JP2007088137A - Method for manufacturing silicon substrate having super-clean surface by local selective cleaning and its manufacturing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a silicon substrate having a super-clean surface in which, when a silicon wafer is treated, a repetitive cleaning is abolished by applying a local selective cleaning. <P>SOLUTION: The method for manufacturing the silicon substrate by the local selective cleaning is a method for removing a surface impurity from a surface of a member to be treated. The method comprises the series of steps of (a) feeding a material having at least one impurity particle to the surface, (b) supplying a liquid to the surface of the material near at least one impurity particle, and (c) evaporating the liquid instantly to remove the impurity particle as a part of the liquid to be evaporated. Also, the manufacturing equipment using the same is provided. Laser heating is used for instant evaporation, and chucking can be performed near the surface particles so as to promote a removal of the surface particles detected in the evaporation step. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus by local selective cleaning of a substrate containing impurities, such as a silicon substrate, and more specifically, by combining an inspection process and a local selective cleaning process to perform subsequent epitaxial growth and adhesion. Alternatively, the present invention relates to a method for manufacturing a silicon substrate having a super-clean surface and an apparatus for manufacturing the same, which can improve a manufacturing process such as SIMOX (Separation by Implant Oxygen).

  In the production of silicon wafers used for electronic components, it is well known that particles existing on the surface cause defects in subsequent manufacturing processes, and this has been experimentally verified. Yes. For example, in the epitaxial layer, surface particles before processing become a factor causing defects.

  FIG. 1 is a pie chart that normalizes the probability that surface particles before epitaxial processing produce defects of 1 micron or more. In the pie chart shown in FIG. 1, light scattering defects (Light Scattering Defects, hereinafter referred to as “LSD”) on a silicon wafer are displayed in XY coordinates before and after the epitaxial lamination process by an automatic surface inspection machine. It was obtained by measuring the dimensions.

  The legend shown in the pie chart of FIG. 1 shows the LSD dimension before epitaxial processing (Pre-Epi, “PRE”), and the unit of the LSD dimension detected on the substrate is expressed in microns. The probability of LSD on a substrate that causes an epitaxial defect exceeding 1 micron after epitaxial processing by an optical surface inspection system is determined by the ratio at the defect XY coordinate position after epitaxial processing corresponding to the LSD position before epitaxial stacking. It is calculated by obtaining.

  According to this analysis result, the probability of generating defects exceeding 1 micron after epitaxial processing increases in proportion to the LSD size, and if these LSDs are all removed before epitaxial lamination, the occurrence of epitaxial defects is significantly reduced. This is clearly shown. In other words, it is desirable to reduce the number of particles on the wafer surface to reduce epitaxial defects.

  This is not limited to growing defect-free epitaxial layers, such as the production of bonded wafers that result in imperfect adhesion due to particles on the surface, usually resulting in defects known as voids, etc. The same applies to the above, and can be applied to other manufacturing methods.

  In industry, the most common response to alleviate this problem is to clean all wafers before moving on to the next manufacturing step. The general cleaning process at this time is to remove the surface particles through a batch cleaning using chemicals. As a device for a specific application, the supersonic pulse is ruptured on the wafer surface. Some increase the cleaning effect.

  A typical example is a method in which a batch containing wafers is immersed in a chemical solution and left there for several minutes. These steps are repeated several times, after which the cleaning process is completed by treatment with ultra high purity deionized water (DI).

  In other words, it can be said that the number of particles / impurities on the wafer surface is gradually reduced. In the primary cleaning, for example, the number of particles is reduced to 10 to 30 per wafer. This cleaning is a batch cleaning in which a plurality of wafers are thoroughly cleaned to remove stains and impurities on the surface.

  However, this cleaning process is usually insufficient as a pretreatment of the surface in the subsequent manufacturing process and generally requires a secondary cleaning process. Surface inspection is performed after this first cleaning, and the removed wafer is sent to the secondary cleaning process, and the number of particles is further reduced, for example, to 5 per wafer.

  As this secondary cleaning step, batch cleaning is also employed, but single wafer processing using a cleaning jig such as a brush or chemical spray processing is typical. Thereafter, a second surface inspection is performed, and a wafer that does not pass is re-cleaned by the same method or the same method as the secondary cleaning. Wafers that do not pass the third surface inspection after re-cleaning are discarded. On the other hand, the wafer that has passed the third surface inspection is sent to the next manufacturing process.

  A significant disadvantage of these cleaning methods is the problem of particles reattaching as the wafer passes through the boundary area between the cleaning solution liquid surface and air. For this reason, a lower limit of the particle level that can be generally achieved is provided, and this prevents the particles from becoming zero.

  As described above, in the prior art, a wafer cleaning jig for single wafers is employed following batch processing of wafers many times. In this single wafer cleaning process, particles are prevented from reattaching by spraying chemicals onto the rotating wafer.

  Therefore, in the case of a single wafer cleaning process, the processed wafer remains stationary at the processing position and different chemicals are applied with a spray nozzle or rotating brush as compared to the batch method in which the wafer moves. can do. For this reason, when the wafer is cleaned by single wafer processing, the number of LSDs can be reduced. However, since the random adhesion of particles still occurs, this problem can be sufficiently improved. Not.

  Therefore, in order to improve the manufacturing process after the cleaning, another method improved in the cleaning process is required to remove the surface particles of the silicon wafer and other substrates. The gist of the present invention is to obtain a silicon wafer or other substrate having an ultra-clean surface by suppressing the occurrence of accidental surface particle adhesion at a low level.

  The first object of the present invention is to provide a better method for reducing the occurrence of defects during the processing of silicon wafers.

  Another object of the present invention is to provide a method for removing impurities on a material surface, particularly on a surface of a silicon wafer.

  A further object of the present invention is to provide an apparatus for removing impurities present on the surface of a material, particularly the surface of a silicon wafer.

  In addition, another object of the present invention is to remove the impurities on the surface from the surface of the material to be processed using instantaneous and explosive evaporation (hereinafter referred to as “instantaneous evaporation”) using a liquid. It is to provide a method and apparatus for removal.

  Other objects and effects are clearly described in the description of the present invention.

  In order to solve the above-described problems and to further demonstrate the above-described objects and effects, as one embodiment of the present invention, there is provided a further superior method and apparatus applied to a cleaning treatment of a material to be processed, particularly a silicon wafer surface. Composed. In addition, the material to be processed of the present invention is not limited to a silicon wafer, and can be any material that contains impurities that need to be removed in use.

  In one configuration of the embodiment of the present invention, a method for removing impurities on the surface from the material surface is indispensable. In this method, a material having at least one particle on the material surface is first targeted, and a liquid is supplied to the material surface in the vicinity of the at least one particle. In this method, the surface particles, which are impurities, are removed as part of the evaporated water by the instantaneous evaporation of the liquid supplied to the material surface.

  As one of the best embodiments of the present invention, instantaneous evaporation is performed by using laser heating and irradiating the vicinity of a liquid and particles with a laser beam. The liquid may be supplied by any method, but it is preferable to use a humidified gas and supply water to the vicinity of the particles by condensation.

  Any means may be adopted to remove the combined body of the liquid and particles, but suction is preferably performed at or near the place where the particles are present. Furthermore, it is preferable to monitor the process in which the instant evaporation proceeds to confirm whether or not the particles are removed. On the other hand, it is preferable to use a water-containing gas as a liquid supply source, but the liquid may be water, a water-based composition, an alcohol, or an alcohol-containing composition.

  The cleaning method of the present invention is extremely effective in the processing of silicon wafers in which surface defects are inspected. In this regard, in the method of the present invention, a plurality of wafers are inspected for the presence of surface particles present on the wafer surface. From the plurality of wafers, some wafers that do not pass a predetermined inspection standard are selected. These wafers specify the position of each surface particle, and the sorted wafers are sent to a laser cleaning process. Thereafter, the cleaned wafer can be sent to the next manufacturing process together with the unsorted wafer or alone.

  As an embodiment of the present invention, a material to be processed, particularly a silicon wafer, which is not necessarily limited thereto, includes an apparatus for removing impurities on the surface of the material. The apparatus comprises means for identifying the position of at least one particle on the surface of the material and means for supplying a liquid to the material surface in the vicinity of the at least one particle. Further, as a part of the apparatus, a means for instantaneously evaporating the liquid is provided, and the surface particles as impurities are removed as a part of the evaporated liquid.

  As the means for supplying the liquid, it is possible to employ a gas supply device capable of allowing the gas and particles to exist at a temperature such that the liquid in the gas is preferably condensed in the vicinity of the particles to be removed.

  Any heating source can be used as a part of the means for generating the instantaneous evaporation of the liquid as long as it is a heating source that evaporates the liquid supplied to the surface of the material, but a laser device is preferably used.

  The particles and the liquid may be collected by any method when removed from the material surface. However, as one of the preferred embodiments, an aspirator can be disposed in the vicinity of the impurity particles. In addition, a monitoring device such as a microscope may be provided to monitor the particles and the area surrounding them, and may be used to determine whether the particles have been removed or whether further processing is necessary.

  The type and source of the liquid supplied to the material surface can be applied to the method and apparatus of the present invention as long as instantaneous evaporation is possible. Preferred liquids include water or water containing compositions such as humidified gas, or alcohol or alcohol containing compositions.

  According to the method and apparatus for manufacturing a silicon substrate of the present invention, particularly when processing a substrate containing particles or impurities such as a silicon wafer, a two-step approach process composed of an original inspection process and a local cleaning process is performed. By applying this method, it is possible to eliminate the repeated cleaning that has been essential for improving the surface quality of the wafer, and by processing the first cleaned wafer in the two-step approach process, The silicon substrate can be secured, and the subsequent manufacturing process can be improved and the yield can be improved.

  The present invention can be widely applied to a material to be processed containing impurities, and is particularly suitable for processing a silicon wafer before a manufacturing process in which a wafer and other materials are combined. As an example of this manufacturing process, there is a process of depositing an epitaxial layer on a silicon wafer. As another example of the manufacturing process, there is a process of manufacturing an SOI wafer by an adhesion method or a SIMOX method.

  In this connection, the present invention employs a two-step approach process in order to eliminate the surface particles present on the silicon wafer. The first is to eliminate the repeated cleaning described in the prior art. Instead of cleaning the wafer multiple times, the present invention treats the initially cleaned wafer in a two-step approach process consisting of characteristic inspection and local selective cleaning.

  That is, a wafer that passes a predetermined inspection standard is sent to a storage wafer transfer jig for further processing. The predetermined inspection standard may be any numerical value indicating characteristics related to the particles detected on the wafer surface, such as the size of the particles, the number of particles per wafer, the number of particles in a specific region, and the like. Known means can be used as means for identifying the particles and confirming them against a predetermined inspection standard.

  After the wafer inspection, the wafers that do not satisfy the predetermined inspection standard are collected in another transport jig as another group and sent to a cleaning process that employs the local cleaning method of the present invention.

  When the wafer is re-cleaned, it may be sent to the next manufacturing process together with the wafer that has passed the inspection, or may be sent separately to the next manufacturing process.

  In order to verify the effect of the present invention, an experiment using a wafer having zero surface particles was performed. This group of wafers was subjected to a commercially available sheet-fed wafer brush cleaner, and then the wafer surface was re-inspected to check for surface particles. After this brush cleaning, it was found that only 85% of the wafer was free of particles (zero). From this it can be seen that re-washing does not necessarily result in better performance results.

  In one embodiment of the present invention, the removed wafer is re-cleaned using a local cleaning method employing laser heating. This comprehensive cleaning platform incorporates two unique approaches. The first originality is that the surface inspection is integrated with the laser cleaning module as one integrated cleaning platform. The second originality is the application of local selective cleaning in which one or more identified and treated particles are removed by laser heating using flash evaporation of a liquid, such as water.

In the present invention, for example, another heating source known in the prior art that enables instantaneous evaporation of water may be employed as the liquid heating source. As a method for heating the liquid film instantaneously and explosively, a method using a laser wavelength of a certain spectrum (for example, 2 to 5 microns) can be preferably applied, but carbon dioxide gas at other wavelengths, for example, 10.2 microns. Even a (CO ₂ ) laser can perform an appropriate function.

The above wavelengths are well absorbed by the liquid film, but are selected so as not to damage the underlying silicon. It is also preferable to employ a pulse width in nano units (damage to the wafer in picoseconds and no sufficient impact is applied in microseconds) and an energy flux of 1 J / cm ² or less.

  FIG. 2 is a diagram schematically showing an overall cleaning platform by a wafer processing unit. A platform 10 shown in FIG. 2 contains an inspection station 1, for example, an excitation inspection station and a cleaning station 3. In use, the wafer is fed from path 5 to inspection station 1 where it is inspected for the presence, size and / or distribution of one or more particles or other imperfections / impurities to be removed from the surface.

  When a target particle or particle group is specified and its position is recorded, the parameter characteristics of the particle are compared with a predetermined inspection standard such as a particle size and / or distribution and the number of particles. Specifically, any inspection standard can be appropriately set according to the manufacturing process applied thereafter. The identification of the surface particles to be processed may be performed by a method conventionally used, and the present invention is not limited in this respect.

  In FIG. 2, when the wafer passes the inspection standard, the process proceeds to the next manufacturing process via the path 6. On the other hand, if the wafer fails the inspection standard, it is sent to the cleaning station 3 via the path 7. In the cleaning station 3, a wafer that needs to be cleaned at the entrance 9 is placed on the cassette container 11 and received. The cleaning station 3 is provided with a position / direction adjusting jig shown as a box 18, and a further precise position of particles to be processed by the local cleaning device 17 by placing a wafer on the device mount 15. Adjust the direction.

  Although not shown in the figure, the apparatus base 15 can be provided with a position / direction adjusting jig for positioning for wafer cleaning. In order to operate the wafer at the cleaning station 3, an operation robot 18 or the like may be arranged instead of the position / direction adjusting jig. The cleaning station 3 includes a fan unit with a filter indicated by a box 19 and manages the atmosphere at the time of entering and exiting for the cleaning work.

  When the wafer is cleaned, the wafer is unloaded from the cleaning station 3 through the cassette container 20. The cleaned wafer is sent to the next processing along a path 22 by a standard mechanical interface (“SMIF”) loader 24.

The local selective cleaning that constitutes the present invention can form the following embodiments (1) to (4).
(1) For the wafer inspected at the inspection station 1, each of the LSDs larger than the inspection standard selected in advance is specified and recorded with XY coordinates.
(2) An apparatus base 15 movable in the X and Y directions is provided, whereby the specified particles are moved and positioned under the laser cleaning module of the cleaning apparatus 17.
(3) To-be-processed part which consists of the area | region of the LSD vicinity, for example, about 1 mm < ² > under the temperature conditions controlled appropriately so that a water film may each condense around each LSD To supply.
(4) The water film is directly heated by an infrared laser pulse, and particles are removed by the instantaneous evaporation of water. The laser device may be a conventional IR pulse type as long as it supplies heat sufficient to instantaneously evaporate water around the particles. Furthermore, the present invention may be other types of lasers, devices thereof, or means that allow local heating of water for flash evaporation.

  Regarding the removal of the dropped particles, the removal can be promoted by applying local suction to the dropped particles. In addition, other removal methods or means for applying pressure or mechanical shock to remove water vapor from the wafer surface can be applied. It is also possible to suck the entire processing chamber in order to remove the evaporated water from the wafer surface. The removal of the particles described above does not cause damage to the crystal structure of the wafer being processed.

  FIG. 3 is a diagram schematically showing a configuration example of the cleaning apparatus of the present invention. FIG. 3 shows a state in which particles 23 are attached to the surface of the wafer 21. Although not shown, the apparatus below the wafer is provided with a function that enables rotation and / or movement so as to perform positioning for removing target particles. In the figure, the rotation movement is indicated by an arrow A, and the movement movement is indicated by an arrow B.

  By arranging the cleaning process monitoring microscope 25 or other observation means, it is possible to observe all operations and determine whether particles have been removed. If it is determined from this observation that the cleaning is not sufficient, this cleaning process can be repeated. In this monitoring process, repeated cleaning is allowed, and the cleaning result can be judged. Also, no separate wafer inspection process is required for this monitoring.

  The wafers observed in the monitoring are those that are identified as the next processing feed after cleaning is completed, those that are identified as requiring additional cleaning, such as one or more flash evaporations to remove particles, or other prior art It is classified into those that require cleaning or those that are discarded.

  The pulse-type infrared laser device 27 includes an attenuation rotator 29, a focusing lens, and a mirror 31. The laser device 27 irradiates the particles 23 or water 26 in the vicinity thereof and supplies heat as a laser beam 33 that generates instantaneous evaporation. Means for supplying liquid in the vicinity of the particles to be removed is also arranged. In the present invention, water is the best liquid, and the dry nitrogen gas 35 is humidified and supplied, and the dry nitrogen gas 35 is supplied through the humidifier 37. The humidified nitrogen gas 39 is sent to the vicinity of the particles 23 to be removed through the path 41.

  The temperatures of the nitrogen gas 39 and the wafer 21 are controlled or set so that the water in the gas condenses in the vicinity of the particles to be removed. The photosensitive diode 43 is arranged, the reflected light from the supplied water is checked, and the presence of water near the particles required for the evaporation process is confirmed. Although the water is supplied using the humidified nitrogen gas 39, it is possible to supply liquid near the particles to be treated by supplying water directly by other methods and means, for example, without condensing. Good. Even if the gas used is other than nitrogen, a gas inert to the cleaning environment can be used.

  A dark field illumination laser 45 may be arranged to illuminate the region where the particles 23 are located. Further, a local suction device 47 and a tip 49 located in the vicinity of the particles 23 are arranged to collect evaporated water and removed particles to prevent reattachment to the wafer surface.

  The effects of the present invention are compared and shown in the following two items. The first comparison is the recovery rate (%) for wafers with particles exceeding 0.8 microns being zero and particles exceeding 0.3 microns being less than three. The recovery rate according to the prior art of performing primary cleaning, inspection, secondary cleaning, secondary inspection, and re-cleaning of the wafer was about 72%. On the other hand, in the case of the primary cleaning according to the present invention, the inspection, and the cleaning according to the present invention, the recovery rate is 85%, which is a significant improvement over the recovery rate of the prior art. Therefore, the essential feature of the present invention is to omit the re-cleaning step in the prior art.

  The second comparison relates to the distribution of light scattering defects, or LSD, on the wafer. For comparison, wafers that had undergone two cleanings, two inspections, that is, the above-described primary thorough cleaning, inspection, second thorough cleaning, and secondary inspection were taken as a comparative example group.

  The second group is an example of the present invention, in which laser cleaning was performed on wafers that were excluded by thorough cleaning, surface inspection, and inspection. The cleaned wafer was then sent to the secondary inspection to compare the comparative group with the inventive group. In this comparison, a thorough cleaning method according to the prior art was compared with the laser cleaning method of the present invention.

  FIG. 4 is a diagram showing a comparison result between the comparative example group and the inventive example group. In the figure, the normalized LSD counts per wafer are divided into LSD dimensions for comparison. A light shade bar graph indicated by “Pre” indicates a comparative example group, and a dark shade bar graph indicated by “Post” indicates an example group of the present invention.

  As is apparent from the results shown in FIG. 4, it is significantly lower than that of the normalized LSD number comparison example group in the case of the inventive example group. For example, the number normalized for LSD greater than 0.3 microns is less than 0.2 per wafer in the case of the inventive example group, compared to 1.0 per wafer in the case of the comparative example group. Become.

  In addition, improvements were observed for large LSD dimensions. For example, in the case of the LSD exceeding 1.0 microns, in the case of the comparative example group, the number is 0.4 per wafer, whereas in the case of the inventive example group, the number is almost zero. In the case of the LSD exceeding 10 microns, 0.2 defects per wafer still remain in the case of the comparative example group, but all defects are removed without any problem in the present invention group.

  This comparative example group and the inventive example (laser cleaning) group were sent to epitaxial lamination processing, and the relationship between defects (LSD dimensions) and epitaxial growth was measured for comparison. The measurement results are shown in Table 1. The defects (LSD dimensions) were classified into three levels, and the yield was evaluated for the comparative example group and the inventive example group. The yield% is based on the comparative example group, that is, the comparative example group is normalized, and the yield is a characteristic indicating the number of defects per wafer.

  From the results in Table 1, it is demonstrated that the yield obtained in the case of the laser-cleaned inventive example group is significantly improved compared to the comparative example group, and the number of defects generated on the wafer is reduced due to the improved yield. It becomes clear.

  Although water has been exemplified as the instantly evaporating liquid, alcohols in other liquids, or water-based liquids that use water and other materials, or alcohol-containing liquids such as alcohol and water may be used. Any liquid can be applied to the present invention as long as it is heated in the vicinity of the particles or impurities to be removed to cause instantaneous evaporation and remove the particles. In addition, the liquid can contain an additive such as a surfactant in order to enhance particle removal performance.

  As described above, the present invention achieves all the objectives, and provides a new and more excellent method and apparatus that can improve the surface quality of a target material to be processed, particularly a silicon wafer. , Based on the best embodiment of the present invention.

  Of course, those of ordinary skill in the art will consider making various changes, improvements and modifications to the disclosure herein without departing from this intended policy and category. The invention is limited only by the appended claims.

  According to the method and apparatus for manufacturing a silicon substrate of the present invention, particularly when processing a substrate containing particles or impurities such as a silicon wafer, a two-step approach process composed of an original inspection process and a local cleaning process is performed. By applying this method, it becomes possible to eliminate the repeated cleaning that has been essential for improving the quality of the wafer surface. By treating the first cleaned wafer in the two-step approach process, the ultra-clean surface can The silicon substrate can be secured, and the subsequent manufacturing process can be improved and the yield can be improved. Thereby, it can utilize widely as a process of the silicon wafer used for epitaxial growth, adhesion | attachment, or SIMOX.

It is the figure which normalized the probability that the surface particle before an epitaxial process will produce a defect more than 1 micron, and showed it by the pie chart. It is a figure which shows typically the comprehensive cleaning platform by the unit for wafer processing. It is a figure which shows typically the structural example of the washing | cleaning apparatus of this invention. It is a figure which shows the comparison result of a comparative example group and this invention example group.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Inspection station 3: Cleaning station 5, 6, 7, 22, 41: Path | route 9: Entrance 10: Comprehensive cleaning platform 11, 20: Cassette container 15: Apparatus mount 17: Local cleaning apparatus 18: Position direction Adjusting jig, operation robot 19: fan unit with filter, 21: wafer 23: particle, 24: standard inter-device connection (SMIF) loader 25: monitoring microscope, 26: liquid, water 27: infrared laser device 29: attenuation Rotating body 31: Focusing lens / mirror 33: Laser beam 35: Dry nitrogen gas 37: Humidifier 39: Humidified nitrogen gas 43: Photosensitive diode 45: Laser for field illumination 47: Local suction device 49: Tip Part

Claims (20)

A method for reducing the incidence of defects during processing of silicon wafers,
The plurality of wafers are inspected for the presence of surface particles on the wafer surface, and one or more wafers having one or more surface particles that do not pass a predetermined inspection standard parameter are extracted from the plurality of wafers. While sorting, identify the position of each of the surface particles,
In the cleaning process for processing the selected wafer, a liquid is supplied in the vicinity of each detected surface particle, instantaneous evaporation is performed, and each detected surface particle is removed as a part of the evaporated liquid,
A method of manufacturing a silicon substrate by local selective cleaning, wherein the selected wafer is sent to the next manufacturing process together with the unselected wafer or alone.   The method of manufacturing a silicon substrate by local selective cleaning according to claim 1, wherein laser heating is used for instantaneous evaporation.   The method of manufacturing a silicon substrate by local selective cleaning according to claim 1, wherein suction is performed in the vicinity of the detected surface particles so as to promote the removal of the detected surface particles in the evaporation process.   The method for manufacturing a silicon substrate by local selective cleaning according to claim 1, wherein the instantaneous evaporation is monitored to confirm the removal of the detected particles.   The method for manufacturing a silicon substrate by local selective cleaning according to claim 1, wherein the liquid is supplied after being condensed from a gas.   The method for producing a silicon substrate by local selective cleaning according to claim 1, wherein the liquid is water, a water-based composition, an alcohol, or an alcohol-containing composition. A method for removing surface impurities from the surface of a material to be treated, comprising: a) providing a material having at least one impurity particle on the surface;
b) supplying a liquid to the surface of the material in the vicinity of at least one of the impurity particles;
c) A method of manufacturing a silicon substrate by local selective cleaning comprising a series of steps in which the liquid is instantly evaporated and the impurity particles are removed as part of the liquid to be evaporated.   The method of manufacturing a silicon substrate by local selective cleaning according to claim 7, wherein laser heating is used for instantaneous evaporation.   The method for manufacturing a silicon substrate by local selective cleaning according to claim 7, wherein the liquid is supplied after being condensed from a gas.   The method for manufacturing a silicon substrate by local selective cleaning according to claim 7, wherein the detected surface particles are sucked during the instantaneous evaporation step so as to promote the removal of the detected surface particles.   The method for manufacturing a silicon substrate by local selective cleaning according to claim 7, further comprising a step of monitoring the instantaneous evaporation for removing particles.   The method of manufacturing a silicon substrate by local selective cleaning according to claim 7, wherein the liquid has water, a water-based composition, an alcohol, or an alcohol-containing composition.   12. The method of manufacturing a silicon substrate by local selective cleaning according to claim 11, wherein, when it is found that particles are not removed in the monitoring step, the steps b) and c) are repeated once or more. An apparatus for removing surface impurities from the surface of a material to be treated, comprising: a) means for identifying the position of at least one impurity particle on the material surface;
b) means for supplying a liquid to the near surface of the at least one impurity particle;
c) An apparatus for manufacturing a silicon substrate by local selective cleaning, comprising: means for removing the impurity particles as a part of the liquid to be evaporated by instantaneous evaporation of the liquid.   And means for supplying a gas in the vicinity of at least one of the impurity particles and causing the gas and particles to exist at a temperature at which the liquid condenses from the gas in the vicinity of the at least one of the impurity particles. The silicon substrate manufacturing apparatus by local selective cleaning according to claim 14.   15. The apparatus for manufacturing a silicon substrate by local selective cleaning according to claim 14, wherein the means for instantaneously evaporating the liquid comprises a laser device.   The apparatus for manufacturing a silicon substrate by local selective cleaning according to claim 14, further comprising means for sucking in the vicinity of at least one impurity particle and promoting particle removal by instantaneous evaporation.   The apparatus for manufacturing a silicon substrate by local selective cleaning according to claim 14, further comprising means for monitoring instantaneous evaporation for removing the impurity particles.   15. The apparatus for producing a silicon substrate by local selective cleaning according to claim 14, comprising means for supplying the liquid of water or a water-based composition, or alcohol or an alcohol-containing composition. The apparatus for manufacturing a silicon substrate by local selective cleaning according to claim 14, wherein the material to be processed is a silicon wafer, and a handling unit of the silicon wafer cooperates with a unit that supplies the liquid.

Images