KR101844482B1 - High resolution terahertz focusing module, scatteed light detecting module and high resolution detecting apparatus using terahertz bessel beam - Google Patents

Abstract

A terahertz wave focusing module according to one embodiment of the present invention comprises: a first lens for changing an angle of a terahertz wave that is emitted while a terahertz wave Bessel beam penetrates through an object to be inspected to be smaller; and a second lens for collecting the terahertz wave passed through the first lens to a detector.

Description

TECHNICAL FIELD [0001] The present invention relates to a high-resolution TeraHertz wave condensing module, a scattered-light detecting module, and a high-resolution inspection device using a terahertz wavelength beam,

The present invention relates to a high-resolution terahertz wave condensing module having a high resolution below a diffraction limit beyond a diffraction limit, by using a non-destructive method using a terahertz wave.

In addition, the present invention forms a ring beam using a vessel beam, detects scattered light reflected or transmitted through an object to be inspected when the object is inspected using the formed ring beam, and detects scattered light Module.

The present invention also relates to a high resolution inspection apparatus using a terahertz laser beam to synchronize an optical head and a condensing head according to the shape of an object by using a scanner.

In order to examine objects or substances in a non-destructive way, imaging methods are mainly used. Mainly, two methods of image detection using a continuous output light source and image detection using a spectroscopic method are mainstream. These methods have advantages and disadvantages, respectively, but image detection methods using continuous output light sources are widely used in fields requiring relatively high power such as transmission images.

Terahertz waves are widely used in the field of qualitatively identifying hidden objects or substances in a non-destructive way due to their excellent properties such as permeability to materials, possibility of qualitative confirmation, and safety to the living body.

In recent years, terahertz waves have been used in various fields such as airport and security facility search devices, food and pharmaceutical company quality inspection devices, semiconductor inspection devices, and engineering plastic inspection devices.

Terahertz waves are increasingly used in production sites, and continuous improvements have been made in terms of major performance indices such as detection resolution, detection speed, and detection area.

Previously, only a single lens was used to collect terahertz waves that were transmitted through an object to obtain terahertz paraffin images. In this case, if the apical angle of the axicon lens forming the vessel beam is made small so as to make the beam size of the terahertz wave focused on the object to be inspected less than the wavelength, the terahertz vessel beam passes through the object to be inspected, There arises a problem that the light is diverged and is not concentrated on the detection unit. Accordingly, the light-condensing property is remarkably reduced, and the signal-to-noise ratio (SNR) of the inspection apparatus is remarkably reduced, so that a normal image can not be obtained.

Further, in the case of a transparent object to be inspected, it is difficult to obtain a clear image. Therefore, there is a need for research and development of a method for enhancing the contrast of a transparent object to be inspected with little loss of terahertz wave.

Further, there is a problem that the depth of focus of the vessel beam can not reach the end portion of the object to be inspected, so that a high-resolution image can not be obtained.

Further, when the object to be inspected contains a large amount of water, the rate at which the THz waves penetrate the object to be inspected is remarkably deteriorated due to the property that the THz waves are absorbed well by the moisture. Therefore, the terahertz wave detecting unit has a problem that the object to be inspected can not be accurately inspected because the signal of the terahertz wave to be detected is weak.

Korean Patent No. 10-1392311

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a high-resolution terahertz wave condensing module capable of increasing a condensing efficiency of a terahertz beam beam transmitted through an object to be inspected.

The present invention also provides a scattered light detection module capable of forming a ring beam without loss of a terahertz wave, thereby increasing the contrast of a transparent object to be inspected.

Further, according to the present invention, the optical head moves along the contour of the object to be inspected as much as possible according to the shape of the object, so that the depth of focus of the vessel beam can reach the end of the object. And to provide a high-resolution inspection apparatus using the same.

In addition, the present invention provides a high-resolution inspection apparatus using a terahertz Pervasell beam that allows a terahertz wave to penetrate an object to be inspected including moisture by rapidly quenching the object to be inspected using a terahertz wave do.

Other objects and advantages of the present invention will become apparent from the following description, and it will be understood by those skilled in the art that the present invention is not limited thereto. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to another aspect of the present invention, there is provided a high resolution inspection apparatus using a vessel beam, including: a scanner for scanning a shape of an object to be inspected; a terahertz wave generating unit for generating a terahertz wave, A terahertz wave condensing head for detecting a terahertz wave transmitted through the object to be inspected; a first transfer unit for moving the terahertz wave optical head according to the shape of the object to be inspected scanned by the scanner; And a second conveying unit synchronized with the first conveying unit to move the terahertz wave condensing head in the same manner as the optical head.

The first transfer unit may be configured to transmit the inspection object and the terahertz wave optical head to a predetermined distance based on the thickness of the scanned object to be inspected so that the object is positioned within the focal depth of the generated terahertz wave. The terahertz wave optical head can be moved so as to be maintained.

A high resolution inspection apparatus using a terahertz Farber beam further comprises a quenching device for keeping the object to be inspected in a low temperature state, wherein the terahertz wave optical head and the terahertz wave condensing head are disposed apart from both sides of the quenching apparatus .

The quenching device may be composed of a housing including a window through which the generated terahertz wave can be transmitted.

The high resolution inspection apparatus using the terahertz Farbeth beam may include a defrosting apparatus disposed at the rear end of the quenching apparatus and defrosting the inspection object.

According to another aspect of the present invention, there is provided a high resolution inspection apparatus using a vessel beam, comprising: a terahertz wave generating unit for generating a terahertz wave; and a terahertz wave generating unit for generating a terahertz wave by using a terahertz wave incident from the terahertz wave generating unit, A first lens that changes the angle of a terahertz wave emitted from the terahertz Pavel cell through the object while changing the angle of the terahertz wave to be passed through the first lens; A second lens for condensing one THz wave into a detector; And a terahertz wave detecting unit for detecting a terahertz wave condensed by the second lens.

The vessel beam forming unit may be a first axicon lens having a vertex angle in which the diameter of the terahertz wave plasma beam is smaller than the wavelength of the terahertz wave generated in the terahertz wave generating unit.

The first lens may be a second axicon lens arranged symmetrically with respect to the first axicon lens with reference to the object to be examined.

The second axicon lens may have an apex angle that is the same as that of the first axicon lens.

The high resolution inspection apparatus using the vessel beam may further include an angle changing unit for changing the angle of the terahertz wave incident from the terahertz generating unit to change the angle of the terahertz wave to be incident on the vessel beam forming unit.

Wherein the angle changing unit is a first convex lens for changing the angle of the terahertz wave incident from the terahertz generating unit to a small angle and the second lens is a second convex lens for deflecting the second convex lens arranged symmetrically to the first convex lens on the basis of the inspection object, Lt; / RTI >

The second lens may be a third axicon lens having the same shape as the second axicon lens and arranged symmetrically to the second axicon lens with respect to an axis perpendicular to the optical axis.

The first lens may be a third convex lens that changes the angle of the terahertz wave that is emitted while the terahertz Farber beam penetrates the object.

The second lens may be a fourth convex lens disposed symmetrically with respect to the third convex lens with respect to an axis perpendicular to the optical axis.

According to another embodiment of the present invention, there is provided a high-resolution terahertz wave condensing module, comprising: a first lens for changing a tera-hertz wave radiated from a terahertz laser beam while changing an angle of a terahertz wave; And a second lens for converging the terahertz wave passed through the first lens to a detector.

The first lens forms the terahertz spectacle beam on the basis of the object to be inspected, and the diameter of the terahertz wave incident on the detector is formed to be smaller than the wavelength of the terahertz wave generated in the terahertz wave generator And a second axicon lens disposed symmetrically to the first axicon having a vertex angle.

The second axicon lens may have an apex angle that is the same as that of the first axicon lens.

The second lens may be a second convex lens arranged symmetrically with respect to the first convex lens for changing the angle of the terahertz wave incident from the terahertz generating unit to a small value with reference to the object to be inspected.

The second lens has the same shape as the second axicon lens and may be disposed symmetrically with respect to the second axicon lens with respect to an axis perpendicular to the optical axis.

The first lens may be a third convex lens that changes the angle of the terahertz wave that is emitted while the terahertz Farber beam penetrates the object.

The second lens may be a fourth convex lens disposed symmetrically with respect to the third convex lens with respect to an axis perpendicular to the optical axis.

According to another aspect of the present invention, there is provided a high-resolution inspection apparatus using a terahertz Farber beam, comprising: a terahertz wave generating unit for generating a terahertz wave; and a terahertz wave generating unit for generating a terahertz wave using the terahertz wave incident from the terahertz wave generating unit, A ring beam forming unit for forming a ring beam by using the terahertz laser beam and condensing a ring beam formed as an object to be inspected, A scattered light detector for detecting scattered light generated from an object; And a ring beam detecting unit for detecting a ring beam transmitted through the object to be inspected.

The ring beam forming portion includes a third lens that forms a ring beam and condenses the formed ring beam into an object to be inspected.

The scattered light detecting unit includes a reflected scattered light detecting unit that is provided in the third lens and detects scattered light reflected from the inspection object.

The reflected scattered light detecting unit may be provided inside the ring beam emitted from the third lens.

The scattered light detection unit may include a transmitted scattered light detection unit that detects scattered light transmitted from the object to be inspected.

The transmitted scattered light detection unit may be disposed inside the ring beam incident from the third lens.

The third lens includes a path changing unit that changes the path of scattered light reflected from the inspection object, and the reflected scattered light detecting unit can detect scattered light incident from the path changing unit.

The ring beam forming unit may include a fourth lens that changes the angle of the terahertz Pervasel beam incident from the vessel beam forming unit to a small angle and makes the third lens enter the ring beam forming unit.

The vessel beam forming unit may be a fourth axicon lens having a vertex angle in which the diameter of the terahertz wave plasma beam is smaller than the wavelength of the terahertz wave generated in the terahertz wave generating unit.

And the fourth lens may be a fifth exicon lens arranged symmetrically with respect to the fourth exicon lens based on the object to be inspected.

The fifth axicon lens may have a vertex angle of the same size as the fourth axicon lens.

The apparatus for high resolution inspection using a terahertz Pervasell beam may further include an angle changing unit for changing the angle of the terahertz wave incident from the terahertz generating unit to change the angle of the terahertz wave to be incident on the vessel beam forming unit.

And the third lens is a fifth convex lens for changing the angle of the terahertz wave incident from the terahertz generating unit to a small angle, and the third lens is a sixth convex lens arranged symmetrically to the fifth convex lens on the basis of the object to be inspected, Lt; / RTI >

The third lens may be a sixth axicon lens having the same shape as the fifth axicon lens and arranged symmetrically with respect to the fifth axicon lens with respect to an axis perpendicular to the optical axis.

The fourth lens may be a seventh convex lens that changes the angle of the terahertz wave that is emitted while the terahertz Pervasell beam transmits through the object.

The fourth lens may be an eighth convex lens disposed symmetrically with respect to the seventh convex lens with respect to an axis perpendicular to the optical axis.

A scattered light detecting module according to an embodiment of the present invention includes a ring beam forming unit for forming a ring beam using a terahertz laser beam and condensing a ring beam formed as an object to be inspected; And a scattered light detector for detecting scattered light generated from the inspection object.

The ring beam forming portion includes a third lens that forms a ring beam and condenses the formed ring beam into an object to be inspected.

The scattered light detecting unit includes a reflected scattered light detecting unit provided in the ring beam emitted from the third lens and detecting scattered light reflected from the inspection object.

The scattered light detecting unit includes a transmitted scattered light detecting unit disposed inside the ring beam incident from the third lens and detecting scattered light transmitted from the inspection object.

The third lens includes a path changing unit for changing the path of the scattered light reflected from the inspection object, and the reflected scattered light detecting unit detects the scattered light incident from the path changing unit.

According to the disclosed invention, since the terahertz wave transmitted through the object to be inspected can be condensed with almost no loss, the light condensing efficiency can be increased.

Further, by making the diameter of the terahertz wave beam focused on the object to be inspected be equal to or less than the wavelength of the terahertz wave, a clear image can be obtained by increasing the resolution.

Further, the ring beam can be formed without loss of the terahertz wave, so that the contrast of the transparent object to be inspected can be increased.

Further, by detecting the scattered light generated from the object to be inspected, it is possible to enhance the contrast of the transparent object to be inspected.

In addition, by arranging the scattered light detection unit inside the generated ring beam, a separate space due to the addition of the scattered light detection unit is not required, and miniaturization is possible.

Further, even if the vertex angle of the axicon of the vessel beam forming section is made small to realize high resolution, the diameter of the ring beam generated by using two lenses of the ring beam forming section can be reduced and a high resolution image can be obtained.

In addition, by allowing the optical head to move along the contour of the object to be inspected as much as possible according to the shape of the object to be inspected, the object to be inspected can be positioned in the super lunch of the vessel beam, and a clear transparent image can be obtained.

Further, the object to be inspected is quenched and inspected using a terahertz wave, so that the terahertz wave can be transmitted through the object to be inspected including moisture.

1 is a view for explaining a high resolution inspection apparatus using a terahertz Pervasel beam according to an embodiment of the present invention.
2 is a diagram for explaining a high resolution inspection apparatus using the terahertz Pervasel beam of FIG. 1 in detail.
3 is a view for explaining a high-resolution inspection apparatus using a terahertz Pervasel beam according to another embodiment of the present invention.
4 is a view for explaining a high resolution inspection apparatus using a vessel beam according to another embodiment of the present invention.
5 is a view for explaining a vessel beam forming unit according to an embodiment of the present invention.
6 is a diagram for calculating the diameter of a terahertz wave beam focused on different vertex angles using Equation (4).
FIGS. 7 and 8 are views for explaining an inspection apparatus for collecting light using a single lens. FIG.
9 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 4 according to the first embodiment.
FIG. 10 is a diagram for explaining the high-resolution inspection apparatus of FIG. 4 according to the second embodiment.
11 is a diagram for explaining the high-resolution inspection apparatus of FIG. 4 according to the third embodiment.
Figs. 12 and 13 are transmission images obtained by measuring the object to be inspected using the apparatuses shown in Figs. 8 to 11. Fig.
14 is a view for explaining a high resolution inspection apparatus using a terahertz Pervasel beam according to another embodiment of the present invention.
15 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the first embodiment.
FIG. 16 is a view of the ring beam forming unit 1540 of FIG.
17 is a view for explaining a high resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the second embodiment.
18 is a view for explaining a high resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the third embodiment.
19 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the fourth embodiment.
20 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the fifth embodiment.
21 is a view for explaining a high resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the sixth embodiment.
22 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the seventh embodiment.
23 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the eighth embodiment.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a view for explaining a high resolution inspection apparatus using a terahertz Pervasel beam according to an embodiment of the present invention.

Referring to FIG. 1, a high resolution inspection apparatus 100 using a vessel beam includes a scanner 110, a terahertz wave optical head 120, an object to be inspected 130, a terahertz wave condensing head 140, (150), and a second transfer unit (160).

The scanner 110 can scan the shape of the object to be inspected.

The terahertz wave optical head 120 generates a terahertz wave and irradiates the generated terahertz wave to the object 130 to be inspected.

The terahertz condenser head 140 can detect the terahertz wave transmitted through the object to be inspected 130.

The first transfer unit 150 may move the terahertz wave optical head 120 according to the shape of the object to be inspected scanned by the scanner 110. The first transfer unit 150 can move the terahertz wave optical head 120 in a direction perpendicular to the two-dimensional plane and the two-dimensional plane.

For example, the first transferring unit 150 may be configured to transfer the scanned object 130 to the object 130 so that the object 130 is positioned within the focal depth of the terahertz wave generated by the terahertz wave optical head 120. [ It is possible to move the terahertz optical head 120 so that the terahertz wave optical head 120 and the object to be inspected 130 are kept at a predetermined distance based on the thickness.

Specifically, assuming that the object to be inspected has a thickness A and a thickness B, the first transferring unit 150 may scan the optical head 120 in the vertical direction X . In addition, the first transfer unit 150 can move the optical head 120 in the vertical direction by Y when scanning a portion having a thickness of B.

The first transfer unit 150 allows the optical head 120 to move along the outer shape of the object 130 as much as possible so that the object to be inspected is positioned within the vessel lunch of the vessel, .

The second transfer unit 160 may synchronize with the first transfer unit 150 to move the terahertz wave condensing head 140 in the same manner as the terahertz wave optical head 120. The first transfer unit 150 and the second transfer unit 160 may be arranged such that the terahertz wave optical head 120 and the terahertz wave condensing head 140 are disposed on a straight line.

2 is a diagram for explaining a high resolution inspection apparatus using the terahertz Pervasel beam of FIG. 1 in detail.

2, a high resolution inspection apparatus 100 using a vessel beam includes a scanner 110, a terahertz wave optical head 120, an object to be inspected 130, a terahertz wave condensing head 140, (150), and a second transfer unit (160).

The scanner 110 can scan the shape of the object to be inspected. The scanner 110 may be disposed in a separate frame or may be disposed integrally in front of the terahertz wave optical head 120.

The terahertz wave optical head 120 generates a terahertz wave and irradiates the generated terahertz wave to the object 130 to be inspected.

The first transfer unit 150 may be mechanically coupled to the terahertz wave optical head 120. The first transfer unit 150 may move the terahertz wave optical head 120 according to the shape of the object to be inspected scanned by the scanner 110. The first transfer unit 150 can move the terahertz wave optical head 120 in a direction perpendicular to the two-dimensional plane and the two-dimensional plane.

The object to be inspected 130 may be placed on the conveyor belt and moved from the scanner 110 toward the terahertz wave optical head 120. The object to be inspected 130 may be moved by a conveyor belt or the like as in the present embodiment, but may be fixedly disposed at a specific position.

The terahertz condenser head 140 can detect the terahertz wave transmitted through the object to be inspected 130.

The second transfer unit 160 may synchronize with the first transfer unit 150 to move the terahertz wave condensing head 140 in the same manner as the terahertz wave optical head 120.

The first transfer unit 150 and the second transfer unit 160 may be arranged such that the terahertz wave optical head 120 and the terahertz wave condensing head 140 are disposed on a straight line.

In this embodiment, since the structure is merely a structure for understanding the shape of the high resolution inspection apparatus using the terahertz laser beam, the high resolution inspection apparatus using the terahertz laser beam can be realized in various types of structures.

3 is a view for explaining a high-resolution inspection apparatus using a terahertz Pervasel beam according to another embodiment of the present invention.

3, a high resolution inspection apparatus using a vessel beam includes a terahertz wave optical head 120, an object to be inspected 130, a terahertz wave condensing head 140, a first transfer unit 150, 2 feeder 160, a quench device 300 and a defrosting device 320.

The terahertz wave optical head 120, the object 130 to be inspected, the terahertz wave condensing head 140, the first transfer unit 150 and the second transfer unit 160 are the same as those in FIG. 1, I will not.

The terahertz wave optical head 120 and the terahertz wave condensing head 140 may be disposed on both sides of the quenching apparatus 300.

The quenching apparatus 300 can maintain the object 130 to be inspected at a low temperature. For example, the quenching apparatus 300 can cool the object to be inspected 130 to a solid state. Since the object to be inspected 130 is maintained at a low temperature or maintained in a solid state, the rate of absorption of the THz wave into the object 130 can be reduced.

The quenching apparatus 300 may be composed of a housing including a window 310 through which the generated terahertz wave can be transmitted. The object to be inspected 130 can pass through the inside of the housing of the quenching apparatus 300. For example, the window 310 may be composed of a heat insulating foam foam that can pass through a terahertz wave with a high insulation effect.

The defrosting device 320 is disposed at the rear end of the quenching device 300 and is capable of defrosting the quenched object to be inspected 130.

The structure of the quenching apparatus 300 in this embodiment is only one embodiment shown for the sake of explanation, and the quenching apparatus 300 can be implemented in various types of structures.

The object to be inspected 130 is quenched and the terahertz wave is transmitted well so that the object to be inspected containing the moisture can be inspected with high resolution by the high resolution inspection apparatus using the terahertz laser beam.

4 is a view for explaining a high resolution inspection apparatus using a vessel beam according to another embodiment of the present invention.

Referring to FIG. 4, a high resolution inspection apparatus 400 using a vessel beam may include a terahertz wave optical head 410, an object 420 to be inspected, and a terahertz wave condensing head 430. Although not shown in FIG. 4, the scanner 110, the first conveyance unit 150, and the second conveyance unit 160 shown in FIG. 1 may be additionally provided in this embodiment.

The terahertz wave optical head 410 may include a terahertz wave generating unit 411, an angle changing unit 412, and a vessel beam forming unit 413. In the present embodiment, the terahertz wave generating unit 411, the angle changing unit 412, and the vessel beam forming unit 413 are all included in the terahertz wave optical head 410, but the terahertz wave generating unit 411, The wavefront 410 may be implemented to include only a part of the terahertz wave generating unit 411, the angle changing unit 412, and the vessel beam forming unit 413.

The Bessel beam is a set of Maxwell's equations for free space. It is known as an undiffracted beam. It was introduced for the first time by Durnin in 1987, and has axial symmetry, concentrating energy around the axis like a needle like a certain length. Since it is realized by an optical system having a limited aperture, not an infinite aperture, there is no limitless Beessel beam, which is usually called Quasi-Bessel-Beam (QBB). This QBB can be made of a funnel-shaped lens known as a combination of a hologram, a circular mask with multiple rings or a finite aperture, and a lens, axicon.

The terahertz wave generating unit 110 may generate a terahertz wave. Means an electromagnetic wave in a terahertz blue terahertz range, and preferably has a frequency of 0.1 THz to 10 THz. However, even if the range is somewhat deviated from the above range, it is needless to say that the present invention can be regarded as a terafar insofar as those skilled in the art can easily think of it.

The angle changing unit 120 may change the angle of the terahertz wave incident from the terahertz wave generating unit 411 to be smaller and enter the vessel beam forming unit 413. For example, the angle changing unit 412 may change the incident terahertz wave to a smaller angle or less parallel to the optical axis. The angle changing unit 412 may be a convex lens for refracting the incident terahertz wave in parallel or a parabolic mirror for reflecting the incident terahertz wave in parallel.

The vessel beam forming unit 413 may use a terahertz wave incident from the angle changing unit 412 to form a terahertz Pervasell beam on at least a part of the object to be inspected.

When the angle changing unit 412 is not provided, the vessel beam forming unit 413 uses a terahertz wave incident from the terahertz wave generating unit 411 to irradiate a terahertz wave plasma beam to at least a part of the object to be inspected .

Since the vessel beam forming section 413 is difficult to form an ideal vessel beam in reality, the vessel beam formed by the vessel beam forming section 413 can be called a quasi-bessel beam (QBB). The vessel ring forming structure by the vessel beam forming section 413 will be described in more detail with reference to FIG.

The vessel beam forming unit 413 may be disposed such that the terahertz wave whose angle is changed by the angle changing unit 412 is incident perpendicularly to the light incident surface of the vessel beam forming unit 413. [

The vessel beam forming section 413 may be constituted by a diffractive optical element in which a plurality of circular grooves or circular holes are formed, a lens having a positive refractive index, an excitonic lens, a hologram optical element, or the like .

The vessel beam forming unit 413 may be a first axicon lens having a vertex angle such that the diameter of the terahertz wave plasma beam focused on the object is smaller than the wavelength of the terahertz wave generated by the terahertz wave generating unit have. In this embodiment, the apex angle that forms the diameter of the terahertz Pervasel beam below the wavelength is defined as the maximum apex angle.

In this case, the maximum value of the apex angle τ of the first axicon lens is the Full Width at Half Maximum diameter (ρ _FWHM ) of the terahertz Persell beam focused on the inspection object ), The wavelength?, And the refractive index (n, n ₀ ).

[Equation 1]

가 되어야 하고, 이 값을 만족하는 z=1.1264이다. 이에, 1.1264=k*ρ_FWHM*sinα₀ 식으로부터 위의 수학식 1이 도출될 수 있다. J₀ ²(z)=0.5에서 0.5 값은 변경될 수 있다.In order to satisfy J ₀ ² (z) = 0.5, J ₀ (z) is a first-order Bessel function of J ₀ (z) = 1 /

And z = 1.1264 which satisfies this value. From the equation 1.1264 = k *? _FWHM * sin? ₀ , the above equation 1 can be derived. The value of 0.5 at J ₀ ² (z) = 0.5 can be changed.

&Quot; (2) "

&Quot; (3) "

&Quot; (4) "

Where J _{0 is the} zero order Bessel function

ρ _{FWHM : FWHM of the} focused terahertz Farbessel beam

        λ: wavelength of terahertz wave

α _{0 :} Half value of the crossing angle of the terahertz wave passing through the axicon lens

        n: the refractive index of the first axicon lens

n ₀ : average refractive index of the surrounding environment

        τ: apex angle of the first axicon lens

Equation (4) is a mathematical formula derived using Equations (1), (2) and (3).

On the other hand, the minimum value of the apex angle of the first axicon lens may be the apex angle of the first axicon lens that does not cause total internal reflection according to the refractive index of the first axicon.

Thus, the vertex angle of the first axicon lens having the diameter of the terahertz wave plasma beam formed to be smaller than the wavelength of the terahertz wave generated by the terahertz wave generating unit can be formed between the maximum value and the minimum value as observed above.

The object to be inspected 420 means an object to be inspected and may be disposed between the terahertz wave optical head 410 and the terahertz wave condensing head 430.

The terahertz wave condensing head 430 includes a first lens 431, a second lens 432, and a detection unit 433. [ In this embodiment, the case where the first lens 431, the second lens 432, and the detection unit 433 are included in the terahertz wave condensing head 430 will be described as a reference. However, the terahertz wave condensing head 430, May include only a part of the first lens 431, the second lens 432 and the detecting unit 433. [

The first lens 431 can change the angle of the terahertz wave generated while the terahertz laser beam generated by the vessel beam forming unit 413 is transmitted through the object 420 to be smaller. For example, the first lens 431 can change the angle of the terahertz wave to be less than or equal to a certain angle with respect to the optical axis.

The second lens 432 can condense the terahertz wave that has passed through the first lens 431 to the detector 433.

In the present invention, the high-resolution terahertz wave condensing module means an apparatus including a first lens 431 and a second lens 432. For example, the high-resolution THz wave condensing module (first lens and second lens) spreads in the form of a ring-shaped circular beam while moving away from the vessel beam forming portion 413, So that the condensed terahertz wave can be directed to the detecting unit 433. [

For example, the high-resolution terahertz wave condensing module may be implemented in various types of configurations such as a convex lens, a concave mirror, a parabolic mirror, an ellipsoidal mirror, and the like.

The detection unit 433 can detect the terahertz wave condensed by the second lens. For example, the detection unit 433 can detect the intensity of the terahertz wave. For example, the detection unit 433 may be implemented with a Schottky diode.

And a video image can be generated using the vessel beam detected through the video generator (not shown) The generated image may be displayed on a display unit (not shown).

The high resolution inspection apparatus using the vessel beam can collect the terahertz wave transmitted through the object to be inspected with almost no loss, thereby increasing the light collection efficiency.

Further, a high resolution inspection apparatus using a vessel beam can obtain a clear image by increasing the resolution by making the diameter of the terahertz wave reaching the detection section to be equal to or lower than the wavelength of the terahertz wave.

5 is a view for explaining a vessel beam forming unit according to an embodiment of the present invention.

Referring to FIG. 5, the vessel beam forming unit may include an axicon 500. R is the radius of the axicon lens, τ is the apex angle of the axicon lens, α ₀ is half of the intersection angle of the beam crossing the axicon lens, and w ₀ is the radius of the parallel light incident on the axicon lens. In addition, the zone in which the vessel beam is formed is represented by Z _max in FIG. 5, and the terah waves incident on the excimer lens gather energy at the center along the z axis through the constructive interference in this region.

At this time, the Gaussian beam incident on the axicon lens and the vessel beam formed by the axicon lens are distributed in an axial symmetry, and a field is distributed in a circular shape along the z axis. That is, when viewed from the left to the right with reference to FIG. 5, both the Gaussian beam in front of the axicon lens and the vessel beam in the rear of the axicon lens are formed in a circular shape. In particular, the vessel lens formed by the axicon lens is moved away from the axicon lens and spread out into a ring-shaped circular beam.

On the other hand, the most important factor for determining the resolution of an image in a transmitted image obtained by moving a point, such as raster scanning, is the diameter of a beam incident on the object 1 to be inspected.

In particular, in the case of a vessel beam formed by an excitonic lens, its diameter is determined by the wavelength of teraharas and? ₀ , where? ₀ can be obtained by using Snell's law using the following equation (1).

&Quot; (5) "

Here, n ₀ denotes the refractive index in air, n denotes the refractive index of the axicon lens, and τ denotes the apex angle of the axicon lens.

On the other hand, Z _max corresponds to the depth of focus, which can be expressed by the following equation (6).

&Quot; (6) "

Z _max = w ₀ / tan 留₀

Here, w ₀ represents the radius of the beam incident on the axicon lens, as shown in Fig. Referring to these equations, it can be seen that the depth of focus also depends on? ₀ .

Therefore, by combining these points, it can be seen that the resolution and the depth of focus of the image largely change by the value of α ₀ .

5, it is assumed that n ₀ is 1.0, n is 1.54 (High Density Polyethylene), τ is 150 °, R is 25 mm, and α ₀ and the depth of focus Is calculated as follows.

First, when α ₀ is calculated using Equation (5), α ₀ can be calculated to 8.5 °. Further, when the depth of focus (Z _max ) is calculated using Equation (6), Z _max can be calculated as 40.2 mm.

The vessel beam forming portion may include a diffractive optical element in which a plurality of circular grooves or circular holes are arranged concentrically and a lens having a positive refractive index. At this time, the circular grooves or holes formed in the diffractive optical element may be formed in the form of concave plate or through-hole of the diffractive optical element. The lens having such a positive refractive index is arranged opposite to the direction in which the parallel light is incident on the diffractive optical element.

In addition to this embodiment, the vessel beam forming unit may be configured in various forms with a hologram structure or the like.

6 is a diagram for calculating the diameter of a terahertz wave beam focused on different vertex angles using Equation (4).

Referring to FIG. 6, when the wavelength λ of the terahertz wave is 2.14 mm, the refractive index n of the first axicon lens is 1.54, and the average refractive index n ₀ of the surrounding environment is 1, The maximum value of the apex angle? Of the cone lens is about 119 degrees, and the minimum value of the apex angle? Of the first axicon lens is about 99 degrees.

FIGS. 7 and 8 are views for explaining an inspection apparatus for collecting light using a single lens. FIG.

7 and 8, an inspection apparatus 700 includes a terahertz wave generating unit 710, an angle changing unit 720, a vessel beam forming unit 730, a condensing unit 740, and a detecting unit 750 .

The terahertz wave generating unit 710 may generate a terahertz wave.

The angle changing unit 720 may change the angle of the terahertz wave incident from the terahertz wave generating unit 710 to be smaller and enter the vessel beam forming unit 730.

The vessel beam forming unit 730 may use a terahertz wave incident from the angle changing unit 720 to form a terahertz Pervasell beam on at least a part of the object to be inspected. For example, the vessel beam forming portion may be an excicon. The object to be inspected may be formed between the vessel beam forming unit 730 and the light collecting unit 740.

The light collecting portion 740 may be implemented as a single lens.

The detector 750 can detect the terahertz wave condensed by the condenser 740.

Referring to FIG. 7, when the apex angle of the axicon, which is the vessel beam forming unit 730, is 140 degrees, the radius of the terahertz wave that is transmitted through the object to be examined and enters the detector 750 is about 5.1 mm, The terahertz wave diameter at 750 is about 10.2 mm.

In this case, most of the terahertz wave incident from the light collecting part 740 using a single lens has a diameter of about 9 mm and can be condensed by the detection part 750 having a horn.

Referring to FIG. 8, in order to form the diameter of the terahertz laser beam focused on the object under the wavelength of the terahertz wave, the apical angle of the exciton must be small. In other words, the apex angle of the axicon must be small in order to realize high resolution. Thus, it was formed at 110 degrees smaller than the apex angle of the axicon in Fig.

When the apex angle of the excicon, which is the bemem beam forming unit 730, is 110 degrees, the radius of the terahertz wave incident on the detection unit 750 through the object to be inspected is about 17 mm, The wave diameter is about 34 mm.

As the diameter of the terahertz wave incident on the detector 750 increases, only a part of the terahertz wave incident from the light collecting portion 740 using the single lens is condensed by the detector 750. In other words, much of the terahertz wave incident from the light collecting portion 740 is not incident on the detecting portion 750, and the detecting performance of the detecting portion 750 is remarkably deteriorated.

9 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 4 according to the first embodiment.

9, the high resolution testing apparatus 900 includes a terahertz wave generating unit 910, an angle changing unit 920, a vessel beam forming unit 930, a first lens 940, a second lens 950, And a detection unit 960.

The terahertz wave generating unit 910 may generate a terahertz wave.

The angle changing unit 920 may change the angle of the terahertz wave incident from the terahertz wave generating unit 910 to be smaller and enter the vessel beam forming unit 930.

The vessel beam forming unit 930 may use a terahertz wave incident from the angle changing unit 920 to form a terahertz wave plasma beam on at least a part of the object to be inspected. For example, the vessel beam forming portion may be an excicon.

The object to be inspected may be formed between the vessel beam forming unit 930 and the first lens 940.

The vessel beam forming unit 930 may be a first axicon lens having a vertex angle in which the diameter of the terahertz wave plasma beam is smaller than the wavelength of the terahertz wave generated in the terahertz wave generating unit.

The maximum value of the apex angle of the first axicon lens can be calculated based on Equations (1) to (3). For example, when the wavelength λ of the terahertz wave is 2.14 mm, the refractive index n of the first axicon lens is 1.54, and the average refractive index n ₀ of the surrounding environment is 1, Has a value of about 119 degrees. Thus, the maximum value of the apex angle of the first axicon lens is about 119 degrees.

On the other hand, the minimum value of the first X-con lens may be a vertex angle of the first X-axis lens that does not cause total internal reflection according to the refractive index of the first axicon. With respect to the refractive index in this embodiment, the critical angle due to total reflection is 99 degrees. Therefore, the minimum value of the twist angle of the first axicon lens is about 99 degrees.

Finally, if the vertex angle of the first axicon lens is formed between 119 degrees, which is the maximum value, and 99 degrees, which is the minimum value, the diameter of the terahertz wavelength laser beam is smaller than the wavelength of the terahertz wave generated by the terahertz wave generator do.

The first lens 940 can change the angle of the terahertz wave generated by the vessel beam forming unit 930 to be transmitted while passing through the object to be inspected.

The first lens 940 may be a second axicon lens arranged symmetrically with respect to the first axicon lens 930 on the basis of the object to be inspected.

The second axicon lens 950 may have an apex angle equal to that of the first axicon lens 930. In this case, the size of the second exicon lens 930 may be smaller than or equal to the size of the first exicon lens 930. When the apex angle of the second axicon lens is the same as that of the first axicon lens 930, the efficiency with which the terahertz wave is condensed by the detection unit 950 is the best.

If the angle changing portion 920 is a first convex lens, the second lens 950 may be a second convex lens arranged symmetrically with respect to the first convex lens with respect to the object to be inspected.

When the wavelength lambda of the terahertz wave is 2.14 mm and the first axicon lens of the vessel beam forming section 930 is 110 degrees, since the radius of the terahertz wave in the detecting section 960 is 0.006 mm, The diameter of the wave is 0.012 mm.

The terahertz wave condensed by the detection unit 960 is condensed by the detection unit 950 in Fig. 8 by condensing the terahertz wave using the first lens 940 and the second lens 950. [ The condensing efficiency can be increased.

Accordingly, when the terahertz wave is condensed by using the first lens 940 and the second lens 950, even when the vertex angle of the first axicon lens is small, high condensing efficiency can be obtained, resolution can be remarkably increased, A test image can be obtained.

FIG. 10 is a diagram for explaining the high-resolution inspection apparatus of FIG. 4 according to the second embodiment.

10, the high resolution inspection apparatus 1000 includes a terahertz wave generating unit 1010, an angle changing unit 1020, a vessel beam forming unit 1030, an object to be inspected 1040, a first lens 1050, A second lens 1060, and a detection unit 1070.

The terahertz wave generating unit 1010 may generate a terahertz wave.

The angle changing unit 1020 can change the angle of the terahertz wave incident from the terahertz wave generating unit 1010 to be smaller and enter the vessel beam forming unit 1030.

The vessel beam forming unit 1030 may use a terahertz wave incident from the angle changing unit 1020 to form a terahertz wave plasma beam on at least a part of the object to be inspected. For example, the vessel beam forming portion may be an excicon.

The object to be inspected may be formed between the vessel beam forming unit 1030 and the light collecting unit 1040.

The vessel beam forming unit 1030 may be a first axicon lens having a vertex angle in which the diameter of the terahertz wave plasma beam is smaller than the wavelength of the terahertz wave generated in the terahertz wave generating unit.

The first lens 1040 may be a third convex lens that changes the angle of the terahertz wave that is emitted while the terahertz laser beam passes through the object to be inspected.

The second lens 1050 may be a fourth convex lens disposed symmetrically with respect to the third convex lens with respect to an axis perpendicular to the optical axis.

When the wavelength? Of the terahertz wave is 2.14 mm, the radius of the terahertz wave transmitted through the object to be examined and entering the detection unit 1060 is about 2.5 mm, so that the diameter of the terahertz wave in the detection unit is about 5 mm .

By condensing the terahertz wave using the first lens 1040 and the second lens 1050, the condensing efficiency can be increased by significantly reducing the diameter of the terahertz wave condensed by the detecting unit 350 in Fig. Thus, the high resolution inspection apparatus according to the present embodiment can achieve a high condensation efficiency even when the apex angle of the first axicon lens is small, and can remarkably increase the resolution, thereby obtaining a high-resolution inspection image.

11 is a diagram for explaining the high-resolution inspection apparatus of FIG. 4 according to the third embodiment.

11, the high resolution inspection apparatus 1100 includes a terahertz wave generating unit 1110, an angle changing unit 1120, a vessel beam forming unit 1130, an object to be inspected 1140, a first lens 1150, A second lens 1160, and a detection unit 1170.

The terahertz wave generating unit 1110 may generate a terahertz wave.

The angle changing unit 1120 can change the angle of the terahertz wave incident from the terahertz wave generating unit 1110 to be smaller and enter the vessel beam forming unit 1130.

The vessel beam forming unit 1130 may use a terahertz wave incident from the angle changing unit 1120 to form a terahertz Pervasell beam on at least a part of the object to be inspected. For example, the vessel beam forming portion may be an excicon.

The object to be inspected may be formed between the vessel beam forming portion 1130 and the light collecting portion 1140.

The vessel beam forming unit 1130 may be a first axicon lens having a vertex angle in which the diameter of the terahertz wave plasma beam is smaller than the wavelength of the terahertz wave generated in the terahertz wave generating unit.

The first lens 1140 may be a second axicon lens arranged symmetrically with respect to the first axicon lens 1130 on the basis of an object to be inspected.

The second axicon lens may have an apex angle equal to that of the first axicon lens 1130.

The second lens 1150 has the same shape as the second axicon lens 1140 and may be disposed symmetrically with respect to the second axicon lens 1140 with respect to an axis perpendicular to the optical axis.

When the wavelength? Of the terahertz wave is 2.14 mm, since the radius of the terahertz wave transmitted through the object to be examined and entering the detection unit 1160 is about 1.7 mm, the diameter of the terahertz wave in the detection unit 1160 is About 3.4 mm.

By converging the terahertz wave using the first lens 1140 and the second lens 1150, the condensing efficiency can be increased by significantly reducing the diameter of the terahertz wave condensed by the detecting unit 350 in Fig. Thus, the high resolution inspection apparatus according to the present embodiment can achieve a high condensation efficiency even when the apex angle of the first axicon lens is small, and can remarkably increase the resolution, thereby obtaining a high-resolution inspection image.

Figs. 12 and 13 are transmission images obtained by measuring the object to be inspected using the apparatuses shown in Figs. 8 to 11. Fig.

Specifically, Fig. 12 shows the measurement of the object to be inspected using the apparatus shown in Fig. 8, and Fig. 13 shows the measurement of the object to be inspected using the apparatuses shown in Figs.

Referring to FIG. 12, it can be confirmed that the object to be inspected can not be identified at all with the transmission image obtained by condensing with only a single lens.

On the other hand, referring to FIG. 13, it can be seen that the object to be inspected can be clearly identified with the transmission image obtained by focusing with the lens configuration of FIGS. 8 to 11. FIG.

As described above, a high resolution image can be obtained by using a high resolution inspection apparatus using a vessel beam according to the present invention.

14 is a view for explaining a high resolution inspection apparatus using a terahertz Pervasel beam according to another embodiment of the present invention.

14, a high resolution inspection apparatus 1400 using a vessel beam may include a terahertz wave optical head 1410, an object to be inspected 1420, and a terahertz wave condensing head 1430. Although not shown in FIG. 14, the scanner 110, the first conveyance unit 150, and the second conveyance unit 160 shown in FIG. 1 may be additionally provided in this embodiment.

The terahertz wave optical head 1410 may include a terahertz wave generating unit 1411, an angle changing unit 1412, a vessel beam forming unit 1413, and a ring beam forming unit 1414. In this embodiment, the case where the terahertz wave optical head 1410 includes the angle changing portion 1412, the vessel beam forming portion 1413, and the ring beam forming portion 1414 is described as a reference, The beam forming section 1410 may be implemented to include only the angle changing section 1412, the vessel beam forming section 1413, and the ring beam forming section 1414. [

The terahertz wave generating unit 1411 can generate a terahertz wave.

The angle changing unit 1412 may change the angle of the terahertz wave incident from the terahertz wave generating unit 1411 to be smaller and enter the vessel beam forming unit 1413. For example, the angle changing unit 1412 can change the incident terahertz wave to a small angle or less parallel to the optical axis. The angle changing unit 1412 may be a convex lens for refracting the incident terahertz wave in parallel or a parabolic reflector for reflecting the incident terahertz wave in parallel.

The vessel beam forming unit 1413 can generate a terahertz Pervasell beam using the terahertz wave incident from the angle changing unit 1412.

When the angle changing unit 1412 is not provided, the vessel beam forming unit 1413 can form a terahertz Pervasell beam using the terahertz wave incident from the terahertz wave generating unit 1411.

Since the vessel beam forming part 1413 is difficult to form an ideal vessel beam in reality, the vessel beam formed by the vessel beam forming part 1413 can be called a quasi-bessel beam (QBB). The Bezel beam forming structure by the vessel beam forming part 1413 has already been described in detail with reference to FIG.

The vessel beam forming unit 1413 may be disposed such that the terahertz wave whose angle is changed by the angle changing unit 1412 is incident perpendicularly to the incoming surface of the vessel beam forming unit 1413.

Bezel beam forming unit 1413 may be a fourth exicon lens having a vertex angle such that the diameter of the terahertz Farber beam focused on the object to be inspected is smaller than the wavelength of the terahertz wave generated by the terahertz wave generating unit have. In this embodiment, the apex angle that forms the diameter of the terahertz Pervasel beam below the wavelength is defined as the maximum apex angle.

In this case, the maximum value of the apex angle τ of the fourth exicon lens is the Full Width at Half Maximum diameter (ρ _FWHM ) of the terahertz Pervasel beam focused on the object to be inspected ), The wavelength?, And the refractive index (n, n ₀ ). A detailed description thereof has already been given in FIG. 4, so that it will not be described below.

The ring beam forming portion 1414 can form a ring beam using a terahertz laser beam and condense the formed ring beam to the object 1420 to be inspected.

For example, the ring beam forming unit 1420 can collect the terahertz Pervasell beam focused through the vessel beam forming unit 1413 and then diverging the beam into a ring-shaped circular beam shape on the object to be inspected.

For example, the ring beam forming portion 1420 may be a third lens that forms a ring beam and condenses the formed ring beam into an object to be inspected.

The description of the ring beam forming portion 1420 will be specifically described with reference to FIGS. 15 to 23. FIG.

The object 1420 to be inspected means an object to be inspected and may be disposed between the terahertz wave optical head 1410 and the terahertz wave condensing head 1430.

The terahertz wave condensing head 1430 may include a ringing detection unit 1431 and a scattered light detection unit 1432. Although not shown in this embodiment, the first lens and the second lens (the 'light collecting portion') described in FIGS. 4 to 11 may be further included between the object 1420 to be inspected and the terahertz wave condensing head 1430 . Thus, the first lens and the second lens can improve the resolution of the inspection apparatus by focusing the ring beam transmitted through the inspection object 1420 by the ring beam detection unit 1431.

The ring beam detecting section 1431 can detect the ring beam transmitted through the object 1420 to be inspected.

The scattered light detection unit 1432 can detect the scattered light generated from the object 1420 to be inspected. For example, the scattered light detection unit 1432 includes a reflected scattered light detection unit capable of detecting scattered light reflected from the object 1420 or a transmitted scattered light detection unit capable of detecting scattered light transmitted from the object 1420 can do.

The image generating unit (not shown) may generate a video image using the vessel beam detected through the ring beam detecting unit 1431 and the scattered light detecting unit 1432. The generated image may be displayed on a display unit (not shown).

A high resolution inspection apparatus using a vessel beam can form a ring beam without loss of a terahertz wave, thereby enhancing the contrast of a transparent object to be inspected.

Further, the high resolution inspection apparatus using the vessel beam can increase the contrast of a transparent object to be inspected by detecting scattered light generated from the object to be inspected.

In addition, the high-resolution inspection apparatus using the vessel beam can arrange the scattered-light detection unit inside the generated ring beam, so that a separate space for adding the scattered-light detection unit is not required, thereby enabling miniaturization.

In order to realize a high resolution, a high resolution inspection apparatus using a vessel beam can obtain a high resolution image by reducing the diameter of a ring beam generated by using two lenses of the ring beam forming unit, even if the vertex angle of the axicon of the vessel beam forming unit is small .

15 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the first embodiment.

15, a high resolution inspection apparatus 1500 using a vessel beam includes a terahertz wave generating unit 1510, an angle changing unit 1520, a vessel beam forming unit 1530, a ring beam forming unit 1540, An object 1550, a ring beam detecting unit 1560, a transmitted scattered light detecting unit 1570, and a reflected scattered light detecting unit 1571.

The terahertz wave generating unit 1510 may generate a terahertz wave.

The angle changing unit 1520 can change the angle of the terahertz wave incident from the terahertz wave generating unit 1510 to be smaller and enter the vessel beam forming unit 1530.

The vessel beam forming unit 1530 may form a terahertz Pervasell beam using the terahertz wave incident from the angle changing unit 1520. [ For example, the vessel beam forming portion may be an excicon.

The ring beam forming unit 1540 forms a ring beam using the terahertz Pervasel beam incident from the vessel beam forming unit 1530 and condenses the formed ring beam onto the object 1550 to be inspected And may be a third lens.

The ring beam detecting unit 1560 can detect the ring beam transmitted through the object 1550 to be inspected.

The transmitted scattered light detection unit 1570 can detect scattered light transmitted from the object 1550 to be inspected. For example, the transmitted scattered light detection unit 1570 can be disposed inside the ring beam incident from the third lens. By disposing the transmission scattered light detection unit 1570 inside the ring beam, there is an advantage that the overall size of the apparatus is not changed even if the transmission scattered light detection unit 1570 is additionally provided.

The reflected scattered light detecting unit 1571 is disposed inside the ring beam emitted from the third lens 1540, which is a ring beam forming unit, and may be provided in the third lens 1540.

FIG. 16 is a view of the ring beam forming unit 1540 of FIG.

Referring to FIG. 16, the ring beam forming unit 1540 may include a member capable of receiving the reflected light and the light detecting unit 1571. For example, the ring beam forming portion 1540 may include a hole 1600, and the reflected scattered light detecting portion 1571 may be disposed inside the hole 1600. For example, the reflected scattered light detecting unit 1571 is disposed inside the ring beam forming unit 1640, and may be disposed inside the ring beam emitted from the third lens 1540. By arranging the reflection scattered light detection unit 1571 inside the ring beam formation unit 1540, there is an advantage that the size of the entire apparatus does not change even if the reflection scattered light detection unit 1571 is additionally provided.

A high resolution inspection apparatus using a vessel beam can increase the contrast of a transparent object to be inspected by detecting scattered light generated from the object to be inspected.

In addition, the high-resolution inspection apparatus using the vessel beam can arrange the scattered-light detection unit inside the generated ring beam, so that a separate space for adding the scattered-light detection unit is not required, thereby enabling miniaturization.

17 is a view for explaining a high resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the second embodiment.

17, a high resolution inspection apparatus 1700 using a vessel beam includes a terahertz wave generating unit 1710, an angle changing unit 1720, a vessel beam forming unit 1730, a ring beam forming unit 1740, An object 1750, a ring beam detecting unit 1760, a path changing unit 1770, a transmitted scattered light detecting unit 1780, and a reflected scattered light detecting unit 1781.

The terahertz wave generating unit 1710, the angle changing unit 1720, the vessel beam forming unit 1730, the ring beam forming unit 1740, and the object to be inspected 1750 have already been described.

The ring beam detecting unit 1760 can detect the ring beam transmitted through the object to be inspected 1750.

The path changing unit 1770 can change the path of the scattered light reflected from the inspection object 1750. [ For example, the path changing section 1770 can cause the reflected scattered light from the object to be inspected 1750 to be incident on the reflected scattered light detecting section 1781.

The path changing unit 1770 may be a device of various types capable of inputting the scattered light to the reflected light detecting unit 1781. [

The ring beam forming portion 1740 may include a member capable of accommodating the path changing portion 1770.

The transmission scattered light detection unit 1780 can detect scattered light transmitted from the object to be inspected 1750. For example, the transmitted scattered light detection unit 1780 can be disposed inside the ring beam incident from the third lens. By disposing the transmission scattered light detection unit 1780 inside the ring beam, there is an advantage that the overall size of the apparatus is not changed even if the transmission scattered light detection unit 1780 is additionally provided.

The reflected scattered light detecting unit 1781 can detect scattered light incident from the path changing unit 1770. [

A high resolution inspection apparatus using a vessel beam can increase the contrast of a transparent object to be inspected by detecting scattered light generated from the object to be inspected.

18 is a view for explaining a high resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the third embodiment.

18, a high resolution inspection apparatus 1800 using a vessel beam includes a terahertz wave generating unit 1810, an angle changing unit 1820, a vessel beam forming unit 1830, ring beam forming units 1840 and 1850, An object 1860 to be inspected, a ring beam detecting unit 1870, a transmitted scattered light detecting unit 1880, and a reflected scattered light detecting unit 1881. [

The terahertz wave generating unit 1810, the angle changing unit 1820, the vessel beam forming unit 1830, the object 1860 to be inspected, the ring beam detecting unit 1870, the transmitted scattered light detecting unit 1880 and the reflected scattered light detecting unit 1881, The description of FIG. 17 has already been made in FIG. 17, so that the description will be omitted in the present embodiment.

The ring beam forming units 1840 and 1850 may include a fourth lens 1840 that changes the angle of the terahertz Pervasell beam incident from the vessel beam forming unit to be smaller and enters the third lens 1850, And a first lens 1850 that forms a ring beam using the terahertz laser beam incident from the light source 1840 and condenses the formed ring beam into the object 1860 to be inspected.

When the vessel lens forming unit 1830 is a fourth exicon lens, the fourth lens 1840 is a fifth exicon lens arranged symmetrically with respect to the fourth exicon lens 1830 with respect to a line perpendicular to the optical axis. .

The fifth exicon lens 1840 may have an apex angle equal to that of the fourth exicon lens 1830. [ In this case, the size of the fifth exicon lens may be smaller than or equal to the size of the fourth exicon lens 1830. [

The third lens 1850 may be a sixth axicon lens having the same shape as the fifth axicon lens 1840 and arranged symmetrically with respect to the fifth axicon lens 1840 with respect to an axis perpendicular to the optical axis.

By implementing the ring beam forming unit using the fourth lens 1840 and the third lens 1850 as described above, even when the apex angle of the fourth exicon lens is reduced to improve the resolution, The diameter can be reduced. Therefore, the resolution can be remarkably increased, and high-resolution reflection and transmission inspection images can be obtained.

19 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the fourth embodiment.

19, a high resolution inspection apparatus 1900 using a vessel beam includes a terahertz wave generating unit 1910, an angle changing unit 1920, a vessel beam forming unit 1930, ring beam forming units 1940 and 1950, An object to be inspected 1960, a ring beam detecting unit 1970, a transmitted scattered light detecting unit 1980, and a reflected scattered light detecting unit 1981.

A terahertz wave generating unit 1910, an angle changing unit 1920, a vessel beam forming unit 1930, an inspection object 1960, a ring beam detecting unit 1970, a transmitted scattered light detecting unit 1980, and a reflected scattered light detecting unit 1981, The description of FIG. 17 has already been made in FIG. 17, so that the description will be omitted in the present embodiment.

The angle changing unit 1920 may be a fifth convex lens that changes the angle of the terahertz wave incident from the terahertz generating unit 1910 small.

The ring beam forming units 1940 and 1950 include a fourth lens 1940 for changing the angle of the terahertz Pervasel beam incident from the vessel beam forming unit to be incident on the third lens, And a third lens 1950 that forms a ring beam using a terahertz Farber beam and condenses the formed ring beam onto an object to be inspected 1960.

The fourth lens 1940 may be a seventh convex lens that changes the angle of the terahertz wave that is emitted while the terahertz laser beam passes through the object to be inspected.

The third lens 1950 is disposed symmetrically with respect to the fifth convex lens as the angle changing portion 1920 with respect to the axis perpendicular to the optical axis and is disposed symmetrically with respect to the fourth convex lens as the fourth convex lens, Lt; / RTI > The seventh convex lens and the eighth convex lens may have the same shape / size.

Thus, by implementing the ring beam forming portion using the second lens and the first lens, the diameter of the ring beam incident on the object to be inspected can be reduced even when the apex angle of the fourth exicon lens is reduced to improve the resolution . Therefore, the resolution can be remarkably increased, and high-resolution reflection and transmission inspection images can be obtained.

20 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the fifth embodiment.

20, a high resolution inspection apparatus 2000 using a vessel beam includes a terahertz wave generating unit 2010, an angle changing unit 2020, a vessel beam forming unit 2030, ring beam forming units 2040 and 2050, An object to be inspected 2060, a ring beam detecting unit 2070, a transmitted scattered light detecting unit 2080, and a reflected scattered light detecting unit 2081. [

A terahertz wave generating unit 2010, an angle changing unit 2020, a vessel beam forming unit 2030, an inspection object 2060, a ring beam detecting unit 2070, a transmitted scattered light detecting unit 2080, and a reflected scattered light detecting unit 2081, The description of FIG. 17 has already been made in FIG. 17, so that the description will be omitted in the present embodiment.

The angle changing unit 2020 may be a fifth convex lens that changes the angle of the terahertz wave incident from the terahertz generating unit 2010 to a small value.

The ring beam forming units 2040 and 2050 may include a fourth lens 2040 that changes the angle of the terahertz Pervasell beam incident from the vessel beam forming unit to be smaller and enters the third lens 2050, And a third lens 2050 for forming a ring beam using the terahertz Pervasel beam incident from the second lens 2040 and condensing the formed ring beam to the inspection object 2060.

When the vessel lens forming unit 2030 is a fourth exicon lens, the fourth lens 2040 is a fifth exicon lens arranged symmetrically with respect to the fourth exicon lens 2030 with respect to a line perpendicular to the optical axis. .

The third lens 2050 may be a sixth convex lens disposed symmetrically with respect to the fourth convex lens as the angle changing unit 2020 with respect to the axis perpendicular to the optical axis.

Thus, by implementing the ring beam forming portion using the second lens and the first lens, the diameter of the ring beam incident on the object to be inspected can be reduced even when the apex angle of the fourth exicon lens is reduced to improve the resolution . Therefore, the resolution can be remarkably increased, and high-resolution reflection and transmission inspection images can be obtained.

21 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the sixth embodiment.

21, a high resolution inspection apparatus 2100 using a vessel beam includes a terahertz wave generating unit 2110, an angle changing unit 2120, a vessel beam forming unit 2130, ring beam forming units 2140 and 2150, An object to be inspected 2160, a ring beam detecting unit 2170, a path changing unit 2180, a transmitted scattered light detecting unit 2190, and a reflected scattered light detecting unit 2191.

A terahertz wave generating unit 2110, an angle changing unit 2120, a vessel beam forming unit 2130, an inspection object 2160, a ring beam detecting unit 2170, a path changing unit 2180, a transmitted scattered light detecting unit 2190, And the reflected-scattered-light detecting unit 2191 have already been described with reference to FIG. 17, the description will be omitted in this embodiment.

The ring beam forming portions 2140 and 2150 include a second lens 2140 for changing the angle of the terahertz Pervasel beam incident from the vessel beam forming portion to be incident on the third lens 2150 and a fourth lens 2140 And a third lens 2150 that forms a ring beam using the terahertz Pervasel beam incident from the first lens 2150 and condenses the formed ring beam into the inspection object 2160.

When the vessel lens forming unit 2130 is a fourth exicon lens, the fourth lens 2140 is a fifth exicon lens arranged symmetrically with respect to the fourth exicon lens 2130 with reference to a line perpendicular to the optical axis. .

The fifth exicon lens 2140 may have an apex angle of the same size as the fourth exicon lens 2130. In this case, the size of the fifth exicon lens may be smaller than or equal to or larger than the size of the fourth exicon lens 2130. When the vertex angle of the fifth exicon lens is the same as that of the fourth exicon lens 2130, the efficiency with which the terahertz wave is condensed by the detection unit 2170 is the best.

The third lens 2150 may be a fifth axicon lens having the same shape as the fifth axicon lens 2140 and arranged symmetrically with respect to the fifth axicon lens 2140 with respect to an axis perpendicular to the optical axis.

22 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the seventh embodiment.

22, a high resolution inspection apparatus 2200 using a vessel beam includes a terahertz wave generating unit 2210, an angle changing unit 2220, a vessel beam forming unit 2230, ring beam forming units 2240 and 2250, An object to be inspected 2260, a ring beam detecting unit 2270, a path changing unit 2280, a transmitted scattered light detecting unit 2290 and a reflected scattered light detecting unit 2291.

A terahertz wave generating unit 2210, an angle changing unit 2220, a vessel beam forming unit 2230, an inspection object 2260, a ring beam detecting unit 2270, a path changing unit 2280, a transmitted scattered light detecting unit 2290, And the reflected-scattered-light detecting unit 2291 have already been described with reference to FIG. 17, the description will be omitted in this embodiment.

The angle changing unit 2220 may be a fifth convex lens that changes the angle of the terahertz wave incident from the terahertz generating unit 2210 small.

The ring beam forming units 2240 and 2250 include a fourth lens 2240 for changing the angle of the terahertz Pervasel beam incident from the vessel beam forming unit to be incident on the third lens 2250, And a third lens 2250 that forms a ring beam using the terahertz Pervasell beam incident from the second lens 2250 and condenses the formed ring beam into the inspection object 2260.

The third lens 2240 may be a seventh convex lens that changes the angle of the terahertz wave that is emitted while the terahertz laser beam passes through the object to be inspected.

The third lens 2250 is disposed symmetrically with respect to the fifth convex lens as the angle changing portion 2220 with respect to the axis perpendicular to the optical axis and is disposed symmetrically with respect to the fourth convex lens as the fourth convex lens, Lt; / RTI >

23 is a view for explaining a high-resolution inspection apparatus using the terahertz Pervasel beam of FIG. 14 according to the eighth embodiment.

23, a high resolution inspection apparatus 2300 using a vessel beam includes a terahertz wave generating unit 2310, an angle changing unit 2320, a vessel beam forming unit 2330, ring beam forming units 2340 and 2350, An object 2360 to be inspected, a ring beam detecting unit 2370, a path changing unit 2380, a transmitted scattered light detecting unit 2390 and a reflected scattered light detecting unit 2391. [

The terahertz wave generating unit 2310, the angle changing unit 2320, the vessel beam forming unit 2330, the ring beam forming units 2340 and 2350, the object to be inspected 2360, the ring beam detecting unit 2370, 2380, the transmitted scattered light detecting unit 2390 and the reflected scattered light detecting unit 2391 have already been described with reference to FIG. 17, the description will be omitted in this embodiment.

The angle changing unit 2320 may be a fourth convex lens that changes the angle of the terahertz wave incident from the terahertz generating unit 2310 small.

The ring beam forming units 2340 and 2350 may include a fourth lens 2340 and a fourth lens 2340 which change the angle of the terahertz Pervasell beam incident from the vessel beam forming unit to be incident on the third lens 2350, And a third lens 2350 for forming a ring beam by using the terahertz Pervasell beam incident from the objective lens 2360 and condensing the formed ring beam to the object 2360 to be inspected.

When the vessel lens forming unit 2330 is a fourth exicon lens, the fourth lens 2340 is a fifth exicon lens arranged symmetrically with respect to the fourth exicon lens 2330 with reference to a line perpendicular to the optical axis. .

The third lens 2350 may be a sixth convex lens arranged symmetrically with respect to the fifth convex lens as the angle changing portion 2320 with respect to the axis perpendicular to the optical axis.

The embodiments described may be constructed by selectively combining all or a part of each embodiment so that various modifications can be made.

It should also be noted that the embodiments are for explanation purposes only, and not for the purpose of limitation. In addition, it will be understood by those of ordinary skill in the art that various embodiments are possible within the scope of the technical idea of the present invention.

100: High-resolution inspection system using vessel beam
110: Scanner
120: terahertz wave optical head
130: object to be inspected
140: terahertz wave condensing head
150:
160: Second transfer section

Claims (27)

delete delete delete delete delete delete delete A ring beam forming part including a third lens for forming a ring beam using a terahertz Farber beam and condensing a ring beam formed as an object to be inspected; And
And a reflected-scattered light detection unit provided in the ring beam emitted from the third lens and detecting scattered light reflected from the object to be inspected.
delete delete A ring beam forming part including a third lens for forming a ring beam using a terahertz Farber beam and condensing a ring beam formed as an object to be inspected; And
And a transmission scattered light detection unit disposed inside the ring beam incident from the third lens and detecting scattered light transmitted from the object to be inspected.
9. The method of claim 8,
The third lens includes:
And a path changing unit for changing a path of scattered light reflected from the inspection object,
The reflected-scattered-light detecting unit detects,
And detects scattered light incident from the path changing unit.
delete delete delete delete A terahertz wave generating unit for generating a terahertz wave;
A Bezel beam forming unit for generating a terahertz Farber beam using the terahertz wave incident from the terahertz wave generating unit;
A ring beam forming unit for forming a ring beam using the terahertz Pervasell beam and condensing a ring beam formed as an object to be inspected;
A scattered light detector for detecting scattered light generated from the object; And
And a ring beam detecting unit for detecting a ring beam transmitted through the object to be inspected, using a terahertz laser beam.
18. The method of claim 17,
The ring-
And a third lens that forms a ring beam and condenses the formed ring beam into an object to be inspected. A high resolution inspection apparatus using a terahertz wavelength laser beam.
19. The method of claim 18,
The scattered-
And a reflected-scattered light detection unit provided in the ring beam emitted from the third lens and detecting scattered light reflected from the inspection object.
19. The method of claim 18,
The scattered-
And a transmission scattered light detection unit provided inside the ring beam incident from the object to be inspected and detecting scattered light transmitted from the object to be inspected.
A scanner for scanning a shape of an object to be inspected;
A terahertz wave optical head for generating a terahertz wave and irradiating the object to be inspected with the generated terahertz wave;
A terahertz wave condensing head for detecting a terahertz wave transmitted through the object to be inspected;
A first transfer unit for moving the terahertz wave optical head according to a shape of an object to be inspected scanned by the scanner; And
And a second transporting unit synchronized with the first transporting unit to move the terahertz wave condensing head in the same manner as the optical head,
The terahertz wave optical head includes:
A terahertz wave generating unit for generating a terahertz wave;
A Bezel beam forming unit for generating a terahertz Farber beam using the terahertz wave incident from the terahertz wave generating unit; And
And a ring beam forming unit for forming a ring beam using the terahertz laser beam and condensing the formed ring beam as an object to be inspected,
The terahertz wave condensing head comprises:
A scattered light detector for detecting scattered light generated from the object; And
And a ring beam detecting unit for detecting a ring beam transmitted through the object to be inspected, using a terahertz laser beam.
22. The method of claim 21,
The first transfer unit
And the terahertz wave optical head is positioned at a predetermined distance on the basis of the thickness of the scanned object in order to place the object in the depth of focus of the generated terahertz wave, A high resolution inspection apparatus using a terahertz Farbessel beam for moving a Hertz wave optical head.
delete delete 22. The method of claim 21,
Further comprising a quenching device that keeps the object to be inspected at a low temperature,
Wherein the terahertz wave optical head and the terahertz wave condensing head are disposed on both sides of the quenching device.
26. The method of claim 25,
The quenching device comprises:
And a housing including a window through which the generated terahertz wave can be transmitted,
And a defrosting device disposed at a rear end of the quenching device and defrosting the object to be inspected. delete

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