Abstract:
A method of helping particle detection and a method of particle detection include an adsorption/infiltration step where an organic gas is brought into contact with organic particles to cause an organic gas component to be adsorbed and infiltrate to the organic particles; a foaming step where a heated gas is brought into contact with the organic particles contacted with the organic gas to foam/expand the organic particles; and an organic-particle detection step where the foamed/expanded organic particles are irradiated with light and light scattered by the organic particles is received to detect the organic particles. Further, the methods include an oxidation step where inorganic particles and the organic particles are oxidized to decompose the organic particles and expand the inorganic particles; and an inorganic particle detection step where the expanded inorganic particles are irradiated with light and light scattered by the inorganic particles is received to detect the inorganic particles.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a particle detection helping method for helping detection of organic or inorganic particles by selectively expanding the organic or the inorganic particles causing defects of semiconductors in a semiconductor manufacturing process, a particle detection method using the particle detection helping method, a particle detection helping apparatus and a particle detection system for performing the above methods, respectively. 
       BACKGROUND OF THE INVENTION 
       [0002]    When particles peeled off from an inner wall of a semiconductor manufacturing chamber are adhered to a surface of a semiconductor wafer, short circuit in wiring of semiconductor devices occurs and a production yield of the semiconductor devices decreases. Therefore, it is required to detect particle generation, e.g., the number of particles, the sizes of particles and the like, in a semiconductor manufacturing process. As for a method for detecting particles, there is used a light scattering method for detecting particles by irradiating light to the particles and measuring the amount of light scattered by the particles. 
         [0003]    Further, semiconductor devices are highly miniaturized, and a currently processed line width reaches a level smaller than 50 nm. Moreover, a processing technique for line width of 30 nm is expected to be established in a near future. However, a light scattering technique capable of detecting particles smaller than or equal to 30 nm have not yet been developed. Accordingly, the relationship between a product yield and particles in that scale could not be discussed, and the product yield of semiconductor devices may decrease without having such technique. 
         [0004]    Meanwhile, in order to improve light scattering detection accuracy, there is proposed a particle detection method capable of detecting finer particles by improving an intensity of light scattered from particles by adhering water droplets to particles on a semiconductor wafer (see, e.g., Patent Document 1). 
         [0005]    Patent Document 1: Japanese Patent Application Publication No. H5-340885 
         [0006]    However, the particle detection method disclosed in Patent Document 1 suffers from a drawback that the number of particles could not be accurately detected. This is because when a laser beam for light scattering is irradiated to the particles, the water droplets adhered to the particles are evaporated immediately. 
       SUMMARY OF THE INVENTION 
       [0007]    In view of the above, it is an object of the present invention to provide a particle detection helping method for foaming and expanding organic particles to accurately detect fine organic particles that could not be detected by a conventional light scattering method, a particle detection method that uses the particle detection helping method to detect organic particles more accurately compared to a conventional particle detection method, and a particle detection helping apparatus and a particle detection system for performing the above methods, respectively. 
         [0008]    It is another object of the present invention to provide a particle detection helping method for foaming and expanding organic particles and oxidizing and expanding inorganic particles to accurately detect fine organic and inorganic particles that could not be detected by a conventional light scattering method, a particle detection method which uses the particle detection helping method to detect organic and inorganic particles more accurately compared to a conventional particle detection method, a particle detection helping apparatus and a particle detection system for performing the above methods, respectively. 
         [0009]    It is still another object of the present invention to provide a particle detection helping method for oxidizing and expanding inorganic particles to accurately detect fine inorganic particles that could not be detected by a conventional light scattering method, a particle detection method which uses the particle detection helping method to detect inorganic particles more accurately compared to a conventional particle detection method, a particle detection helping apparatus and a particle detection system for performing the above methods, respectively. 
         [0010]    It is still another object of the present invention to provide a particle detection method capable of detecting finer organic particles by effectively foaming and expanding organic particles. 
         [0011]    It is still another object of the present invention to provide a particle detection method capable of detecting finer inorganic particles by effectively oxidizing and expanding inorganic particles. 
         [0012]    In accordance with a first aspect of the present invention, there is provided a particle detection helping method for helping detection of organic particles by selectively expanding, among organic and inorganic particles causing defects of semiconductors in a semiconductor manufacturing process, the organic particles, the method including: an adsorption and infiltration step in which an organic gas component is adsorbed and infiltrated into the organic particles by bringing the organic gas into contact with the organic particles; and a foaming step in which the organic particles are foamed and expanded by heating the organic particles contacted with the organic gas. 
         [0013]    In accordance with a second aspect of the present invention, the particle detection helping method described above further includes, after the foaming step, an oxidation step in which the inorganic and the organic particles are oxidized to thereby decompose the organic particles and expand the inorganic particles. 
         [0014]    In accordance with a third aspect of the present invention, there is provided a particle detection helping method for helping detection of inorganic particles by selectively expanding, among organic and inorganic particles causing defects of semiconductors in a semiconductor manufacturing process, the inorganic particles, the method including an oxidation step in which the inorganic and the organic particles are oxidized to thereby decompose the organic particles and expand the inorganic particles. 
         [0015]    In accordance with a fourth aspect of the present invention, there is provided a particle detection method for detecting organic particles by selectively expanding among organic and inorganic particles causing defects of semiconductors in a semiconductor manufacturing process, the organic particles, the method including: an adsorption and infiltration step in which an organic gas component is adsorbed and infiltrated into the organic particles by bringing the organic gas into contact with the organic particles; a foaming step in which the organic particles are foamed and expanded by heating the organic particles contacted with the organic gas; and an organic-particle detection step in which the foamed and expanded organic particles are irradiated with light and light scattered by the organic particles is received to thereby detect the organic particles. 
         [0016]    In accordance with a fifth aspect of the present invention, in the particle detection method, the organic particles are heated by bringing a heated gas into contact with the organic particles contacted with an organic gas or by irradiating heating light to the organic particles in a nitrogen gas atmosphere in the foaming step. 
         [0017]    In accordance with a sixth aspect of the present invention, in the particle detection method, a temperature of the organic particles in the adsorption and infiltration step is lower than a boiling point of the organic gas. 
         [0018]    In accordance with a seventh aspect of the present invention, in the particle detection method, the particle detection method described above further includes, after the organic-particle detection step, an oxidation step in which the organic and the inorganic particles are oxidized to thereby decompose the organic particles and expand the inorganic particles; and an inorganic-particle detection step in which the expanded inorganic particles are irradiated with light and light scattered by the inorganic particles is received to thereby detect the inorganic particles. 
         [0019]    In accordance with an eighth aspect of the present invention, in the particle detection method, there is provided a particle detection method for detecting inorganic particles by selectively expanding, among organic and inorganic particles causing defects of semiconductors in a semiconductor manufacturing process, the inorganic particles, the method including: an oxidation step in which the organic particles and the inorganic particles are oxidized to thereby decompose the organic particles and expand the inorganic particles; and an inorganic-particle detection step in which the expanded inorganic particles are irradiated with light and light scattered by the inorganic particles is received to thereby detect the inorganic particles. 
         [0020]    In accordance with a ninth aspect of the present invention, in the particle detection method, the organic and the inorganic particles are oxidized by irradiating UV rays of the excimer lamp to the organic and the inorganic particles in an atmosphere of a gaseous mixture of oxygen and nitrogen in the oxidation step. 
         [0021]    In accordance with a tenth aspect of the present invention, there is provided a particle detection helping apparatus for helping detection of organic particles by selectively expanding, among organic and inorganic particles causing defects of semiconductors in a semiconductor manufacturing process, the organic particles, the apparatus including: one or more processing chambers, each for accommodating a detection target object having organic and inorganic particles; an organic gas supply line for supplying an organic gas into one of the processing chambers; an organic gas supply valve for opening and closing the organic gas supply line; a heated gas supply line for supplying a heated gas into one of the processing chambers; a heated gas supply valve for opening and closing the heated gas supply line; and a control unit for controlling opening and closing of the organic gas supply valve and the heated gas supply valve so as to sequentially open the organic gas supply valve, close the organic gas supply valve and open the heated gas supply valve in that order. 
         [0022]    In accordance with an eleventh aspect of the present invention, the particle detection helping apparatus described above further includes a UV lamp for irradiating UV rays to the detection target object, wherein the control unit turns on the UV lamp after closing the heated gas supply valve. 
         [0023]    In accordance with a twelfth aspect of the present invention, the particle detection helping apparatus described above further includes: an oxidizing gas supply line for supplying into one of the processing chambers an oxidizing gas containing organic particles and inorganic particles; and an oxidizing gas supply valve for opening and closing the oxidizing gas supply line, wherein the control unit opens the oxidizing gas supply valve after closing the heated gas supply valve. 
         [0024]    In accordance with a thirteenth aspect of the present invention, there is provided a particle detection helping apparatus for helping detection of organic particles by selectively expanding, among organic and inorganic particles causing defects of semiconductors in a semiconductor manufacturing process, the organic particles, the apparatus including: one or more processing chambers, each for accommodating a detection target object having organic and inorganic particles; an organic gas supply line for supplying an organic gas into one of the processing chambers; an organic gas supply valve for opening and closing the organic gas supply line; a heating lamp for irradiating heating light to the detection target object; and a control unit for controlling opening and closing of the organic gas supply valve and turning-on of the heating lamp so as to sequentially open the organic gas supply valve, close the organic gas supply valve and turn on the heating lamp in that order. 
         [0025]    In accordance with a fourteenth aspect of the present invention, the particle detection helping apparatus described above further includes a UV lamp for irradiating UV rays to the detection target object, wherein the control unit turns on the UV lamp after turning off the heating lamp. 
         [0026]    In accordance with a fifteenth aspect of the present invention, the particle detection helping apparatus described above further includes: an oxidizing gas supply line for supplying into one of the processing chambers an oxidizing gas for oxidizing the organic and the inorganic particles; and an oxidizing gas supply valve for opening and closing the oxidizing gas supply line, wherein the control unit opens the oxidizing gas supply valve after turning off the heating lamp. 
         [0027]    In accordance with a sixteenth aspect of the present invention, there is provided a particle detection helping apparatus for helping detection of inorganic particles by selectively expanding, among organic and inorganic particles causing defects of semiconductors in a semiconductor manufacturing process, the inorganic particles, the apparatus including: a processing chamber for accommodating a detection target object having organic particles and inorganic particles; and a UV lamp for irradiating UV rays to the detection target object accommodated in the processing chamber. 
         [0028]    In accordance with a seventeenth aspect of the present invention, there is provided a particle detection helping apparatus for helping detection of inorganic particles by selectively expanding, among organic and inorganic particles causing defects of semiconductors in a semiconductor manufacturing process, the inorganic particles, the apparatus including: a processing chamber for accommodating a detection target object having organic particles and inorganic particles; an oxidizing gas supply line for supplying into the processing chamber an oxidizing gas for oxidizing the organic and the inorganic particles; and an oxidizing gas supply valve for opening and closing the oxidizing gas supply line. 
         [0029]    In accordance with an eighteenth aspect of the present invention, there is provided a particle detection system including one of the particle detection helping apparatuses described above and a particle detection apparatus for detecting organic or inorganic particles by irradiating light to the organic and the inorganic particles and receiving the light scattered by the organic and the inorganic particles. 
         [0030]    In the first, the fourth, the fifth, the tenth, the thirteenth and the eighteenth aspect, the organic gas is brought into contact with the organic particles in the adsorption and infiltration step. The organic gas component contacted with the organic particles is adsorbed and infiltrated into the organic particles, so that the organic particles are foamed and expanded. The organic particles are heated in the next foaming step. For example, the organic particles are heated by bringing the heated gas into contact with the organic particles. Alternatively, the organic particles are heated by irradiating heating light to the organic particles in a nitrogen gas atmosphere. When the organic particles are heated, the organic gas component adsorbed and infiltrated into the organic particles serves as a foaming agent and, thus, the organic particles are further foamed and expanded. The organic particles that have been foamed and expanded in the foaming step are deformed and thus maintain the expanded size even after the organic gas component is volatilized by the light irradiation during the particle detection. Therefore, the organic particles do not shrink during light scattering detection, and this can help to make an accurate detection of the organic particles. Furthermore, since inorganic particles are not foamed and expanded, the organic particles can be selectively foamed and expanded. 
         [0031]    Especially, in accordance with the particle detection helping apparatus of the tenth aspect, the control unit performs the above-described particle detection helping method by controlling opening and closing of the organic gas supply valve and the heated gas supply valve. First, the control unit introduces the organic gas into one of the processing chambers by opening the organic gas supply valve and brings the organic gas into contact with the organic particles of the detection target object in the processing chamber. Next, the control unit closes the organic gas supply valve and opens the heated gas supply valve to thereby introduce the heated gas into one of the processing chambers. Accordingly, the organic particles are further foamed and expanded. 
         [0032]    Moreover, in accordance with the particle detection helping apparatus of the thirteenth aspect, the control unit performs the above-described particle detection helping method by controlling opening and closing of the organic gas supply valve and turn-on of the heating lamp. First, the control unit introduces the organic gas into one of the processing chambers by opening the organic gas supply valve and brings the organic gas into contact with the organic particles of the detection target object in the processing chamber. Next, the control unit closes the organic gas supply valve and turns on the heating lamp to thereby heat the organic gas. As a consequence, the organic particles are further foamed and expanded. 
         [0033]    Further, in accordance with the particle detection method and the particle detection system of the fourth, the fifth and the eighteenth aspect, the foamed and expanded organic particles are irradiated with light and light scattered by the organic particles is received to thereby detect the organic particles. As described above, the organic particles do not shrink in spite of the light irradiation, and this enables effective detection of the organic particles. 
         [0034]    Besides, the detection target object is not limited to a solid such as a semiconductor wafer and may also be a gas containing organic particles and inorganic particles. 
         [0035]    In the sixth aspect, the temperature of the organic particles in the adsorption and infiltration step is lower than the boiling point of the organic gas. Thus, the organic gas component in a liquid state can be adsorbed and infiltrated into the organic particles, and the organic particles can be effectively foamed and expanded in the foaming step. 
         [0036]    In the second, the seventh, the eleventh, the twelfth, the fourteenth, the fifteenth and the eighteenth aspect, the inorganic and the organic particles are oxidized in the oxidation step. Due to the oxidation, the organic particles are decomposed and the inorganic particles are expanded. Especially, in the particle detection apparatus of the eleventh and the fourteenth aspect, the control unit closes the heated gas supply valve and then turns on the UV lamp to thereby decompose the organic particles and oxidize and expand the inorganic particles. Moreover, in the particle detection apparatus of the twelfth and the fifteenth aspect, the control unit closes the heated gas supply valve and then opens the oxidizing gas supply valve to thereby introduce the oxidizing gas into one of the processing chambers and oxidize and expand the inorganic particles. The inorganic particles that have been expanded in the oxidation step are deformed and, thus, maintain the expanded size even after the light is irradiated to the inorganic particles during the particle detection. Therefore, the inorganic particles do not shrink during light scattering detection, and this can help accurate detection of the inorganic particles. Further, since the organic particles are decomposed by the oxidation, the inorganic particles can be selected and expanded. 
         [0037]    Besides, in the particle detection method and the particle detection system of the seventh and the eighteenth aspect, the expanded inorganic particles are irradiated with light and light scattered by the inorganic particles is received to thereby detect the organic particles. As described above, the inorganic particles do not shrink in spite of the light irradiation, so that the inorganic particles can be detected effectively. 
         [0038]    In the third, the eighth, the sixteenth, the seventeenth and the eighteenth aspect, the inorganic and the organic particles are oxidized in the oxidation step. Due to the oxidation, the organic particles are decomposed and the inorganic particles are expanded. Especially, in the particle detection helping apparatus of the sixteenth aspect, the control unit turns on the UV lamp so as to decompose the organic particles and expand the inorganic particles. Further, in the particle detection helping apparatus of the seventeenth aspect, the control unit opens the oxidizing gas supply valve to introduce the oxidizing gas into a processing chamber and expand the inorganic particles. The inorganic particles expanded in the oxidation step are deformed and, thus, maintain the expanded size even if light is irradiated thereto for particle detection. Therefore, the inorganic particles do not shrink during light scattering detection, and this can help to make an accurate detection of the inorganic particles. Further, the organic particles are decomposed by the oxidation reaction, so that the inorganic particles can be selected and expanded. 
         [0039]    Besides, in the eighth and the eighteenth aspect, the expanded inorganic particles are irradiated with light and light scattered by the inorganic particles is received to thereby detect the inorganic particles. As described above, the inorganic particles do not shrink in spite of the light irradiation, so that the inorganic particles can be detected effectively. 
         [0040]    In the ninth aspect, UV rays from the excimer lamp are irradiated to the inorganic particles in the atmosphere of the gaseous mixture of oxygen and nitrogen to thereby oxidize the inorganic particles. The UV rays have a high energy short wavelength of 172 nm and can generate oxygen radicals. Hence, the inorganic particles can be oxidized and expanded more effectively compared to the case of using an oxidation method using ozone gas or the like. 
       EFFECTS OF THE INVENTION 
       [0041]    In accordance with the first, the fourth, the fifth, the tenth, the thirteenth and the eighteenth aspect of the present invention, fine organic particle that could not be detected by a conventional light scattering method is foamed and expanded to have a detectable size, and this can help to make an accurate detection of organic particles. Further, fine organic particles that could not be detected by the conventional light scattering method can be detected accurately. 
         [0042]    That is, it is possible to detect organic and inorganic particles smaller than or equal to 30 nm which could not be detected by employing the conventional light scattering method. Hence, a mass production yield of semiconductors can be easily increased. 
         [0043]    In accordance with the sixth aspect of the present invention, fine organic particles can be detected by effectively foaming and expanding organic particles. 
         [0044]    In accordance with the second, the seventh, the eleventh, the twelfth, the fourteenth, the fifteenth and the eighteenth aspect of the present invention, fine organic and inorganic particle that could not be detected by the conventional light scattering method are foamed and expanded, and oxidized and expanded to have detectable sizes, and this can help to make an accurate detection of the organic and the inorganic particles. Further, fine organic and inorganic particles that could not be detected by the conventional light scattering method can be accurately detected. Moreover, since the organic and the inorganic particles can be selectively expanded and detected, it is possible to determine whether the organic particles or the inorganic particles cause a decrease in mass production yield of semiconductors. 
         [0045]    In accordance with the third, the eighth, the sixteenth, the seventeenth and the eighteenth aspect of the present invention, fine inorganic particles that could not be detected by the conventional light scattering method are oxidized and expanded to have detectable sizes, and this can help to make an accurate detection of the inorganic particles. Further, fine organic particles that could not be detected by the conventional light scattering method can be detected accurately. 
         [0046]    In accordance with the ninth aspect of the present invention, fine inorganic particles are detected by effectively oxidizing and expanding inorganic particles. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0047]      FIG. 1  is a top view schematically showing a particle detection system in accordance with a first embodiment of the present invention; 
           [0048]      FIG. 2  provides a block diagram illustrating a configuration of the particle detection system; 
           [0049]      FIG. 3  depicts a flowchart showing a processing sequence of a control unit in accordance with the first embodiment of the present invention; 
           [0050]      FIGS. 4A to 4D  offer explanatory diagrams conceptually illustrating an organic particle detection helping method and an organic particle detection method; 
           [0051]      FIGS. 5A to 5C  are explanatory diagrams conceptually describing an inorganic particle detection helping method and an inorganic particle detection method; 
           [0052]      FIG. 6  presents a top view schematically showing a particle detection system in accordance with a second embodiment of the present invention; 
           [0053]      FIG. 7  represents a flowchart showing a processing sequence of a control unit in accordance with the second embodiment of the present invention; 
           [0054]      FIG. 8  sets forth a top view schematically depicting a particle detection system in accordance with a third embodiment of the present invention; and 
           [0055]      FIG. 9  is a flowchart illustrating a processing sequence of a control unit in accordance with the third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0056]    Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
       First Embodiment 
       [0057]      FIG. 1  is a top view schematically showing a particle detection system in accordance with a first embodiment of the present invention, and  FIG. 2  provides a block diagram illustrating a configuration of the particle detection system. A particle detection system in accordance with the present invention is a device for detecting fine organic particles P 1  and fine inorganic particles P 2  (having a diameter smaller than or equal to 30 nm) adhered to a detection target object W, e.g., a semiconductor wafer, and carries out a particle detection helping method and a particle detection method in accordance with the first embodiment of the present invention. The particle detection system includes a processing chamber  1  where a transfer unit for transferring the detection target object W is installed. Provided around the transfer chamber  1  are a detection target object accommodating chamber  3 , an adsorption and infiltration chamber  4 , a foaming chamber  5 , an oxidation chamber  6 , and a particle detection chamber  7 . 
         [0058]    The adsorption and infiltration chamber  4  has a processing chamber  41  and an organic gas supply unit  42  for supplying into the processing chamber  41  an organic gas, e.g., a hydrocarbon-based gas such as butane, pentane, alcohol, acetone, xylene or the like. The processing chamber  41  and the organic gas supply unit  42  are connected to each other by an organic gas supply line  43 , and an organic gas is supplied from the organic gas supply unit  42  into the processing chamber  41  through the organic gas supply line  43 . The organic gas supply line  43  is provided with an organic gas supply valve  44  for opening and closing the organic gas supply line  43 . The organic gas supply valve  44  is, e.g., an electromagnetic valve. 
         [0059]    The foaming chamber  5  has a processing chamber  51  and a heated gas supply unit  52  for supplying into the processing chamber  51  a heated gas, e.g., high-temperature steam of 100° C. or above. Further, the heated gas does not include any gas that heats and oxidizes the organic particles P 1 . The processing chamber  51  and the heated gas supply unit  52  are connected to each other by a heated gas supply line  53 , and the heated gas is supplied from the heated gas supply unit  52  into the processing chamber  51  through the heated gas supply line  53 . The heated gas supply line  53  is provided with a heated gas supply valve  54  for opening and closing the heated gas supply line  53 . The heated gas supply valve  54  is, e.g., an electromagnetic valve. 
         [0060]    The oxidation chamber  6  has a processing chamber  61 , an excimer lamp  65  provided at an inner ceiling portion of the processing chamber  61  and an oxygen gas supply unit  62  for supplying a gaseous mixture of oxygen and nitrogen into the processing chamber  61 . The excimer lamp  65  is a UV (Ultraviolet) lamp capable of irradiating UV rays of a short wavelength of 172 nm of high energy (7.2 eV). The processing chamber  61  and the oxygen gas supply unit  62  are connected to each other by an oxygen gas supply line  63 , and the gaseous mixture of oxygen and nitrogen is supplied from the oxygen gas supply unit  62  into the processing chamber  61  through the oxygen gas supply line  63 . The oxygen gas supply line  63  is provided with an oxygen gas supply valve for opening and closing the oxygen gas supply line  63 . The oxygen gas supply valve  64  is, e.g., an electromagnetic valve. 
         [0061]    The particle detection chamber  7  has a processing chamber  71 , a light irradiating unit  72  provided in the processing chamber  71  and a light receiving unit  73  for receiving the light scattered by the organic particles P 1  and the inorganic particles P 2  adhered to the detection target object W. 
         [0062]    In addition, the particle detection system includes a control unit  81  for controlling the transfer unit  2 , the organic gas supply valve  44 , the heated gas supply valve  54  and the like. The control unit  81  is, e.g., a CPU of a microcomputer, and is connected via a bus  86  to a ROM  82 , a RAM  83 , an input device  84  and an output device  85 . The ROM  82  is a nonvolatile memory such as a mask ROM, EEPROM or the like which stores a control program required for an operation of the computer. The RAM  83  is a volatile memory such as a DRAM, an SRAM or the like which temporarily stores various data generated when the control unit  81  performs operation. The input device  84  is an input button, a keyboard or the like which receives user&#39;s manipulation of the particle detection system. The output device  85  is a display device for outputting a particle detection result. 
         [0063]    Further, the control unit  81  is connected via an interface (not shown) to the organic gas supply valve  44 , the heated gas supply valve  54 , the excimer lamp  65 , the oxygen gas supply valve  64 , the light irradiating unit  72 , the light receiving unit  73  and the transfer unit  2 . The control unit  81  is configured to control an operation of each unit by sending a control signal. 
         [0064]    Moreover, the adsorption and infiltration chamber  4 , the foaming chamber  5 , the oxidation chamber  6  and the transfer unit  2  form a particle detection helping apparatus for performing the particle detection helping method of the present invention. 
         [0065]      FIG. 3  depicts a flowchart showing a processing sequence of the control unit  81  in accordance with the first embodiment of the present invention.  FIGS. 4A to 4D  offer explanatory diagrams conceptually illustrating a particle detection helping method and a particle detection method for the organic particles P 1 .  FIGS. 5A to 5C  are explanatory diagrams conceptually describing a particle detection helping method and a particle detection method for the inorganic particles P 2 . 
         [0066]    Particle detection can be started by a user&#39;s instruction inputted through the input device  84 , and the control unit  81  receives the start instruction of the particle detection. When the start instruction of the particle detection is received from the input device  84 , the control unit  81  reads out a computer program related to a particle detection process and a particle detection helping process stored in the ROM  82  and loads the computer program onto the RAM  83 , thereby performing following processes. First, the control unit  81  controls an operation of the transfer unit  2  to load the detection target object W to the adsorption and infiltration chamber  4  as shown in  FIG. 4A  (step S 11 ). 
         [0067]    Next, the control unit  81  opens the organic gas supply valve (step S 12 ). When the organic gas supply valve  44  is opened, the organic gas is supplied into the processing chamber  41 . The organic gas supplied into the processing chamber  41  is brought into contact with organic particles P 1  and adsorbed and infiltrated into the organic particles P 1 . Thus, the organic particles P 1  are expanded as depicted in  FIG. 4B . 
         [0068]    Preferably, a type of an organic gas is selected or a temperature of the detection target object W is controlled so that the temperature of the detection target object W becomes lower than a boiling point of the organic gas. If the temperature of the detection target object W is lower than the boiling point of the organic gas, the organic gas is effectively adsorbed and infiltrated into the organic particles P 1 . Accordingly, the organic particles P 1  are expanded. 
         [0069]    When a predetermined period of time elapses after the organic gas supply valve  44  is opened, the control unit  81  closes the organic gas supply valve  44  (step S 13 ). Next, the control unit  81  controls the operation of the transfer unit  2  to load the detection target object W from the adsorption and infiltration chamber  4  into the foaming chamber  5  (step S 14 ). 
         [0070]    Then, the control unit  81  opens the heated gas supply valve  54  (step S 15 ). When the heated gas supply valve  54  is opened, the heated gas is supplied into the processing chamber  51 . The heated gas supplied into the processing chamber  51  is brought into contact with the organic particles P 1  and heats the organic particles P 1 . The heated organic particles P 1  are softened and also foamed and expanded as illustrated in  FIG. 4C . 
         [0071]    When a predetermined period of time elapses after the heated gas supply valve  54  is opened, the control unit  81  closes the heated gas supply valve  54  (step S 16 ). Next, the control unit  81  controls an operation of the transfer unit  2  to load the detection target object W from the foaming chamber  5  into the particle detection chamber  7  (step S 17 ). 
         [0072]    Next, as shown in  FIG. 4D , the light irradiating unit  72  is turned on by the control unit  81  to irradiate light to the foamed and expanded organic particles P 1 , and the light scattered by the organic particles P 1  is received by the light receiving unit  73 . The organic particles P 1  are detected based on the intensity of the received light (step S 18 ). 
         [0073]    Thereafter, the control unit  81  controls the operation of the transfer unit  2  to load the detection target object W from the particle detection chamber  7  into the oxidation chamber  6  as shown in  FIG. 5A  (step S 19 ). 
         [0074]    Then, the control unit  81  turns on the excimer lamp  65  while supplying a gaseous mixture of oxygen and nitrogen by opening the oxygen gas supply valve  63 , thereby oxidizing the organic particles P 1  and the inorganic particle P 2  adhered to the detection target object W (step S 20 ). Due to UV rays from the excimer lamp  65 , oxygen in the processing chamber  61  becomes ozone and oxygen radicals, and the organic particles P 1  and the inorganic particles P 2  are oxidized. As a result of the oxidation reaction, the organic particles P 1  are decomposed and the inorganic particles P 2  are expanded, as can be seen from  FIG. 5B . 
         [0075]    A preferable concentration of oxygen supplied into the processing chamber  61  is a few %. This is because when the oxygen concentration is too high, the UV rays are adsorbed into oxygen, and this disturbs effective oxidation of the organic particles P 1  and the inorganic particles P 2 . 
         [0076]    Moreover, the control unit  81  controls the operation of the transfer unit  2  to load the detection target object W from the oxidation chamber  6  into the particle detection chamber  7  (step S 21 ). 
         [0077]    Then, as shown in  FIG. 5C , the light irradiating unit  72  is turned on by the control unit  81  to irradiate light to the expanded inorganic particles P 2 , and the light scattered by the inorganic particles P 2  is received by the light receiving unit  73 . The inorganic particles P 2  are detected based on the intensity of the received light (step S 22 ), and the process is completed. 
         [0078]    In an application of the particle detection helping method, the particle detection method, the particle detection helping apparatus or the particle detection system in accordance with the first embodiment of the present invention, fine organic particles P 1  and fine inorganic particles P 2  which could not be detected by the conventional light scattering method can be expanded to have detectable sizes, and this can help the detection of the organic particles P 1  and the inorganic particles P 2 . 
         [0079]    Further, since the foamed and expanded organic particles P 1  and the oxidized and expanded inorganic particles P 2  are deformed, the organic particles P 1  and the inorganic particles P 2  do not shrink even if the light for particle detection is irradiated. This can help to make the accurate detection of the particles P 1  and P 2 . 
         [0080]    Further, by expanding the organic and the inorganic particles P 1  and P 2  as described above, it is possible to accurately detect fine organic and inorganic particles P 1  and P 2  smaller than or equal to 30 nm which could not be detected by the conventional light scattering method. Hence, the mass production yield of semiconductors can be easily increased. 
         [0081]    Furthermore, the organic particles P 1  and the inorganic particles P 2  are selectively expanded and detected. Therefore, fine organic particles P 1  and fine organic particles P 2  can be selectively detected. 
         [0082]    In addition, when the temperature of the organic particles P 1  is set to be lower than that of the organic gas, the organic particles P 1  are effectively foamed and expanded, which enables detection of finer organic particles P 1 . 
         [0083]    Besides, the organic particles P 1  and the inorganic particles P 2  are oxidized by UV rays from the excimer lamp  65 . Accordingly, the inorganic particles P 2  can be effectively expanded by radicals, and finer inorganic particles P 2  can be accurately detected. 
         [0084]    In the first embodiment, the adsorption and infiltration chamber, the foaming chamber, the oxidation chamber and the particle detection chamber are separately provided. However, a single processing chamber may serve as each of the above chambers. The particle detection process and the particle detection helping process may be carried out in the single processing chamber. 
         [0085]    Although a semiconductor wafer has been described as an example of the detection target object, the present invention may be applied to the case where a gas containing organic particles and inorganic particles is used as the detection target object. 
         [0086]    Moreover, although the example in which organic particles and inorganic particles are detected by a light scattering method is described in the first embodiment, the expanded particles may be detected by an SEM (Scanning Electron Microscope) or by other devices. 
       Second Embodiment 
       [0087]      FIG. 6  presents a top view schematically showing a particle detection system in accordance with a second embodiment of the present invention. As in the particle detection system in accordance with the first embodiment, the particle detection system in accordance with the second embodiment includes the transfer chamber  1 , the transfer unit  2 , the detection target object accommodating chamber  3 , the adsorption and infiltration chamber  4 , the foaming chamber  5 , an oxidation chamber  206 , the particle detection chamber  7  and the control unit  81 . However, the particle detection system of the second embodiment is different from that of the first embodiment in the structure of the oxidation chamber  7  and the processing sequence of the control unit  81 . Thus, the differences will be described only hereinafter. 
         [0088]    The oxidation chamber  206  has a processing chamber  61  and an oxidizing gas supply unit  262  for supplying into the processing chamber  61  an oxidizing gas, e.g., ozone gas. 
         [0089]    The processing chamber  61  and the oxidizing gas supply unit  262  are connected to each other by an oxidizing gas supply line  263 , and an oxidizing gas is supplied from the oxidizing gas supply unit  262  into the processing chamber  61  through the oxidizing gas supply line  263 . The oxidizing gas supply line  263  is provided with an oxidizing gas supply valve  264  for opening and closing the organic gas supply line  263 . The organic gas supply valve  264  is, e.g., an electromagnetic valve. 
         [0090]    As in the first embodiment, the control unit  81  is connected via an interface (not shown) to the ROM  82 , the RAM  83 , the input device  84 , the output device  85 , the organic gas supply valve  44 , the heated gas supply valve  54 , the light irradiating unit  72 , the light receiving unit  73  and the transfer unit  2 . Further, the control unit  81  is connected to the oxidizing gas supply valve  264  instead of the excimer lamp  65  and the oxidizing gas supply valve  64  in the first embodiment. 
         [0091]      FIG. 7  represents a flow chart showing a processing sequence of the control unit  81  in accordance with the second embodiment of the present invention. The control unit  81  executes, in steps S 31  to S 39 , the processing of the steps S 11  to S 19  for foaming, expanding and detecting the organic particles P 1  which have been described in the first embodiment. 
         [0092]    Then, the control unit  81  opens the oxidizing gas supply valve  264  (step S 40 ). When the oxidizing gas supply valve  264  is opened, the oxidizing gas is supplied into the processing chamber  61 . The oxidizing gas supplied into the processing chamber  61  is brought into the organic particles P 1  and the inorganic particles P 2  and oxidizes the particles P 1  and P 2 . Due to the oxidation reaction, the organic particles P 1  are decomposed and the inorganic particles P 2  are expanded. 
         [0093]    When a predetermined period of time elapses after the oxidizing gas supply valve  264  is opened, the control unit closes the oxidizing gas supply valve  264  (step S 41 ). Next, the control unit  81  executes, in steps S 42  and S 43 , the processing of the steps S 21  and S 22  for detecting the inorganic particles P 2  which have been described in the first embodiment. 
         [0094]    The particle detection helping method, the particle detection method, the particle detection helping apparatus and the particle detection system in accordance with the second embodiment can provide the similar effects of the first embodiment. 
         [0095]    The other configurations, operations and effects of the particle detection system of the second embodiment are similar to those of the particle detection system of the first embodiment. Therefore, like reference numerals will be used for like parts, and detailed description thereof will be omitted. 
       Third Embodiment 
       [0096]      FIG. 8  sets forth a top view schematically depicting a particle detection system in accordance with a third embodiment of the present invention. As in the particle detection system in accordance with the first embodiment, the particle detection system in accordance with the third embodiment includes the transfer chamber  1 , the transfer unit  2 , the detection target object accommodating chamber  3 , the adsorption and infiltration chamber  4 , a foaming chamber  305 , the oxidation chamber  6 , the particle detection chamber  7  and the control unit  81 . The particle detection system of the third embodiment is different from that of the first embodiment in the structure of the foaming chamber  305  and the processing sequence of the control unit  81 . Thus, only the differences will be described only hereinafter. 
         [0097]    The foaming chamber  305  has a processing chamber  51 , a heating lamp  355  provided at an inner ceiling portion of the processing chamber  51  and a nitrogen gas supply unit  352  for supplying a nitrogen gas into the processing chamber  51 . The heating lamp  355  is an infrared lamp for irradiating infrared rays (heating light) for heating the organic particles P 1  in a nitrogen gas atmosphere, a UV lamp for irradiating UV rays (heating light) which do not decompose the organic particles P 1 , or the like. The processing chamber  51  and the nitrogen gas supply unit  352  are connected to each other by a nitrogen gas supply line  353 , and a nitrogen gas is supplied from the nitrogen gas supply unit  352  into the processing chamber  51  through the nitrogen gas supply line  353 . The nitrogen gas supply line  353  is provided with a nitrogen gas supply valve  354  for opening and closing the nitrogen gas supply line  353 . The nitrogen gas supply valve  354  is, e.g., an electromagnetic valve. 
         [0098]    As in the first embodiment, the control unit  81  is connected via an interface (not shown) to the ROM  82 , the RAM  83 , the input device  84 , the output device  85 , the organic gas supply valve  44 , the excimer lamp  65 , the oxygen gas supply valve  64 , the light irradiating unit  72 , the light receiving unit  73  and the transfer unit  2 . Further, the control unit  81  is connected to the nitrogen gas supply valve  354  and the heating lamp  355  instead of the gas supply valve  54  in the first embodiment. 
         [0099]      FIG. 9  is a flowchart illustrating a processing sequence of the control unit  81  in accordance with the third embodiment of the present invention. The control unit  81  executes, in steps S 51  to S 54 , the processing of the steps S 11  to S 14  for expanding the organic particles P 1  which have been described in the first embodiment. 
         [0100]    Then, the control unit  81  opens the nitrogen gas supply valve  354  (step S 55 ). When the nitrogen gas supply valve  354  is opened, the nitrogen gas is supplied into the processing chamber  51 . Thereafter, the control unit  81  turns on the heating lamp  355  (step S 56 ). When the heating light is irradiated to the organic particles P 1  in a nitrogen gas atmosphere, the organic particles P 1  are heated. The heated organic particles P 1  are softened and also foamed and expanded. 
         [0101]    When a predetermined period of time elapses after the heating lamp  355  is turned on, the control unit  81  turns off the heating lamp  355  and closes the nitrogen gas supply valve  354  (step S 57 ). Next, the control unit  81  executes, in steps S 58  and S 63 , the processing of the steps S 17  to S 22  for detecting the organic and the inorganic particles P 1  and P 2  which have been described in the first embodiment. 
         [0102]    The particle detection helping method, the particle detection method, the particle detection helping apparatus and the particle detection system in accordance with the third embodiment can provide the similar effects of the first embodiment. 
         [0103]    In addition, the effects of the first embodiment can also be obtained by applying the configuration of the heating lamp of the third embodiment to the second embodiment. 
         [0104]    The other configurations, operations and effects of the particle detection system of the third embodiment are similar to those of the particle detection system of the first embodiment. Therefore, like reference numerals will be used for like parts, and the detailed description thereof will be omitted. 
         [0105]    The above-described embodiments are illustrative in all aspects, and do not limit the present invention. While the invention has been shown and described with respect to the embodiments, various changes and modification may be made without departing from the scope of the invention as defined in the following claims.