment of the present invention the 8th aspect.The cross section of the array of wave plate shown in Figure 23 2301, polarizer array 2302 and photodetector array 2305.This occasion, channel patterns territory 2303 forms at regular intervals in the wave plate array 2301, and just there is the zone of channel patterns in the zone of working as wave plate.Other zone of no groove is a multilayer film only, to optical transparency or opaque.Equally, on polarizer array base palte 2302, what form polarizer pattern 2304 also only is a part, and other zone is to optical transparency or opaque.With such 2 wave plate arrays and polarizer array and photodetector array combination, and to light incident direction tilted configuration.As shown in the figure, by the pitch of suitable selection channel patterns or the interval and the insertion angle of 2 arrays, can significantly reduce the component that behind multipath reflection between each face, detects in the light by the reflection of polarizer array by photo detector.

(embodiment 5)

Another embodiment about the method for the influence of light multipath reflection between the wave plate array that reduces the present invention the 8th aspect and polarizer array and the photodetector array shown in Figure 24.This is to be configured between wave plate array 2403 and the polarizer array 2404 or the structure between wave plate array 2404 and the photodetector array 2405 by light absorbing substrate 2401 and 2402.With these component affixings or by on a substrate, becoming methods such as film production to come incorporate occasion too.In this structure, itself can die down transmittance intensity, but thinks that the sensitivity of strength ratio optical detector of common incident light is fully strong, the therefore practical no problem of going up.The light that reflects on polarizer array 2404 or photodetector array 2405 etc. is absorbed in the process in propagating absorption layer 2401 and 2402 and dies down gradually, so can fully reduce secondary reflection and the component that detected by detector again.

(embodiment 6)

As the embodiment of the present invention the 9th aspect, Figure 25 is illustrated between each zone of wave plate array and the polarizer array transparent region is set, and measures the structure example that incident intensity distributes or the loss of wave plate array and polarizer array distributes.Each zone of wave plate array 2501 is arranged separated from one anotherly, equally each zone of polarizer array 2502 is arranged separated from one anotherly.The zone of the pattern of no polarizer array of design or wave plate array is to optical transparency in advance.When utilizing photonic crystal, the structure that diagram is complicated like that also can simply make by processing once.During with this wave plate array and polarizer array and photodetector array 2503 combinations, each photo detector can be divided into the zone 2504 of mensuration by the light component of two of wave plate and the polarizers; Measure the zone 2505 of only passing through the light of wave plate; Measure the zone 2506 of only passing through the light of the polarizer; And measure not zone 2507 by the light (by the light of transparent region) of the wave plate and the polarizer.Can be by learning intensity distribution of incident light information in the light intensity distributions of zone 2507 mensuration.Can distribute by the loss of the 2505 intensity distributions evaluation wave plate arrays of measuring equally, by the loss distribution of estimating polarizer array in regional 2506 intensity distributions of measuring in the zone.Utilize these data, recoverable is measured the intensity distributions of measuring on the zone 2504, can do high-precision polarized wave analysis.

(embodiment 7)

As second embodiment of the present invention the 9th aspect, the periphery that Figure 26 is illustrated in wave plate array and polarizer array is provided with the example of transparent region.The part that works as wave plate in the wave plate array base palte 2601 only is near certain zone of the periodic pattern central authorities, and other neighboring area is a transparent region.Equally, in polarizer array base palte 2602 as the polarizer work only near the central authorities, peripheral part becomes transparent region.Complicated patterns also can utilize the photonic crystal technology simply to form like this.Polarizer array and wave plate array become rectangular shape respectively, and the end limit of pattern is not overlapping when overlapping 2 arrays, and only the light by a certain side also arrives photo detector.In this case, zone 2604 mensuration of photodetector array 2603 are by wave plate and the polarizer two sides' light intensity distributions.Only by the light of wave plate, zone 2606 acceptance are only by the light of the polarizer in zone 2605 acceptance, and regional 2607 measure the light intensity by one of the polarizer and wave plate.The loss of being learnt the wave plate array by the measurement result in zone 2605 distributes, and learns that from the mensuration in zone 2606 loss of polarizer array distributes.In addition, think that incident light is generally Gaussian beam, therefore also can estimate the beam distribution of incident light by the measurement result in zone 2607.Utilize the loss distribution and the intensity distribution of incident light that are obtained, can make the high-precision correction of determination data.

(embodiment 8)

In polarization analysis apparatus of the present invention, near each zone boundary of employed wave plate array and polarizer array, can not avoid scattering of light or diffraction on the structure, so the picture of light is mixed and disorderly.For the light of the boundary vicinity of removing this array, and obtain clearer and more definite intensity distributions pattern, Figure 27 illustrates the embodiment of the present invention the 10th aspect.Disposed the lightproof area of representing with black line 2703 at wave plate array 2701 and polarizer array 2702 each regional boundary member, the light that incides this part can not arrive photo detector.Perhaps, the zone from wave plate array and the light incident partly of polarizer array boundary in photodetector array 2704 is provided with lightproof area 2705, thereby can remove scattered light and diffraction light.

(embodiment 9)

As the embodiment of the present invention the 11st aspect, Figure 28 illustrates an example polarization analysis apparatus of the present invention is configured in 4 planes, the method for the error at measurment that avoidance incident beam shift in position causes.By utilizing photonic crystal, can realize fully small-sized polarization analysis apparatus among the present invention, therefore easily a plurality of polarization analysis apparatus are configured in the zonule, or easily that a plurality of polarization analysis apparatus are integrated and be integrated into a device.Planar dispose polarization analysis apparatus 2801 to 2804 side by side, thereby in the occasion of incident beam change, light also can shine 4 middle arbitrary regions.By suitably being designed into the beam diameter of irradiating light beam, no matter light beam irradiates to which position, also can obtain the equal above information of intensity distributions by the polarization analysis apparatus acquisition of playscript with stage directions invention.For example diagram when light incides the middle section 2805 of 4 polarization analysis apparatus, respectively obtains 1/4 strength distributing information by each zone like that, can carry out analysis of polarized light by synthetic these information.If further the quantity of the polarization analysis apparatus of configuration in the increase face then can be tackled bigger light beam change.

(embodiment 10)

As the embodiment of the present invention the 13rd aspect, Figure 29 illustrates the ellipsometers that combination polarization analysis apparatus of the present invention and lasing light emitter are realized.Figure 29 only is that an example adopts ellipsometers of the present invention, adopts the present invention to realize that the structure of ellipsometers also can consider other any.In configuration composite wave chip arrays and the photo detector 2903 of polarizer array and the device central authorities of lasing light emitter 2902, dispose test portion platform 2906 among this figure.Polarized light state from the emergent light of laser instrument is predicted.On test portion platform 2906, be provided with and want the Film sampling 2901 measured, adjust lens, make laser convergence arrive sampling, make reflected light become parallel beam simultaneously and arrive polarization analysis apparatus 2903 2904.Detect from the reflected light of taking a sample with polarization analysis apparatus 2903, and calculate the polarization of reflected light light state from the intensity distributions that is measured to by CPU2905.In the ellipsometers, generally the polarisation of light light state is used P ripple and S wave amplitude strength ratio (Ψ) and phase differential (Δ) expression.Usually incident light adopts 45 ° rectilinearly polarized light (Ψ=1, Δ=0), measures at this moment catoptrical Ψ ' and Δ '.Can obtain the Fresnel reflection rate (R of P ripple in the sampling, S ripple by measurement result _P, R _S), i.e. film thickness and refractive index.

(embodiment 11)

As another embodiment of the present invention the 13rd aspect, Figure 30 illustrates the simple type beam split ellipsometers that adopts polarization analysis apparatus of the present invention to realize.At this moment also same with the occasion of the ellipsometers of embodiment 10, on test portion platform 3004, place test portion substrate 3001, irradiation is from the light of different wavelength of laser source group 3002 respectively, and adopts respectively that the shaven head group 3003 that is subjected to of corresponding each wavelength detects the reflected light of each wavelength.Analyze the polarized light state that detected by shaven head by CPU3005, but by utilizing a plurality of wavelength can estimate the thickness of test portion, membranous more exactly.

If realize this beam split ellipsometers with conventional art, then need to be provided with a plurality of high-precision rotating mechanisms or drive part, having not only, device becomes shortcoming large-scale but also that minute is elongated.By comparison, can realize the small polarization light analytical equipment by utilizing photonic crystal among the present invention, not only easily a plurality of optical systems be accommodated in the device, can realize the device of high reliability owing to no drive part.In addition, can differentiate polarized light state, can make minute very short by the moment as a result that photodetector array obtains.

(embodiment 12)

As the embodiment of the present invention the 14th and the 15th aspect, Figure 31 illustrates the thickness/membranous monitor in the films formation processing such as a routine evaporation or sputter.Consider to place in the vacuum tank 3106 substrates 3101, make the processing unit (plant) of substance source 3107 film forming to the substrate by control circuit 3105 is controlled.As shown in the figure, what lasing light emitter 3102 and polarized wave analytical equipment of the present invention were set in the container of this film formation device is subjected to shaven head 3103, and laser is shone to substrate, detects reflected light from substrate by the light accepting part head.Among the figure miniature laser source is arranged in the container, also light source can be configured in external container, utilize the optical fiber of polarized wave maintenance etc., import light in the container.Analyze from the signal that is subjected to shaven head among the CPU3104, can monitor the thickness and the refractive index of film in the film forming procedure in real time by light intensity distributions.In addition, with the thickness that monitors or membranous information feedback auto levelizer,, can carry out tight film forming management by the control membrance casting condition.

Thisly form real-time thickness/membranous monitor in the processing at film, extremely useful to high-precision thickness, membranous management, be the technology that did not in the past have.Traditional ellipsometers is a large-scale plant, almost can not monitor thickness/membranous in processing unit (plant) in real time.In addition, there is for example such film thickness monitor of quartz crystal, comprises the membranous of refractive index but can not monitor.By the present invention, can realize the subminiaturization or the high reliability of ellipsometers, therefore as vacuum processed thickness/membranous monitor, can import to device inside easily.In addition, such as already described, the present invention does not need the information of light intensity absolute value, can differentiate thickness/membranous and only distribute with relative intensity.Thereby, can not be subjected to film forming matter to be attached to window etc. and cause the influence ground of light intensity change to be monitored.

In common vacuum processing unit (plant), general for forming uniform film, while make rotation of substrate supporter or revolution (or two sides) carry out film forming.In the past to the unusual difficulty of the thickness of this roving substrate or membranous monitoring.In this case,, thickness/membranous mensuration fully at a high speed can be realized,, thickness/membranous can be monitored in real time for example by consistent with the sample period of mensuration etc. the method for the swing circle that makes the substrate supporter by utilizing the present invention.If the sample period is worked hard, then once to the occasion of a plurality of substrate film forming, also can be by each substrate monitoring thickness/membranous.In addition, have at the substrate supporter and to rock and the incoming position of light when change is arranged, also can be by enlarging the beam diameter of incident light, or adopt the intensity distributions bearing calibration shown in the present invention the 9th aspect and embodiment 6 and embodiment 7 or the method for the change of the reply light-beam position shown in the present invention the 11st aspect and the embodiment 9 to avoid measuring error.

(embodiment 13)

As the embodiment of the present invention the 16th aspect, Figure 32 illustrates the structure that processing unit (plant) inside is imported a plurality of ellipsometers.In this example,, utilize optical fiber 3208 that laser is imported in the vacuum tank 3206 from the lasing light emitter 3202 of processing unit (plant) outside.Fiber optic tap is a plurality of, and the diverse location reflection of light on each substrate 3201 from the optical fiber end outgoing detected respectively by polarization analysis apparatus group 3203 of the present invention.By this structure, not only can monitor thickness in the film forming procedure/membranous, and the thickness/membranous distribution of different parts on the monitoring substrate in real time.The distributed intelligence that CPU3204 is calculated feeds back to the film forming control device 3205 of device, as long as the component that can controlling diaphragm or the distribution of rate of film build just can form uniform more film.

To carrying out simple declaration by the homogenization method of film in the processing of the present invention's realization.Figure 33 is the example that the offside sputtering unit is installed a plurality of film thickness monitoring devices.Target 3301 vertically disposes, installation base plate around rotary drum 3302.Usually, thickness and membranous on the sense of rotation of substrate evenly, but vertically inhomogeneous and past more peripheral thickness is just more little.Therefore, for enlarging homogeneous area longitudinally, arrangement corrects plate 3303 around target has been proposed and the method for control plasma density.All the time, in order to improve the homogeneity of film, have to adopt the film thickness distribution after the off-line mode is measured film forming, and adjust the shape of shield and the method that the complexity of the condition that provides is repeated in the installation site, therefore very difficulty with distribution homogenization to 1～2% or below it.In contrast to this, adopt the occasion of ellipsometers 3304 of the present invention, by real-time measurement result, thickness/membranous distributed intelligence that the calculating of CPU3305 is obtained, feed back to film forming control device 3306, control is applied to the aperture of the electric power and the shield of target, thereby it is certain to adjust film thickness distribution by online mode.

Figure 34 illustrates another example of the homogenization of film in the relevant sputtering unit.Consideration is disposed a plurality of gas introduction ports 3402 around target 3401, be respectively equipped with the sputtering unit of the mass flow controller 3403 of control airshed.In this sputtering unit, supply with target airshed on every side by control, can local control plasma density.Membranous and the rate of film build of general film forming is relevant with plasma density, therefore by the plasma density in each position of control, each locational thickness of may command/membranous.As long as can utilize ellipsometers 3404 of the present invention, the information feedback of and the thickness that will be obtained by CPU3405 in real time/membranous is to control circuit 3406, and with plasma density in the online mode control device, just can accomplish evenly and the film forming of homogeneous.

Figure 35 illustrates the 3rd example about the method for the film forming control that utilizes sputtering unit.In negative electrode 3501 inside of magnetron sputter reactor device, 3,503 two of configuration permanent magnet 3502 and electromagnet.In this device, can flow through current of electromagnet by control, control the density of all plasmas.The distributed intelligence that utilizes ellipsometers 3504 of the present invention and CPU3505 to monitor is fed back to control circuit 3506 and carries out the control of electromagnet, thereby can control plasma density in real time, but therefore online mode control thickness/membranous.

At last film homogenization method in the one routine vacuum deposition apparatus is shown at Figure 36.Consideration can be disposed the multi-source evaporation coating device of a plurality of vapor deposition source 3602 in container.In this device, be added to the electric power partition of each vapor deposition source by control, can control thickness and membranous distribution.Utilize ellipsometers 3603 of the present invention, real-time monitoring substrate 3601 each locational thickness/membranous, and the distributed intelligence that CPU3604 calculates fed back to film forming control device 3605.If control the electric power amount that is added to each vapor deposition source, just can make evenly and the film of homogeneous according to the distributed intelligence that obtains after measured.

(embodiment 14)

Utilize the polarization analysis apparatus of the new method of the wave plate array that uses among the present invention and polarizer array, have no drive division and the reliability height, and compare advantages such as significantly to shorten minute with conventional apparatus.In addition, utilize photonic crystal, not only can realize fully small-sized device, and can on the major axes orientation of each array, carry out very high-precision control.But,,, also be difficult to accomplish and i.e. 1/4 wavelength (pi/2 radian) strict conformance of ideal value even carry out detailed machining control for the phase differential (hysteresis) of wave plate array.If consider the structure and the creating method of photonic crystal, when then not distributing in processing, the phase differential in each wave plate zone of wave plate array becomes certain value also predicting on region-wide with design load occasion devious.

As the method for the phase differential skew of proofreading and correct this wave plate array, Figure 37 illustrates first embodiment of the present invention the 21st aspect.This is a phase differential of being obtained wave plate by the strength distributing information that the light time to the wavy attitude of a certain specific polarization of polarization analysis apparatus incident observes, proofreaies and correct the method for its skew.As an example, consider to adopt Glan-high polarizers 3701 of extinction ratio such as thomson prism, to the occasion of polarization analysis apparatus 3702 incident rectilinearly polarized lights.The angle of inclination of polarized wave (this moment be any) at this moment, the light intensity distributions that the phase differential that the interior wave plate array of polarization analysis apparatus is shown observes when being respectively 70 °, 90 ° and 110 °.As mentioned above, the intensity distributions pattern during rectilinearly polarized light incident is " hull bottom shape " shape, and the elliptical shape of hull bottom (ellipticity) changes with the phase differential of wave plate array as seen from the figure.Thereby, by analyzing the shape of the intensity distributions pattern that the light time obtained of incident linearly polarized wave on the polarization analysis apparatus, can accurately estimate the phase differential skew of wave plate array.Here, the method for patterning that observes during as the incident of analysis rectilinearly polarized light can adopt level line analytic approach or the Fourier analysis method stated.

(embodiment 15)

As the method for the phase differential skew of proofreading and correct the wave plate array, Figure 38 illustrates second embodiment of the present invention the 21st aspect.To the light of polarization analysis apparatus 3801 incident random polarization light states, and the light intensity distributions that observes is carried out Fourier transform by CPU3802.At this moment each frequency content that obtains through Fourier transform as mentioned above, by formula 8 expressions.Each frequency component is placed the occasion of X, Y, Z, and the phase differential (α) in each wave plate zone of wave plate array can be obtained by following formula.

Or (formula 11)

Promptly, when adopting Fourier transform analytic intensity distribution shape, by the value of each frequency component of trying to achieve, as mentioned above through Fourier transform, not only can obtain the ellipticity (ε) of incident light and the slope (γ) of polarized wave, and can obtain phase differential (α) value of wave plate simultaneously.

As mentioned above, in polarization analysis method of the present invention, as long as the phase differential of wave plate array is in region-wide certain (evenly) of array, the phase differential size just can be a problem.No matter phase difference value is got what value (except that the occasion of α=0 °), by the intensity distributions pattern that assay determination is arrived, can both accurately estimate the skew of phase differential, can obtain the value of correct incident polarized light.This compares very effective with the ellipsometers that adopted the single wave plate or the polarizer in the past.For example, the light extinction method that in traditional ellipsometers, adopts, when the phase differential of use wave plate when 1/4 wavelength is offset a little, because extinction point can not be done polarized wave analysis accurately from original position deviation when the rotation polarizer or wave plate.

(embodiment 16)

The wave plate array of the polarization analysis apparatus that uses among the present invention and polarizer array are arranged zones of different a plurality of, and scattering of light or diffraction take place for each regional boundary member and discontinuous.Scattered light and diffraction light manifest on signal Processing and are noise, become the essential factor of deterioration analysis of polarized light precision.Therefore, in order to realize high-precision device, existence is shown in the present invention the 10th aspect, wave plate array that in polarization analysis apparatus, uses or polarizer array or photodetector array configuration lightproof area, not accept the method for scattered light or diffraction light, but eliminate the method for the influence of scattered light or diffraction light as not adopting this light-shielding structure, Figure 16 illustrates the embodiment of the signal processing method shown in the present invention the 22nd aspect.

Light by wave plate array 1601 and polarizer array 1602 incides photodetector array 1603.As photodetector array, to suppose to adopt general CCD, then single photo detector is of a size of several μ m degree, and this each area size with wave plate array and polarizer array compares fully little.Thereby, accepting there are a plurality of photo detectors respectively by through intersecting on the photo detector zone of each regional light that wave plate array and polarizer array make.In the electric signal of these photo detector outputs, do not adopt from accepting to comprise signal from zone 1604 outputs of the light of the scattered light of the boundary member of wave plate array and polarizer array or diffraction light, and, so just can realize high-precision analysis of polarized light by only the signal from zone 1605 outputs of the light of the influence of accepting no scattered light or diffraction light being added up to or on average obtaining each regional light intensity.Among the figure, do not use the zone 1604 of signal to account for the amount of a row photo detector up and down in each zone, but the method that occupies in zone or be of a size of arbitrarily can change with the structure of polarization analysis apparatus.The sort signal disposal route can the very simple and supercomputing with CPU, therefore is the very effective method of improvement of polarized light being measured precision.

The industrial possibility of utilizing

The polarization analysis apparatus realized by the present invention and utilize this polarization analysis apparatus Ellipsometers, no drive division and small-sized, but and high accuracy and high speed analysis incident light Polarized light state. By utilizing photonic crystal to cut down composed component, the position adjustment is held Easily, and the phase difference skew that can proofread and correct by pattern analysis the wave plate array, therefore can realize The very high and device at a low price of manufacturing.

Thereby, can by after at 1 apparatus for manufacturing thin film a plurality of ellipsometers being set with Online mode is measured the film of the test portion that the large-scale plant that in the past utilizes high price measures in the off-line mode Thick or membranous. Polarization analysis apparatus of the present invention like this or ellipsometers are suitable for thin Control or qualitative control that film is made, replaceable conventional method.

Claims (35)

1. a polarization analysis apparatus is characterized in that comprising: the wave plate array that is provided with a plurality of zones that the phase differential that brings transmitted light is the same and optical axis direction is different; And the polarizer array that is provided with the different a plurality of zones of the polarized wave direction that sees through, each polarizer of each wave plate of described wave plate array and described polarizer array is configuration overlappingly respectively, and has disposed the photodetector array that can accept individually by the light that only makes the zone that the specific polarization wave component sees through of the described wave plate and the described polarizer.

2. a polarization analysis apparatus is characterized in that comprising: the wave plate array that is provided with at least 2 above strip regions that the phase differential that brings transmitted light is the same and optical axis direction is different separately; And the polarizer array that is provided with at least 2 different above strip regions of the polarized wave direction that sees through, described wave plate array and described polarizer array dispose striped separately with crossing one another, and have disposed the photodetector array that can individually accept by the light of each intersection region.

3. as claim 1 or the described polarization analysis apparatus of claim 2, it is characterized in that: described wave plate array and described polarizer array are made of the dielectric multilayer film, the shape of this dielectric multilayer film on the stacked direction upper strata has periodically, and has the periodicity concaveconvex shape of repetition in the shape of each layer direction in the face of determining by each zone.

4. as claim 1 or the described polarization analysis apparatus of claim 2, it is characterized in that: between described wave plate array and the described polarizer array or the side between described polarizer array and the described photodetector array or two sides the layer of light absorption is set, perhaps on described wave plate array, described polarizer array and described photodetector array at least 1, by on each regional border of described array, forming transparent region or zone of opacity, make unwanted multipath reflection optical attenuation.

5. as claim 1 or the described polarization analysis apparatus of claim 2, it is characterized in that: be provided with the isotropic transparent region of incident polarized light in the neighboring area of described wave plate array and described polarizer array, perhaps be provided with the isotropic transparent region of incident polarized light in the part of described each regional boundary member of wave plate array and the part of described each regional boundary member of polarizer array, thereby when measuring the light intensity distributions in and each polarizer zone regional by each wave plate, the transmission loss of measuring intensity distribution of incident light and described wave plate array and described polarizer array distributes, with the correcting determination result.

6. as claim 1 or the described polarization analysis apparatus of claim 2, it is characterized in that: shading light part is set at described wave plate array and each regional boundary member of described polarizer array, the perhaps regional shading of photodetector array that will be corresponding with described wave plate array and described each regional boundary member of polarizer array, thus the influence of diffraction of light or scattering in boundary member in earlier stage suppressed.

7. polarization analysis apparatus is characterized in that comprising: the wave plate array that is provided with the same and a plurality of zones that phase differential transmitted light is different of optical axis direction; And the polarizer array that is provided with the different a plurality of zones of the polarized wave direction that sees through, described wave plate array and described polarizer array dispose with overlapping each other, and have disposed the photodetector array that can individually accept by the light that only makes the zone that the specific polarization wave component sees through of described wave plate array and described polarizer array.

8. polarization analysis apparatus, it is characterized in that comprising: the wave plate array that is provided with the same and at least 2 the above strip regions that phase differential transmitted light is different of optical axis direction, and the polarizer array that is provided with at least 2 different above strip regions of the polarized wave direction that sees through, described wave plate array and described polarizer array dispose striped separately with crossing one another, and have disposed the photodetector array that can individually accept by the light of each intersection region.

9. as claim 7 or the described polarization analysis apparatus of claim 8, it is characterized in that: described wave plate array is had periodically by shape on stacked direction, and have the repetition period of determining by each zone and on a common direction, have the periodically dielectric multilayer film formation of concaveconvex shape, described polarizer array is had periodically by shape on stacked direction, and each layer shape direction in the face of determining by each zone has the dielectric multilayer film formation of the periodicity concaveconvex shape of repetition.

10. as claim 7 or the described polarization analysis apparatus of claim 8, it is characterized in that: between described wave plate array and the described polarizer array or the side between described polarizer array and the described photodetector array or two sides the layer of light absorption is set, perhaps on described wave plate array, described polarizer array and described photodetector array at least 1, by on each regional border of described array, forming transparent region or zone of opacity, make unwanted multipath reflection optical attenuation.

11. as claim 7 or the described polarization analysis apparatus of claim 8, it is characterized in that: be provided with the isotropic transparent region of incident polarized light in the neighboring area of described wave plate array and described polarizer array, perhaps be provided with the isotropic transparent region of incident polarized light in the part of described each regional boundary member of wave plate array and the part of described each regional boundary member of polarizer array, thereby when measuring the light intensity distributions in and each polarizer zone regional by each wave plate, the transmission loss of measuring intensity distribution of incident light and described wave plate array and described polarizer array distributes, with the correcting determination result.

12. as claim 7 or the described polarization analysis apparatus of claim 8, it is characterized in that: shading light part is set at described wave plate array and each regional boundary member of described polarizer array, the perhaps regional shading of photodetector array that will be corresponding with described wave plate array and described each regional boundary member of polarizer array, thus the influence of diffraction of light or scattering in boundary member in earlier stage suppressed.

13. polarization analysis apparatus, it is characterized in that: possess claim 1 each described polarization analysis apparatus and claim 7 each described polarization analysis apparatus to the claim 9 to the claim 3 simultaneously, make the light beam of measurement incide each polarization analysis apparatus.

14. polarization analysis apparatus as claimed in claim 13, it is characterized in that: between described wave plate array and the described polarizer array or the side between described polarizer array and the described photodetector array or two sides the layer of light absorption is set, perhaps on described wave plate array, described polarizer array and described photodetector array at least 1, by on each regional border of described array, forming transparent region or zone of opacity, make unwanted multipath reflection optical attenuation.

15. as claim 13 or the described polarization analysis apparatus of claim 14, it is characterized in that: be provided with the isotropic transparent region of incident polarized light in the neighboring area of described wave plate array and described polarizer array, perhaps be provided with the isotropic transparent region of incident polarized light in the part of described each regional boundary member of wave plate array and the part of described each regional boundary member of polarizer array, thereby when measuring the light intensity distributions in and each polarizer zone regional by each wave plate, the transmission loss of measuring intensity distribution of incident light and described wave plate array and described polarizer array distributes, with the correcting determination result.

16. as claim 13 or the described polarization analysis apparatus of claim 14, it is characterized in that: shading light part is set at described wave plate array and each regional boundary member of described polarizer array, the perhaps regional shading of photodetector array that will be corresponding with described wave plate array and described each regional boundary member of polarizer array, thus the influence of diffraction of light or scattering in boundary member in earlier stage suppressed.

17. a polarization analysis apparatus is characterized in that: a plurality of by each described polarization analysis apparatus in the claim 1 to 16 is planar disposed, avoid the error at measurment that causes by the incident beam shift in position.

18. an optical measurement instrument is characterized in that: adopt claim 1 each described polarization analysis apparatus to the claim 17.

19. a photo measure mode is characterized in that: adopt claim 1 each described polarization analysis apparatus to the claim 17.

20. ellipsometers, it is characterized in that: make polarized light incident mensuration test portion at a predetermined angle, to import claim 1 each described polarization analysis apparatus to the claim 17 from the reflected light of measuring test portion, by the light intensity distributions that photodetector array obtains, obtain the amplitude reflectivity ratio of P polarized light component and S polarized light component.

21. ellipsometers, it is characterized in that: form in the device at vacuum film, make the polarized light substrate surface in the incident thin-film deposition at a predetermined angle, to import claim 1 each described polarization analysis apparatus to the claim 17 from the reflected light of substrate surface, the light intensity distributions that is obtained by photodetector array is obtained the amplitude reflectivity ratio of P polarized light component and S polarized light component.

22. a thickness and membranous control device is characterized in that: will feed back to the control device of film forming speed or film formation time by the thickness and the membranous information of claim 20 or the described ellipsometers acquisition of claim 21.

23. a thickness and membranous control device, it is characterized in that: be provided with at least 2 above claims 20 or the described ellipsometers of claim 21, thickness and the membranous information that obtains by each position measurement with the substrate diverse location feed back to thickness and membranous distribution correction control apparatus.

24. polarization analysis method, it is characterized in that: the wave plate array that is provided with a plurality of zones that phase differential is certain and optical axis direction is different, and the polarizer array that is provided with the different a plurality of zones of the polarized wave direction that sees through, on the direction of light incident, make described wave plate array in front, described polarizer array is overlay configuration in the back, and can accept individually by certain zone of wave plate and with the photodetector array two-dimensional arrangement of the light in the polarizer zone of this region overlapping, in such polarization analysis apparatus, the two-dimensional intensity distribution pattern that utilization observes by described photodetector array is obtained the polarization of incident light light state only by discrete cosine component and maximum three features that frequency component is represented.

25. polarization analysis method as claimed in claim 24, it is characterized in that: utilize the maximum point of the intensity distributions pattern that observes by described photodetector array or near the pattern form feature the smallest point, with sampling value match or interpolation, calculate extinction point or the wave plate of light quantity smallest point and the orientation of the polarizer of bringing oval symmetry, and obtain the polarization of incident light light state.

26. polarization analysis method as claimed in claim 24 is characterized in that: carry out Fourier transform by the intensity distributions pattern that described photodetector array is measured to, obtain the polarization of incident light light state.

27. a polarization analysis method is characterized in that: and, obtain the polarization of incident light light state with described polarization analysis method of claim 25 and the described polarization analysis method of claim 26.

28. as claim 24 each described polarization analysis method to the claim 27, it is characterized in that: by analyzing the shape of the intensity distributions pattern that described photodetector array observes, detect the value of the described wave plate array phase difference of using in the described polarization analysis apparatus, the error of phase differential when proofreading and correct described wave plate array and making.

29. analysis of polarized light system, it is characterized in that: the wave plate array that is provided with a plurality of zones that phase differential is certain and optical axis direction is different, and the polarizer array that is provided with the different a plurality of zones of the polarized wave direction that sees through, on the direction of light incident, make described wave plate array in front, described polarizer array is overlay configuration in the back, and can accept individually by certain zone of wave plate and with the photodetector array two-dimensional arrangement of the light in the polarizer zone of this region overlapping, in such polarization analysis apparatus, the two-dimensional intensity distribution pattern that utilization observes by described photodetector array is obtained the polarization of incident light light state only by discrete cosine component and maximum three features that frequency component is represented.

30. analysis of polarized light as claimed in claim 29 system, it is characterized in that: utilize the maximum point of the intensity distributions pattern that observes by described photodetector array or near the pattern form feature the smallest point, with sampling value match or interpolation, calculate extinction point or the wave plate of light quantity smallest point and the orientation of the polarizer of bringing oval symmetry, and obtain the polarization of incident light light state.

31. analysis of polarized light as claimed in claim 29 system is characterized in that: carry out Fourier transform by the intensity distributions pattern that described photodetector array is measured to, obtain the polarization of incident light light state.

32. an analysis of polarized light system is characterized in that: and, obtain the polarization of incident light light state with described polarization analysis method of claim 25 and the described polarization analysis method of claim 26.

33. as claim 29 each described analysis of polarized light system to the claim 32, it is characterized in that: by analyzing the shape of the intensity distributions pattern that described photodetector array observes, detect the value of the described wave plate array phase difference of using in the described polarization analysis apparatus, the error of phase differential when proofreading and correct described wave plate array and making.

34. signal processing method, it is characterized in that: in claim 24 to the claim 28 in each described polarization analysis method, in order to remove from described wave plate array or the scattered light of each regional boundary member of polarizer array and the influence of diffraction light, and from the signal of described photodetector array output, remove signal from the photo detector zone of accepting described scattered light and diffraction light.

35. signal processing method, it is characterized in that: in claim 29 to the claim 33 in each described analysis of polarized light system, in order to remove from described wave plate array or the scattered light of each regional boundary member of polarizer array and the influence of diffraction light, and from the signal of described photodetector array output, remove signal from the photo detector zone of accepting described scattered light and diffraction light.

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