CN217981290U - Optical detection equipment - Google Patents

Abstract

An optical detection device comprises a detection system and a decontamination system, wherein the detection system comprises a detection light source component for emitting a measuring light beam to the surface of an object to be detected, and the decontamination system comprises a decontamination light source component for emitting a decontamination light beam and a light path conversion piece positioned on the light path of the decontamination light beam; the light path conversion piece is used for enabling at least part of decontamination beams to be incident on the object to be measured so as to remove pollutants on the surface of the object to be measured. The light path conversion part is used for converting the light path of the decontamination light beam, so that the position of the decontamination light beam forming light spots on the surface of the object to be measured is at least partially overlapped with the position of the measurement light beam forming light spots on the surface of the object to be measured, and before the detection system is started to carry out optical detection on a certain area position of the object to be measured, the decontamination light beam can be used for clearing away pollutants on the area position, so that the accuracy of a detection result can be ensured, high-precision repeated measurement can be carried out on the same position to be measured of the object to be measured, and the consistency of the measurement result is ensured.

Description

Optical detection equipment

Technical Field

The utility model relates to a semiconductor field, concretely relates to optical detection equipment.

Background

Optical inspection is one of the main methods for high-precision and nondestructive defect inspection in the modern semiconductor industry, and in the manufacturing process of semiconductor chips, optical inspection is adopted to detect certain properties of the wafer surface, such as film thickness, particle pollution, other critical dimensions, surface defects and the like, so that the optical inspection is an important link for ensuring the product quality.

When the existing optical detection equipment is used for detecting and measuring a wafer, a measured value is strongly influenced by factors such as atmospheric conditions (such as temperature, humidity and the like) in a detection environment, the time for exposing the wafer to air and the like, and particularly the measured value is obtained when the wafer is repeatedly detected; for example, when the humidity in the environment is high, the measured film thickness tends to be high; as another example, the measured film thickness may also exhibit an increasing trend as the wafer is exposed to air for longer periods of time. Therefore, the variation of the measurement value caused by such factors not only affects the accuracy of the measurement result, but also greatly reduces the feasibility of repeated measurements with better accuracy.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the main technical problem who solves provides an optical detection equipment to reach the purpose that strengthens measuring repeatability and improve the testing result accuracy.

An embodiment provides an optical inspection apparatus, comprising an inspection system and a decontamination system, the inspection system comprising an inspection light source assembly, the decontamination system comprising a decontamination light source assembly and a light path conversion element; wherein:

the detection light source assembly is used for emitting a measuring light beam to the surface of an object to be detected so that the measuring light beam forms a signal light beam after passing through the object to be detected;

the decontamination light source assembly is used for emitting decontamination beams, and the light path conversion piece is positioned on the light path of the decontamination beams and used for enabling at least part of the decontamination beams to enter the object to be detected and enabling the position of the decontamination beams, which forms light spots on the surface of the object to be detected, to be at least partially overlapped with the position of the measurement beams, which forms light spots on the surface of the object to be detected, so as to remove pollutants on the surface of the object to be detected.

In one embodiment, the optical path conversion element comprises a first conversion element for converting the optical path of the decontaminating beam so that the optical path of the decontaminating beam coincides with the optical path of the measuring beam.

In one embodiment, the first conversion member is a beam splitter, and the beam splitter is arranged at a position where the optical path of the measuring beam and the optical path of the decontaminating beam intersect, so that the decontaminating beam and the measuring beam after passing through the beam splitter share the optical path; or

The first conversion member is a reflecting mirror configured to be movable to a position where an optical path of the measuring beam intersects an optical path of the decontaminating beam, so that the decontaminating beam and the measuring beam after passing through the reflecting mirror share an optical path.

In one embodiment, the decontamination light source assembly includes a decontamination light source for emitting a decontamination beam and a first focusing mirror for focusing the decontamination beam.

In one embodiment, the detection light source assembly includes a detection light source, the detection light source is configured to emit a measurement light beam to the first focusing mirror, and the first focusing mirror is further configured to focus the measurement light beam to form a light spot on a surface of an object to be measured.

In one embodiment, the detection light source assembly includes a detection light source for emitting a measurement light beam and a second focusing mirror for focusing the measurement light beam to form a light spot on the surface of the object.

In one embodiment, the focal length of the first focusing mirror is greater than the focal length of the second focusing mirror; the decontamination light source assembly further comprises a first beam expander, the first beam expander is used for expanding the decontamination light beam, and the first focusing lens is used for focusing the decontamination light beam expanded by the first beam expander.

In one embodiment, the focal length of the first focusing mirror is 180mm-250mm, and the focal length of the second focusing mirror is 45mm-60mm.

In one embodiment, the focal length of the first focusing lens is smaller than that of the second focusing lens, the detection light source assembly further includes a second beam expander, the second beam expander is used for expanding the measuring light beam, and the second focusing lens is used for focusing the measuring light beam expanded by the second beam expander.

In one embodiment, the optical path of the decontaminating beam emitted by the decontaminating light source component is parallel to the optical path of the measuring beam emitted by the detecting light source component.

In one embodiment, the light path conversion element further comprises a second conversion element for converting the light path of the decontamination beam so that the light path of the decontamination beam intersects the light path of the measurement beam, the second conversion element being located at the output end of the decontamination light source assembly.

In one embodiment, the detection system further includes a detection chamber for being disposed opposite to the object to be measured, the detection light source assembly and the decontamination light source assembly are both disposed in the detection chamber, one end of the detection chamber facing the surface of the object to be measured is provided with a light beam channel, and the light beam channel is used for passing either or both of the measuring light beam and the decontamination light beam.

In one embodiment, the decontamination beam is a gaussian infrared pulsed beam or a gaussian ultraviolet pulsed beam and the measurement beam is a broad spectrum beam.

The optical detection device according to the above embodiment comprises a detection system and a decontamination system, wherein the detection system comprises a detection light source assembly for emitting a measuring light beam to the surface of the object to be detected, and the decontamination system comprises a decontamination light source assembly for emitting a decontamination light beam and a light path conversion piece positioned on the light path of the decontamination light beam; the light path conversion piece is used for enabling at least part of decontamination beams to be incident on the object to be measured so as to remove pollutants on the surface of the object to be measured. The system architecture of the detection system and the decontamination system is fused, so that the optical detection equipment has double functions of optical detection and decontamination, and the integration level of the equipment function is enhanced; the light path conversion function of the light path conversion piece on the decontamination beam light path is utilized, so that the position of the decontamination beam forming the light spot on the surface of the object to be measured is at least partially overlapped with the position of the measuring beam forming the light spot on the surface of the object to be measured, and before the detection system is utilized to carry out optical detection on the position of a certain area of the object to be measured, the decontamination system can be started to remove pollutants in the position of the area, so that the accuracy of a detection result can be ensured, high-precision repeated measurement can be carried out on the same position to be measured of the object to be measured, and the consistency of the measurement result can be ensured.

Drawings

Fig. 1 is a schematic diagram of a first exemplary structure of an optical path system in an optical detection apparatus according to the present application.

Fig. 2 is a schematic diagram of a second exemplary structure of an optical path system in the optical detection apparatus of the present application.

Fig. 3 is a third exemplary structural diagram of an optical path system in the optical detection apparatus of the present application.

Fig. 4 is a schematic diagram of a fourth exemplary structure of an optical path system in the optical detection apparatus of the present application.

Fig. 5 is a schematic diagram of a fifth exemplary structure of an optical path system in the optical detection apparatus of the present application.

In the figure:

11. detecting a light source; 12. a second focusing mirror; 13. a detection chamber; 21. a decontamination light source; 22. a first focusing mirror; 23. a first conversion member; 24. a second conversion member; 25. a first beam expander; s1, measuring a light beam; s2, decontaminating light beams; A. and (5) a wafer.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous specific details are set forth in order to provide a better understanding of the present application. However, one skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.

The ordinal numbers used herein for the components, such as "first," "second," etc., are used merely to distinguish between the objects described, and do not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).

The term "location" as used herein refers to a point or region of an analyte; for example, a "location under test" can be understood as a point or area on an object under test that requires detection; as another example, the "position of the light spot" may be understood as a point or area where the light beam forms the light spot on the object to be measured.

It is found through research that the variation of the measured value is caused by the fact that the surface of the wafer continuously adsorbs pollutant particles in the environment, which include, for example, hydrocarbon molecules, inorganic gas molecules, etc., and the pollutant layer on the surface of the wafer grows, when the wafer is exposed to normal atmospheric conditions, water molecules in the air adsorb the pollutant particles, so that the pollutant layer is formed, and the thickness of the pollutant layer continuously increases to a certain thickness along with the time. Therefore, due to the existence of the pollutant layer, when the existing optical detection equipment detects the wafer, the obtained measurement value is not accurate; when a certain position of the wafer is repeatedly detected, the measurement results are often inconsistent.

The application provides an optical detection equipment, through carrying out system architecture and function integration with detecting system and decontamination system, can utilize decontamination system to get rid of in advance or clear away the pollutant of the position of awaiting measuring on the determinand surface before carrying out optical detection to the determinand to eliminate because of the existence of pollutant to detecting precision, detecting process etc. produced serial influence, ensure the accuracy of testing result, and create the condition for repeatability detection measurement.

In order to describe the structure and the functional principle of the optical inspection apparatus more clearly and in detail, the following description takes the object to be inspected as a wafer as an example, but it should be noted that the wafer is only a specific inspection object of the optical inspection apparatus in practical application, and the inspection object may be other semiconductor devices or workpieces requiring inspection of items such as surface defects, critical dimensions, etc. by using an optical inspection method.

Example one

Referring to fig. 1, fig. 2 and fig. 3, an optical inspection apparatus provided in this embodiment includes an inspection system and a decontamination system, which are respectively described below.

The detection system is mainly used for detecting and measuring common defects or characteristic parameters such as surface redundancy, crystal defects, mechanical damage (such as scratches, cracks and patterns), critical dimensions (such as film thickness) and the like of the wafer; the detection system can adopt an optical system framework of detection instruments such as a spectrometer, an ellipsometer, a spectrum confocal measurement device, a white light interferometer, an optical imaging device and the like according to detection items, actual detection requirements and the like, so as to form a brand new product with double functions of optical detection measurement and decontamination through structural fusion with a decontamination system, or directly utilize the optical system of the detection instrument as the detection system, fuse the decontamination system to a detection instrument main body through improvement on related structures (such as a detection cavity space) of the detection instrument, and further enable the detection instrument to have the decontamination function besides the functions of optical detection measurement; moreover, the detection instrument and the decontamination system can be combined in a system structure, so that the detection instrument and the decontamination system form a complete instrument combination system matched with each other.

Referring to fig. 1 to 3, in general, the detection system mainly includes two parts, namely a detection light source assembly and a signal light detection assembly, wherein the detection light source assembly is used for emitting a measuring beam S1 to the surface of the wafer a, so that the measuring beam S1 forms a signal beam after passing through the wafer a (such as reflection, scattering, transmission, etc.); the signal light detection assembly is used for detecting the signal light beam and finally obtaining the related detection information of the wafer A according to the signal light beam; in view of the related detecting instruments and the detecting systems thereof listed herein, those skilled in the art should know the specific detecting principle and the related structure of the detecting system, and therefore the functional coordination relationship and the organization and arrangement relationship between the signal light detecting element and the detecting light source element are not described herein too much.

In one embodiment, referring to fig. 1 to 3, the detecting light source assembly mainly includes a detecting light source 11, a second focusing lens 12 and other components as required; the detection light source 11 is configured to emit a measuring light beam S1 to the second focusing mirror 12, and the second focusing mirror 12 is disposed on a light emitting side of the detection light source 11 or on a light path of the measuring light beam S1, and is configured to focus the measuring light beam S1, so that a measuring light spot capable of meeting detection requirements can be formed at a certain position to be detected on the surface of the wafer a. In this embodiment, the measuring beam S1 is a broad spectrum beam (it can also be understood that the detecting light source 11 is a broad spectrum light source), and the wavelength range of the broad spectrum beam may include one or more of visible light, ultraviolet light, and infrared light, so that the material characteristics and the structural characteristics of the wafer a can be measured more accurately. In other embodiments, the wavelength range of the measuring beam S1 may be defined to meet different measurement requirements.

Referring to fig. 1 to 3, the decontamination system is mainly used for emitting a light beam (i.e., decontamination light beam S2) with a certain wavelength or wavelength range to the surface of the wafer a to clean and remove the contaminants on the surface of the wafer a, for example, after the decontamination light beam S2 contacts the contaminants, the contaminants are vaporized in a heating manner to clean the contaminants; the device is mainly formed by combining and building a decontamination light source component and a light path conversion piece; the decontamination light source assembly is used for emitting a decontamination light beam S2, and the light path conversion member is fixedly or movably arranged on the light path of the decontamination light beam S2 and used for converting the light path of the decontamination light beam S2, so that on one hand, at least part of or all of the decontamination light beam S2 can be incident to the surface of the wafer A, and on the other hand, the position of the decontamination light beam S2 forming a light spot on the surface of the wafer A can be at least partially superposed with the position of the measuring light beam S1 forming the light spot on the surface of the wafer A, so as to ensure that the position to be decontaminated on the surface of the wafer A is the same or basically the same as the position to be measured, so that pollutants at the position to be measured can be removed in advance before optical detection measurement is performed on the position to be measured, and conditions are created for improving the accuracy of a detection result and the consistency of a repeated measurement result.

In one embodiment, referring to fig. 1, the decontamination light source assembly includes a decontamination light source 21 and a first focusing lens 22, and the light path conversion member includes a first conversion member 23 and a second conversion member 24; the decontamination light source 21, the first focusing mirror 22 and the second conversion element 24 are sequentially arranged along the same straight line, and the arrangement path (or track) of the decontamination light source 21, the first focusing mirror 22 and the second conversion element is parallel to the optical path of the measuring beam S1, that is, the optical path of the decontamination beam S2 emitted by the decontamination light source assembly is parallel to the optical path of the measuring beam S1 emitted by the detection light source assembly. The decontamination light source 21 is used for emitting a decontamination beam S2 with a certain wavelength or a certain wavelength range, and the first focusing mirror 22 is arranged on a light path (namely, the light path of the decontamination beam S2) on the light emitting side of the decontamination light source 21 and is used for focusing the decontamination beam S2, so that the decontamination beam S2 can form a required decontamination spot on the surface of the wafer A, and the energy or light utilization rate of the decontamination beam S2 is improved to enhance the cleaning effect on pollutants; the second conversion element 24 may employ an optical element having light reflection or light reflection capability, such as a mirror, a beam splitter, etc., for converting the optical path of the focused decontamination beam S2, so that the optical path of the decontamination beam S2 can exist in a cross distribution with the optical path of the measurement beam S1 (e.g., the actual optical paths or the extended lines of the optical paths of the two beams are in a plane cross or a space cross distribution); correspondingly, the first conversion member 23 employs an optical element having a certain refractive or reflective power to the light beam, such as a mirror, a beam splitter, etc., which is disposed on the light-emitting end side of the second conversion member 24 and located on the light path of the decontamination light beam S2, and is mainly used for converting the light path of the decontamination light beam S2 again, so that the light path of the decontamination light beam S2 is finally overlapped with the light path of the measurement light beam S1, or the light path of the decontamination light beam S2 intersects with the light path of the measurement light beam S1 at the surface position (specifically, the position to be detected) of the wafer a, thereby ensuring that the position where the detection light spot is formed on the surface of the wafer a and the position where the decontamination light spot is formed are at least partially overlapped, so as to sequentially perform contaminant removal and feature detection on the same position on the surface of the wafer a, and ensure the accuracy of the measurement result and the consistency of the repeated measurement result.

It should be noted that the first converting element 23 and the second converting element 24 do not only represent one converting element, but they may also be a set of converting elements composed of a plurality of converting elements, i.e., "first" and "second" herein refer to not only the number of converting elements, but also the grouping thereof.

In another embodiment, referring to fig. 2 and fig. 3, without considering the overall structural space utilization rate or the volume size of the apparatus, the second conversion element 24 may be omitted, and the first conversion element 23 is directly used to change the optical path of the decontamination beam S2 emitted from the decontamination light source assembly so as to coincide with the optical path of the measurement beam S1, or intersect the optical path of the measurement beam S1 at the surface position of the wafer a; for example, referring to fig. 2, the second conversion element 24 is omitted, the optical path of the decontamination beam S2 emitted from the decontamination light source assembly is parallel to the optical path of the measurement beam, and the decontamination beam S2 crosses the optical path of the measurement beam S1 at a certain position on the surface of the wafer a after passing through the first conversion element 23; for another example, referring to fig. 3, the second converter 24 is omitted, the layout path (or track) of the decontamination light source 21, the first focusing mirror 22 and the first converter 23 is set to be in a cross distribution with the optical path of the measuring beam S1, the first converter 23 is fixedly or movably disposed at a position where the optical path of the measuring beam S1 and the optical path of the decontamination beam S2 cross, so that the measuring beam S1 and the decontamination beam S2 share the optical path, or the first converter 23 is fixedly or movably disposed at another position, and the optical path of the decontamination beam S2 intersects the optical path of the measuring beam S1 at a position on the surface of the wafer a by using the first converter 23.

Firstly, when the equipment is actually applied, a decontamination system can be started in advance to remove pollutants on the surface of the wafer A, and then a detection system is used for carrying out optical detection on the characteristics of the wafer A; since the spot forming position of the decontamination beam S2 on the surface of the wafer a and the spot forming position of the measurement beam S1 on the surface of the wafer a are partially or completely overlapped, it can be understood that: the position of pollutant removal (namely: decontamination position) and the position of optical detection (namely: detection position) are the same or approximately the same, so that the position to be detected of the wafer A can be quickly detected after decontamination, and the wafer A is effectively prevented from being polluted again within the time difference from the decontamination to the detection; in turn, the pollution probability can be reduced, the detection precision can be improved, the accuracy of the detection result can be effectively ensured, high-precision repeated measurement can be carried out on the same position to be measured of the wafer, and the consistency of the measurement result can be ensured.

Secondly, on the basis of not changing the basic architecture of the detection system in the existing optical detection device, the decontamination system and the detection system can be combined by fully utilizing or improving the local structure (such as the detection cavity for accommodating the detection system) of the existing optical detection device, so that the optical detection device can have the double functions of detection and dirt on the premise of not greatly improving the device improvement or manufacturing cost.

In an embodiment, referring to fig. 1 and fig. 3, the first conversion element 23 may employ an optical element such as a mirror having a simple light reflection performance, and in an embodiment that the optical path of the decontamination beam S2 needs to be converted to coincide with the optical path of the measurement beam S1 by the first conversion element 23 to achieve a common optical path between the decontamination beam S2 and the measurement beam S1, the first conversion element 23 may be configured to have a member capable of moving in a certain stroke and a certain direction by using some existing mechanical connection structures or movement mechanisms (such as a translation linkage mechanism, etc.), so as to controllably move the first conversion element 23 to a position where the optical path of the measurement beam S1 intersects with the optical path of the decontamination beam S2, on one hand, the optical path of the decontamination beam S2 passing through the first conversion element 23 is changed to enable the optical path of the decontamination beam S2 to be recombined with the optical path of the measurement beam S1, thereby ensuring that the position where the decontamination beam S2 forms a spot on the surface of the wafer a can be maximally overlapped with the position where the measurement beam S1 forms a spot on the surface of the wafer a, on the other hand, and on the other hand, the decontamination beam S2 can be reflected to the wafer a, thereby improving the utilization rate of the detection beam S2 and avoiding the detection signal component from being damaged by the detection element, thereby avoiding the detection element.

In another embodiment, the first conversion member 23 may also adopt a light source element such as a beam splitter, in which case, the first conversion member 23 may be fixedly disposed at a position where the optical path of the measuring beam S1 intersects with the optical path of the decontaminating beam S2, or a beam splitting device that is native to the detection system may be directly used as the first conversion member 23; therefore, the number of elements which are required to be increased due to the arrangement of the decontamination system of the optical detection equipment can be effectively reduced, the structure of the optical detection equipment can be simplified, the structure compactness can be enhanced, and the related functional elements can be fully utilized.

In one embodiment, referring to fig. 1 to 3, the detection system further includes a detection chamber 13, where the detection chamber 13 may be an original structural chamber of the existing optical detection apparatus (e.g. a machine structural space for accommodating and providing the detection system to perform its detection function), or may be a structural member (e.g. a housing, which can accommodate the detection system and the decontamination system in one space) independently installed or configured at a later stage; specifically, the detection chamber 13 has a cavity space for accommodating the detection light source assembly and the decontamination light source assembly, and also has a light beam channel through which the measuring light beam S1 and the decontamination light beam S2 can respectively and independently pass or simultaneously pass; when the optical detection device is actually used, the detection chamber 13 and the wafer a may be arranged oppositely, so that the beam channel is aligned with the surface of the wafer a, so that the decontamination beam S2 can irradiate the surface of the wafer a and complete the removal of the contaminants after passing through the beam channel, and the measurement beam S1 can irradiate the surface of the wafer a and form a signal beam after passing through the beam channel, thereby finally completing the detection and measurement of the features of the wafer a.

When the system structure of the decontamination system and the detection system needs to be integrated to form an optical detection device with a compact structure, the problem of insufficient structural space is usually faced; for example, when the decontamination system is integrated into the main body of the detection apparatus, the decontamination system cannot be disposed due to the limited space of the main body of the detection apparatus or the disposed decontamination system cannot satisfactorily perform its intended function; as another example, structurally integrating the decontamination system with the detection system to form an integrated optical detection device can easily result in an oversized device. In view of this, in the embodiment, the focal length of the first focusing mirror 22 and the focal length of the second focusing mirror 12 are selectively set in a differentiated manner, so that the first focusing mirror 22 and the second focusing mirror 12 are spatially staggered, thereby solving the problem of insufficient spatial configuration and making the overall system structure of the device more compact.

In one embodiment, referring to fig. 1 to 3, the focal length of the first focusing mirror 22 is greater than that of the second focusing mirror 12; at this time, the decontamination light source assembly further comprises a first beam expander 25, the first beam expander 25 is arranged on the light path of the decontamination light beam S2 between the decontamination light source 21 and the first focusing mirror 22, and is used for adjusting and transforming the diameter and the divergence angle of the decontamination light beam S2 emitted by the decontamination light source 21, so as to implement beam expansion processing on the decontamination light beam S2, so as to reduce the size of a light spot finally formed on the surface of the wafer a after the decontamination light beam S2 passes through the first focusing mirror 22, thereby solving the problems that the focus effect of the light spot is poor and the size of the light spot is too large due to the large focal length of the first focusing mirror 22; thus, the first focusing mirror 22 and the second focusing mirror 12 can be arranged in a staggered manner in space by utilizing the characteristic that the focal length of the first focusing mirror 22 is greater than that of the second focusing mirror 12; meanwhile, under the cooperation of the first beam expander 25, the size of the decontamination light spot can be ensured to meet the decontamination requirement, and the energy or light utilization rate of the decontamination light beam S2 can be improved in an auxiliary manner. In one particular embodiment, the first focusing mirror 22 may be configured to have a focal length controllably adjustable between 180mm-250mm, and the second focusing mirror 12 may be configured to have a focal length controllably adjustable between 45mm-60 mm; the size of a light spot formed on the surface of the wafer A by the decontamination light beam S2 is adjusted by adjusting the focal length of the first focusing lens 22, so that the utilization rate of decontamination light energy is improved by reducing the size of the light spot, and the removal effect of pollutants is ensured; by adjusting the focal length of the second focusing mirror 12, the measuring beam S1 can form a required measuring spot on the surface of the wafer a, so as to meet the requirements of detection and measurement.

In another embodiment, the focal length of the first focusing mirror 22 is less than the focal length of the second focusing mirror 12, such as the first focusing mirror 22 is configured to controllably adjust the focal length between 45mm-60mm, and the second focusing mirror 12 is configured to controllably adjust the focal length between 180mm-250 mm; at this time, the detection light source assembly further includes a second beam expander (not shown in the figure), and the second beam expander is located on the light path of the measurement light beam S1 between the detection light source 11 and the second focusing mirror 12, so as to expand the measurement light beam S1 by using the second beam expander, and make the expanded measurement light beam S1 incident to the second focusing mirror 12; in this embodiment, the measuring beam S1 may be a gaussian beam; in this way, the first focusing mirror 22 and the second focusing mirror 12 can be spatially offset, and the spot focusing effect of the measuring beam S1 can be ensured, and more specifically, as described in the foregoing embodiment, will not be repeated here.

In one embodiment, referring to fig. 1 to 3, the decontamination light source 21 employs an infrared laser to emit an infrared beam as a decontamination beam S2, and the infrared beam has a large absorption coefficient for moisture, so that contaminants on the surface of the wafer, which are formed after water molecules adsorb the contamination particles, can be removed well. More specifically, when the infrared laser is selected or modulated, the emitted decontamination beam S2 preferably exists in a gaussian pulse beam form, and the decontamination beam S2 contacts with the pollutants in an ultra-short and instantaneous high-energy manner by using the periodic characteristics of the pulse beam and the energy distribution characteristics of the gaussian beam, so as to ensure the effect of removing the pollutants. In another embodiment, the decontamination light source 21 may also be a light emitting device capable of emitting ultraviolet light or visible light, such as an ultraviolet laser, a visible light laser, etc., according to the type difference of the object to be measured and the surface contaminants thereof, and in this case, the decontamination light beam S2 may also exist in a gaussian pulse beam manner.

Example two

Referring to fig. 4 and fig. 5 in combination with fig. 1 to fig. 3, a difference between the optical detection apparatus of the second embodiment and the first embodiment is that: the detection system and the decontamination system share a focusing mirror to simplify the structure of the optical detection device by saving the number of focusing mirrors.

By omitting either the first focusing mirror 22 or the second focusing mirror 12 and selecting the type, arrangement position, number, etc. of the light path switching pieces, it is possible to make the detection light source assembly correspond to the decontamination light source assembly and use the same focusing mirror.

In one embodiment, referring to fig. 4, the second focusing lens 12 is omitted, and the first focusing lens 22 is used as a focusing lens for the detection light source assembly and the decontamination light source assembly; the first focusing mirror 22 is arranged on the optical path of the measuring beam S1, the optical path of the decontamination beam S2 emitted by the decontamination light source assembly is parallel to the optical path of the measuring beam S1, and the optical path conversion member is provided with a first conversion member 23 and a second conversion member 24; as for the first conversion member 23, or using an optical element such as a beam splitter, disposed in a fixed position on the optical path of the measuring beam S1 between the detection light source 11 and the first focusing mirror 22; or optical elements such as a reflecting mirror and the like are adopted, and the optical elements can be moved to the optical path of the measuring beam S1 in a controllable manner and are positioned between the detection light source 11 and the first focusing mirror 22; the decontamination light source assembly comprises a decontamination light source 21, a first beam expander 25 and a second converter 24 which are sequentially arranged along the same straight line, wherein the second converter 24 is used for changing the optical path of the expanded decontamination light beam S2, so that the decontamination light beam S2 enters the first converter 23, the optical path of the decontamination light beam S2 is superposed with the optical path of the measurement light beam S1 under the action of the first converter 23, and the decontamination light beam S2 is finally focused by the first focusing lens 22 and then enters the surface of the wafer a to remove pollutants.

In another embodiment, please refer to fig. 5, the second focusing mirror 12 and the second converting element 24 are omitted, the first focusing mirror 22 is used as a focusing mirror common to the detection light source assembly and the decontamination light source assembly, the first focusing mirror 22 is disposed on the light path of the measurement light beam S1, and the light path plane of the decontamination light beam S2 emitted by the decontamination light source assembly intersects the light path of the measurement light beam S1, at this time, based on the type selection of the first converting element 23, the first converting element 23 may be disposed at a position where the light path of the decontamination light beam S2 intersects the light path of the measurement light beam S1 in a movable manner or a fixed position manner, so that the expanded decontamination light beam S2 can propagate along the light path of the measurement light beam S1 after passing through the first converting element 23, and finally enters the surface of the wafer a after being focused by the first focusing mirror 22, so as to remove the contaminants.

It is right to have used specific individual example above the utility model discloses expound, only be used for helping to understand the utility model discloses, not be used for the restriction the utility model discloses. To the technical field of the utility model technical personnel, the foundation the utility model discloses an idea can also be made a plurality of simple deductions, warp or replacement.

Claims (13)

1. An optical inspection apparatus comprising an inspection system and a decontamination system, wherein the inspection system comprises an inspection light source assembly, and the decontamination system comprises a decontamination light source assembly and a light path conversion member; wherein:

the detection light source assembly is used for emitting a measuring light beam to the surface of an object to be detected so that the measuring light beam forms a signal light beam after passing through the object to be detected;

the decontamination light source assembly is used for emitting decontamination beams, and the light path conversion piece is positioned on the light path of the decontamination beams and used for enabling at least part of the decontamination beams to enter an object to be detected and enabling the position of the decontamination beams, which forms light spots on the surface of the object to be detected, to be at least partially overlapped with the position of the measurement beams, which forms the light spots on the surface of the object to be detected, so as to remove pollutants on the surface of the object to be detected.

2. The optical detection apparatus according to claim 1, wherein the optical path conversion member includes a first conversion member for converting the optical path of the decontaminating beam so that the optical path of the decontaminating beam coincides with the optical path of the measuring beam.

3. The optical inspection apparatus according to claim 2, wherein the first conversion member is a beam splitter disposed at a position where an optical path of the measuring beam intersects an optical path of the decontaminating beam, so that the decontaminating beam and the measuring beam after passing through the beam splitter are in a common optical path; or

The first conversion member is a reflecting mirror configured to be movable to a position where an optical path of the measuring beam intersects an optical path of the decontaminating beam, so that the decontaminating beam and the measuring beam after passing through the reflecting mirror share an optical path.

4. The optical inspection apparatus of any of claims 1-3, wherein the decontamination light source assembly includes a decontamination light source for emitting a decontamination beam and a first focusing mirror for focusing the decontamination beam.

5. The optical inspection apparatus of claim 4 wherein the inspection light source assembly includes an inspection light source configured to direct a measuring beam toward the first focusing mirror, the first focusing mirror further configured to focus the measuring beam to form a spot on the surface of the object.

6. The optical inspection apparatus of claim 4, wherein the inspection light source assembly includes an inspection light source for emitting the measurement light beam and a second focusing mirror for focusing the measurement light beam to form a light spot on the surface of the object.

7. The optical inspection device of claim 6 wherein the focal length of the first focusing mirror is greater than the focal length of the second focusing mirror; the decontamination light source assembly further comprises a first beam expander, the first beam expander is used for expanding the decontamination light beam, and the first focusing lens is used for focusing the decontamination light beam expanded by the first beam expander.

8. The optical inspection device of claim 7 wherein the focal length of the first focusing mirror is 180mm to 250mm and the focal length of the second focusing mirror is 45mm to 60mm.

9. The optical inspection device of claim 6 wherein the focal length of the first focusing mirror is less than the focal length of the second focusing mirror, the inspection light source assembly further comprising a second beam expander for expanding the measurement beam, the second focusing mirror for focusing the measurement beam after expansion by the second beam expander.

10. An optical inspection apparatus according to any of claims 1 to 3, wherein the optical path of the decontaminating beam exiting the decontaminating light source assembly is parallel to the optical path of the measuring beam exiting the inspection light source assembly.

11. An optical inspection apparatus according to claim 10, wherein the optical path conversion element further comprises a second conversion element for converting the optical path of the decontaminating beam so that the optical path of the decontaminating beam intersects the optical path of the measuring beam, the second conversion element being located at the output end of the decontaminating light source assembly.

12. The optical inspection apparatus of claim 1 wherein the inspection system further comprises an inspection chamber for opposing the test object, the inspection light source assembly and the decontamination light source assembly being disposed within the inspection chamber, the inspection chamber having a light beam path at an end thereof facing the surface of the test object, the light beam path being for passing either or both of the measuring beam and the decontamination beam.

13. The optical inspection apparatus of claim 1 wherein the decontaminant beam is a gaussian infrared pulsed beam or a gaussian ultraviolet pulsed beam and the measurement beam is a broad spectrum beam.

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