Patent Publication Number: US-6992016-B2

Title: Chemical processing method, and method of manufacturing semiconductor device

Description:
This application is a division of Ser. No. 10/615,769, filed Jul. 10, 2003, now U.S. Pat. No. 6,849,865. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a chemical processor and a chemical processing method for subjecting a member to be processed, such as a semiconductor wafer, to chemical processing, as well as to a method of manufacturing a semiconductor device using the processor and method. 
   2. Background Art 
   A semiconductor device is generally produced from a semiconductor wafer made of group IV compounds such as silicon or III–V group compounds such as gallium arsenide. Via holes penetrating through a semiconductor substrate from the front to back thereof are formed in a finished semiconductor device for establishing electrical contact with ground electrodes provided on the back of a semiconductor substrate formed by slicing a semiconductor wafer. In many cases, the via holes are subjected to chemical processing, such as that pertaining to a cleaning process and that pertaining to a plating process. A semiconductor wafer which has not yet been separated into a plurality of semiconductor devices is subjected to processing pertaining to the cleaning process and that pertaining to the plating process. Via holes are formed in areas of the semiconductor wafer which are to become semiconductor substrates of a plurality of semiconductor devices. The semiconductor wafer is subjected to processing pertaining to the cleaning process and that pertaining to the plating process while an opening provided at one end of each via hole is closed; that is, while the via holes are held in the form of blind holes. 
   During the cleaning process, contaminants, and etch residues or resist residues which remain in blind holes are removed. For instance, during a process for manufacturing a semiconductor device having such blind holes, blind holes are formed through, e.g., reactive ion etching. Organic polymer residues and resist residues, which include carbon and chloride produced during reactive ion etching, still remain in the blind holes formed through reactive ion etching. Hence, before proceeding to the plating process, the wafer is subjected to processing pertaining to the cleaning process for removing the residues. 
   In many cases, interior surfaces of the blind holes are plated with gold (Au). Processing pertaining to the plating process is performed subsequent to that pertaining to the cleaning process. A plating layer is formed on the interior surfaces of the respective via holes formed in the form of blind holes. Processing pertaining to the plating process includes electroless plating and electrolytic plating. 
   Processing pertaining to the cleaning process and that pertaining to the plating process involve a necessity of bringing a chemical, such as a cleaning fluid or a plating fluid, into contact with interior surfaces of the blind holes. However, the semiconductor wafer that has not yet been immersed in a chemical remains dry, and interior surfaces of the respective blind holes also remain dry. When such a dry semiconductor wafer is immersed in a chemical, air traps including air bubbles are often formed inside the blind holes. Such an air trap corresponds to air bubbles building up at one location on the interior surface of the blind hole, thereby hindering the chemical from coming into contact with the entire internal surface of the blind hole. When the air traps have developed, failure to clean or plate the insides of the blind holes arises, which in turn results in lower reliability of a finished semiconductor device or a decrease in yield. 
   FIG. 1 of JP-A-5-299406 shows a proposed substrate cleaning bath which cleans a substrate by causing a cleaning fluid supplied from a cleaning fluid supply port of the substrate cleaning bath to flow parallel to the substrate through use of a straightening vane. JP-A-5-21413 also describes a proposed cleaning apparatus and method for cleaning a semiconductor substrate by causing a chemical to flow in parallel through use of a slit wall surface. However, these publications fail to describe a chemical processor and a chemical processing method for use with blind holes. 
   SUMMARY OF THE INVENTION 
   The purpose of the invention is to provide an improved chemical processor capable of preventing occurrence of processing failures on a surface which is to be processed and has blind holes, which would otherwise be caused by air traps. 
   The purpose of the invention is to provide an improved chemical processing method which prevents occurrence of processing failures on blind holes, which would otherwise be caused by air traps. 
   The purpose of the invention is to provide a semiconductor device manufacturing method including an improved chemical processing process capable of preventing occurrence of processing failures, which would otherwise be caused by air traps. 
   According to one aspect of the present invention, a chemical processor comprises a chemical processing cup, in which a member-to-be-processed is to be provided, and a pumping device for circulating a liquid chemical within the chemical processing cup, the member-to-be-processed includes a surface-to-be-processed which is placed face up. The surface-to-be-processed is chemically processed while the liquid chemical is circulated along the surface-to-be-processed in substantially a given direction at all times and at a velocity gradient of 300/second or more. 
   According to another aspect of the present invention, in a chemical processing method, a member-to-be-processed having a plurality of blind holes formed in a surface-to-be-processed is placed in a chemical processing cup such that the surface-to-be-processed is oriented upward. The surface-to-be-processed is chemically processed while a liquid chemical is circulated along the surface-to-be-processed in substantially a given direction at all times and at a velocity gradient of 300/second or more. 
   According to other aspect of the present invention, in a method for manufacturing a semiconductor device a semiconductor wafer having a plurality of blind holes formed in a surface-to-be-processed is placed in a chemical processing cup such that the surface-to-be-processed is oriented upward. The surface-to-be-processed is chemically processed while a liquid chemical is circulated along the surface-to-be-processed in substantially a given direction at all times and at a velocity gradient of 300/second or more. 
   Other and further objects, features and advantages of the invention will appear more fully from the following description. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram showing a chemical processor according to a first embodiment. 
       FIG. 2  is a cross-sectional view of a chemical processing cup according to a first embodiment. 
       FIG. 3  is a schematic cross-sectional view showing a portion of a member-to-be-processed and the flow of a chemical according to the present invention. 
       FIG. 4  shows the flow of a chemical over a surface-to-be-processed according to the present invention. 
       FIG. 5  shows a relationship between a chemical processing time and the rate of elimination of air bubbles; 
       FIG. 6  is a cross-sectional view of a chemical processing cup according to a second embodiment. 
       FIG. 7  is a cross-sectional view of a chemical processing cup according to a third embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   First Embodiment 
     FIG. 1  is an overall block diagram showing a first embodiment of a chemical processor according to the present invention. The chemical processor shown in  FIG. 1  will be described along with a chemical processing method using the chemical processor of the first embodiment and a method of manufacturing a semiconductor device using the method. 
   A chemical processor  100  shown in  FIG. 1  has a chemical processing cup  10 ; a chemical tank  40  which stores a chemical; a pumping device  50  for supplying a chemical (specifically, a liquid chemical) to the chemical processing cup  10 ; and a chemical circulation system  60 . 
   The chemical processing cup  10  has a chemical supply port  11  and a chemical drain port  12 . The chemical tank  40  has chemical circulation ports  41 ,  42 . The pumping device  50  has a chemical outlet  51  and a chemical inlet  52 . The outlet port  51  of the pumping device  50  is connected to the chemical supply port  11  of the chemical processing cup  10  via a pipe  61 , and the chemical drain port  12  of the chemical processing cup  10  is connected to the chemical circulation port  41  of the chemical tank  40  by means of a pipe  62 . The circulation port  42  of the chemical tank  40  is connected to the inlet  52  of the pumping device  50  by means of a pipe  63 . The chemical circulation system  60  comprises the chemical processing cup  10 , the chemical tank  40 , the pumping device  50 , and the pipes  61 ,  62 ,  63 . 
     FIG. 2  is a cross-sectional view showing the internal configuration of the chemical processing cup  10 . The chemical processing cup  10  is constituted in the form of a closed chemical processing cup for processing a member-to-be-processed  30 , that is, a semiconductor wafer, with a chemical. The chemical processing cup  10  has a closed processing chamber  15  enclosed by, e.g., a rectangular-parallelepiped container  13 . The chemical supply port  11  and the chemical drain port  12 , both communicating with the processing chamber  15 , are formed in the side surfaces of the container  13  so as to oppose each other. 
   The processing chamber  15  is constructed such that a chemical  20  supplied from the pumping device  50  to the chemical supply port  11  is circulated toward the chemical drain port  12  under a predetermined pressure and at a predetermined flow rate. A wafer holding table  17  is provided on a bottom wall surface of the container  13 , and a semiconductor wafer  30  is mounted, as a member to be processed, on the wafer holding table  17 . The member-to-be-processed  30 ; that is, a semiconductor wafer, is mounted face-up such that a surface-to-be-processed  31  faces a vertical direction. The chemical  20  is circulated in a substantially horizontal direction within the processing chamber  15  from the chemical supply port  11  to the chemical drain port  12 . The chemical  20  is circulated at a predetermined velocity gradient along and over the surface-to-be-processed  31 . 
   Circulation of the chemical  20  in the processing chamber  15  of the chemical processing cup  10  is performed by the pumping device  50 . For instance, a magnetic pump is used for the pumping device  50 . The magnetic pump  50  supplies the chemical  20  to the chemical supply port  11  at substantially a given pressure at all times. In the processing chamber  15 , the chemical  20  is circulated toward the chemical outlet port  12  in substantially a given direction along the surface-to-be-processed  31  at all times. 
     FIG. 3  shows circulation of the chemical  20  over the member-to-be-processed  30 ; that is, the surface-to-be-processed  31  of the semiconductor wafer, in an enlarged manner. A portion of the member-to-be-processed  30  is illustrated in an enlarged manner, and a blind hole  33  is opened in the surface-to-be-processed  31 . The blind hole  33  is made by closing a lower opening end of a via hole. The semiconductor wafer  30  is one which has not yet been sliced into pieces of semiconductor devices. At least one blind hole  33  is formed in each of the semiconductor devices. The blind hole  33  is formed in a semiconductor device separated from the semiconductor wafer  30  so as to impart a predetermined potential to the back of a semiconductor substrate of the device.  FIG. 3  shows only a portion of the semiconductor wafer  30  including only one blind hole  33 . In reality, the blind holes  33  are formed so as to correspond to respective semiconductor devices. Upper ends of the plurality of blind holes  33  are opened in the surface-to-be-processed  31 . 
   The chemical  20  is circulated along the surface-to-be-processed  31  at a predetermined flow rate V and in substantially one direction at all times in the form of a laminar flow, such as that designated by the arrow shown in  FIG. 3 , while remaining in contact with the surface-to-be-processed  31 . Flow of the chemical  20  is substantially in parallel with the surface-to-be-processed  31 . An air bubble  35  entrapped in the blind hole  33  is withdrawn by the flow of the chemical  20  over the surface-to-be-processed  31 . 
   Details of the flow of the chemical  20  effected over the surface-to-be-processed  31  are provided in the descriptive view shown in  FIG. 4 . As shown in  FIG. 4 , the horizontal axis represents the surface-to-be-processed  31 , and the vertical axis represents a distance Z from the surface-to-be-processed  31 . The chemical  20  flows at all times in the direction A shown in  FIG. 4 ; that is, in substantially a given direction along the surface-to-be-processed  31 . The chemical  20  located on the surface-to-be-processed  31  assumes a velocity of 0. However, as can be seen from the descriptive view of  FIG. 4 , as the chemical departs from the surface-to-be-processed  31 , the velocity of the chemical  20  becomes greater, in the manner of V 1 , V 2 , and V 3  (V 1 &lt;V 2 &lt;V 3 ). At the largest velocity V 3 , the speed is saturated and becomes constant. The maximum speed V 3  is achieved at a distance Z 3  from the surface-to-be-processed  31 . 
   The velocity V is increased in proportion to the distance Z within a range in which the distance Z from the surface-to-be-processed  31  is Z 3  or less. A gradient of change in the velocity V; that is, a velocity gradient α, is defined as dV/dZ. The unit of velocity gradient α is per second (/second). 
   The present invention is characterized in that chemical processing is performed through use of the chemical  20  while a velocity gradient α of the chemical  20  effected over the surface-to-be-processed  31  is set to a predetermined value; 300/second or more. According to the invention, attention should be paid to the principle that, as the velocity gradient α of the chemical  20  over the surface-to-be-processed  31  becomes larger, an effect for withdrawing the air bubbles  35  remaining in the blind holes  33  by means of flow of the chemical  20  becomes greater. The effect of withdrawing the air bubbles  35  by the flow of the chemical  20  is based on a phenomenon called an entrainment phenomenon. As described in “The Seventh Issue of Mechanical Engineering Handbook,” A5, p48, The Japan Society of Mechanical Engineers, the entrainment phenomenon is that a fluid located outside a boundary layer of a flow (i.e., an air bubble trapped in a blind hole) of the flow is absorbed in and flows into the boundary layer. 
     FIG. 5  shows a result of an experiment showing a relationship between a rate of elimination of air bubbles (hereinafter simply called an “air bubble elimination rate”) from the surface-to-be-processed  31  of the semiconductor wafer  30  and a processing time while the velocity gradient α is taken as a parameter. As shown in  FIG. 5 , the horizontal axis represents a processing time (minutes) which lapses from a point in time when processing is started, and the vertical axis represents a rate of elimination of air bubbles from the blind holes  33  (%). A curve B 5  indicated by solid circles represents the result of a test carried out when the velocity gradient α of the chemical  20  over the surface-to-be-processed  31  is set to 600/second. A curve B 4  indicated by solid squares shows the result of a test carried out when the velocity gradient α of the chemical  20  is set to 450/second. A curve B 3  indicated by solid triangles shows the result of a test carried out when the velocity gradient α is set to 300/second. A curve B 2  indicated by solid rhombuses shows the result of a test carried out when the velocity gradient α is set to 150/second. Further, a curve B 1  indicated by crosses shows the result of a test carried out when the velocity gradient α is set to 0/second. 
   As shown in  FIG. 5 , if the velocity gradient α is set to 600/second, as indicated by the curve B 5 , an air bubble elimination rate of 100 (%) is obtained after lapse of 20 (minutes) after the start of processing. If the velocity gradient α is 450/second, as indicated by the curve B 4 , an air bubble elimination rate of 100(%) is obtained after lapse of 40 (minutes) after the start of processing. If the velocity gradient α is 300/second, as indicated by the curve B 3 , an air bubble elimination rate of 100% is obtained after lapse of 40 (minutes) after the start of processing. If the velocity gradient α is 150/second or 0/second, as indicated by the curves B 2 , B 1 , an air bubble elimination rate is 20% or less even after lapse of an hour after the start of processing. 
   According to the present invention, on the basis of the foregoing tests, the chemical processor  100  is constructed so as to circulate the chemical  20  along the surface-to-be-processed  31  in substantially a given direction at all times and at a velocity gradient α of 300/second or more. According to the chemical processing method of the present invention, the surface-to-be-processed  31  is subjected to chemical processing while the chemical  20  is circulated along the surface-to-be-processed  31  in substantially a given direction at all times and at a velocity gradient α of 300/second or more. Further, according to the semiconductor device manufacturing method of the present invention, the surface-to-be-processed  31  of the semiconductor wafer  30  is subjected to chemical processing in the chemical processing process while the chemical  20  is circulated in substantially a given direction along the surface-to-be-processed  31  at all times and at a velocity gradient α of 300/second or more. 
   The test results shown in  FIG. 5  correspond to test results pertaining to the semiconductor wafer  30  including a plurality of blind holes  33 , each hole having an aspect ratio of 2. Each of the blind holes  33  is set to assume an aperture diameter of 50 μm and a depth of 100 μm. From the test results shown in  FIG. 5 , a processing result analogous to that mentioned previously is considered to be obtained by setting the velocity gradient α of the chemical  20  over the surface-to-be-processed  31  to 300/second or more with regard to the blind hole  33  having an aspect ratio of 2 or less. Since the aspect ratio of blind holes  33  of the semiconductor wafer  30  is generally 2 or less, the present invention provides effective chemical processing of the semiconductor wafer  30 . 
   The first embodiment of the invention will now be described by reference to more specific examples. 
   First and second examples in which the surface-to-be-processed  31  of the semiconductor wafer  30  is first subjected to cleaning processing will be described. The first and second examples are carried out through use of the chemical processor  100  shown in  FIGS. 1 and 2 . More specifically, a plurality of via holes  33  are formed in the semiconductor wafer  30  during the process of manufacture of a semiconductor device. After lower open ends of the respective via holes  33  have been closed, to thereby form blind holes  33 , the semiconductor wafer  30  is set face up on the wafer holding table  17  in the processing chamber  15  such that the surface-to-be-processed  31  of the semiconductor wafer  30  is oriented upward, and in this state the surface-to-be-processed  31  is subjecting to cleaning processing. The semiconductor wafer  30  is made of gallium arsenide. The via holes  33  are formed by means of, e.g., plasma etching or RIE. Residues associated with etching, such as carbon or chlorine, and resist residues are present in the blind holes  33 . 
   EXAMPLE 1 
   In the first example, a resist stripper S 710  manufactured by Tokyo Ohka Kogyo Co., Ltd. was used as the chemical  20 . The chemical  20  contained orthodichlorobenzene, phenol, and alkylbenzene-sulfonate. The chemical  20  was circulated through the processing chamber  15  of the chemical processing cup  10  by means of the pumping device  50 . A magnetic pump was used for the pumping device  50 , and the chemical  20  was circulated in substantially a given direction over the surface-to-be-processed  31  at all times. Pressure exerted onto the chemical at the outlet  51  of the pumping device  50  was set to 0.12 mega-pascal (MPa), and the chemical  20  was circulated at a flow rate of 13 (liters/minute). In the processing chamber  15 , the velocity gradient α of the chemical  20  over the surface-to-be-processed  31  was set to 600/second. In this state, as a result of the surface having been cleaned for thirty minutes, a superior result of cleaning of the surface-to-be-processed  31  including the blind holes  33  was achieved. No failures to remove residues due to build-up of air bubbles were observed. 
   The temperature of the chemical  20  in the processing chamber  15  was set to 100° C. to 120° C. 
   EXAMPLE 2 
   In the second embodiment, a resist stripper EKC265 manufactured by EKC Co., Ltd. of U.S.A. was used as the chemical  20 . The chemical  20  contains ethanolamine as the main ingredient. The temperature of the chemical in the processing chamber  15  was set to about 85° C. In other respects, all conditions were made identical with those employed in the first example. Consequently, a result of cleaning of the surface-to-be-processed  31  including the blind holes  33  was satisfactory, and no failures to remove residues due to build-up of air bubbles was observed. 
   In any of the first and second examples, cleaning failures, such as remaining of residues in the blind holes  33 , were not ascertained. The reason for this is considered to be that the air bubbles remaining in the blind holes  33  were withdrawn at the velocity gradient α=600/second of the chemical  20  over the surface-to-be-processed  31 . 
   Next, third and fourth examples in which the surface-to-be-processed  31  of the semiconductor wafer is subjected to electroless plating will be described. Electroless plating was performed after processing pertaining to the cleaning process described in connection with the first or second example had been performed during the course of manufacture of a semiconductor device. The third and fourth examples were carried out while the plurality of via holes  33  were formed in the semiconductor wafer  30  and while lower ends of openings of the via holes  33  were closed so as to form blind holes  33 . 
   Specifically, the electroless plating includes three processes; that is, a palladium activation process, an electroless plating process, and a gold substitution plating process. Both third and fourth examples are the examples of the gold substitution plating process. 
   The palladium activation process is a process for imparting a palladium catalyst to the surface-to-be-processed  31  that belongs to the semiconductor wafer  30  to be processed and has the blind holes  33 . The chemical processor shown in  FIGS. 1 and 2  was not used in the palladium activation process. A palladium activation liquid containing palladium chloride (PdCl 2 ) as the main ingredient was placed in a container differing from the chemical processing cup  10 . Further, the semiconductor wafer  30  was immersed in the liquid. 
   The electroless plating process is a process for plating the surface-to-be processed  31  with, e.g., nickel-phosphor (Ni—P) without use of electrolysis. Specifically, a mixture consisting of nickel sulfate (NiSO 4 ) and sodium hypophosphite (NaH 2 PO 4 ) was heated to a temperature of 60° C. to 90° C. The semiconductor wafer  30  that had completed undergoing palladium activation processing was immersed in the liquid, to thereby form an Ni—P plating layer to a thickness of 0.2 μm to 0.5 μm. Processing pertaining to the electroless plating process was also performed without use of the chemical processor shown in  FIGS. 1 and 2  and through use of a container different from the chemical processing cup  10 . 
   Processing pertaining to third and fourth examples of the final gold substitution plating process were performed through use of the chemical processor  100  shown in  FIGS. 1 and 2 . The gold substitution plating process is a process for substituting the surface of an Ni—P plating layer with gold. In the third and fourth examples, a magnetic pump was used for the pumping device  50 . The chemical  20  was circulated in substantially a given direction along the surface-to-be-processed  31  at a velocity gradient α of 450/second. 
   EXAMPLE 3 
   (1) Composition of the chemical  20   
   Metal supply agent: potassium gold cyanide (several grams/liter) 
   Stabilizer: chelating agent, complexing agent (tens of grams/liter) 
   Additive: trace amount 
   PH: 6 to 7 
   Temperature of the liquid in the processing chamber  15 : 80° C. to 90° C. 
   (2) Plating time: 45 min to 50 min. 
   (3) Thickness of a substituted gold plating layer: 0.1 μm 
   (4) Velocity gradient α of the chemical  20 : 450/second on the surface-to-be-processed  31   
   (5) Plating failures: none 
   EXAMPLE 4 
   (1) Composition of the chemical  20   
   Metal supply agent: gold sulfite (several grams/liter) 
   Stabilizer: chelating agent, complexing agent (tens of grams/liter) 
   Additive: trace amount 
   PH: 7 to 8 
   Temperature of the liquid in the processing chamber  15 : 50° C. to 70° C. 
   (2) Plating time: 45 min to 50 min. 
   (3) Thickness of a substituted gold plating layer: 0.1 μm 
   (4) Velocity gradient α of the chemical  20 : 450/second on the surface-to-be-processed  31   
   (5) Plating failures: none 
   In any of the third and fourth examples, plating failures were not found in the blind holes  33 . The reason for this is considered to be that air bubbles are withdrawn from the inside of the blind holes  33  by means of the velocity gradient α of the chemical  20  over the surface-to-be-processed  31 . 
   EXAMPLE 5 
   In both the third and fourth examples, the blind holes  33  were subjected to electroless plating. The fifth example is directed toward electroplating interior surfaces of the blind holes  33 . Processing pertaining to the fifth example of electroplating, for example, in third or fourth example, was performed by forming a layer of gold (Au) on interior surfaces of the blind holes  33  through electroless plating, thus imparting a cathode potential to that layer. An anode electrode is also provided in the processing chamber  15 . 
   For instance, when interior surfaces of the blind holes  33  formed in the semiconductor wafer  30 , the wafer being formed from, e.g., gallium arsenide, were plated with gold (Au), a sulfurous-acid-based plating liquid or cyan-based plating liquid was used as the chemical  20 . A plating liquid containing gold sodium sulfite or sodium sulfite as a main ingredient is used as the sulfurous-acid-based plating liquid. A plating liquid containing, e.g., gold sodium cyanide, as a main ingredient is used as the cyan-based plating fluid. The temperature of the chemical  20  in the processing chamber  15  was set within the temperature range of 40° C. to 70° C.; e.g., a temperature of 50° C. or 65° C. The interior surfaces were electroplated with gold (Au) in the same manner as that mentioned previously while the chemical  20  was supplied to the processing chamber  15  by means of the pumping device  50  embodied by a magnetic pump and circulated in substantially a given direction along the surface-to-be-processed  31  at all times and at a velocity gradient α of 300/second or more. By means of the velocity gradient α of the chemical  20 , air bubbles were withdrawn from the insides of the blind holes  33 . Hence, the interior surfaces of the blind holes  33  can be electroplated without involvement of occurrence of a failure which would be caused by an air trap. 
   The chemical processor according to the first embodiment of the present invention has the chemical processing cup  10  in which the member-to-be-processed  30  is to be placed, and the pumping device  50  which circulates the chemical  20  in the chemical processing cup  10 . The surface-to-be-processed  31  is chemically processed face up while the surface-to-be-processed  31  of the member-to-be-processed  30  is oriented upward. The chemical  20  is circulated over the surface-to-be-processed  31  in substantially a given direction at all times at a velocity gradient of 300/second or higher, thereby processing the surface-to-be-processed  31  with a chemical. In relation to the chemical processor which processes the surface-to-be-processed  31  face up, a configuration for processing the surface-to-be-processed  31  while the chemical  20  is circulated in substantially a given direction at all times along the surface-to-be-processed  31  at a velocity gradient of 300/second or higher also yields an effect of withdrawing air bubbles from blind holes in connection with the surface-to-be-processed  31  having the blind holes  33 . Occurrence of a processing failure, which would otherwise arise in a surface-to-be-processed having blind holes, for reasons of an air trap, can be prevented. 
   The chemical processing method of the invention described in connection with the first embodiment is to process the surface-to-be-processed  31  with a chemical while the member-to-be-processed  30  having a plurality of blind holes  33  formed in the surface-to-be-processed  31  is placed in the chemical processing cup  10  such that the surface-to-be-processed  31  is oriented upward. The surface-to-be-processed  31  is processed with a chemical while the chemical  20  is circulated over the surface-to-be-processed  31  in substantially a given direction at all times at a velocity gradient of 300/second or higher. Even under this chemical processing method, the chemical  20  is circulated in substantially a given direction at all times over the surface-to-be-processed  31  at a velocity gradient of 300/second or higher, thereby withdrawing air bubbles from the blind holes  33 . As a result, chemical processing can be effected while processing failures due to air bubbles are eliminated. 
   Under the chemical processing method, the member-to-be-processed  30  is the semiconductor wafer  30  having the plurality of blind holes  33 , and the insides of the blind holes  33  are cleansed with the chemical  20 . By means of this method, residues remaining in the blind holes  33  can be cleansed without involvement of occurrence of cleaning failures which would otherwise be caused by air bubbles. 
   Under this chemical processing method, the member-to-be-processed  30  is the semiconductor wafer  30  having a plurality of blind holes  33 . The blind holes  33  are plated with the chemical  20 . By means of this method, the blind holes  33  can be plated without involvement of occurrence of plating failures which would otherwise be caused by air bubbles in the blind holes  33 . 
   The semiconductor device manufacturing method of the invention described in connection with the first embodiment includes a chemical processing process for the semiconductor wafer  30  having the plurality of blind holes  33  formed in the surface-to-be-processed  31 . In the chemical processing process, the semiconductor wafer  30  is placed in the chemical processing cup  10  such that the surface-to-be-processed  31  is oriented upward. The chemical  20  is circulated along the surface-to-be-processed  31  in substantially a given direction at all times and at a velocity gradient of 300/second or more, whereby the surface-to-be-processed  31  is chemically processed. Even during the chemical processing process in the semiconductor device manufacturing method, the chemical  20  is circulated along the surface-to-be-processed  31  in substantially a given direction at all times and at a velocity speed of 300/second or more, whereby air bubbles are withdrawn from the blind holes  33 . Thus, processing failures due to air bubbles are prevented, so that the surface-to-be-processed can be chemically processed. 
   Under the semiconductor device manufacturing method, the insides of the blind holes  33  are cleansed in a chemical processing process. Residues remaining in the blind holes  33  can be cleansed without involvement of occurrence of cleaning failures caused by air bubbles. 
   Under the semiconductor device manufacturing method, the blind holes  33  are plated through the chemical processing process. The blind holes can be plated without involvement of occurrence of plating failures caused by air bubbles remaining in the blind holes  33 . 
   Second Embodiment 
     FIG. 6  shows a chemical processing cup  10 A according to a second embodiment of the chemical processor of the present invention. A regulation member  18  capable of regulating an effective aperture area of the drain port  12  is provided on an interior surface of the chemical drain port  12  of the container  13 . In other respects, the chemical processor is identical in configuration with the chemical processor  100  shown in  FIGS. 1 and 2 . 
   The regulation member  18  has a pair of regulation plates  181 ,  182  which are provided along a sidewall surface of the container  13  and capable of moving vertically. An effective aperture  180  is formed between the regulation plate  181  and the regulation plate  182 . The regulation plate  181  can be moved vertically within an area located above the center of the drain port  12 , and the regulation plate  182  can be moved vertically within an area located below the center of the drain port  12 . The effective aperture area of the drain port  12  can be changed by means of changing an overlapping area located between the regulation plate  181  and the drain port  12  and that located between the regulation port  182  and the drain port  12 . By means of the effective aperture area of the drain port  12  being changed by the regulation member  18 , the liquid current status of the chemical  20  in the processing chamber  15  provided in the chemical processing cup  10  is changed. The velocity gradient α of the chemical  20  on the surface-to-be-processed  31  can be readily regulated while the chemical  20  is maintained in substantially the same direction over the surface-to-be-processed  31  of the semiconductor wafer  30 . Further, variations in the velocity gradient α can also be diminished. By means of regulating operation of the regulation member  18 , the velocity gradient α on the surface-to-be-processed  31  is held at a predetermined value of 300/second or more, thereby increasing an effect of suppressing occurrence of cleaning failures or plating failures, which would otherwise be caused by the air bubbles  35 . 
   Third Embodiment 
     FIG. 7  shows a chemical processing cup  10 B according to a third embodiment of the chemical processor of the present invention. The chemical processing cup  10 B of the third embodiment is embodied by additionally placing a flow rate regulation plate  19  in the processing chamber  15  of the container  13 . In other respects, the chemical processor is identical in configuration with the chemical processor  100  shown in  FIGS. 1 and 2 . 
   The flow rate regulation plate  19  is provided in parallel with the surface-to-be-processed  31  and fitted along respective internal sidewall surfaces of the processing chamber  15 , thereby limiting the flow of the chemical  20  in a lower portion of the flow rate regulation plate  19 . The flow rate regulation plate  19  can be moved vertically within the processing chamber  15  while remaining in parallel with and spaced a distance “d” away from the surface-to-be-processed  31 . By means of the flow rate regulation plate  19 , the flow of the chemical  20  over the surface-to-be-processed  31  is held in substantially the same direction. In addition, the velocity gradient α of the chemical  20  over the surface-to-be-processed  31  is regulated by vertical movement of the regulation plate  19 , thereby diminishing variations in the velocity gradient α. By means of causing the flow rate regulation plate  19  to approach the surface-to-be-processed  31 , the velocity gradient α over the surface-to-be-processed  31  can be increased. By means of regulation operation of the flow rate regulation plate  19 , the velocity gradient α over the surface-to-be-processed  31  is held at a predetermined value of 300/second or more. An effect of preventing cleaning failures or plating failures, which would otherwise be caused by the air bubbles  35 , can be enhanced. 
   The features and advantages of the present invention may be summarized as follows. 
   According to one aspect, the chemical processor of the present invention, even when the surface-to-be-processed of the member-to-be-processed includes blind holes, can chemically process the surface-to-be-processed while air traps in the blind holes are eliminated. 
   According to another aspect, the surface-to-be-processed can be chemically processed while the air traps in the blind holes formed in the surface-to-be-processed are eliminated. 
   According to other aspect, the surface-to-be-processed of the semiconductor wafer can be chemically processed while the air traps in the blind holes formed in the surface are eliminated, thereby enabling an improvement in the reliability of a finished semiconductor device and a yield. 
   Obviously many modification and variation of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may by practiced otherwise than as specifically described. 
   The entire disclosure of a Japanese Patent Application No.2002-337539, filed on Nov. 21, 2002 including specification, claims, drawings and summary, on which the Convention priority of the present application is based, are incorporated herein by reference in its entirety.