Abstract:
A single-wafer-type cleaning apparatus is provided. The single-wafer-type cleaning apparatus is configured to be capable of controlling electrostatic charges generated s due to rotating a wafer during a semiconductor cleaning process and a defect caused by the electrostatic charges. The cleaning process uses an ionizer mounted on a chuck.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2015-0001264 filed on Jan. 6, 2015, the disclosure of which is hereby incorporated by reference in its entirety. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Embodiments of the inventive concepts relate to a single-wafer-type cleaning apparatus which cleans a wafer by rotating the wafer. 
         [0004]    2. Description of Related Art 
         [0005]    Generally, semiconductor devices are manufactured by repeatedly performing various unit processes such as deposition, photolithography, etching, polishing, and cleaning. 
         [0006]    When these unit processes are performed, the cleaning process is performed to remove residues, small particles, contaminants, or unnecessary layers remaining on the surface of a wafer. Recently, the importance of the cleaning process has been further increased as a pattern formed on a wafer is miniaturized. 
         [0007]    The cleaning process includes chemically or physically separating contaminants from a wafer, rinsing, and drying. In the cleaning process, circuits and/or films included in a wafer can be damaged when charges accumulated in the wafer are discharged. 
       SUMMARY 
       [0008]    Example embodiments of the inventive concepts provide a single-wafer-type cleaning apparatus including an ionizer. 
         [0009]    Example embodiments of the inventive concepts provide a wafer cleaning method which controls defects generated in a manufacturing process of a semiconductor device by controlling electrostatic charges generated in a single-wafer-type wafer cleaning process. 
         [0010]    In accordance with example embodiments of the inventive concepts, a single-wafer-type cleaning apparatus may include a chamber, a chuck disposed in the chamber, an ionizer mounted on the chuck and configured to generate ions, at least one cleaning chemical dispensing nozzle disposed in the chamber, and a wafer fixing part disposed on the chuck. 
         [0011]    In some embodiments, the ions generated from the ionizer may be emitted onto a back surface of a wafer fixed on the wafer fixing part to neutralize charged particles accumulated in the wafer. 
         [0012]    In some embodiments, the ionizer may generate the ions using a corona method, a piezo high frequency alternating current (HF-AC) method, or an X-ray method. 
         [0013]    In some embodiments, a voltage using a HF-AC or a pulsed AC method may be applied to the ionizer. 
         [0014]    In some embodiments, ionizer may have at least one of a bar type, a ring type, and a radial type. 
         [0015]    In some embodiments, the chuck may include a non-rotating body disposed at a center of the chuck and a rotating body configured to surround the non-rotating body. 
         [0016]    In some embodiments, the ionizer may be mounted on the non-rotating body. 
         [0017]    In some embodiments, the cleaning chemical dispensing nozzle may include a first cleaning chemical dispensing nozzle configured to spray a cleaning chemical onto a front surface of a wafer disposed on the fixed on the wafer fixing part. 
         [0018]    In some embodiments, the cleaning chemical dispensing nozzle may include a second cleaning chemical dispensing nozzle configured to spray the cleaning chemical onto the back surface of the wafer. 
         [0019]    In some embodiments, the single-wafer-type cleaning apparatus may further include an air supplier injecting air toward the front surface of the wafer. 
         [0020]    In some embodiments, the chuck may further include a ground peak being in contact with a wafer fixed on the wafer fixing part. 
         [0021]    In accordance with example embodiments of the inventive concepts, a method for treating a wafer may include loading a wafer on a chuck including an ionizer mounted thereon, generating ions from the ionizer, emitting the ions onto a back surface of the wafer to neutralize charged particles accumulated in the wafer, and cleaning the wafer. 
         [0022]    In some embodiments, cleaning the wafer may include spraying a cleaning chemical onto the wafer through at least one chemical dispensing nozzle. 
         [0023]    In some embodiments, the chuck may include a rotating body and a non-rotating body, and the ionizer may be mounted on the non-rotating body. 
         [0024]    In some embodiments, the single-wafer-type cleaning apparatus may rotate the wafer with the rotating body, and generate ions from the ionizer. 
         [0025]    In accordance with example embodiments of the inventive concept, a single-wafer-type cleaning apparatus may include a chamber, a chuck disposed in the chamber and including a rotating body and a non-rotating body, a ionizer disposed on the non-rotating body and configured to generate ions, a wafer fixing part disposed on the rotating body, and a cleaning chemical spray part including a first cleaning chemical dispensing nozzle configured to spray cleaning chemical onto a front surface of the wafer disposed on the wafer fixing part. 
         [0026]    In some embodiments, the single-wafer-type cleaning apparatus may include a second cleaning chemical dispensing nozzle disposed on the non-rotating body configured to spray a cleaning chemical onto the back surface of the wafer. 
         [0027]    In some embodiments, the single-wafer-type cleaning apparatus may further include a conductive ground peak disposed on the rotating body and configured to contact the back surface of the wafer disposed on the wafer fixing part and a ground wire embedded in the chuck. 
         [0028]    In some embodiments, the single-wafer-type cleaning apparatus may further include a motor and a motor shaft configured to rotate the rotating body, and the ground wire may be electrically connected to the motor shaft. 
         [0029]    In some embodiments, the ground peak may include the wafer fixing part coated with a conductive material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The foregoing and other features and advantages of the inventive concepts will be apparent from the more particular description of preferred embodiments of the inventive concepts, as illustrated in the accompanying drawings in which like reference numerals denote the same respective parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the inventive concepts. In the drawings: 
           [0031]      FIGS. 1 and 6 through 8  are cross sectional views respectively illustrating single-wafer-type cleaning apparatuses according to example embodiments of the inventive concepts; 
           [0032]      FIGS. 2 through 5  are top views respectively illustrating various types of ionizers mounted on chucks of single-wafer-type cleaning apparatuses according to example embodiments of the inventive concepts; and 
           [0033]      FIG. 9  is a flow chart illustrating a wafer cleaning method using the single-wafer-type cleaning apparatus according to example embodiments of the inventive concepts. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0034]    Advantages and features of the inventive concepts and methods of achieving the same will be clearly understood with reference to the accompanying drawings and the following detailed embodiments. However, the inventive concepts are not limited to the embodiments to be disclosed, but may be implemented in various different forms. The embodiments are provided in order to fully explain the inventive concepts and fully explain the scope of the inventive concepts to those skilled in the art. Accordingly, the scope of the inventive concepts is defined by the appended claims. 
         [0035]    The terminology used here is for describing particular example embodiments only and is not intended to be limiting. As used here, the singular forms “a,” “an,” and “the” are intended to include plural forms as well unless the context clearly indicates otherwise. 
         [0036]    It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and/or components. 
         [0037]    The example embodiments of the inventive concepts will be described with reference to cross-sectional views and/or plan views which are ideal exemplary views. In the drawings, elements and thicknesses of areas are exaggerated for effective illustrations of the technical concept. Forms of the embodiments may be modified by the manufacturing technology and/or tolerance. Therefore, the embodiments of the invention are not intended to be limited to illustrated specific forms, and include modifications of forms generated according to the manufacturing processes. For example, an area illustrated as a rectangle will, typically, have rounded or curved features. Therefore, areas illustrated in the drawings have overview properties, shapes of the areas are illustrated special forms of the areas of a device, and are not intended to limit the scope of the inventive concepts. 
         [0038]    Like numbers refer to like elements throughout. Thus, the same or similar numbers may be described with reference to other drawings even if they are neither mentioned nor described in the corresponding drawing. Also, elements that are not denoted by reference numbers may be described with reference to other drawings. 
         [0039]      FIG. 1  is a cross sectional view illustrating schematically a single-wafer-type cleaning apparatus according to example embodiments of the inventive concepts.  FIGS. 2 through 5  are top views respectively illustrating various types of ionizers mounted on chucks of the single-wafer-type cleaning apparatuses according to example embodiments of the inventive concepts. 
         [0040]    Referring to  FIGS. 1 and 2 through 5 , the single-wafer-type cleaning apparatus  10  according to the example embodiments of the inventive concepts may include a chamber  20 , a chuck  50  disposed in the chamber  20 , ionizers  40  disposed on the chuck  50 , and a wafer fixing part  31  disposed on the chuck  50 . The chuck  50  may include a non-rotating body  52  disposed at the center of the chuck and a rotating body  51  surrounding the non-rotating body  52 . The rotating body  51  may have an annular or disk shape, and the non-rotating body  52  may have a circle or disk shape. 
         [0041]    The single-wafer-type cleaning apparatus  10  may further include a first cleaning chemical dispensing nozzle  61  disposed on the non-rotating body  52 . The first cleaning chemical dispensing nozzle  61  may protrude from an upper surface of the non-rotating body  52  of the chuck  50 . The first cleaning chemical dispensing nozzle  61  may spray a cleaning chemical on a back surface  30   b  of a wafer  30  disposed on the wafer fixing part  31 . 
         [0042]    In some embodiments, the wafer  30  may include at least one film formed on the front surface  30   a  of the wafer  30 . The first cleaning chemical dispensing nozzle  61  may include an upper end part at a level lower than an upper end part of the wafer fixing part  31 . 
         [0043]    The first cleaning chemical dispensing nozzle  61  may be spaced apart from the wafer  30 . The cleaning chemical may comprise various types of chemicals according to a cleaning or etching process. For example, the cleaning chemical may include ammonia (NH 4 OH), hydrogen peroxide (H 2 O 2 ), diluted hydrochloric acid (HCl), diluted sulfuric acid (H 2 SO 4 ), and diluted hydrofluoric acid (HF), or a combination thereof. 
         [0044]    The cleaning chemical may be sprayed onto the center of the back surface  30   b  of the rotating wafer  30 . The cleaning chemical may be entirely spread on the back surface  30   b  of the wafer  30  by centrifugal force. 
         [0045]    The first cleaning chemical dispensing nozzle  61  may be connected to a first cleaning chemical supply pipe  63   c  passing through the non-rotating body  52 . The first cleaning chemical supply pipe  63   c  may supply the cleaning chemical to the first cleaning chemical dispensing nozzle  61  from a cleaning chemical tank  64  located outside of the chamber  20 . 
         [0046]    The ionizer  40  may be mounted on the chuck  50 . For example, the ionizer  40  may be mounted on the non-rotating body  52 . The ionizer  40  may be connected to an ionizer controller  43  located outside of the chamber  20  through a voltage supply wire  42  passing through the non-rotating body  52  of the chuck  50 . 
         [0047]    The ionizer controller  43  denotes all devices which may adjust the voltage supply state of the ionizer  40 . The ionizer  40  may generate ions using a corona method, a piezo high frequency alternating current (HF-AC) method, or an X-ray method. The ionizer  40  may be applied with a voltage using a HF-AC or pulsed AC method. 
         [0048]    The ionizer  40  may be driven to the extent where an amount of charge of a charged object (e.g., a wafer) is offset, may be detached from, mounted on, or fixed on the upper surface of the chuck  50 , and may be made in the required shape. 
         [0049]    As shown in  FIG. 2 , the ionizer  40  may include a bar-type ionizer  40   a.  The bar-type ionizer  40   a  may be mounted on the non-rotating body  52  of the chuck  50 . 
         [0050]    When the wafer  30  is fixed on the chuck  50  by the wafer fixing part  31 , the bar-type ionizer  40   a  may generate ions through an ion generating part  41  when the rotating body  51  rotates. The ions generated from the bar-type ionizer  40   a  may be emitted toward the back surface  30   b  of the wafer  30 . For example, the ions may move to the back surface  30   b  of the wafer  30  along with a rotating air flow and/or an upstream air flow according to the rotation of the wafer  30 . The ions generated from the ionizer  40   a  may move toward an outside of the wafer from a center of the back surface  30   b  of the wafer  30 . Such movement has the positive effect of effectively neutralizing charged particles of which an amount of charge increases closer to the center of the wafer  30  as the wafer  30  is rotated rapidly. 
         [0051]    The upstream air flow may include a fluid flow pattern such as a vertical upstream air flow, a directional air flow, and a helical air flow. 
         [0052]    The bar-type ionizers  40   a  may be disposed at both sides of the first cleaning chemical dispensing nozzle  61 . 
         [0053]    In some embodiments, as shown in  FIG. 3 , the ionizer  40  may include a ring-type ionizer  40   b.  The ring-type ionizer  40   b  may be mounted on the non-rotating body  52  of the chuck  50 . The first cleaning chemical dispensing nozzle  61  may be the center point of the ring-type ionizer  40   b.    
         [0054]    In some embodiments, as shown in  FIG. 4 , the ionizer  40  may include a plurality of ring-type ionizers  40   c.  The plurality of the ring-type ionizers  40   c  may have a shape in which a plurality of ring shapes having different diameters are concentrically disposed around the first cleaning chemical dispensing nozzle  61 . Although  FIG. 4  shows the ionizer  40   c  in which two ring-type ionizers having different diameters are concentrically disposed, the ionizer  40   c  may have a shape in which three or more ring-type ionizers are concentrically disposed. 
         [0055]    In some embodiments, as shown in  FIG. 5  the ionizer  40  may include a radial-type ionizer  40   d.  The radial-type ionizer  40   d  may be mounted on the non-rotating body  52  of the chuck  50 . The radial-type ionizer  40   d  may include the plurality of bar-type ionizers  40   a  radially disposed around the first cleaning chemical dispensing nozzle  61 . 
         [0056]    Although  FIG. 5  shows the ionizer  40   d  having a shape in which  4  bars are radially disposed, at least three bars may be radially disposed around the first cleaning chemical dispensing nozzle  61 . 
         [0057]    The single-wafer-type cleaning apparatus  10  may further include a cleaning chemical recovery part  70  recovering the cleaning chemical leaving the wafer  30  when the wafer  30  rotates with the rotating body  51  in the chamber  20 . 
         [0058]    The cleaning chemical recovery part  70  may include a cleaning chemical recovering body  71 . The cleaning chemical recovering body  71  may be a device to recover and drain the cleaning chemical leaving the wafer  30 . 
         [0059]    The cleaning chemical recovering body  71  may be connected to a cleaning chemical storage part  73  through a cleaning chemical recovering pipe  72 . The cleaning chemical recovering pipe  72  may pass through the chamber  20  and be connected to the cleaning chemical storage part  73  disposed outside of the chamber  20 . 
         [0060]    Referring to  FIG. 6 , the single-wafer-type cleaning apparatus  10  according to the example embodiments of the inventive concepts may further include a ground part  80 . 
         [0061]    The ground part  80  may include a ground peak  81 , a ground wire  82 , and a motor shaft  83 . The ground peak  81  may be disposed at the side of the rotating body  51  of the chuck  50 , and may protrude from the surface of the rotating body  51 . 
         [0062]    The ground peak  81  may contact a side surface  30   c  of the wafer  30 , and may be electrically connected to the motor shaft  83  through the ground wire  82 . The chuck  50  may further include a motor (not shown) and the motor shaft  83  for rotating the rotating body  51 . 
         [0063]    The ground wire  82  may be embedded inside of the chuck  50 . The ground peak  81  may include carbon, silicon, or a metal. The ground wire  82  and the motor shaft  83  may include a conductive material. 
         [0064]    The ground peak  81  may be in contact with a back surface  30   b  of the wafer  30 . In some embodiments, the ground peak  81  may include the wafer fixing part  31  coated with a conductive material. 
         [0065]    Referring to  FIG. 7 , the single-wafer-type cleaning apparatus  10  according to the example embodiments of the inventive concepts may include an air supplier  90  including an air injecting part  91  jetting air in the chamber  20 . 
         [0066]    The air injecting part  91  may be spaced apart from the wafer  30 , and may inject air toward the front surface  30   a,  the side surface  30   c,  or the back surface  30   b  of the wafer  30 . Ions generated from the ionizer  40  and emitted toward the back surface  30   b  of the wafer  30  may be moved by riding the air flow injected from the air jet  91 . 
         [0067]    The air injecting part  91  may be located inside of the chamber  20 , pass through the chamber  20 , and be connected to an air storage part  93  outside of the chamber  20  through an air supplying pipe  92 . The air may include N 2 . The air may accelerate drying of the wafer  30 . 
         [0068]    Referring to  FIG. 8 , the single-wafer-type cleaning apparatus  10  according to the example embodiments of the inventive concepts may further include a second cleaning chemical dispensing nozzle  62  for spraying a cleaning chemical on the front surface  30   a  of the wafer  30 . 
         [0069]    The second cleaning chemical dispensing nozzle  62  may be connected to an outside cleaning chemical tank  64  outside of the chamber  20  through a second cleaning chemical supply pipe  63   e.  The first cleaning chemical dispensing nozzle  61  and the first cleaning chemical supply pipe  63   c  may share the cleaning chemical tank  64  located outside of the chamber  20  along with the second cleaning chemical dispensing nozzle  62  and the second cleaning chemical supply pipe  63   e.    
         [0070]    The chuck  50  in which an ionizer  40  of the single-wafer-type cleaning apparatus  10  according to the example embodiments of the inventive concepts is mounted may be applied to other types of single-wafer-type processing apparatuses (e.g., a coating apparatus, a thermal processing apparatus, or a polishing apparatus). 
         [0071]      FIG. 9  is a flow chart showing a wafer cleaning method using the wafer cleaning apparatus of  FIG. 1 through 8  according to example embodiments of the inventive concepts. 
         [0072]    Referring to  FIG. 9 , the wafer cleaning method according to the example embodiments of the inventive concepts may include loading a wafer  30  on the chuck  50  inside of the chamber of the cleaning apparatus  10  (S  10 ). For example, the wafer  30  including at least one film formed on the front surface  30   a  thereof may be disposed on the wafer fixing part  31  of the chuck  50 . 
         [0073]    The method may include rotating the wafer  30 , emitting ions to the back surface  30   b  of the wafer  30 , and neutralizing charged particles accumulated in the wafer  30  (S 20 ). For example, the wafer  30  is rotated by rotating the rotating body  51  of the chuck  50 , ions generated from the ionizer  40  mounted on the non-rotating body  52  of the chuck  50  including the rotating body  51  and the non-rotating body  52  are emitted to a back surface  30   b  of the wafer  30  by rotating the wafer  30 , and charged particles embedded in the films of the wafer  30  may be neutralized. The ionizer  40  may have one of the shapes shown in  FIGS. 2 through 5 . 
         [0074]    The method may include cleaning the wafer  30  using a cleaning chemical (S 30 ). For example, the wafer  30  may be cleaned by spraying a cleaning chemical on the front surface  30   a  and/or the back surface  30   b  of the wafer  30  through the first and/or second cleaning chemical dispensing nozzles  61  and/or  62 . Although the process of generating ions and the process of spraying a cleaning chemical may be performed simultaneously, it is not limited to this. In some embodiments, the process of generating ions may be started first, and then the process of generating ions and the process of spraying a cleaning chemical may be performed simultaneously. 
         [0075]    The method may include unloading the cleaned wafer  30  from the chuck  50  (S 40 ). For example, the method may include unloading the cleaned wafer  30  from the wafer fixing part  31  on the chuck  50 . The unloaded wafer  30  may be transferred to the outside of the chamber  20 . 
         [0076]    The cleaning chamber and/or the cleaning apparatus including a cleaning chamber according to example embodiments of the inventive concepts may be configured to effectively remove charged particles which are further accumulated at the center of the wafer when the wafer cleaning process is performed and thus, a defect rate in at least one film at the front side of the wafer due to electrostatic discharging of charged particles can be reduced. 
         [0077]    Although a few embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages. Accordingly, all such modifications are intended to be included within the scope of these inventive concepts as defined in the claims.