JP2008171923A - Wafer cleaning apparatus and wafer cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer cleaning apparatus and a wafer cleaning method capable of improving the ability to remove foreign matters formed on a wafer while suppressing physical damage to a wiring pattern shape.
A wafer chuck 12 capable of rotating a target wafer 11 to be mounted about an axis perpendicular to the mounting surface, and an orientation specifying mark attached to the target wafer 11 to recognize the target wafer. Pattern direction recognition means 14 for recognizing the main device wiring pattern direction d2 of the device formed on 11, and the wafer surface parallel component (first injection direction) of the injection direction in which the injection means 15 injects the fluid 16. The cleaning fluid 16 to which the ultrasonic wave is applied by the ultrasonic wave application unit 19 while moving while maintaining the positional relationship between the wafer surface and the injection unit 15 so that d0 and the device wiring pattern direction d2 are parallel to each other. Are sprayed onto the wafer surface of the target wafer 11.
[Selection] Figure 3

Description

  The present invention relates to a wafer cleaning apparatus and a wafer cleaning method, and more particularly to a single wafer cleaning apparatus and a wafer cleaning method for cleaning wafers one by one.

  In the processing process of semiconductor wafers that are becoming finer, foreign substances such as reaction products and particles generated during etching may adhere to the wafer surface. If these foreign substances remain on the wafer surface, the process may proceed, resulting in pattern defects and device characteristics degradation due to the presence of foreign substances, which may result in a defective product. There is. For this reason, in order to remove such foreign matter, a normal semiconductor process includes a wafer cleaning process for cleaning the wafer surface. Particularly in recent years, a cleaning method using ultrasonic waves has been widely adopted in order to effectively remove foreign substances adhering to the side walls of the device wiring pattern.

  As a cleaning apparatus for cleaning wafers, there are generally two types: a batch type that cleans semiconductor wafers simultaneously, for example, every lot, such as a lot unit, and a single wafer type that cleans semiconductor wafers one by one. Type is used. Here, while the batch type is an efficient cleaning method in that the cleaning process is performed simultaneously for a plurality of sheets, the chemical solution used for the cleaning process is usually changed every several to several tens of cleaning processes. As compared with the single wafer type in which cleaning is performed for each wafer and a new chemical is supplied for each cleaning, the amount of foreign matters such as particles is large. Further, since a plurality of wafers are cleaned at the same time, there is a drawback that mutual contamination with other semiconductor wafers may occur.

  For this reason, in a fine processing step requiring a high clean level, a single wafer type having a higher cleaning ability than a batch type is often used. In addition, the single wafer type is also useful in terms of excellent in-plane uniformity of the amount of wet etching with a chemical solution due to the structure of the apparatus.

  FIG. 8 is a conceptual diagram for explaining a single wafer type wafer cleaning process of a conventional configuration. As shown in FIG. 8, the wafer surface is cleaned by spraying a cleaning fluid (chemical liquid, pure water, etc.) 16 from the spraying means 15 onto the semiconductor wafer 11 while the semiconductor wafer 11 is rotated. Do. The fluid 16 ejected from the ejecting means 15 is ejected onto the wafer surface in a state where ultrasonic waves are applied as described above in order to enhance the cleaning effect.

  That is, according to the conventional method, the ultrasonic cleaning process is performed in a state where the semiconductor wafer 11 is rotated. Therefore, the miniaturized device wiring pattern formed on the semiconductor wafer 11 is affected by the ultrasonic wave. As a result, part of the pattern shape may be missing, processing defects, crystal defects, or the like may occur. In addition, there is also a problem that reaction products generated on the side walls of the miniaturized device wiring pattern cannot be efficiently removed only by applying ultrasonic waves to the cleaning fluid.

  In order to solve the above problems, a wafer cleaning apparatus capable of controlling the spray angle, spray speed, and the like of a cleaning fluid with respect to a semiconductor wafer has been conventionally provided (see, for example, Patent Document 1).

JP 2006-019642 A

  FIG. 9 is a conceptual diagram for explaining a wafer cleaning process performed using the cleaning apparatus described in Patent Document 1.

  A cleaning apparatus 30 shown in FIG. 9 has a wafer chuck 12 on which a semiconductor wafer 11 to be cleaned is placed, a rotary shaft 13 for rotating the wafer chuck 12, and a cleaning fluid 16 for the semiconductor wafer 11. It is the structure provided with the control means 31 which controls the injection means 15 for injecting, and the said injection means 15. FIG.

  The cleaning device 30 is configured such that the control unit 31 can control the injection angle of the injection unit 15, the position of the injection port, or the injection speed for each process according to the amount of physical damage to the semiconductor wafer 11. . Further, the rotational speed of the wafer chuck 12 is also controllable.

  When configured in this way, for example, in a process that is less susceptible to physical damage because it is protected by a protective film or the like, the cleaning performance itself is increased by increasing the injection speed and rotation speed, and conversely device wiring. In a process where there is a region that is susceptible to physical damage as in the case where the pattern is exposed, the spraying speed is reduced, the spraying angle, or the like so that the region is not damaged by the spraying of the cleaning fluid 16. By adjusting the position, it is possible to achieve both improvement in the ability to remove foreign substances and suppression of physical damage.

  However, in the case of the method disclosed in Patent Document 1, since there are many objects to be controlled, such as the injection angle, the position of the injection port, the injection speed, and the rotation speed of the wafer chuck 12, the control mechanism (the control means 31 and the like) that the cleaning apparatus should have. There is a problem that the scale increases and the control content becomes complicated. This also increases the manufacturing cost of the cleaning device.

  In the case of the method disclosed in Patent Document 1, although the cleaning conditions are changed by changing each parameter for each process, the pattern direction of the device wiring pattern formed on the semiconductor wafer 11 is considered. Absent. Therefore, it cannot be said that it is a configuration that can sufficiently prevent processing defects such as pattern loss due to ultrasonic cleaning, crystal defects, etc., and removal of reaction products generated on the side wall portion of the miniaturized device wiring pattern It cannot be said that the efficiency can be sufficiently improved.

  In view of the above problems, the present invention provides a wafer cleaning apparatus and a wafer cleaning method capable of improving the ability to remove foreign matters formed on a wafer while suppressing physical damage to a wiring pattern shape. With the goal.

  In order to achieve the above object, a wafer cleaning apparatus according to the present invention is a single wafer cleaning apparatus, on which a target wafer to be cleaned is placed, and an axis perpendicular to the placement surface. A wafer chuck that is rotatable around, pattern direction recognition means for recognizing a main device wiring pattern direction of a device formed on the target wafer, and jetting that jets a cleaning fluid from obliquely above the target wafer And an ultrasonic application unit capable of applying an ultrasonic wave to the fluid ejected from the ejection unit, and when the target wafer is placed on the wafer chuck, the pattern direction The recognizing means recognizes the orientation specifying mark attached on the target wafer to specify the crystal orientation, and the installation position of the orientation specifying mark on the target wafer Recognizing the main device wiring pattern direction based on the main device wiring pattern direction recognized by the pattern direction recognizing means and the ejection direction of the fluid ejected from the ejecting means on the target wafer. Rotate until the first injection direction related to the parallel component when the wafer surface is decomposed into a parallel component and a vertical component, and either one or both of the injection means and the wafer chuck By moving while maintaining the parallel relationship, ultrasonic waves are applied to the ejection unit under a state where the position of the ejection destination of the fluid ejected from the ejection unit on the target wafer changes. A first feature is that the fluid is sprayed onto the target wafer.

  Here, the main device wiring pattern direction means the longitudinal direction of the main wiring pattern, specifically, for example, formed on the uppermost layer of the target wafer placed on the wafer chuck. Of the wiring patterns, the direction with the largest number of wirings extending in the same direction may be defined as the “main device wiring pattern direction”, and the total wiring length of wirings extending in the same direction is the longest. The direction may be defined as “main device wiring pattern direction”.

  According to the first characteristic configuration of the wafer cleaning apparatus according to the present invention, the position of the target wafer on the wafer chuck is set so that the first jetting direction is parallel to the main device wiring pattern direction. The device wiring pattern in which the ultrasonic wave is applied to the main device wiring pattern by ejecting a cleaning fluid while moving either one or both of the ejecting means and the wafer chuck while maintaining the parallel relationship. The cleaning fluid can be sprayed onto the entire wafer surface of the target wafer without applying the film to the forming surface from various angles. Therefore, as in the past, while using the ultrasonic cleaning method for improving the cleaning capability, the simple device control for maintaining the main device wiring pattern direction of the target wafer in parallel with the first ejection direction can be performed on the wiring pattern. It is possible to suppress physical damage.

  When the main device wiring pattern directions are formed in two orthogonal directions, specifically, device wiring patterns having substantially the same number or approximately the same total wiring length are formed in two orthogonal directions. In this case, after performing the above-described spraying process by defining any one direction as the “main device wiring pattern direction”, the remaining other direction is defined as the “main device wiring pattern direction” and the spraying is performed. It does not matter even if it is the composition which performs a process.

  Further, in the wafer cleaning apparatus according to the present invention, in addition to the first characteristic configuration, the injection unit has an injection port in a direction orthogonal to the first injection direction on a plane parallel to the wafer surface of the target wafer. A second feature is that the fluid to which ultrasonic waves are applied is jetted onto the target wafer while swinging.

  According to the second characteristic configuration of the wafer cleaning apparatus according to the present invention, the side wall surface of the device wiring extending in the main device wiring pattern direction while maintaining the parallel relationship between the main device wiring pattern direction and the first injection direction. Since the cleaning fluid to which the ultrasonic wave is applied can be applied, the removal efficiency for foreign substances such as reaction products formed on the pattern side wall surface is suppressed while suppressing the influence on the shape of the device wiring pattern. Can be improved.

  In addition to the first or second characteristic configuration, the wafer cleaning apparatus according to the present invention has a third characteristic that the orientation specifying mark is a notch or an orientation flat.

  According to the third characteristic configuration of the wafer cleaning apparatus according to the present invention, the orientation specifying mark attached in the existing semiconductor process can be used, so the main device wiring pattern direction without introducing new equipment. Can be recognized.

  The wafer cleaning method according to the present invention is a single wafer cleaning method in which a target wafer to be cleaned is mounted on a wafer chuck that is rotatable about an axis perpendicular to the mounting surface. A first step of placing and recognizing an orientation specifying mark for specifying a crystal orientation attached to the placed target wafer, and forming the orientation specifying mark on the target wafer based on an installation position of the orientation specifying mark A second step of recognizing the main device wiring pattern direction of the device being used, the main device wiring pattern direction, and the spraying direction of the cleaning fluid sprayed from the spraying means parallel to the wafer surface of the target wafer A third step of rotating the wafer chuck so that a first injection direction related to the parallel component when the component is decomposed into a component and a vertical component is in parallel relation; and the injection means or the wafer chuck The ultrasonic wave is applied while changing the position on the target wafer of the spray destination of the fluid sprayed from the spraying means by moving one or both of the fluids while maintaining the parallel relationship. And a fourth step of jetting the fluid from the jetting unit obliquely downward with respect to the target wafer.

  According to the first feature of the wafer cleaning method of the present invention, the target wafer position on the wafer chuck is set so that the first injection direction is parallel to the main device wiring pattern direction. Then, while maintaining this parallel relationship, the cleaning fluid is sprayed while moving either one or both of the spraying means and the wafer chuck, thereby forming the main device wiring pattern of the fluid to which the ultrasonic wave is applied. The cleaning fluid can be sprayed onto the entire wafer surface of the target wafer without giving the surface from various angles. Therefore, as in the past, while using the ultrasonic cleaning method for improving the cleaning capability, the simple device control for maintaining the main device wiring pattern direction of the target wafer in parallel with the first ejection direction can be performed on the wiring pattern. It is possible to suppress physical damage.

  Further, in the wafer cleaning method according to the present invention, ultrasonic waves are applied while the jetting unit swings the jetting port in a direction perpendicular to the first jetting direction on a plane parallel to the wafer surface of the target wafer. A second feature is that the fluid is sprayed onto the target wafer.

  According to the second feature of the wafer cleaning method of the present invention, the side wall surface of the device wiring extending in the main device wiring pattern direction while maintaining the parallel relationship between the main device wiring pattern direction and the first injection direction. In contrast, the cleaning fluid to which ultrasonic waves are applied can be applied, so that the effect on the shape of the device wiring pattern is suppressed and the removal efficiency of foreign substances such as reaction products formed on the pattern side wall surface is improved. Can be made.

  Further, in addition to the first or second feature, the wafer cleaning method according to the present invention, after the completion of the first step and before the start of the second step, rotates the wafer chuck while rotating the wafer chuck. A third feature is that the method includes a step of ejecting the fluid to which no ultrasonic wave is applied to the target wafer.

  According to the third feature of the wafer cleaning method of the present invention, the shape of the device wiring pattern is obtained by performing cleaning without using ultrasonic waves on the entire wafer surface before performing cleaning with ultrasonic waves. The ability to clean the wafer surface of the target wafer can be improved while suppressing the influence on the wafer.

  The wafer cleaning method according to the present invention has a fourth feature that, in addition to any one of the first to third features, the orientation specifying mark is a notch or an orientation flat.

  According to the fourth feature of the wafer cleaning method of the present invention, since the orientation specifying mark attached in the existing semiconductor process can be used, the main device wiring pattern direction can be obtained without introducing new equipment. Recognition is possible.

  According to the configuration of the present invention, it is possible to provide a wafer cleaning apparatus and a wafer cleaning method capable of improving the ability to remove foreign matters formed on a wafer while suppressing physical damage to the wiring pattern shape.

  Hereinafter, embodiments of a wafer cleaning apparatus according to the present invention (hereinafter referred to as “the present invention apparatus” as appropriate) and a wafer cleaning method (hereinafter referred to as “the present invention method” as appropriate) will be described with reference to the drawings. To do.

[First Embodiment]
A first embodiment of the device of the present invention and the method of the present invention (hereinafter referred to as “this embodiment” as appropriate) will be described with reference to FIGS. In the following drawings, the same components as those described in the conventional configuration are denoted by the same reference numerals, and the description thereof is simplified.

  FIG. 1 is a schematic configuration diagram of the apparatus of the present invention. The apparatus 1 of the present invention shown in FIG. 1 includes a wafer chuck 12, a rotating shaft 13, a pattern direction recognition unit 14, an ejection unit 15, and an ultrasonic application unit 19.

  The wafer chuck 12 is a mounting table for mounting a semiconductor wafer 11 (hereinafter referred to as “target wafer” as appropriate) 11 to be cleaned, and a rotating shaft 13 connected perpendicularly to the mounting surface. The configuration is such that the target wafer 11 placed on the placement surface can be rotated.

  The pattern direction recognition unit 14 includes a transmission laser irradiation unit, a light reception unit, and the like. A mark (hereinafter referred to as “azimuth”) for specifying a crystal orientation such as a notch and an orientation flat attached to the mounted target wafer 11. And the pattern direction of the device wiring pattern formed on the wafer is recognized based on the recognition result.

  In general, a semiconductor wafer formed of single crystal silicon has a certain orientation in an arranged crystal. Since a later process formation step is performed based on this crystal orientation, as a marker for suggesting the crystal orientation, usually in a step of manufacturing (cutting) a semiconductor wafer from an ingot, a part on the wafer A defect portion (notch) is provided, or a substantially linear flat portion (orientation flat, orientation flat) is provided on a part of the wafer surface. At the time of mask alignment in the lithography process in the subsequent process, alignment is performed based on the positions of these notches or orientation flats.

  The pattern direction recognizing means 14 irradiates the target wafer 11 with a transmission laser and receives and analyzes the reflected light from the wafer surface, thereby recognizing the position of the notch or orientation flat (orientation specifying mark). Then, the crystal orientation is recognized based on the recognized position of the orientation specifying mark. As described above, since the process forming step is performed based on the crystal orientation, the main device wiring pattern direction of the device formed on the target wafer 11 can be recognized as a result of recognizing the crystal orientation. Here, the main device wiring pattern direction means the longitudinal direction of the main wiring pattern, and specifically, for example, among the wiring patterns formed on the uppermost layer of the target wafer 11 placed thereon. The direction with the largest number of wires extending in the same direction may be defined as the “main device wiring pattern direction”, and the direction with the longest total wiring length of the wires extending in the same direction may be defined as “the main device wiring pattern direction”. It may be defined as “device wiring pattern direction”.

  Usually, since a device is formed while performing alignment with the orientation specifying mark as a reference so that the wiring pattern direction is a constant direction, the main device wiring pattern direction is specified based on the position of the orientation specifying mark. It is possible. Information on the positional relationship between the main device wiring pattern direction and the orientation specifying mark (hereinafter referred to as “wafer information”) is registered in advance for each target wafer 11, and the pattern direction recognition means 14 recognizes the information. The main device wiring pattern direction of the target wafer 11 is recognized on the basis of the position information of the orientation specifying mark and the above-described wafer information.

  The ejection unit 15 ejects a fluid (chemical solution, pure water, etc.) for cleaning the target wafer 11 from the ejection port 15a. Here, the fluid ejected from the ejecting means 15 is configured to be able to apply ultrasonic waves output from the ultrasonic applying means 19. Note that whether or not to apply an ultrasonic wave to the fluid ejected from the ejecting means 15 is selectable.

  Here, the ejection unit 15 is configured to eject the fluid while moving in at least one direction (hereinafter referred to as “ejection unit movement direction”). It is also possible to eject the fluid while swinging the ejection port 15a in a direction orthogonal to the direction of movement of the ejection means on a plane parallel to the wafer surface of the target wafer. That is, the ejection unit 15 can eject the fluid while swinging the ejection port 15a to the left and right.

  The method of the present invention for cleaning the target wafer 11 using the apparatus 1 of the present invention configured as described above will be described below. FIG. 2 is a flowchart describing the method of the present invention in the order of each process, and each step in the following description represents each step on the flowchart of FIG.

  First, semiconductor wafers to be cleaned are carried one by one into the cleaning processing chamber (wafer carry-in process, step # 1). The loaded semiconductor wafer (target wafer 11) is placed on the wafer chuck 12, and the wafer chuck 12 is rotated from the ejecting means 15 while rotating the wafer chuck 12 by the rotating shaft 13 in a fixed state. A cleaning fluid (chemical solution, pure water) is sprayed onto the surface (pre-cleaning step, step # 2). In this step, for example, the rotation speed of the wafer chuck 12 is set to 500 rpm at the time of chemical injection, and the rotation speed is set to 2000 rpm at the time of pure water injection.

  The process related to Step # 2 is the same as the conventional cleaning method shown in FIG. 8, but unlike the conventional method, ultrasonic waves are not applied to the cleaning fluid in this step. That is, in the cleaning process of this step, there is no problem such as partial omission of the pattern shape due to the influence of ultrasonic waves unlike the conventional method.

  When the pre-cleaning process according to Step # 2 is completed, the pattern direction recognition unit 14 recognizes the main device wiring pattern direction of the target wafer 11, and the main device wiring pattern direction recognized and the cleaning device sprayed from the spraying unit 15 are used. A direction related to the parallel component (hereinafter referred to as a “first injection direction”) when the fluid ejection direction is decomposed into a parallel component and a vertical component with respect to the wafer surface of the target wafer has a parallel relationship. Thus, the direction of the target wafer 11 is set (wafer mounting direction setting step, step # 3).

  Specifically, the pattern direction recognizing means 14 is used while the wafer chuck 12 is rotated by the rotating shaft 13 (for example, the rotation speed is set to about 10 rpm) while the target wafer 11 is fixed on the wafer chuck 12. The position of the orientation specific mark (notch, orientation flat, etc.) is detected by irradiating the wafer 11 with a transmission laser and analyzing the reflected light from the target wafer 11. Next, the main pattern direction of the device wiring pattern formed on the target wafer 11 (hereinafter referred to as “main device wiring pattern direction”) is recognized based on the detection position of the orientation specifying mark, and the main device wiring pattern is recognized. The wafer chuck 12 (and its wafer chuck) with the detection position of the azimuth specifying mark set to a reference position of 0 ° (reference angle) so that the direction and the first ejection direction of the fluid ejected from the ejection means 15 are parallel to each other. The target wafer 11) placed on the substrate 12 is rotated within a range of ± 180 °. In this case, for example, in the control means (not shown) for controlling the rotation of the wafer chuck 12, the first jetting direction of the fluid jetted from the jetting means 15 is stored in advance, and the recognition from the pattern direction recognition means 14 is performed. Based on the result, the rotation angle of the wafer chuck 12 can be determined so that the main device wiring pattern direction and the first injection direction are in a parallel relationship.

  Next, in the state where the first ejection direction and the main device wiring pattern direction are set to be in a parallel relationship in step # 3, the ejection unit 15 applies the ultrasonic wave applied by the ultrasonic application unit 19 Are sprayed obliquely downward with respect to the target wafer 11 at a fixed angle with respect to the wafer surface (main cleaning step, step # 4). At this time, the ejecting means 15 ejects the fluid while moving while maintaining the parallel relationship between the first ejection direction and the main device wiring pattern direction so that the ejected fluid spreads over the entire surface of the target wafer 11. . Furthermore, at this time, in order to effectively remove the reaction product generated on the side wall portion of the device wiring pattern, the fluid is ejected while the ejection port 15a is appropriately swung in the direction orthogonal to the ejection direction.

  As an example of the injection conditions at this time, the flow rate of the chemical solution is 0.6 liter / minute, the angle of the injection port 15a with respect to the wafer surface is 30 °, and the height of the injection port 15a is 30 mm. Can have a frequency of 3 MHz and an input power of 0.7 W. The ultrasonic wave application conditions may be changed for each device wiring pattern formed on the target wafer 11. On the other hand, the injection condition can be set to a constant condition regardless of the device wiring pattern.

  3 and 4 are conceptual diagrams for explaining the wafer cleaning process according to Step # 4. FIG. 3 is a side view of the device 1 of the present invention during cleaning, and FIG. 4 is the present invention during cleaning. It is the figure which looked at the apparatus 1 from the top.

  As shown in FIG. 3, in step # 4, the parallel relationship is maintained in a state in which the first injection direction d0 and the main device wiring pattern direction d2 are set in parallel in step # 3. At the same time, the cleaning fluid 16 is sprayed onto the target wafer 11 while moving the spraying means 15 in the spraying means moving direction d1 (for example, at a moving speed of about 25 mm / second). For example, when there is a notch on the end edge w2 side, the injection means 15 is moved from the end edge w1 side where the notch is not formed until the end edge w2 completely passes under the injection means 15. The fluid is ejected while That is, it is assumed that the ejection unit 15 ejects the fluid 16 while moving a distance equal to or larger than the diameter of the target wafer. As a result, the cleaning fluid 16 can be spread over the entire range of the target wafer 11 in the main device wiring pattern direction (the range from the end edge w1 to the opposite end edge w2 in FIG. 3).

  When the fluid 16 is injected, as shown in FIG. 4, the injection port 15a is set within a predetermined swing range in a direction d3 orthogonal to the first injection direction d0 of the injection means 15. By ejecting the fluid while swinging at a swing speed (for example, about 50 mm / second), the fluid can be distributed to the side wall portion 18a of the device wiring pattern 18, and the reaction generated on the side wall portion 18a. The removal efficiency of things can be improved. Hereinafter, the direction d3 is appropriately described as a “swinging direction d3”.

  FIG. 5 is a conceptual diagram for explaining a method of calculating the oscillation width of the injection port 15a. In FIG. 5, u1 is the diameter of the target wafer 11, u2 is the minimum interval between the installed injection ports 15a, and u3 is a half value of the minimum installation interval between the injection ports 15a (u3 = u2 / 2). , U4 is the maximum installation interval between the injection ports 15a installed on the outermost side, and u5 is 1 / of the value obtained by subtracting the maximum installation interval (u4) between the injection ports 15a from the diameter (u1) of the target wafer 11. Two values (u5 = (u1-u4) / 2) are shown.

  In the configuration shown in FIG. 5, the device 1 of the present invention sets the larger one of u3 and u5 as the minimum value of the swing width D of the injection port 15a. For example, when the diameter (u1) of the target wafer 11 is 200 mm, the minimum interval (u2) between the injection ports 15a is 30 mm, and the maximum interval (u4) between the outermost injection ports 15a is 150 mm (30 mm × 5) , U3 = u2 / 2 = 15 mm and u5 = (u1−u4) / 2 = 25 mm, so that u5> u3 and the minimum value of the swing width D of the injection port 15a is set to 25 mm. Thereby, a sufficient fluid can be given also to the side wall part 18a of the device wiring pattern 18, and the removal efficiency of the reaction product formed in the side wall part 13a can be improved.

  That is, in this step # 4, the wiring pattern shape is affected by ejecting the fluid 16 onto the target wafer 11 while moving a distance equal to or larger than the diameter of the target wafer 11 with respect to the ejection unit moving direction. In addition, the entire wafer surface can be cleaned, and further, spraying is performed while swinging the spray port 15a in the left-right direction within the range of the predetermined swinging width D, so that the main device wiring pattern direction can be obtained. The removal efficiency of reaction products generated on the side wall portion of the formed wiring pattern can be improved.

  In the case where the injection direction of the injection port 15a can be changed, as described above, the fluid 16 was injected while moving the injection means 15 from the end edge w1 to the end edge w2 in FIG. After (first main cleaning step), the injection means 15 is moved in the opposite direction (from the edge w2 to the edge w1) while changing the injection direction and inverting the first injection direction d0 by 180 °. However, the fluid 16 may be ejected again (second cleaning step). As a result, even if there is a region where the device wiring pattern becomes a wall in the first cleaning process and cannot be sufficiently cleaned, the second cleaning process can clean the region, and the target wafer 11 can be cleaned over the entire surface.

  In the case where the injection direction of the injection port 15a cannot be changed, the injection means 15 is once returned to the position before the start of the first main cleaning step with the injection direction kept unchanged, and then the wafer chuck 12 Is rotated 180 °, and the position of the target wafer 11 is changed so that the edge w2 in FIG. 3 is located on the ejection unit 15 side and the edge w1 is located on the opposite side of the ejection unit 15. By performing the same cleaning process as the first main cleaning process again, the same effect as the second main cleaning process can be obtained.

  After completion of the main cleaning process in Step # 4, the ultrasonic application unit 19 was stopped, and the movement of the injection unit 15, the oscillation of the injection port 15a, and the injection of the fluid 16 from the injection port 15a were stopped. In this state, the target wafer 11 after cleaning is dried while rotating the target wafer 11 by rotating the wafer chuck 12 (drying step, step # 5).

  Note that, in the main cleaning process of step # 4, when the ejection unit 15 ejects the fluid 16 while swinging the ejection port 15a left and right, each of the plurality of ejection ports 15a included in the ejection unit 15 is different from the other ejection ports. The structure may be configured to swing independently from side to side, or the structure of the injection port mechanism in which all the injection ports 15a are integrated may swing from side to side as a whole.

  Further, the swinging direction d3 of the injection port 15a and the first injection direction d0 of the injection means 15 do not have to be completely orthogonal, but may be in a substantially perpendicular direction. Specifically, the angle formed by the swing direction d3 of the injection port 15a and the first injection direction d0 of the injection unit 15 may be within a range of approximately 75 ° to 105 °.

[Second Embodiment]
Hereinafter, a second embodiment of the device of the present invention and the method of the present invention (hereinafter referred to as “this embodiment” as appropriate) will be described with reference to FIGS. 6 and 7. Note that the present embodiment is different from the first embodiment only in the main cleaning process according to Step # 4 in FIG. 2, and the other processes are the same as those in the first embodiment. Below, only a different point from 1st Embodiment is demonstrated.

  6 and 7 are conceptual diagrams for explaining the wafer cleaning process according to Step # 4 in this embodiment. FIG. 6 is a side view of the device 1 of the present invention during cleaning, and FIG. It is the figure which looked at the present invention device 1 from the top.

  The device 1 of the present invention in the present embodiment is configured so that the wafer chuck 12 can move with the target wafer 11 placed thereon. Then, in the main cleaning process in Step # 4, the parallel relationship between the first ejection direction and the main device wiring pattern direction is maintained so that the fluid ejected from the ejection unit 15 is spread over the entire surface of the target wafer 11. By moving (or expanding and contracting) the wafer chuck 12, the fluid 16 is ejected from the ejection means 15 to the target wafer 11 in a state where the target wafer 11 is moved along with the movement. As in the first embodiment, in order to effectively remove reaction products generated on the side wall portion of the device wiring pattern, the fluid is ejected while the ejection port 15a is appropriately swung in the direction orthogonal to the ejection direction. I do.

  According to the configuration of the present embodiment, the wafer chuck 12 is moved a distance equal to or larger than the diameter of the target wafer 11 while maintaining the parallel relationship between the first injection direction and the main device wiring pattern direction. By ejecting the fluid 16 while changing the position of the ejection destination of the fluid 16 from the ejecting means 15, as in the first embodiment, cleaning is performed on the entire wafer surface without affecting the wiring pattern shape. Can do. Further, by performing injection while swinging the injection port 15a in the left-right direction, it is possible to improve the removal efficiency of reaction products generated on the side walls of the wiring pattern formed in the main device wiring pattern direction. .

  In FIG. 6, after the wafer chuck 12 is moved, the fluid 16 is ejected while moving the ejection destination position of the fluid 16 from the ejecting means 15 from the end edge portion w1 to the end edge portion w2. (Main cleaning step), the wafer chuck 12 is rotated by 180 °, the wafer chuck 12 is moved again, and the fluid 16 from the ejecting means 15 is moved again from the edge w1 to the edge w2. In the case where there is a region where the device wiring pattern becomes a wall in the first main cleaning step and sufficient cleaning cannot be performed, as in the first embodiment, by adopting the configuration of performing 16 injections (second main cleaning step) Even so, the region can be cleaned by the second main cleaning process, and the entire surface of the target wafer 11 can be cleaned.

  In the present embodiment, the moving speed of the wafer chuck 12 may be approximately the same as the moving speed of the spraying unit 15 in the first embodiment described above, and other spraying conditions (swing speed and swing of the spraying port 15a). The moving width (including the moving width) and ultrasonic application conditions may be the same as those in the first embodiment.

  Further, in the present embodiment, it is also possible to adopt a configuration in which the ejecting means 15 is moved together with the wafer chuck 12 in the main cleaning step as in the first embodiment. In this case, the moving speeds of the wafer chuck 12 and the ejecting means 15 may be set so that the relative speed of the ejecting means 15 when viewed from the wafer chuck 12 is approximately equal to the moving speed of the ejecting means 15 in the first embodiment.

  Furthermore, in this embodiment, the wafer chuck 12 itself is moved. However, the target wafer 11 is placed on a movable placement mechanism (wafer transfer arm or the like) that is different from the wafer chuck 12. The main cleaning process (step # 4) may be performed while moving the wafer 11.

[Another embodiment]
In each of the above-described embodiments, in the main cleaning process in Step # 4, the ejection unit 15 or the wafer chuck 12 (a mounting table on which the target wafer 11 is placed) is placed between the first ejection direction and the main device wiring pattern direction. The cleaning fluid 16 is jetted while the jet port 15a is swung left and right (in a direction orthogonal to the first jetting direction) while being moved while maintaining the parallel relationship. The injection port 15a may not be rocked. Even in this case, it is possible to clean the entire wafer surface while suppressing the influence on the shape of the device wiring pattern. However, in order to sufficiently improve the foreign substance removal ability of the reaction product formed on the side wall surface of the device wiring pattern, the cleaning is performed by ejecting the fluid 16 while swinging the ejection port 15a left and right. It is preferable.

  <2> In each of the above-described embodiments, the case where one direction can be recognized as the main device wiring pattern direction of the device formed on the target wafer 11 has been described in a limited manner, but the main device wiring pattern direction is When formed in two orthogonal directions, specifically, when device wiring patterns having approximately the same number or approximately the same total wiring length are formed in two orthogonal directions, both of these directions are used. Alternatively, the main cleaning process may be performed. Specifically, first, one of the recognized two directions is defined as the “main device wiring pattern direction”, and the main cleaning process of Step # 4 is performed. Next, after rotating the wafer chuck 12 by 90 ° and changing the other direction to the “main device wiring pattern direction” so as to be parallel to the first injection direction, the main cleaning process of step # 4 is similarly performed. Do. By performing the cleaning in this manner, the target wafer 11 can be effectively cleaned while suppressing the influence on the wiring pattern shape as much as possible even when there are a plurality of main device wiring pattern directions.

Schematic configuration diagram of a wafer cleaning apparatus according to the present invention The flowchart which shows the wafer cleaning method which concerns on this invention in order of each process Schematic diagram for explaining one cleaning step according to the first embodiment of the wafer cleaning method of the present invention. Schematic diagram for explaining one cleaning step according to the first embodiment of the wafer cleaning method of the present invention. Conceptual diagram for explaining a method of calculating the oscillation width of the injection port The conceptual diagram for demonstrating one cleaning process which concerns on 2nd Embodiment of the wafer cleaning method which concerns on this invention. The conceptual diagram for demonstrating one cleaning process which concerns on 2nd Embodiment of the wafer cleaning method which concerns on this invention. Conceptual diagram for explaining a single wafer type wafer cleaning process of a conventional configuration Another conceptual diagram for explaining a single wafer type wafer cleaning process of a conventional configuration

Explanation of symbols

1: Cleaning device according to the present invention 11: Semiconductor wafer (target wafer)
12: Wafer chuck 13: Rotating shaft 14: Pattern direction recognition means 15: Injection means 15a: Injection port 16: Fluid (for cleaning) 18: Device wiring pattern 18a: Device wiring pattern side wall portion 19: Ultrasonic application means 30: Cleaning Device 31: Control means d0: First injection direction d1: Injection means movement direction d2: Main device wiring pattern direction d3: Injection port swing direction u1: Diameter of target wafer u2: Minimum interval between injection ports u3: Minimum injection port 1/2 value of interval u4: Maximum interval of injection port u5: 1/2 value of value obtained by subtracting maximum interval of injection port from diameter of target wafer w1: Wafer edge w2: Wafer edge

Claims (7)

A single wafer cleaning device,
A wafer chuck on which a target wafer to be cleaned is placed, and rotatable about an axis perpendicular to the placement surface;
Pattern direction recognition means for recognizing a main device wiring pattern direction of a device formed on the target wafer;
Jetting means for jetting a cleaning fluid;
Ultrasonic application means capable of applying ultrasonic waves to the fluid ejected from the ejection means,
When the target wafer is placed on the wafer chuck,
The pattern direction recognizing unit recognizes an orientation specifying mark attached on the target wafer in order to specify a crystal orientation, and the main device wiring based on an installation position of the orientation specifying mark on the target wafer Recognize the pattern direction,
The wafer chuck is configured such that the main device wiring pattern direction recognized by the pattern direction recognition means, and the jet direction of the fluid jetted from the jetting means are parallel and perpendicular to the wafer surface of the target wafer. Rotate until the first injection direction related to the parallel component when broken down into a parallel relationship,
Either or both of the jetting unit and the wafer chuck move while maintaining the parallel relationship, so that the position of the jetting destination of the fluid jetted from the jetting unit on the target wafer changes. Below, the said cleaning means sprays the said fluid to which the ultrasonic wave was applied toward diagonally downward with respect to the said object wafer, The wafer cleaning apparatus characterized by the above-mentioned.   The jetting unit jets the fluid to which the ultrasonic wave is applied to the target wafer while swinging the jetting port in a direction orthogonal to the first jetting direction on a plane parallel to the wafer surface of the target wafer. The wafer cleaning apparatus according to claim 1, wherein:   3. The wafer cleaning apparatus according to claim 1, wherein the orientation specifying mark is a notch or an orientation flat. A single wafer cleaning method,
A first step of placing a target wafer to be cleaned on a wafer chuck that is rotatable about an axis perpendicular to the placement surface;
The main device of the device formed on the target wafer by recognizing the orientation specifying mark for specifying the crystal orientation attached on the mounted target wafer and based on the installation position of the orientation specifying mark A second step of recognizing the wiring pattern direction;
The first ejection relating to the parallel component when the main device wiring pattern direction and the ejection direction of the cleaning fluid ejected from the ejection means are decomposed into a parallel component and a vertical component with respect to the wafer surface of the target wafer. A third step of rotating the wafer chuck so that the direction is parallel to the direction;
While changing one or both of the jetting means and the wafer chuck while maintaining the parallel relationship, while changing the position of the jetting destination of the fluid jetted from the jetting means on the target wafer, And a fourth step of ejecting the fluid, to which ultrasonic waves are applied, obliquely downward from the ejection means to the target wafer.   The jetting unit jets the fluid to which the ultrasonic wave is applied to the target wafer while swinging the jetting port in a direction orthogonal to the first jetting direction on a plane parallel to the wafer surface of the target wafer. The wafer cleaning method according to claim 4, wherein:   After the first step, and before the start of the second step, the step of ejecting the fluid to which no ultrasonic wave is applied to the target wafer from the ejection unit while rotating the wafer chuck. The wafer cleaning method according to claim 4 or 5.   The wafer cleaning method according to claim 4, wherein the orientation specifying mark is a notch or an orientation flat.