CN1871505A

CN1871505A - Spherical light-scatter and far-field phase measurement

Info

Publication number: CN1871505A
Application number: CN 200480005304
Authority: CN
Inventors: 雷蒙德·J·卡斯顿瓜伊
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-02-26
Filing date: 2004-02-26
Publication date: 2006-11-29

Abstract

A far-field measurement instrument (10, 50, 150) has multiple imaging lenses (14, 40) cut into a pentagon shape and arranged in geodesic spherical configuration with a common field of view focused on the source (S) of the scattered light (26) to be measured. Aspheric lenses (40) are used to facilitate collimation of large incident angles of scattered light. A measurement module (12, 78), such as a camera, is used behind each lens (14). The measurement module may consist of an interferometer or a Shack-Hartman wavefront sensor (74), thereby enabling the measurement of both intensity and phase of the scattered light (26).

Description

Spherical light-scatter and far-field phase measurement

Related application

The application is the U.S. Provisional Application of the sequence number 60/452,300 of proposition on March 5th, 60/450,185 and 2003 based on the sequence number that proposed on February 26th, 2003.

Technical field

The present invention relates to the scatterometry technology.Particularly, it relates to by using hemisphere face and/or spherical light-scatter and phase measurement to measure the far-field measurement of the scattering wave front of reflection or transmission simultaneously.

Background technology

Scatterometer is used for how analyzing light source and material behavior in sphere (" scattering ") radiation reflection or transmitted light by measuring specific material or surface.If the light of surperficial non-radiating oneself, the situation of LED for example, then can with certain angle for example the light source-guide of laser to the surface, to produce scattered light from incidence point.If the surface is a minute surface, and is perhaps opposite, the surface is with one way system radiation incident light, and then all light all will be directed leaving from the surface along single light beam.Otherwise reflected light can be scattered and radiation spreads all over hemisphere on the test surfaces.The science of scattered light and mathematics have obtained development well.For example, see the book of J.C.Stover: " light scattering: measure and analyze ", McGraw-Hill, NY (1990).

Typical scatterometer comprises: laser instrument, and it sends light beam on test surfaces; And single detector, it mechanically scans the circular arc of 180 degree around the point that illuminates.The visual field of detecting device remain on the point that illuminates and no matter the visual angle how.At each place, visual angle, carry out the measurement of light intensity, thereby generate the space distribution of scattered light.The characteristic of test surfaces is depended in distribution on the scan bow, comprises under type of material, surfaceness, reflectivity, color, surface structure, the surface damaging and other.

Scan single detecting device and greatly limited for example ability in the big zone of whole hemisphere of measurement scanning, and the ability of the great dynamic range of measured intensity.In addition, scan whole hemisphere and take a lot of times.So, just become very unrealistic with the scattering on the many points on the single detectors measure test surfaces.Measuring dynamic event in a plurality of measuring positions in this way is impossible equally.

In order to overcome these restrictions, a plurality of detecting devices that on bigger hemispherical area, distribute have been used with single detecting element.For example, placed the detecting device (10 to 120 detecting devices) of limited quantity along arc, wherein, described arc center is a measurement point.When scattered field (or as here far-field pattern of regulation) evenly the time, this method is carried out smoothly, but when far-field pattern be at random or when having the high frequency composition, this method just can't have been worked.

Another kind of art methods is, by the hole in the translucent ball top with laser beam irradiation on the specimen that is positioned at the dome center.Scattered light from specimen has illuminated the inner dome surface, because described dome is translucent, so this allows to use video camera to observe scattered light from the outer surface of dome.This method gets satisfactory for some basic application work.Yet light equally can laterally scattering between the inside and outside surface of dome, causes producing the measurement result of deterioration.This method can't take into account equally from perpendicular to the simple measurement near the light of angle (that is edge of the hemisphere face dome) scatterings of 90 degree of the direction on the surface of video camera.

In U.S. Patent No. 5,313, described in 542, No.5,475,617, No.5,615,294, No.5,640,246 and No.5,729,640 and be used for the another kind of method that the hemisphere face scattered light is measured.This method is based on using fibre bundle to measure the part of hemisphere in three dimensions.By realizing this point on the tapered part that spherical face is divided into fibre bundle.The terminal relatively of fibre bundle tapers to very little size, to be connected to video camera.This method allows the very high resolution measurement on part hemisphere.Yet its major defect is the loss of the expense, light of lower dynamic range, the fibre bundle phase information during by spread fiber and the mechanical scanning needs measured for hemisphere face fully.

Thus, all these art methods restriction with common far field coverage and measurement of angle resolution.In addition, they can not Measurement Phase.Therefore, the system that the enough single devices of energy are measured sphere scattering and phase place in real time will be that wish very much this area, and unprecedented medical diagnosis ability will be provided.The invention provides the solution of many problems of prior art equipment, and can obtain significantly more measurement data with former impossible speed.In addition, can obtain sphere and phase information simultaneously from scattered light.

Summary of the invention

The present invention uses unique lens design, will be mapped to from the light that the sample light source sends on the one group of measurement module that is suitable for measured intensity and phase place.As a result, the invention enables and on the hemisphere or the whole world, to measure scattering or the radiant light of collecting from the light source that is positioned at ball center in high resolving power ground.Resulting measurement result has produced image, its be similar to by human eye from the vantage points of 360 degree observe that light sources see three dimensions like that, all is high resolving power and is simultaneously.In addition, Measurement Phase simultaneously, thereby the data that can use easily are provided, with disclose independent working strength measurement result the important material behavior that can't obtain.

According to an aspect of the present invention, preferred embodiment comprises the far-field measurement device, and it has a plurality of imaging lens, and described imaging len is cut into pentagonal shape and arranges in the grid spherical structure.Pentagonal shape allows lens to cooperate in grid dome figure, in described grid dome figure, all lens all have focus on basically will be measured light source on common visual field.This lens configuration allows to collect all light from pointolite radiation radially, thereby the important advantage above prior art is provided, and prior art has been used and can produce the circular collection optical device in dead band on measured zone.Other non-circular lens also are fine, but definite, and pentagonal shape has provided the optimal balance of picture quality, lens number, dome size and far-field measurement coverage.All lens all have common visual field, and wherein, if arrange lens in basic structure for hemisphere face or sphere, then described visual field is the center of corresponding grid dome.

Create the required lens number of spherical structure in order to reduce, each lens all must be very big, and this causes serious wave-front aberration aberration.So, according to another aspect of the present invention, each pentagonal imaging len is made up of the multicomponent optical device that design is used for reducing wave-front aberration.For example, such optical device can be made up of typical zoom lens, and wherein, first sub-element is the pentagon lens of aspheric surface.As fine understanding in the art, the aspheric surface design allows the big incident angle of scattered light, and the number of proofreading and correct the required sub-lens of aberration is minimized.The Fresnel lens of simulation aspheric surface design can replace non-spherical lens to use.Fresnel lens produces low-qualityer image, but they are thinner in fact, lighter.Therefore, depend on the needs of practical application, perhaps aspheric or Fresnel lens can be used in enforcement the present invention.In pentagon lens back, additional sub-lens is used for calibration and makes wave front straight, for preparing in the video camera that wave front is mapped to measurement module inside.In a preferred embodiment, each module all comprises aspheric surface pentagon lens, collimation lens, field flattener lens and module imaging len.Unit piece pentagon lens can be used in the application of less demand.

Use for example measurement module of video camera in each multicomponent lens back.According to spy's of the present invention embodiment, measurement module comprises the Shack-Hartman wavefront sensor, thereby can measure the intensity and the phase place of the wave front that is detected.In another embodiment, measurement module is an interferometer, and its wave front that need enter has phase shift about the reference wave front of outside.The preferred version of this embodiment comprises point-diffraction interferometer in each measurement module.Point-diffraction interferometer is created its oneself reference beam from the wave front of far field, so just can measured intensity and phase place.Can use the interferometer of other types equally, comprise shearing interferometer.

Each measurement module all has interface with computing machine in a conventional manner, described computer treatmenting information and display result also preferably.In order to obtain simultaneous data, capture dynamic event by synchronous each measurement module of electronics.Owing to contain much information, can be with video or DVD register real-time recorded data, so that analyze after a while.Wish that equally neural network can play the part of the leading role of the raw data that processing obtains from measurement module of the present invention.Resulting data can be used in and characterize many materials and material, comprise smooth and rough surface, semiconductor, airborne particle, biomaterial, gas, liquid and molecular structure.

In the novel feature of specifically noting in description from instructions subsequently and the additional claim, other different purposes of the present invention and advantage will become clear.Yet such accompanying drawing and description have only disclosed some and can implement different modes of the present invention.

Description of drawings

Figure 1A is that inside is coated with substantially is the schematic section side view of hemisphere face dome according to measurement module of the present invention;

Figure 1B is the schematic top view of the dome of Figure 1A;

Fig. 2 A is the synoptic diagram that shows the amplification of the far field light that shines upon on the measurement module;

Fig. 2 B is the synoptic diagram of the amplification of the far field light that shines upon on the Shack-Hartman wavefront sensor;

Fig. 3 A is the side view according to pentagon lens of the present invention;

Fig. 3 B is the front elevation of the pentagon lens of Fig. 3 A;

Fig. 4 A basic is the skeleton view of hemisphere face dome by what six pentagon lens as showing among Fig. 3 B were formed;

Fig. 4 B is the top view of the structure of Fig. 4 A;

Fig. 5 is the synoptic diagram with measurement module of multicomponent lens and video camera;

Fig. 6 A is the view of the dome of Figure 1A, and it has shown according to of the present invention injects the scattering of light of dome to shine upon, and comprises that the use interferometer comes the device of Measurement Phase.

Fig. 6 B has shown the operation of the interferometric measuring means of Fig. 6 A;

Fig. 6 C is the synoptic diagram that design is used to provide the conllinear test and the piezoelectricity interferometric measuring means of the reference beam of assembling with different speed;

Fig. 6 D is the synoptic diagram that design is used to provide the conllinear test and the polarization interference measurement mechanism of the reference beam of assembling with different speed;

Fig. 7 A is the synoptic diagram that is suitable for implementing point-diffraction interferometer of the present invention, and wherein, the crystal delayer is used for phase shift;

Fig. 7 B is the synoptic diagram with another kind of point-diffraction interferometer of phase shift simultaneously;

Fig. 7 C has shown the point-diffraction interferometer element that is used for generating from the test waves front reference wave front;

Fig. 8 A is the skeleton view that comprises the hemisphere face structure of a plurality of measurement modules of the present invention;

Fig. 8 B is the backplan of the structure of Fig. 8 A, and it has shown the hemisphere face cancellated structure of pentagon lens of the present invention;

Fig. 9 A has schematically shown the structure that is used for the video camera of measurement module is connected to image processor and computing machine;

Fig. 9 B has schematically shown the structure that is used for the video camera of measurement module is connected to video recorder.

Embodiment

The invention reside in the combination of the corresponding system of the photodetector of arranging in Aspheric Lens System and the contiguous structure, so that capture and measure all light of the pointolite scattering from the sample simultaneously.In addition, by means of suitable detecting device, can measure the PHASE DISTRIBUTION of scattered light similarly.

As here using, term " far-field pattern " and " scattered light " are used to represent from the light of pointolite with the radiation mode radiation convertibly.Term " sphere " and " hemispherical " are used to indicate such geometric configuration and have the part of the spherical geometry shape geometric configuration of figure (that is on the sphere)." equatorial plane " is defined as and has the plane of equator coplane of the structure of such spherical geometry shape.At last, term " grid " is used to indicate the polyhedral structure with interconnective plane surface, but described plane surface also preferably not necessarily is configured, so that each surperficial side regulation minimal path between the point on hemispherical given surface for example.

With reference to the accompanying drawings, Figure 1A and 1B have shown that show respectively basic is that hemisphere face is constructed the present invention in 10 in sectional view and top view.Measurement module 12 and corresponding lens 14 are connected to hemisphere face supporting construction 16, so that the almost completely covering on hemisphere face surface is provided.Although preferred pentagon lens and corresponding measurement module are implemented the present invention, as mentioned above, for the purpose of showing, in these accompanying drawings, use little rectangular member.In fact, can be expressly understood that the spheric curvature of structure 16 can require each module 12 and lens 14 to leave real square geometry, so that covered structure 16 seamlessly.This design of Figure 1A needs a large number of lens 14, and this can produce high-resolution measurement result, but is cost with high cost, because need corresponding a large number of module 12.

For example the light beam L that is produced by the lasing light emitter (not shown) can throw to specimen S by the hole 18 in the hemisphere face structure 16 with the angle [alpha] of hope.Angle [alpha] can be about the normal of sample surfaces between 0 degree and 90 degree.Can generate light beam L from the small light source of hemisphere face of the present invention inside equally.If sample surfaces S is a partial mirror, then part light L is reflected and leaves the surface and outwards derive by second hole 20 in the hemisphere face structure 16.In order to ensure folded light beam by hole 20 and outwards projection, provide manually or electric platforms 22 (in Figure 1B, schematically showing) suitably to change angle [alpha].This feature is very important for those measurements, wherein, in described measurement, does not wish that light beam L leaves from lens 14 reflection to return towards sample surfaces S.Selectively, be cut into the long and narrow slit of hemisphere face structure 16, can be used in and allow light beam L to enter and guarantee that still it leaves from structure with the angle of any hope along the line 24 of the plane of reflection that is arranged in light beam L.If sample surfaces S is a non-specular surface, then hole 20 and platform are selectable, because all light L are scattered in the hemisphere face inside configuration.Under these circumstances, can replace hole 20 and use other measurement module.

In either case, light beam L is to leave sample surfaces S towards the radial manner scattering of the system of lens 14, as shown in the arrow among Figure 1A 26.According to the present invention, these all scattered lights are collected simultaneously, carry out data analysis with the system that uses lens 14.Shown in Fig. 2 A and 2B, from the part 28 of the far-field pattern of sample surfaces radiation by each lens 14.The purpose of lens 14 is to calibrate and to make sphere far-field pattern 28 straight.Far-field pattern or wave front 30 with resulting processing is directed in the measurement module 12 then, and described measurement module 12 can be the video camera that is used for measured intensity, or is used for the interferometer of measured intensity and phase place.Figure 12 B has shown module 12 with the form of the Shack-Hartman wavefront sensor that is used for measured intensity and phase place.

Lens 14 can be list or multicomponent lens.As skilled in the art readily recognize, the quality that is directed to the wave front 32 of measurement module 12 will depend on lens 14.If lens are little, then it can be realized as single element lens, obtaining high-quality wave front, but needs many measurement modules, and this can be expensive with unpractical.If lens 14 are big, then need measurement module still less, but because be difficult to obtain high wave front quality at the big incident angle β of the edge scatter light of lens 14.Equally, in fact, all conventional lenses all are circular.Therefore, if place traditional round lens abreast in checkerboard pattern, then many gaps of missing are remaining, and this causes drop-out.Therefore, preferably use such lens design to realize the present invention, described lens design is selected to reach the balance of the wisdom between the quality of the complicacy of number, lens shape of lens 14 and wave front 32.

Fig. 3 A and 3B have shown in side view and front elevation according to pentagon lens 40 of the present invention respectively.By making 5 accurate otch 44, round lens 42 is cut into pentagonal shape around lens.In pentagon, the angle γ between the limit (Fig. 3 B) is 108 degree.In a preferred embodiment, each otch 44 is adjusted to about 58.3 degree about the angle δ (Fig. 3 A) on pentagon surface 46, to take into account easy manufacturing and the cooperation together of a plurality of lens.Use 6 pentagon lens 40, just can construct grid dome 50, shown in Fig. 4 A and 4B.The diameter 52 that depends on the circle 54 on the pentagon surface 46 that comprises lens 40, the ball that can generate different size pushes up.In a preferred embodiment, lens 40 have the pentagon limit 56 of diameter 52 and the 40.43mm of 78.94mm.These sizes have produced the dome 50 (Fig. 4 B) of the about 264.8mm of diameter.

Although lens 40 can be various types of, the preferred embodiments of the present invention have been used the aspheric surface design.These permission lens 40 are measured the scattered light with wide-angle β (seeing Fig. 2 A) incident very greatly and still.As fine understanding in the art, the surface 58 of lens 40 and the definite shape on pentagon surface 46 are the key factors in the design of non-spherical lens, because the quality on these two surfaces is being arranged the over-all properties of lens and the quality of last far-field measurement.

Typical non-spherical lens design is arranged by following formula:

Curvature=c=1/R, and

SAG＝Z＝(c×r ²)/(1+(1-(1+k)c ²r ²) ^1/2)+a ₂r ²+a ₄r ⁴+a ₆r ⁶+a ₈r ⁸+…+a _nr ⁿ

Wherein, c is a curvature, and R is a radius, and Z is a sagittal heights, a _nBe constant, and r ⁿBe radial values.Depend on acceptable wave front quality,

non-spherical surface

46 and 58 can be different shape.In a preferred embodiment, the surface 46 is smooth, and it is as follows to be used for the equation parameter of non-spherical surface 58:

R＝35.1657

k＝-0.9532

a ₂＝0

a ₄＝1.2065E-6

a ₆＝1.7981E-10

a ₈＝4.86192E-14

a ₁₀＝-2.9165E-18

Use these equation parameters, the height 60 of non-spherical lens 40 is 33mm.

Another advantage of non-spherical lens is, its feasible number that significantly reduces sub-element required in the multicomponent lens design.For example, as shown in Figure 5, multicomponent lens 62 can utilize the sub-element lens to be incorporated into aberration in the far-field pattern to reduce non-spherical lens 40.This is very important, because its feasible error that can minimize among the last far-field measurement result.Existence can be carried out the various lens sub-elements of this task.In a preferred embodiment of the invention, 3 additional lens have been used.As shown in Figure 5, collimator 64, field flattener 66 and imaging len 68 have been used.Imaging len 68 oneself can be the multicomponent lens equally.So, far-field pattern 28 can enter lens 40, and

scioptics

64,66 and 68 are propagated before arriving measurement module 70.Module 70 can be the video camera that is used for ionization meter, be used for the interferometer of phase place and ionization meter or be used for phase place and the Shack-Hartman wavefront sensor of ionization meter.Measure the phase place of the far-field pattern on the hemisphere face and the ability of intensity, shown the important advance in the scatterometry technical field.

So, except measured intensity (by 30 expressions of the wave front among Fig. 2 A), can carry out the phase place (by wave front in Fig. 2 A 32 expressions) of the present invention equally to measure wave front.This can realize by using interferometer, shown in the module 12 of Fig. 2 A, perhaps can realize by using Shack-Hartman sensor 74, shown in Fig. 2 B.As shown in the drawing, the light 30 that the Shack-Hartman sensor uses microlens array 76 to calibrate focuses on the video camera 78.Lens 14 are selectable, and are used for far-field pattern 28 is calibrated to microlens array 76.Usually, N * N video camera pixel of each lenticule reflection.So, the definite pixel location of the point 80 of the focusing in this grid of video camera pixel just can be used in definite phase place.In order to realize the present invention, preferred every lenticule 15 * 15 video camera pixels.Note folded light beam L ' that the use of Shack-Hartman sensor can show and scattered light 26 dual phase place and the strength information of obtaining among both from Figure 1A.

Shown in Fig. 6 A and 6B, use to set up enter the input interference of light measuring technique of hemisphere face dome of the present invention with influence equally can Measurement Phase.Wide relatively convergence reference beam R and relative narrow test beams T projected respectively together polishing reference surface M and less on the specimen S that puts.For the purpose of this disclosure, think that surperficial M and S are coextensive basically.So, two light beam R, T have just produced conoscope image in zone 82, and wherein, in described regional 82, they are overlapping after test and reference surface reflection, and interferometry sensor 84 can shine upon and measurement pattern.By about the of short duration phase shift reference beam of test beams T R, a series of interferograms required are provided as traditional phase analysis.For example, Fig. 6 C and 6D shown and be suitable for producing and two kinds of methods of phase shift reference and test beams, and described reference and test beams are used for illuminating the sample surfaces of the scatterometer of Figure 1A.

The phase changer of Fig. 6 C has used traditional piezoelectric element 86.By nonpolarized light beam separator 88 the laser beam L that assembles (in the drawings not display light source) is separated into test beams T and reference beam R.Test beams T is made up of the original beam L by separation vessel, and is directed to specimen S (seeing Fig. 6 B).Leave separator surface 90 and produce reference beam R towards convex mirror 92 by folded light beam L, described convex mirror 92 reflects light, is connected to effectively on the minute surface 94 of piezoelectric element 86 by beam splitter and arrival.Convex mirror 92 is used to reduce the convergence rate of laser beam L, so as resulting reference beam R at specimen S place greater than test beams T (shown in Fig. 6 B).Light R is reflected and passes the test beams T reorganization of beam splitter 88 by minute surface 94, then by applying voltage by phase shift to the piezoelectric element 86 that is connected to minute surface 94.The convergence that the convex curvature of minute surface 92 provides reference beam R to shine required minimizing on reference surface M is shown in Fig. 6 B.This unique design allows smooth reference surface M to be placed to below the specimen S in the same optical path of test beams T and reference beam R.Make reference beam R bigger, to guarantee its reflection from reference mirror M.

By making reference and test beams cross polarization, can carry out phase shift with solid-state pattern equally, shown in Fig. 6 D.The light beam L that polarization beam splitter 96 is used for entering is separated into the test beams T and the reference beam R of linear orthogonal polarization.Quarter-wave plate 98 be used for when light beam respectively when

minute surface

100 and 102 is propagated the path along each light beam convert linearly polarized photon to circular polarized light.When beam reflected is returned when propagating by their separately wave plates from these minute surfaces, they are converted back to linearly polarized photon, described linearly polarized photon revolves about their initial linear polarizations and turn 90 degrees, so that separation vessel 96 can suitably be guided these two light beams into the sample target.Reference surface M and test surfaces S reflect the light beam of reorganization then, shown in Fig. 6 B.In interferometry sensor 84, use the polarization phase-shifting interferometer then, with the three or more phase shifting interference that two Beam Transformation is become to be used to analyze with traditional mode.

Use has arbitrary interferometric method of the scatterometer of Fig. 6 A, the outside that consciously beam reflected T ', R ' is propagated into dome arrives interferometry sensor 84, so as to minimize can cause measuring error turn back to the influence of the scattered light of surperficial M from sensor.Around the module 12 of dome is that video camera and module 84 are methods that the fact of interferometer has limited Fig. 6 A.So, just can not measure at the enterprising line phase of whole far-field pattern.In addition, test surfaces S and reference surface M being placed on same position is unpractical for many application.The use of machinery piezo-electric device is because vibration, environmental change and specimen have been introduced restriction over time equally.Similarly, the interferometric method of Fig. 6 D is supposed, can arbitrarily not change the polarization state of light beam R and T owing to the scattering nature of surperficial S and M.Can not carry out this supposition to kinds of surface and material.In addition, if sample target S is self luminous light source, then these two kinds of interferometric methods all can not be worked.At last, although the Shack-Hartman method of Fig. 2 B has these less restrictions, it suffers the measurement of angle resolution lower than interferometric method.

Because these restrictions, preferred point diffraction interference measuring method is as schematically showing among Fig. 7 A and the 7B.Point-diffraction interferometer is from its reference wave front R of test waves front T generation, shown in Fig. 7 C.The quarter-wave plate 110 of test waves front T by having pin hole 112.The part T ' of wave front T by wave plate 110 has and revolves the polarization that turn 90 degrees.The part of wave front T by pin hole 112 is converted into spherical wave front R, keeps its original polarization state simultaneously.So, the wave front T ' of two changes and R have just created conoscope image, wherein, can handle the original test far-field phase figure of described conoscope image with restitution beam T.

Can use two types point-diffraction interferometer.The interferometer 120 that shows among Fig. 7 A uses crystal delayer 122 and linear polarization 124 about test waves front T ' phase shift reference wave front R.Resulting phase shifting interference image is mapped on the video camera 126.The interferometer 130 of Fig. 7 B uses carries out same function based on the locking phase shifting formwork piece 132 of polarization.In two interferometers 120 and 130, lens 134,136,138 and 140 are used for correctly wave front being mapped to measurement module 126 and 132.

Fig. 8 A and 8B have shown the dome structure constructed according to the invention 150 with 6 measurement port 152.In a preferred embodiment, each port has (type 62 that shows among Fig. 5) multicomponent lens and (Class1 30 that shows among Fig. 7 B) interferometry module.In order to simplify demonstration, only shown a port one 52 with complete lens 62 and measurement module 130.Visible six pentagon non-spherical lenses 40 in the backplan of the dome 150 that in Fig. 8 B, shows.Two minute surface duplicate that attention can be made up dome 150 are used for measuring the complete sphere of far-field pattern on the complete 360 degree scopes of three dimensions with establishment.When specimen S is transmissible, perhaps when its on global face during radiant light, preferred this embodiment of the present invention.Otherwise, only need a dome 150 to implement the scatterometry technology, as the present invention's instruction.

Measure the intensity of global face and the advantage of phase information and comprise the ability of measurement from the complete three-dimensional radiation light of trnaslucent materials, described trnaslucent materials is used for the application such as DNA analysis, biological substance, condensate, plastics or the like.And then, can carry out all measurements in real time to monitor dynamic event.

Do not consider concrete lens design, can use diverse ways that measurement module is installed in the spherical structure.For example, with reference to the module of figure 2A, the hole in the spherical structure can be used at each hole installed module 12.Selectively, glass hemisphere face or spherical structure can be used as mould, are used for placing and connecting lens 14 and sensor assembly 12.After placing lens, can remove also and can not remove mould.Lens can have different shape.Yet when lens 14 were single element lens in this design, simple solution was to have biconvex lens, make the curvature of back mate sphere, and the design of the curvature of front was used for calibrating the light from the sphere centre radiation.

In addition, when lens 14 were made up of single element lens, preferable methods was to use the microlens array of single integral body in the shape of hemisphere face or sphere.Such structure can be glass, plastics or the other materials that is suitable for lens arra.Can on lens surface, use antireflecting coating in all cases.Measuring system may be used to measured intensity and/or phase place in all cases.

Thus, shown and the invention provides a kind of device that is suitable on whole sphere measuring the far-field pattern of scattered light.In addition, this device can be measured such scattered light in high resolving power ground with acceptable distortion no any gap in hemisphere face and spherical surface construction of scattered field (blind spot).At last, can on whole sphere, measure light intensity and phase place in the far-field pattern.

As schematically showing among Fig. 9 A, the measurement data from the inner video camera of detector module 12 or 78 (seeing Fig. 2 A and 2B) is converted into electric signal 160, and is sent to the processor 162 in the traditional computer 164, is used for the interferometry analysis.Selectively, shown in Fig. 9 B, electric signal 160 can be sent to video or DVD register 166.Can synchronization module 12 and the video camera of 78 inside, to observe same incident simultaneously.This mark sheet is understood the significant advantage when measuring dynamic event, and is the optimal way of operation.Another advantage of a plurality of video cameras is such fact: each video camera can have its own independent automatic gate and exposure is provided with.Near the low-lying level light in the place of this allows to obtain simultaneously (beam reflected) high-strength light and light scattering minimum.

No less important ground can be found out from Figure 1A, can control the power of the light source that produces light beam L, with the broad range in the light and shade district that forms the scattered light of wanting measured.Can reduce the power of light source, observe the area pellucida of scattered light, then, can increase power to allow module of the present invention, with allow module measure scattered light than the dark space.It is littler and more cheap that another important advantage is that commercial CCD and cmos camera are just becoming.Therefore, the use of low cost CMOS video camera allows to be suitable for to measure the structure of relatively cheap measurement module of whole spherical figure.In addition, can use the cmos camera with built-in pixel processor, described pixel processor allows independent pixel to be eliminated when they become saturated.This allows contiguous pixel to keep not being subjected to potential high light to overflow the influence of (blooming) problem.

Single image acquiring device 162 (Fig. 9 A) is available equally, and it can obtain vision signal simultaneously from a plurality of detector module.As can seeing among Fig. 8 B, exist many measurement module signals to handle; Therefore, it is favourable as far as possible promptly handling them.This can carry out in the following manner: each measurement module is all had single processor, perhaps, each processing module is put into multiplexer be used for continuous processing.In a preferred embodiment of the invention, six measurement modules are used for hemisphere face and cover, and 12 be used for sphere and cover.Therefore, preferred parallel acquisition capability.

Can expect,, and, can obtain to be used for the further improvement and the advantage of multispectral scattered light imaging from the present invention by means of colour TV camera and multiple laser by means of colour TV camera and white light source.In the Shack-Hartman mode, incoherent light source can be used in measuring light scattering strength and phase place.

Skilled person in the art will appreciate that previous exemplary embodiment of the present invention provides the foundation for numerous alternatives and the modification that is deemed to be within the scope of the present invention equally.For example, detector module 12 and lens 14 can enoughly comprise the single hemisphere face or the spherical face replacement of photodetector.Hemisphere face or spherical face can be made up of flexible material, and embed on material or print flexible camera circuitry.Take into account in some zone measured intensity of scattered field and, can in same hemisphere face or spherical structure, use only Measurement Phase module and the only associating of measured intensity module in other part measured intensity and phase places of same scattered field.

Thus, be considered to the most practical and preferred embodiment here, can recognize that those skilled in the art set out thus and can change although the present invention has shown and described.Therefore, the present invention is not the details that is limited to disclosure, but comprises the equipment and the method for any and whole equivalences according to the four corner of claim.

Claims

1. the device of the light propagated of a pointolite that is used to measure from the sample surfaces, this device comprises:

Platform is used to keep sample surfaces;

A plurality of many pixel sensors are used to measure the part light intensity value of the described pointolite radial propagation from the sample surfaces; And

Optical system is used for making the predetermined portions of described part light to aim at of described a plurality of many pixel sensors, so that each described part of the corresponding one group of pixel acceptance division beam split among in described a plurality of many pixel sensors described one.

2. device as claimed in claim 1, wherein, described optical system comprises non-spherical lens.

3. device as claimed in claim 1, wherein, the described a plurality of many pixel sensors that on the supporting construction of spherical geometry shape, distribute, and on the equatorial plane of supporting construction, place described sample surfaces.

4. device as claimed in claim 1, it further comprises testing light source, described testing light source is used for shining sample surfaces with predetermined incident angle with test beams, the described light of propagating with the described pointolite that produces from the sample surfaces.

5. device as claimed in claim 4, it further comprises: reference light source, be used to illuminate reference surface, and interferometer, be used to measure a plurality of interferograms that the interference between the reference beam that is produced by light of propagating from described pointolite and described reference light source causes.

6. device as claimed in claim 5, wherein, the part of described reference surface and described sample surfaces is coextensive basically.

7. device as claimed in claim 6, wherein, described test beams is assembled, and described interferometer is a phase shifting interferometer, be used for by producing described reference beam from test beams from the part of convex mirror reflection measurement light beam, and towards described reference of guiding of sample surfaces conllinear ground and described test beams.

8. device as claimed in claim 6, wherein, described interferometer comprises and is used to produce conllinear ground towards the reference of the cross polarization of sample surfaces and the device and the polarization phase-shifting interferometer of test beams.

9. device as claimed in claim 1, wherein, described a plurality of many pixel sensors comprise a plurality of phase detectors of the phase value of the described part light that is used to measure the pointolite radial propagation from the sample surfaces.

10. device as claimed in claim 9, wherein, described phase detector is the Shack-Hartman sensor.

11. device as claimed in claim 5, wherein, described a plurality of many pixel sensors comprise a plurality of phase detectors of the phase value of the described part light that is used to measure the pointolite radial propagation from the sample surfaces.

12. device as claimed in claim 11, wherein, described phase detector is the Shack-Hartman sensor.

13. the pointolite device of the light of scattering radially that is used to measure from the sample surfaces, this device comprises:

Define the hemispherical basically structure of equatorial plane;

Platform, being used for basically, the position on described equatorial plane keeps sample surfaces;

Testing light source is used for predetermined incident angle irradiation sample surfaces; And

A plurality of many pixel sensors are used to measure towards the part light intensity value of the radially scattering of the discrete portions on the surface, inside of described hemispherical structure basically.

14. device as claimed in claim 13, wherein, described testing light source is by the irradiation of the hole in described hemispherical basically structure sample surfaces.

15. device as claimed in claim 13, wherein, described a plurality of many pixel sensors are used to measure towards the part light intensity value of all basically described internal table area scatterings of hemispherical structure basically.

16. device as claimed in claim 13, it further comprises optical system, described optical system is used for making the part of described part light to aim at of described a plurality of many pixel sensors, so that the corresponding one group of pixel among in described a plurality of many pixel sensors described one receives the described part of described part light.

17. device as claimed in claim 16, wherein, described optical system comprises non-spherical lens.

18. device as claimed in claim 13, it further comprises: reference light source, be used to illuminate reference surface, and interferometer, be used to measure a plurality of interferograms that the interference between the reference beam that is produced by light and reference light source from the pointolite scattering causes.

19. device as claimed in claim 18, wherein, the part of described reference surface and described sample surfaces is coextensive basically.

20. device as claimed in claim 13, wherein, described a plurality of many pixel sensors comprise radially a plurality of phase detectors of the phase value of the described part light of scattering of the pointolite that is used to measure from the sample surfaces.

21. device as claimed in claim 20, wherein, described phase detector is the Shack-Hartman sensor.

22. device as claimed in claim 16, wherein, described a plurality of many pixel sensors comprise radially a plurality of phase detectors of the phase value of the described part light of scattering of the pointolite that is used to measure from the sample surfaces.

23. device as claimed in claim 22, wherein, described phase detector is the Shack-Hartman sensor.

24. device as claimed in claim 13, it further comprises the second hemispherical basically structure of the opposite side that is placed on described equatorial plane; And many pixel sensors more than second, be used to measure towards the described second part light intensity value of the transmission of the discrete portions scattering on the surface, inside of hemispherical structure basically.

25. device as claimed in claim 24, wherein, described more than second many pixel sensors are used to measure towards the second part light intensity value of the described transmission of all basically described inner surface direction scatterings of hemispherical structure basically.

26. device as claimed in claim 25, it further comprises optical system, described optical system is used for making the part of the part light of described transmission to aim at of described more than second many pixel sensors, so that the corresponding one group of pixel among in described more than second many pixel sensors described one receives the described part of the part light of transmission.

27. device as claimed in claim 13, it further comprises optical system, and described optical system is used to make the described a plurality of many pixel sensors of described part optical registration, and described optical system comprises non-spherical lens.

28. device as claimed in claim 27, wherein, described a plurality of many pixel sensors are six, and described optical system is included in six corresponding pentagon non-spherical lenses that connect in the described hemispherical basically structural cancellated structure.

29. device as claimed in claim 27, wherein, in defining the polyhedron structure of the some plane surfaces that are close to described hemispherical basically structure, arrange described a plurality of many pixel sensors, and described optical system comprises corresponding some non-spherical lenses.