Abstract:
A cleaning apparatus and method are provided for the removal of contaminants from semiconductor processing equipment. An electrode to generate a cleaning plasma is provided within a processing chamber and a guide system is capable of moving the electrode over contaminated areas. Advantageously, the present invention saves cleaning time compared with a conventional cleaning method that requires the opening and cleaning of the chamber and also allows for increasing the interval between regular cleanings.

Description:
BACKGROUND  
       [0001]     (a) Field of the Invention  
         [0002]     The present invention relates to semiconductor processing, and in particular relates to an apparatus and method for cleaning of plasma-type manufacturing apparatus.  
         [0003]     (b) Description of Related Art  
         [0004]     A manufacturing method for a semiconductor device requires several apparatuses and equipment for thin film deposition, such as sputter deposition equipment or chemical vapor deposition (CVD) equipment, dry and wet etching equipment for patterning thin films, and photolithography equipment for forming photoresist patterns used as etching masks for patterning thin films.  
         [0005]     This type of equipment is disassembled and cleaned regularly in order to prevent disorder and to improve productivity.  
         [0006]     In particular, a dry etching apparatus significantly requires regular cleaning since it is easily contaminated by polymers of photoresist blown from semiconductor substrates that are combined with etching gases.  
         [0007]     For example, particles attached to a plasma chamber not only serve as a source of contamination but also change the condition of plasma required for dry etching, thereby deteriorating the reliability of semiconductor devices formed in semiconductor substrates.  
       SUMMARY  
       [0008]     The present invention provides an apparatus and method for cleaning and removing contaminants from equipment used in manufacturing semiconductor devices.  
         [0009]     In accordance with one embodiment, a cleaning apparatus is provided, comprising an electrode to generate cleaning plasma in a processing chamber, and a guide system operably coupled to the electrode, the guide system capable of moving the electrode within the processing chamber.  
         [0010]     In accordance with another embodiment, an apparatus for manufacturing a semiconductor device is provided, comprising a processing chamber including a first electrode, a cleaning apparatus within the processing chamber, the cleaning apparatus including a second electrode to generate cleaning plasma within the processing chamber in conjunction with the first electrode, and a guide system operably coupled to the second electrode, the guide system capable of moving the second electrode within the processing chamber.  
         [0011]     In accordance wit yet another embodiment, a method of cleaning a semiconductor processing apparatus is provided, comprising providing a processing chamber including a first electrode, and providing a cleaning apparatus within the processing chamber, the cleaning apparatus including a second electrode and a guide system operably coupled to the second electrode. The method further includes flowing a cleaning gas into the processing chamber, generating a cleaning plasma from the cleaning gas using the first and second electrodes, and applying the cleaning plasma to a contaminant on an interior surface of the processing chamber.  
         [0012]     Advantageously, the present invention saves cleaning time compared with a conventional cleaning method that requires the opening and cleaning of the chamber and also allows for increasing the interval between regular cleanings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The present invention will become more apparent by describing embodiments thereof in detail with reference to the accompanying drawings in which:  
         [0014]      FIG. 1  is a schematic sectional view of a dry etching device according to an embodiment of the present invention;  
         [0015]      FIG. 2  is a plan view of a cleaning unit in the dry etching device shown in  FIG. 1  in accordance with an embodiment of the present invention;  
         [0016]      FIGS. 3 and 4  illustrate a schematic sectional view and a perspective view of a cleaning unit in accordance with an embodiment of the present invention;  
         [0017]      FIG. 5  is a schematic sectional view of a dry etching device according to another embodiment of the present invention; and  
         [0018]      FIG. 6  is a plan view of a cleaning unit in the dry etching device shown in  FIG. 5  in accordance with an embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0019]     The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.  
         [0020]     Apparatus for manufacturing a semiconductor device according to embodiments of the present invention will be described with reference to the accompanying drawings. In one example, a dry etching device according to an embodiment of the present invention will be described in detail with reference to  FIGS. 1 and 2 .  
         [0021]      FIG. 1  is a schematic sectional view of a dry etching device according to an embodiment of the present invention, and  FIG. 2  is a plan view of a cleaning unit in the dry etching device shown in  FIG. 1 .  
         [0022]     Referring now to  FIGS. 1 and 2 , a dry etching device according to an embodiment of the present invention includes an etching chamber  10  containing plasma, lower and upper electrodes  11  and  12  for generating plasma, and a cleaning unit  20  for cleaning the interior of the dry etching device.  
         [0023]     The chamber  10  contains the lower and the upper electrodes  11  and  12  and the cleaning unit  20 . A gas inlet (not shown) for inflow of reactant gases is also provided at the chamber  10 .  
         [0024]     The lower and the upper electrodes  11  and  12  are disposed on a bottom and a top surface of the chamber  10 , respectively, such that they face each other and are spaced apart from each other. The lower electrode  11  is electrically connected to a first power supply  40 , which supplies power to the lower electrode  11  for generating “etching plasma” using inflow gases, while the upper electrode  12  is grounded.  
         [0025]     The lower electrode  11  is proximate an exhaust  13  for discharging reactant gases and air from the chamber  10 . A workpiece, such as a semiconductor substrate  100  for semiconductor devices or display devices, is mounted on lower electrode  11 .  
         [0026]     The upper electrode  12  has a plurality of through holes (not shown) through which reactant gases from the gate inlet pass to reach a reaction area disposed between the lower electrode  11  and the upper electrode  12 . The through holes are arranged such that the reactant gases are uniformly distributed in the reaction area. For example, the concentration or the size of the through holes in the upper electrode  12  becomes larger as it goes away from the exhaust  13 . This prevents the reactant gases from gathering near the exhaust  13  and makes the gases uniformly reach the surface of the substrate  100 , thereby performing uniform etching.  
         [0027]     The cleaning unit  20  includes a cleaning electrode  21  electrically connected to a second power supply  50  which supplies power to the cleaning electrode  21  for generating “cleaning plasma” in cooperation with the upper electrode  12 , by using cleaning gases from the gas inlet. An electrode guide  23  guides the cleaning electrode  21  to move in a horizontal direction, and a plurality of electrode supporters  22  support the cleaning electrode  21  and guide the cleaning electrode  21  to move in a vertical direction. It will be apparent that in other embodiments, the cleaning unit may utilize a single electrode guide  23  and a single electrode supporter  22  for moving the cleaning electrode in horizontal and vertical directions, respectively.  
         [0028]     Now, the operation of the dry etching device shown in  FIGS. 1 and 2  are described in detail.  
         [0029]     Reactant gases containing at least one component flow into the chamber  10  through the gas inlet. The gases pass through the through holes in the upper electrode  12  and diffuse in a reaction area disposed between the upper electrode  12  and the lower electrode  11 . As described above, the size or the concentration of the through holes varies depending on the distance from the exhaust  13  in order to diffuse the reactant gases uniformly.  
         [0030]     The lower electrode  11  is supplied with bias voltage from the first power supply  40  to generate a vertical electric field and a horizontal magnetic field in the chamber  10 .  
         [0031]     Free electrons are discharged from the powered electrode  11  and accelerated by obtaining kinetic energy from the electromagnetic field. The accelerated electrons pass through the reactant gases in the reaction area and impact the reactant gases to transfer their energy to the reactant gases. The reactant gases are then ionized and the reactant gas ions are also accelerated by the electromagnetic field to pass through the reactant gases to transfer their energy to the reactant gases. This process makes a plasma containing positive ions, negative ions, radicals, and atomic groups in the reaction area, and the reactive species in the plasma chemically react to or physically strike a thin film of a wafer or the substrate  100  to etch the thin film.  
         [0032]     At this time, some of the reactant gases are attached to the upper electrode  12  or the walls of the chamber  10  to become a source of contamination, and the contaminating particles are removed by using the cleaning unit  20 .  
         [0033]     Now, a cleaning unit of the dry etching device shown in  FIGS. 1 and 2  and a method of cleaning the dry etching device according to an embodiment of the present invention is described in detail with reference to  FIGS. 3 and 4 .  
         [0034]      FIGS. 3 and 4  illustrate a cleaning unit of the dry etching device shown in  FIGS. 1 and 2  according to an embodiment of the present invention.  
         [0035]     Referring now to  FIGS. 3 and 4 , a cleaning electrode  21  includes a conductor  212  and a protector  211  for covering the conductor  212 . The protector  211  is preferably made of ceramic.  
         [0036]     First, contamination material  60  deposited on walls of the chamber  10  and surfaces of the electrodes  11  and  12  is detected by electrical or optical detection. The conductor  212  of the cleaning electrode  21  is supplied with DC or AC bias voltage from the second power supply  50 . The cleaning electrode  21  is moved in the vertical direction using the electrode supporters  22  until the cleaning electrode  21  is disposed under the upper electrode  12 , and then the cleaning electrode  21  is moved in the horizontal direction using the electrode guide  23 .  
         [0037]     Cleaning gases such as fluorine based gases, chlorine based gases, and inactive gases are flowed into the chamber  10  through the through holes of the upper electrode  12 , and a cleaning plasma  30  containing positive ions, negative ions, radicals, and atomic groups of the cleaning gases is generated between the upper electrode  12  and the cleaning electrode  21 .  
         [0038]     The reactive species of the cleaning gases are subjected to physical and chemical reaction with the contamination  60  to remove the contamination  60  from the walls of the chamber  10  and the upper electrode  12 , after which the contamination  60  is exhausted out of chamber  10  through the exhaust  13 . Polymers of the contamination  60  are mainly removed by fluorine ions or radicals, while metal particles are mainly removed by chlorine ions or radicals, and inactive gases.  
         [0039]     A dry etching device according to another embodiment of the present invention is described in detail with reference to  FIGS. 5 and 6 .  
         [0040]      FIG. 5  is a schematic sectional view of a dry etching device according to an embodiment of the present invention, and  FIG. 6  is a plan view of a cleaning unit in the dry etching device shown in  FIG. 5 .  
         [0041]     Referring now to  FIGS. 5 and 6 , a configuration of a dry etching device according to this embodiment is substantially the same as  FIGS. 1 and 2 . That is, the dry etching device includes a chamber  10 , lower and upper electrodes  11  and  12 , and a cleaning unit  70 .  
         [0042]     However, the cleaning unit  70  of the dry etching device according to this embodiment has a different configuration from that shown in  FIGS. 1 and 2 . The cleaning unit  70  includes a ring-shaped cleaning electrode  71  and a plurality of electrode supporters  72  supporting the cleaning electrode  71  and guiding the cleaning electrode  71  to move in a vertical direction.  
         [0043]     The walls of the chamber  10  are grounded and the cleaning electrode  71  is electrically connected to a power supply  50 , which supplies power to cleaning electrode  71  for generating cleaning plasma. The powered cleaning electrode  71  and the grounded chamber walls generate a cleaning plasma.  
         [0044]     When the increase of a contamination material  60  ( FIG. 3 ) deposited on walls of the chamber  10  and surfaces of the electrodes  11  and  12  is detected by electrical or optical detection, the cleaning electrode  71  is supplied with DC or AC bias voltage from the second power supply  50 . The cleaning electrode  71  is moved in the vertical direction using the electrode supporters  72  and the cleaning electrode  71  generates a cleaning plasma between the cleaning electrode  71  and the chamber walls. The reactive species of the cleaning gases are subjected to physical and chemical reaction with the contamination  60  to remove the contamination  60  from the walls of the chamber  10  or the electrodes  11  and  12 , and they are exhausted out of chamber  10  by the exhaust  13 .  
         [0045]     The cleaning electrode  71  moves upward and downward to remove the particles on the entire surface of the chamber walls.  
         [0046]     The cleaning units according to these embodiments can be applied to reactive ion etch equipment, plasma enhanced (PE) dry etching device, and inductively coupled plasma (ICP) dry etching equipment.  
         [0047]     The cleaning units according to these embodiments can be also applied to sputter equipment for depositing a conductive film and chemical vapor deposition (CVD) equipment for depositing a thin film by chemical reactions. Like the above-described dry etching device, such a sputter equipment or CVD equipment may include a grounded electrode and a powered electrode connected to a power supply for generating a cleaning plasma. The sputter equipment may further include an additional electrode for supporting a sputtering target to be deposited on a semiconductor device or a panel for a display device and electrically connected to a power supply. The CVD equipment may further include a supply for reactant gases. Here, the grounded electrode may be a separate electrode or walls of the chamber  10 .  
         [0048]     The present invention advantageously provides a cleaning electrode for generating a plasma to clean the inside of a chamber to save cleaning time compared with a conventional cleaning method that requires the opening and cleaning of the chamber and also allows for increasing the interval between regular cleanings.  
         [0049]     While the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that various modifications and substitutions can be made thereto without departing from the spirit and scope of the present invention as set forth in the appended claims.