Patent Publication Number: US-2023152201-A1

Title: Particle measuring device

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority under 35 USC § 119 to Korean Patent Applications No. 10-2021-0156750, filed on Nov. 15, 2021 in the Korean Intellectual Property Office (KIPO), the contents of which are incorporated herein in its entirety by reference. 
     BACKGROUND 
     1. Technical Field 
     Example embodiments relate generally to a particle measuring device. More particularly, the inventive concept uses a particle measuring device capable of measuring particles on a surface of an object. 
     2. Description of the Related Art 
     Generally, a particle measuring device measures particles disposed on a surface of an object such as a wafer. In the particle measuring device, a gas is sprayed on the surface using a pump, and particles and the gas, which are scattered from the surface, are inhaled from the surface to count the particles by a particle counter. That is, the spray and inhale are performed by the pump. 
     Particles generated by the operation of the pump may be supplied to the particle counter. Also, since outer gas inflows during the inhaling of the outer gas, particles included in the outer gas may be supplied to the particle counter. Therefore, the particle measuring device may not precisely count the particles on the surface. 
     SUMMARY 
     Some example embodiments provide a particle measuring device capable of precisely measuring particles on a surface of an object. 
     According to some example embodiments, a particle measuring device includes a probe including a nozzle spraying a gas toward a surface facing a surface of an object; and an inlet inhaling the gas and particles scattered from the surface by the gas, a main pipe including an inflow hole through which the gas flows and a discharge hole through which the gas is discharged, a first manifold provided to connect the main pipe to the nozzle, and being configured to supply the gas passing through the main pipe to the nozzle, a second manifold provided to connect the main pipe to the inlet between a connecting portion of the first manifold and the discharge hole, and being configured to supply the particles and the gas to the main pipe, a third manifold branched from the second manifold, and being configured to supply the particles and the gas, a particle counter connected to the third manifold, and being configured to count the particles included in the gas supplied through the third manifold, and an ejector provided on the connection portion where the main pipe and the second manifold are connected to each other, and being configured to inhale and transport the particles and the gas through the second manifold using a pressure energy of the gas passing through the main pipe. 
     In an example embodiment, the particle measuring device may further include a first flow control part provided on the first manifold to control a first flow rate of the gas passing through the first manifold, and a second flow control part provided on the second manifold to control a second flow rate of the gas passing through the second manifold. 
     Here, the first flow control part and the second flow control part may control a ratio of the first flow rate and the second flow rate to be in a range of about 1.3:1 to about 2.7:1 to prevent inflow of an outer gas through the inlet. 
     Further, the first flow control part and the second flow control part control a ratio of the first flow rate and the second flow rate to be in a range of about 1.7:1 to about 2.3:1, respectively, to prevent an outer gas from inflowing through the inlet. 
     In an example embodiment, the inlet may be disposed on a center of the surface, and the nozzle may be disposed in plurality to surround the inlet to prevent inflow of an outer gas through the inlet. 
     In an example embodiment, the surface may include a recess portion having a semi spherical shape on a central portion thereof such that the particles and the gas are to effectively inhaled through the inlet. 
     Here, the inlet may be disposed on a central portion of the recess portion, and the nozzle may be disposed in plurality to surround the inlet along the recessed portion. Further, the surface may further include a flat portion provided around the recess portion to face the surface of the object, and the nozzle may be arranged in plurality to spray a fluid at a constant distance. 
     Furthermore, the particle measuring device may further include a destatic part provided on the recess portion to irradiate an X-ray or an ultraviolet light onto the surface of the object to remove static electricity from the surface of the object and the particles such that the particles from the surface of the object are readily separated. 
     In an example embodiment, the particle measuring device may further include a distance sensor provided on the probe, and being configured to measure a distance toward the surface of the object, and when a distance sensed by the distance sensor is maintained within a reference distance, the probe sprays and inhales the gas and the particle counter measures the particles. 
     In an example embodiment, the particle measuring device may further include a filter provided on the main pipe between the inflow hole and the connecting portion of the first manifold, and being configured to remove particles included in the gas inflowing through the inflow hole. 
     In an example embodiment, the particle measuring device may further include a pump provided to be connected to the particle counter, and being configured to generate a suction force to supply the particles and the gas to the particle counter through the third manifold. 
     According to some example embodiments, a particle measuring device includes a probe including a nozzle spraying a gas toward a surface facing a surface of an object; and an inlet inhaling the gas and particles scattered from the surface by the gas, a main pipe including an inflow hole through which the gas flows and a discharge hole through which the gas is discharged, a first manifold provided to connect the main pipe to the nozzle, and being configured to supply the gas passing through the main pipe to the nozzle, a second manifold provided to connect the main pipe to the inlet between a connecting portion of the first manifold and the discharge hole, and being configured to supply the particles and the gas to the main pipe, a third manifold branched from the second manifold, and being configured to supply the particles and the gas, a particle counter connected to the third manifold, and being configured to count the particles included in the gas supplied through the third manifold, wherein the first manifold may be connected to the main pipe with being inclined to the main pipe, and the gas may be supplied from the main pipe to the nozzle through the first manifold by a pressure of the gas passing through the main pipe. 
     In an example embodiment, the particle measuring device may further include a first flow control part provided on the first manifold to control a first flow rate of the gas passing through the first manifold and a second flow control part provided on the second manifold to control a second flow rate of the gas passing through the second manifold. 
     In an example embodiment, the inlet may be disposed on a center of the surface, and the nozzle may be disposed in plurality to surround the inlet to prevent inflow of an outer gas through the inlet. 
     In an example embodiment, the surface may include a recess portion having a semi spherical shape on a central portion thereof such that the particles and the gas are to effectively inhale through the inlet. 
     Here, the inlet may be disposed on a central portion of the recess portion, and the nozzle may be disposed in plurality to surround the inlet along the recessed portion. 
     Further, the surface may further include a flat portion provided around the recess portion to face the surface of the object, and the nozzle is arranged in plurality to spray a fluid at a constant distance. 
     In an example embodiment, the particle measuring device may further include a destatic part provided on the recess portion to irradiate an X-ray or an ultraviolet light onto the surface of the object to remove static electricity from the surface of the object and the particles such that the particles from the surface of the object are readily separated. 
     In an example embodiment, the particle measuring device may further include a distance sensor provided on the probe, and being configured to measure a distance toward the surface of the object, and when a distance sensed by the distance sensor is maintained within a reference distance, the probe sprays and inhales the gas and the particle counter measures the particles. 
     According to the particle measuring device of the inventive concept, the gas may be sprayed by the pressure of the gas, and the gas may be inhaled by the ejector. The particles and the gas may be supplied to the particle counter by the pump. According to the operation of the pump, particles of the pump may not be supplied to the particle counter although the particles are generated by the operation of the pump. Thus, the particle measuring device may precisely measure the particles on the surface of the object. 
     A first flow rate of the gas flowing the first manifold and a second flow rate of the gas flowing the second manifold may be controlled, and an outer gas may be prevented from being inflowed through the inlet. 
     The inlet may be disposed on a center of the surface of the probe, and the nozzles may be disposed to surround the inlet in plural numbers. Thus, the outer gas may be prevented from being inflowed through the inlet. 
     Since the surface of the probe has a recess portion having a semi-spherical shape on a center thereof, the particles and the gas may be effectively inhaled through the inlet. Also, the surface may be provided around the recess portion. The surface may have a flat portion corresponding to the surface of the object and a nozzle spraying fluid at a constant distance. The outer gas may be prevented from being inflowed through the nozzle. 
     A static electricity on the surface of the object and the particles may be removed by the destatic part disposed on the recess portion. Therefore, the particles may be readily separated from the surface of the object. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Illustrative, non-limiting example embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. 
         FIG.  1    is a side view illustrating a particle measuring according to an embodiment of the inventive concept. 
         FIG.  2    is a bottom view illustrating a probe shown in  FIG.  1   . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, exemplary embodiments of the inventive concept will be described in detail with reference to the accompanying drawings. It will be understand that the inventive concept may be embodied in many alternative forms and should not be construed as limited to the example embodiments set forth herein. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. In describing each drawing, like numerals are used for like elements. In the enclosed drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. Like numerals refer to like elements throughout. 
     It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. For example, a first element discussed below could be termed a second element without departing from the teachings of the present inventive concept. Also, a second element discussed below could be termed a first element without departing from the teachings of the present inventive concept. 
     The terms used in the inventive concept are only used to describe particular embodiments, and it is not intended to limit the inventive concept. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
       FIG.  1    is a side view illustrating a particle measuring according to an embodiment of the inventive concept.  FIG.  2    is a bottom view illustrating a probe shown in  FIG.  1   . 
     Referring to  FIGS.  1  and  2   , the particle measuring device  100  may include a probe  110 , a destatic part  120  (or a static electricity removing part  120 ), a distance sensor  121 , a main pipe  130 , a first manifold  133 , a second manifold  135 , a third manifold  137 , a particle counter  140 , a pump  141 , an ejector  150 , a filter  160 , a first flow control part  170 , and a second flow control part  171 . 
     The probe  110  may be configured to collect particles on a surface of an object (not illustrated). The probe  110  may be disposed to face the surface. 
     When the surface of the object is flat, the probe  110  may be in close contact with the surface. When the surface of the object is not flat, the probe  110  may be spaced apart from the surface. 
     The probe  110  may include nozzles  111  and inlets  113 . The nozzles  111  and the inlets  113  may be disposed on a surface of the probe  110 , which faces the surface (for example, the surface of the object). 
     The nozzles  111  may spray an gas on the surface of the object. The inlets  113  may inhale the gas and the particles sprayed from the surface by the gas. 
     When an air is used as the gas, reactive metal in the air may cause micropollution on the surface. An inert gas may be used as the gas to prevent the micropollution. Examples of the inert gas may include nitrogen gas, argon gas, helium gas, neon gas, etc. 
     The inlet  113  may be disposed on a center of the surface, and the nozzle  111  may be disposed on the surface to surround the inlet  113 . Here, the number of the inlet  113  may be one. In another embodiment, the inlet  113  may be in plural. The gas sprayed from the nozzles  111  may block an outer gas, thereby preventing inflowing of the outer gas through the inlet  113 . 
     The probe  110  may spray the gas onto the surface to scatter the particles, and inhale the gas and the particles inhaled from the surface. Thus, the particles may be collected. 
     The surface of the probe  110  may have a recess portion  115  having a substantially semispherical shape on a central portion thereof. The inlet  113  may be disposed on a center of the recess portion  115 . The nozzles  111  may be disposed along an edge of the recess portion  115  to surround the inlet  113 . Since the recess portion  115  performs a function of collecting the particles and the gas, the particles and the gas may be effectively inhaled by the inlet  113 . 
     Also, the surface of the probe  110  may have a flat portion  117  provided along the recess portion  115 . Also, nozzles may be arranged in plurality through the surface at a constant distance to discharge a fluid (for example, the gas). The fluid may be discharged through the nozzle. Thus, the flat portion  117  may prevent the inflow of the outer gas through the recess portion  117 . 
     Since the probe  110  prevents the inflow of the outer gas to the recess portion  117  and the inlet  113 , the inflow of particles by the outer gas may be prevented. Therefore, the particle measuring device  100  may precisely measure the particles on the surface of the object. 
     The destatic part  120  may be disposed on the probe  110 , for example, on the recess portion  115 . The destatic part  120  may irradiate an X-ray or an ultraviolet light on the surface of the object to remove a static charge of the surface of the object and the particles. The gas may be sprayed through the nozzles  111 , and the particles may be readily separated from the surface of the object. Therefore, the particle measuring device  100  may precisely measure the particles on the surface of the object. 
     The distance sensor  121  may be provided on the probe  110 , and measure a distance toward the surface of the object. When the distance measured by the distance sensor  121  is constantly maintained within a reference distance, the particle measuring device  100  may be automatically operated to measure the particles on the surface of the object. That is, the spraying and inhaling of the gas by the probe  110 , and the measuring of the particles by the particle counter  140  may be performed. Therefore, pushing an additional start button may not be required to operate the particle measuring device  100 . 
     In case that the particle measuring device  100  is slipped or dislocated along the surface of the object by a force pressing the start button, the credibility of the data measured by the particle measuring device  100  may be deteriorated. 
     When the distance sensor  121  is used, since the pressing of the start button is not required in the operation of the particle measuring device  100 , the deterioration of the credibility of the data measured by the particle measuring device  100  may be prevented. 
     The main pipe  130  may be a path for moving the gas. The main pipe  130  may include an inflow hole  130   a  and a discharge hole  130   b . The gas may flow into the main pipe  130  through the inflow hole  130 , and may be discharged through the discharge hole  130   b.    
     The inflow hole  130   a  may be connected to a tank  131  configured to store the gas. The tank  131  may supply the gas to the inflow hole  130   a  at a constant pressure. 
     A valve  132  may be provided at a position adjacent to the inflow hole  130  and may open and close the main pipe  130 . When the valve  132  is opened, the gas may move through the main pipe  130 . When the valve  132  is closed, the movement of the gas through the main pipe  130  may stop. 
     When the particle measuring device  100  is operated by the start button or the distance sensor  121 , the valve  132  may be opened. When the operation of the particle measuring device  100  stops, the valve  132  may be closed. 
     The first manifold  133  may be provided to connect the main pipe  130  to the nozzles  111 , and provide the gas passing through the main pipe  130  to the nozzles  111 . 
     For example, the first manifold  133  may be connected to the main pipe  130  and inclined with respect to the main pipe  130 . The gas may be readily supplied to the nozzles  111  from the main pipe  130  through the first manifold  133  by the pressure of the gas passing through the main pipe  130 . 
     Alternatively, the first manifold  133  may be connected to the main pipe  130  in perpendicular to the main pipe  130 . 
     The gas supplied to the nozzles  111  through the first manifold  133  may be sprayed on the surface of the object and scatter the particles on the surface. 
     The second manifold  135  may be provided to connect the main pipe  130  to the inlet  113  between a connecting portion of the first manifold  133  (for example, a portion at which the first manifold  133  is connected to the main pipe  130 ) and the discharge hole  130   b , and supply the particles and the gas to the main pipe  130 . 
     The second manifold  135  may be connected to the main pipe  130  in perpendicular to the main pipe  130 . A negative pressure may be formed in the second manifold  135  by the pressure of the gas passing through the main pipe  130 . The particles and the gas may be supplied to the main pipe  130  by the negative pressure. 
     The third manifold  137  may be branched from the second manifold  135 , and supply the particles and the air to the particle counter  140 . 
     The particle counter  140  may be connected to the third manifold  137 , and count the particles included in the gas supplied through the third manifold  137 . 
     For example, the particle counter  140  may include a light emitting part and a light receiving part. The light emitting part may emit light. The light receiving part may be provided to correspond to the light emitting part, and measure light irradiated from the light emitting part and scattered by the particles to count the particles. 
     The pump  141  may be provided to be connected to the counter  140 . The pump  141  may generate a suction force, and the particles and the gas may be supplied to the particle counter  140  through the third manifold  137 . Therefore, the particles and the air passing through the third manifold  137  may be readily supplied to the particle counter  140 . 
     Also, the pump  141  may be configured to supply the gas to the particle counter  140  at a predetermined reference flow rate. The reference flow rate may be a flow rate, at which the particle counter  140  may precisely count the particles. 
     The particles and the gas supplied to the particle counter  140  may pass through the pump and be discharged to the outside. Although particles are generated in the pump  141 , the particles of the pump  141  may not be supplied to the particle counter  140  by the operation of the pump  141 . Thus, the particles of the pump  141  may not affect the particle counting of the particle counter  140 . 
     The ejector  150  may be provided at a connecting portion at which the main pipe  130  is connected to the second manifold  135 . The ejector  150  may inhale and transport the particles and the gas through the second manifold  135  using the pressure of the gas passing through the main pipe  130 . The probe  110  may readily inhale the particles and the gas through the inlet  113  by the suction force generated by the ejector  150 . 
     The first flow control part  170  may be provided on the first manifold  133  and control a first flow rate of the gas passing through the first manifold  133 . The first flow control part  170  may control the first flow rate, and the pressure of the gas sprayed from the nozzles  111  may be controlled. Therefore, the scattering degree of the particles on the surface of the object may be controlled. 
     The first flow control part  171  may be provided on the second manifold  135 , and control a second flow rate of the gas passing through the second manifold  135 . Since the second flow control part  171  controls the second flow rate, a suction pressure of the inlet  113  may be controlled. 
     In order to prevent the inflow of the outer gas through the inlet  113 , the first flow rate may, preferably, be greater than the second flow rate. Therefore, the first flow control part  170  and the second flow control part  171  may control the first flow rate to be greater than the second flow rate. For example, a ratio of the first flow rate to the second flow rate may be in a range of about 1.3:1 to about 2.7:1, preferably, in a range of about 1.7:1 to about 2.3:1. 
     In particular, in order to improve the precision of a corresponding ratio of the flow rates, a process of calibration may be performed in the operation of the device through automated control of the flow rates. 
     The filter  160  may be provided on a connecting portion of the main pipe  130  between the inflow hole  130   a  and the first manifold  133 , and remove particles included in the gas which flow through the inflow hole  130   a . The filter  160  may collect particles having a size greater than a certain size, and pass through particles having a size smaller than the certain size. Here, the certain size may be about 3 nm. 
     In the particle measuring device  100 , the gas may be sprayed to the surface of the object by the pressure of the gas, the gas may be inhaled by the ejector  150 , and the particles and the gas may be supplied to the particle counter  140  by the pump  141 . Particles generated by the operation of the pump  141  may not supplied to the particle counter  140 . Also, the probe  110  may prevent the inflow of the outer gas. Since additional particles are not generated or inflowed until the particles are supplied to the particle counter  140 , the particle measuring device  100  may precisely measure the particles on the surface of the object. 
     According to the above-described, the particle measuring device according to the inventive concept may prevent the generation of internal particles and the inflow of the particles from the outside to precisely measure the particles on the surface of the object. Therefore, credibility of the particle measuring device may be improved. 
     Although preferred embodiments of the inventive concept have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the disclosure as disclosed in the accompanying claims and their equivalents.