Abstract:
A multichamber-type processing apparatus and processing method using same, in which a substrate is reliably neutralized without being damaged, thereby ensuring excellent accuracy and throughput. The processing apparatus includes a transfer chamber, etching chambers selectively communicating with the transfer chamber and providing a space to etch a first substrate therein, and ashing chambers selectively communicating with the transfer chamber and providing a space to ash a second substrate therein. A transfer mechanism is installed in the transfer chamber to sequentially transfer the substrate from the transfer chamber into the etching and ashing chambers. The substrate is electrostatically adsorbed to electrostatic chucks in the etching and ashing chambers. An monatomic nitrogen atom supply unit supplies dissociated monatomic nitrogen atoms into the etching and ashing chambers.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a multichamber-type processing apparatus having an arrangement in which a transfer chamber is coupled to a plurality of processing chambers for etching or ashing a substrate to be processed, and a processing method using same.  
         BACKGROUND OF THE INVENTION  
         [0002]    Generally, a multichamber-type processing apparatus, which includes a transfer chamber provided with a transfer arm and coupled to a plurality of processing chambers via gate valves, is known as a processing apparatus for performing etching, ashing, and deposition processes on a plurality of substrates, such as semiconductor wafers or glass substrates, producing high throughput. (see Japanese Patent Laid-open Publication No. 1994-31471)  
           [0003]    An electrostatic chuck is frequently used as a jig to electrostatically adsorb a substrate to be processed, such as a semiconductor wafer in a processing chamber. Such electrostatic chuck incorporates therein an electrode embedded in a dielectric member, and by applying a direct current to the electrode the substrate is electrostatically adsorbed to a surface of the dielectric member by an electrostatic force, such as a Johnsen-Rahbek force or a Coulomb force.  
           [0004]    In case that the substrate is adsorbed to the electrostatic chuck, a small amount of electric charge still remains in the substrate even after the application of the direct current to the electrode is stopped after the substrate is processed. The electric charge remaining on a surface of the substrate in the multichamber-type processing apparatus becomes an issue when transferring a substrate from a processing chamber to another processing chamber by use of the transfer arm. That is, the substrate becomes misaligned on the transfer arm when the transfer arm mounts thereon the substrate from the electrostatic chuck. Hence, when the substrate is transferred from the transfer arm to a processing chamber, the substrate is placed at a misaligned position in the processing chamber. Additionally, such condition also suffers from that it takes a relatively longer amount of time to separate the substrate from the electrostatic chuck, which in turn deteriorates throughput efficiency of the multichamber-type processing apparatus.  
           [0005]    In order to eliminate such ill effects thereof, the charge on the substrate needs to be neutralized. For instance, there are a method of applying a current having an opposite polarity to the current applied to an electrode when a substrate is electrostatically adsorbed to an electrostatic chuck as disclosed in Japanese Patent Laid-open Publication 1997-213780 and a method of neutralizing charge on an object to be processed which is electrostatically adsorbed to an electrostatic chuck, by supplying ionized processing gas thereto as disclosed in Japanese Patent Laid-open Publication No. 1994-275546.  
           [0006]    However, there are drawbacks associated with the method disclosed in Japanese Patent Laid-open Publication No. 1997-213780. In such method, it is difficult to apply the current to the substrate so as to precisely neutralize the electric charge, and thus either positive or negative electric charge still remains on a surface of the substrate when a desired valance is not obtained, reducing neutralization of the substrate.  
           [0007]    Furthermore, in case of employing the process disclosed in Japanese Patent Laid-open Publication No. 1994-275546 there is a concern for damages incurring on the substrate such as the semiconductor wafer, by the ionized processing gas supplied thereto.  
         SUMMARY OF THE INVENTION  
         [0008]    It is, therefore, an object of the present invention to provide a multichamber-type processing apparatus and a processing method using same, which reliably neutralizes a charge on a substrate without incurring damage to the substrate, thereby ensuring excellent accuracy and throughput.  
           [0009]    In accordance with one aspect of the present invention, there is provided a processing apparatus including: a transfer chamber; a plurality of processing chambers for processing therein a substrate to be processed, the processing chambers being coupled to the transfer chamber; a number of electrostatic chucks which are provided in the processing chambers, to electrostatically adsorb the substrate to be processed thereto; a transfer mechanism installed in the transfer chamber to transfer the substrate to be processed between the processing chambers and the transfer chamber; and a monatomic nitrogen atom supply unit for supplying dissociated monatomic nitrogen N (hereinafter N) atoms into the processing chambers.  
           [0010]    In accordance with another aspect of the present invention, there is provided a processing apparatus including: a transfer chamber; a first processing chamber coupled to the transfer chamber, the first processing chamber performing therein a first process on a substrate to be processed; a second processing chamber coupled to the transfer chamber, the second processing chamber performing therein a second process on the substrate to be processed; a transfer mechanism installed in the transfer chamber for sequentially transferring the substrate to be processed into the first and second processing chamber; electrostatic chucks provided in the first and the second processing chambers, the electrostatic chucks electrostatically adsorbing thereto the substrate to be processed; and a monatomic nitrogen atom supply unit for supplying dissociated monatomic N atoms into the first and second processing chamber.  
           [0011]    In accordance with still another aspect of the present, there is provided a processing method employing a processing apparatus, which includes a transfer chamber, a plurality of processing chambers coupled to the transfer chamber, to process therein a target substrate, and a number of electrostatic chucks provided in the processing chambers to electrostatically adsorb the target substrate thereto, including the steps of: transferring the target substrate from the transfer chamber into one of the processing chambers by using a transfer mechanism; placing the target substrate on an electrostatic chuck displaced in said one processing chamber; applying a direct current to an electrode embedded in the electrostatic chuck to electrostatically absorb the target substrate to the electrostatic chuck; processing the target substrate in said one processing chamber, to thereby obtain a processed substrate; terminating the application of the direct current to the electrostatic chuck; supplying dissociated monatomic N atoms into said one processing chamber to remove charge on the electrostatic chuck; and transferring the processed substrate into the transfer chamber using the transfer mechanism.  
           [0012]    In accordance with yet still another aspect of the invention, there is provided a processing method using a processing apparatus, which includes a transfer chamber, a first processing chamber coupled to the transfer chamber, for performing a first process on a target substrate therein, a second processing chamber coupled to the transfer chamber for performing a second process on the target substrate therein, and a first and second electrostatic chucks provided in the first and second processing chambers, respectively, to electrostatically adsorb the substrate thereto, including the steps of: transferring the target substrate from the transfer chamber into the first processing chamber using a transfer mechanism; placing the target substrate on the first electrostatic chuck in the first processing chamber; applying a direct current to an electrode of the first electrostatic chuck to electrostatically adsorb the target substrate to the first electrostatic chuck; performing a first process on the target substrate in the first processing chamber to thereby obtain a processed substrate; terminating the application of the direct current to the first electrostatic chuck; supplying dissociated monatomic N atoms into the first processing chamber to remove charge on the first electrostatic chuck; transferring the processed substrate into the transfer chamber using the transfer mechanism; transferring the processed substrate from the transfer chamber into the second processing chamber; placing the processed substrate on the second electrostatic chuck in the second processing chamber; applying the direct current to an electrode of the second electrostatic chuck to electrostatically adsorb the processed substrate to the second electrostatic chuck; and performing a second process on the processed substrate in the processed second processing chamber.  
           [0013]    In the present invention, N was employed, however, there are elements such as F, O, and Cl that have the electronegativity greater than or equivalent to that of N. Since, however, F reacts with SiO 2  formed on the substrate; O reacts with a resist; and Cl reacts with Si, N is preferred over F, O, and Cl. Furthermore, N is a non-toxic, non-explosive, incombustible, and relatively cheap substance. Moreover, its treatment is relatively easy, which makes N more of a preferred choice over the other elements.  
           [0014]    In the present invention it is preferable that the dissociated monatomic N atoms be supplied near the electrostatic chuck, thereby reliably removing a charge on a substrate adsorbed to the electrostatic chuck.  
           [0015]    Additionally, a charge on a substrate supporting unit of a transfer mechanism or on the substrate mounted thereon may be removed by supplying the dissociated monatomic N atoms into the transfer chamber, thereby further preventing ill effects of electric charge.  
           [0016]    Furthermore, a charge on the substrate is removed at a desired time by controlling a supply timing of the dissociated monatomic N atoms, to effectively remove charge on the substrate.  
           [0017]    Moreover, the energy supply unit may include an ultraviolet irradiation unit for irradiating ultraviolet ray to the N 2  gas. In addition, a portion of a pipe may be made of a dielectric material, and an induction coil as the energy supply unit may be wound around the dielectric portion of the pipe, wherein a high frequency source applies a high frequency to the induction coil. As a result, the dissociated monatomic N atoms are conveniently obtained.  
           [0018]    Furthermore, the dissociated monatomic N atoms may be effectively generated by applying energy, higher than dissociation energy of the N 2  gas and lower than ionization energy of the N 2  gas, to the N 2  gas. When the energy applied to the N 2  gas is lower than the dissociation energy, the N 2  gas is not dissociated into the monatomic N atoms. On the other hand, when the energy applied to the N 2  gas is higher than the ionization energy, more N ions are generated than the dissociated monatomic N atoms, which damages the substrate. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0019]    The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:  
         [0020]    [0020]FIG. 1 schematically illustrates a multichamber-type processing apparatus in accordance with the first embodiment of the present invention;  
         [0021]    [0021]FIG. 2 sets forth an etching chamber provided in the multichamber-type processing apparatus shown in FIG. 1;  
         [0022]    [0022]FIGS. 3A to  3 C are cross sectional views illustrating the etching and ashing of a substrate using the multichamber-type processing apparatus shown in FIG. 1;  
         [0023]    [0023]FIG. 4 is a flow chart describing the etching and ashing of the substrate using the multichamber-type processing apparatus shown in FIG. 1;  
         [0024]    [0024]FIGS. 5A and 5B are cross sectional views illustrating states in which trench-etching, ashing, and liner-removal of the substrate shown in FIG. 3 are performed;  
         [0025]    [0025]FIG. 6 is a cross sectional view of a transfer chamber capable of being neutralized; and  
         [0026]    [0026]FIG. 7 is a cross sectional view illustrating part of another etching chamber using a monatomic nitrogen atom supply unit. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0027]    Hereinafter, the preferred embodiments of the present invention will now be described in reference to the accompanying drawings.  
         [0028]    There is schematically illustrated in FIG. 1 a vacuum processing apparatus in accordance with a first embodiment of the present invention. The vacuum processing apparatus is a multichamber-type processing apparatus used in etching and ashing processes, for etching and ashing an object to be processed, such as a semiconductor wafer (hereinafter, referred to as “wafer”) under a predetermined level of vacuum.  
         [0029]    As shown in FIG. 1, the multichamber-type processing apparatus  100  includes two etching chambers  1   a,    1   b  for etching the wafer W, and two ashing chambers  2   a,    2   b  for ashing the wafer W, wherein the etching and ashing chambers  1   a,    1   b,    2   a,    2   b  are mounted on four sides of a hexagonal transfer chamber  3 , respectively. The two remaining sides of the hexagonal transfer chamber  3  are provided with wafer cassette chambers  4   a,    4   b,  respectively, which accommodate therein a cassette  5  having a plurality of wafers W mounted therein. Each of the etching chambers  1   a,    1   b  and the ashing chambers  2   a,    2   b  includes a susceptor  15  on which the wafers W mounted.  
         [0030]    The etching chambers  1   a,    1   b,  ashing chambers  2   a,    2   b,  and wafer cassette chambers  4   a,    4   b  are connected to the respective sides of the transfer chamber  3  via respective gate valves G as shown in FIG. 1 such that by opening the gate valve G the corresponding chamber communicates with the transfer chamber  3 , and by shutting the gate valve G, the corresponding chamber becomes isolated.  
         [0031]    Furthermore, a wafer transfer mechanism  6  is installed in the transfer chamber  3  to take the object to be processed, e.g., wafer W, out of and into the etching chambers  1   a,    1   b,  ashing chambers  2   a,    2   b,  and wafer cassette chambers  4   a,    4   b.  The wafer transfer mechanism  6  is positioned at a substantially center portion of the transfer chamber  3 , and has a multi-joint arm structure. In particular, there is provided a hand  7  at an end portion thereof on which the wafer W is mounted to carry the wafer W. In addition, an aligning unit  8  is installed near the wafer cassette chambers  4   a,    4   b  in the transfer chamber  3  to align the wafers W.  
         [0032]    Corresponding to process requirements of etching and ashing of the wafers W which are to be conducted under a predetermine level of vacuum, the etching chambers  1   a,    1   b,  the ashing chambers  2   a,    2   b,  and the transfer chamber  3  are all maintained under predetermined vacuum conditions. As for the wafer cassette chambers  4   a,    4   b,  when cassettes  5  are transferred into and from the wafer cassette chambers  4   a,    4   b  through openings (not shown) provided at the wafer cassette chambers  4   a,    4   b,  an atmospheric pressure is established therein, however when the cassettes  5  are loaded in the cassette chambers  4   a,    4   b  for processing, the cassette chambers  4   a,    4   b  are under a predetermined level of vacuum.  
         [0033]    Hereinafter, a detailed description of the etching chambers  1   a,    1   b  will now be given in detail.  
         [0034]    [0034]FIG. 2 illustrates an etching chamber  1   a.  The etching chamber  1   a  includes a chamber  12  made of a metal, such as aluminum having a surface thereof oxidized, wherein the chamber  12  is frame-grounded. A susceptor  15  serving as a lower electrode of a plate electrode is provided on the floor of the chamber  12  via an insulator  13 . Further, the susceptor  15  is connected to a high pass filter  16  (HPF).  
         [0035]    An electrostatic chuck  21  having the wafer W mounted thereon is provided on the susceptor  15 , and electrostatically adsorbs the wafer W thereto, to thereby prevent the wafer W from being moved on the electrostatic chuck  21 . In this respect, the electrostatic chuck  21  is structured such that an electrode  22  is embedded in a dielectric member  21   a.  When a direct current is applied to the electrode  22  from a direct current (DC) power supply  23  connected to the electrode  22 , the wafer W is electrostatically adsorbed to the electrostatic chuck  21  by an electrostatic force, such as a Johnsen-Rahbek force or a Coulomb force. Furthermore, a focus ring  25  made of Si is provided to surround the wafer W, to thereby enhance uniformity in etching of the wafer W. Moreover, lift pins  24  are elevatably installed in the susceptor  15  to be penetrated through a surface of the electrostatic chuck  21 , and are vertically moved by a cylinder  26 .  
         [0036]    A shower head  31  facing the susceptor  15  is installed thereabove to supply a gas into the chamber  12 . The shower head  31  serves as an upper electrode, and is supported in an upper part of the chamber  12  through the insulator  32 . In addition, the shower head  31  includes an electrode plate  34  having a plurality of holes and a supporting member  35  for supporting the electrode plate  34 .  
         [0037]    A gas inlet  36  is formed at a substantially center portion of an upper part of the supporting member  35 , and is connected to one of two ends of a gas supply line  37 , whereas the other end of the gas supply line  37  is connected to an etching gas source  40  via a mass flow controller  38 . Valves  39  are positioned at both an inlet and outlet side of the mass flow controller  38  installed at the gas supply line  37 . An etching gas including, for example, a halogen element F, is supplied from the etching gas source  40  to the chamber  12  through the shower head  31 .  
         [0038]    An exhaust line  41  connected to a gas exhaust unit  45  is provided at a bottom portion of the chamber  12 . Additionally, a gate valve G is installed at a sidewall of the chamber  12  so that the wafer W can be transferred between the chamber  12  and the neighboring transfer chamber  3 .  
         [0039]    The shower head  31  serving as the upper electrode is connected to a low pass filter (LPF)  52  and a high frequency power supply  50  via a matching unit  51 . The susceptor  15  serving as the lower electrode is connected to a high frequency power supply  60  via a matching unit  61 .  
         [0040]    One end of a gas line  71  is connected to the gas supply line  37 , and the other end thereof is connected to a N 2  gas supply source  70  for supplying an N 2  gas used as a charge removal gas into the chamber  12 . A valve  72  is installed at the gas line  71 . Further, an ultraviolet irradiation unit  75  including an ultraviolet irradiation lamp is provided at the sidewall of the chamber  12  such that the ultraviolet irradiation unit  75  is positioned close to the electrostatic chuck  21 , and is connected to an ultraviolet irradiation power supply  76 . The valve  72  and ultraviolet irradiation power supply  76  are controlled by a charge removal controller  80 . In other words, the charge removal controller  80  signals the valve  72  to be opened at a predetermined timing to supply the N 2  gas from the N 2  gas supply source  70  through the shower head  31  into the chamber  12 . Simultaneously, the charge removal controller  80  signals the ultraviolet irradiation power supply  76  to be turned on at a predetermined timing to irradiate ultraviolet ray from the ultraviolet irradiation unit  75  to the N 2  gas, thereby dissociating and converting the N 2  gas to monatomic N atoms in the chamber  12 . The monatomic N atoms contribute to charge removal of the wafers W electrically charged on the electrostatic chuck  21 .  
         [0041]    An etching chamber  1   b  has the same structure as the etching chamber  1   a.  Furthermore, the ashing chambers  2   a,    2   b  each have the same structure as the etching chamber  1   a  with a minor exception of, e.g., using O 2  gas as an ashing gas and a processing pressure different from that of the etching chamber  1   a.    
         [0042]    Hereinafter, a detailed description will now be given for an operation of the multichamber-type processing apparatus  100 . In this respect, there will be described a process of forming via holes and trenches on a low-k film on a Cu wire by a dual damascene technique in which via holes and trenches are first etched followed by an ashing.  
         [0043]    In reference to FIG. 3A, a liner layer  82  made of SiN or SiC is formed on a bottom layer, i.e., Cu wire  81 , and a low-k film  83  is formed thereon. With such structure, a via hole  86  is formed in the low-k film  83  by employing a resist film  85  as a mask. Then, the first resist film  85  is removed from the structure by an ashing process and a sacrificial film  87  is formed, as shown in FIG. 3B. In FIG. 3C, a resist film  88  to be used in a trench etching process is formed on the sacrificial film  87 . Thus formed structure is subject to the etching and ashing processes in the multichamber-type processing apparatus  100  in accordance with to the present invention.  
         [0044]    In reference to FIG. 4, the cassette  5  is loaded into one or both of the wafer cassette chambers  4   a,    4   b  of the multichamber-type processing apparatus  100 (step  1 ). In this regard, the wafers W may be mounted in both cassettes  5  of the wafer cassette chambers  4   a,    4   b,  or in just one cassette  5  of the wafer cassette chambers  4   a,    4   b,  leaving the other cassette  5  empty. At this time, ambient pressures of the transfer chamber  3 , etching chambers  1   a,    1   b,  and ashing chambers  2   a,    2   b  are under predetermined vacuum levels. However, when the cassettes  5  are transferred into the wafer cassette chambers  4   a,    4   b,  the ambient pressure of the wafer cassette chambers  4   a,    4   b  becomes atmospheric, but prior to processing of the wafer W, the wafer cassette chambers  4   a,    4   b  are evacuated, thereby establishing predetermined vacuum levels therein.  
         [0045]    The hand  7  of the wafer transfer mechanism  6  of the transfer chamber  3  enters one of the wafer cassette chambers  4   a  or  4   b,  and a single wafer W is placed on the hand  7  (step  2 ). The wafer transfer mechanism  6  transfers the wafer W to a position in the transfer chamber  3  adjacent to the etching chamber  1   a  while carrying the wafer W on the hand  7 , the gate valve G between the etching chamber  1   a  and the transfer chamber  3  is opened, and the wafer W is transferred into the etching chamber  1   a  (step  3 ). The wafer W is then mounted on an electrostatic chuck  21  in the etching chamber  1   a  (step  4 ). Specifically, the hand  7  transfers the wafer W onto the lift pin  24  protruding from the electrostatic chuck  21 , and after the hand  7  is retracted from the etching chamber  1   a  out to the transfer chamber  3  the lift pin  24  is then lowered, to place the wafer W on the electrostatic chuck  21 .  
         [0046]    After the hand  7  is retracted from the etching chamber  1   a  out to the transfer chamber  3  and the gate valve G is closed, the direct current is applied to the electrode  22  embedded in the electrostatic chuck  21  from the DC power supply  23  to electrostatically adsorb the wafer W to the electrostatic chuck  21  by the electrostatic force, such as the Coulomb force or the Johnsen-Rahbek force (step  5 ). Furthermore, the etching chamber  1   a  is preset to have a lower ambient pressure than that of the transfer chamber  3 , thereby preventing small amounts of residual gas containing F from flowing from the etching chamber  1   a  into the transfer chamber  3  when the gate valve G is opened.  
         [0047]    Thereafter, the valves  39  are opened to supply an etching gas of a predetermined flow rate from the etching gas source  40  through the shower head  31  into the chamber  12 , and the gas exhaust unit  45  is controlled to maintain an ambient pressure of the chamber  12  ranging from about 1 to about 10 Pa. The high frequency power is applied from the high frequency power supply  50  and the high frequency power supply  60  to the shower head  31  serving as the upper electrode and the susceptor  15  serving as the lower electrode, respectively, enabling a generation of a plasma with the etching gas in order to etch the low-k film  83  of the wafer W to form the trench  89  on the wafer W (step  6 ), as shown in FIG. 5A.  
         [0048]    After the completion of the etching process, the supplying of the etching gas into the chamber  12  along with the application of the direct current to the electrostatic chuck  21  is stopped (step  7 ). The chamber  12  is then purged using a purge gas (step  8 ).  
         [0049]    Despite ceased supply of the direct current to the electrostatic chuck  21 , the charge remains on the wafer W. At such state, there is a great difficulty in separating the wafer W from the electrostatic chuck  21 . In addition, when the wafer W is placed on the hand  7  of the wafer transfer mechanism  6 , the wafer W is easily misplaced on the hand  7 . Accordingly, there remains a need to remove the charge on the wafer W. In accordance with the first embodiment of the present invention, the N 2  gas is supplied from the N 2  gas supply source  70  through the shower head  31  into the chamber  12 , while the ultraviolet ray is irradiated from the ultraviolet irradiation unit  75  to the N 2  gas to convert the N 2  gas into the monatomic N atoms. As a result, the monatomic N atoms are supplied into the chamber  12  to remove the charge on the wafer W on the electrostatic chuck  21  (step  9 ).  
         [0050]    Upon completion of removal of the wafer W, a pressure of the chamber  12  is adjusted; the gate valve G is opened; and the lift pin  24  emerges from the electrostatic chuck  21  to lift the wafer W from the electrostatic chuck  21 . The hand  7  of the wafer transfer mechanism  6  is inserted into the chamber  12  to receive the wafer W (step  10 ).  
         [0051]    Then, the wafer W is transferred from the etching chamber  1   a  into the transfer chamber  3 , and is placed on the aligning unit  8  to be aligned. Thereafter, the wafer W is transferred using the wafer transfer mechanism  6  to a position in the transfer chamber  3  adjacent to an ashing chamber  2   a,  a gate valve G between the ashing chamber  2   a  and the transfer chamber  3  is opened, and the wafer W is transferred into the ashing chamber  2   a  (step  11 ). The wafer W is placed on an electrostatic chuck in the ashing chamber  2   a  (step  12 ). Similar to the case of etching chamber  1   a,  the wafer W is electrostatically adsorbed to the electrostatic chuck (step  13 ). Additionally, the ashing gas, such as O 2  gas, is used in the ashing process. Because the ashing process is conducted at higher pressure than in the case of the etching process, the ashing chamber  2   a  has higher ambient pressure than the transfer chamber  3 , thereby preventing the compounds, containing F, from flowing from the transfer chamber  3  into the ashing chamber  2   a.    
         [0052]    Similar to the etching process, the ashing gas of a predetermined flow rate is supplied from an ashing gas source (not shown) through the shower head  31  into the chamber  12 , and the gas exhaust unit  45  is controlled to maintain an ambient pressure of the chamber  12  ranging from 10 to 20 Pa. Additionally, the ashing gas is converted into a plasma to remove the sacrificial film  87  and a resist film  88  through the ashing process and to simultaneously remove an exposed portion of the liner layer  82  (step  14 ), as shown in FIG. 5B.  
         [0053]    Upon completion of the ashing process, the supplying of the ashing gas into the chamber  12  is stopped and the application of the direct current to the electrostatic chuck  21  is simultaneously stopped (step  15 ). The chamber  12  of the ashing chamber  2   a  is then purged using the purge gas (step  16 ). Subsequently, charge on the wafer W adsorbed to the electrostatic chuck  21  is subject to charge removal(step  17 ), similar to the etching process.  
         [0054]    Upon completion of the charge removal on the wafer W, pressure of the chamber  12  is adjusted, and the gate valve G is opened. The hand  7  of the wafer transfer mechanism  6  then receives the wafer W from the electrostatic chuck  21  and transfers the wafer W into the cassette  5  of the wafer cassette chamber  4   a  or  4   b  (step  18 ), thereby completing the etching and ashing of the single wafer W.  
         [0055]    While above wafer W is subject to the etching process in the etching chamber  1   a,  a wafer W is transferred by use of the wafer transfer mechanism  6  into the etching chamber  1   b  to be etched and then transferred from the etching chamber  1   b  into the ashing chamber  2   b  to be ashed. In other words, the etching and ashing processes are conducted using the two sets of etching chambers and ashing chambers, thereby ensuring a relatively high throughput.  
         [0056]    The dissociated monatomic N atoms are used to remove the charge on the wafer W. The monatomic N atoms do not incur damages to the wafer W unlike nitrogen ions and plasmas, while quickly and reliably capturing electrons from the wafer W by merely supplying same to the wafer W. Specifically, because the dissociated monatomic N atoms have lower energy than the nitrogen ions and plasmas, damage to the wafer W by the monatomic N atoms is relatively small. Additionally, since dissociation energy of nitrogen is lower than energy required to convert nitrogen molecules into the nitrogen ions or plasmas, and the monatomic N atoms have relatively high electronegativity, the monatomic N atoms easily capture the electrons from the wafer W, and thus quickly and reliably removing the charge on the wafer W. Accordingly, the multichamber-type processing apparatus  100  ensures excellent accuracy and throughput.  
         [0057]    In this respect, energy of the ultraviolet ray required to produce the dissociated monatomic N atoms is controlled to be higher than the dissociation energy of N 2  and less than ionization energy of N 2 , so as to effectively convert the N 2  gas into the monatomic N atoms without ionizing the N 2  gas. Specifically, since the dissociation energy of N 2  is about 9.8 eV at 0 K and the ionization energy of N 2  is about 15.6 eV at 0 K, it is preferable that the energy of the ultraviolet ray irradiated to the N 2  gas be about 9.8 to about 15.6 eV at a temperature of 0 K.  
         [0058]    Furthermore, since the etching chambers  1   a,    1   b  each have lower ambient pressure than the transfer chamber  3  and the ashing chambers  2   a,    2   b  each have higher ambient pressure than the transfer chamber  3 , even a small amount of residual etching gas in etching chambers  1   a,    1   b,  which contains halogen gas is prevented from flowing into the transfer chamber  3 . Additionally, even in a case of the etching gas leaking from the etching chambers  1   a,    1   b  into the transfer chamber  3 , the flow of the etching gas from the transfer chamber  3  into the ashing chambers  2   a,    2   b  is substantially prevented. In case that the Cu wire is applied to the wafer W, due to very high reactivity of Cu, it is vital to prevent the etching gas from flowing into the ashing chambers  2   a,    2   b,  in which Cu is exposed to the atmosphere Furthermore, since the trench etching; and the ashing and liner removal are conducted in different chambers, it is possible to avoid the deterioration in etching selectivity due to the residual gas when the trench etching is performed, the ashing and liner removal are conducted in the same chamber, thereby ensuring excellent throughput.  
         [0059]    As well, the misalignment between the hand  7  and the wafer W is easily overcome by the charge removal of the wafer W, thereby improving accuracy in aligning the wafer W with the hand  7 . Moreover, in the present invention, the aligning unit  8  is installed in the transfer chamber  3  to align the wafer W with the hand  7 , thereby further improving accuracy in aligning the wafer W with the hand  7 .  
         [0060]    As described above, the charge removal of the wafer W removes a remaining electric charge from the wafer W on the electrostatic chuck, but the electric charge negatively affects the wafer W when the hand  7  is electrically charged. Therefore, charge on the hand  7  may be preferably removed before or after the wafer W is loaded from the hand  7  to the electrostatic chuck  21 ; at the time when the wafer W is loaded from the hand  7  to the electrostatic chuck  21 ; before or after the hand  7  receives the wafer W from the electrostatic chuck  21 ; or at the time when the hand  7  receives the wafer W from the electrostatic chuck  21 . As shown in FIG. 6, an N 2  gas inlet  91  and an ultraviolet irradiation unit  92  may be installed in the transfer chamber  3  to remove the charge on the hand  7  and wafer W in the transfer chamber  3 . In the present invention, the N 2  gas supply source  70  and the etching gas source  40  are separately installed in the processing apparatus  100 , but the etching gas may be supplied through the N 2  gas supply source  70  into the chamber  12  in the case of using the N 2  gas as the etching gas.  
         [0061]    With reference to FIG. 7, there is illustrated another etching chamber using a monatomic nitrogen atom supply unit. In FIGS. 2 and 7, the same reference numerals refer to the same elements throughout, and description thereof is omitted. As shown in FIG. 7, an end of a gas pipe  93  made of a dielectric material communicates with the inside of the chamber  12  through a sidewall of the chamber  12 , and the other end of the gas pipe  93  is connected to a N 2  gas supply source  94 . At this time, the wafer W in the chamber  12  is positioned close to the gas pipe  93 . In addition, an induction coil  96  is wound around the gas pipe  93 , and the high frequency power is applied from a high frequency power supply  97  to the induction coil  96 . Further, a valve  95  is installed at the gas pipe  93 .  
         [0062]    In the etching chamber  12  of FIG. 7, the valve  95  is opened to supply the N 2  gas from the N 2  gas supply source  94  through the gas pipe  93  into the etching chamber  12 , and the high frequency is simultaneously applied from the high frequency power supply  97  to the induction coil  96 . Thereby, the N 2  gas passing through the gas pipe  93  is dissociated to the monatomic N atoms due to an electromagnetic induction, and thus the monatomic N atoms are supplied into the chamber  12 . Accordingly, the wafer W is effectively neutralized without being damaged. At this time, energy applied from the high frequency power supply  97  to the induction coil  96  is higher than the dissociation energy of N 2  and less than the ionization energy of N 2 .  
         [0063]    Numerous modifications and variations of the present invention are possible in light of the above teachings. For instance, in the present invention, the processing apparatus is described to include the two etching chambers and the two ashing chambers, however, it may only include one etching chamber and one ashing chamber, or the three or more etching chambers and the three or more ashing chambers.  
         [0064]    Additionally, in the present invention, only the trench etching and ashing processes according to the dual damascene structure are disclosed. However, the present invention may be applied to etching and ashing processes for other structures. Further, the present invention may be applied to a repeating processing of different types of etching processes. Furthermore, the present invention may be applied to a film-formation process as well as the etching and ashing processes. Moreover, a unit for supplying the dissociated monatomic N atoms into the chamber can be variously modified within the scope of the appended claims.  
         [0065]    Moreover, in the present invention, the semiconductor wafer is used as a substrate, but the present invention may be applied to the other substrates, such as glass substrates for LCD.  
         [0066]    As illustrated by the above description, the present invention provides a multichamber-type processing apparatus, which includes the transfer chamber and the processing chambers connected thereto, in which dissociated monatomic N atoms are supplied into the processing chambers. Accordingly, the substrate electrostatically adsorbed to an electrostatic chuck is quickly and reliably neutralized by relatively low energy without being damaged, thereby ensuring excellent accuracy and throughput.  
         [0067]    While the invention has been shown and descried with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit ands scope of the invention as defined in the following claims.