Abstract:
Gas reaction chamber systems having a gas supply apparatus are provided. In one aspect, a reaction chamber system includes a reaction chamber, a plurality of gas supplies, and a plurality of gas supply conduits connecting the reaction chamber with the gas supplies. Gas supply valves are installed at each of the gas supply conduits, and a substitute gas supply conduit having a substitute gas supply valve is connected to at least one of the gas supply conduits. Thus, during interchanging of wafers, the substitute gas can be supplied into the reaction chamber system in substitution for the processing gases. As a result, the system can minimize an unnecessary consumption of processing gases.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority to Korean Patent Application No. 2003-66326, filed Sep. 24, 2003, which is incorporated herein by reference in its entirety.  
       FIELD OF THE INVENTION  
       [0002]     The present invention relates, generally, to an apparatus used in fabrication of semiconductor devices and, more particularly, to a gas reaction chamber system having a gas supply apparatus.  
       BACKGROUND OF THE INVENTION  
       [0003]     Typically, the fabrication of semiconductor devices includes a variety of process steps using processing gases, such as chemical vapor deposition (CVD) or dry etching processes. In these process steps, the processing gases are supplied into a reaction chamber through predetermined gas supply conduits. U.S. Pat. No. 6,508,913, entitled “Gas Distribution Apparatus For Semiconductor Processing”, discloses conventional embodiments in connection with gas supply conduits.  
         [0004]     In the meantime, a multi-station processing chamber, as disclosed in U.S. Pat. Nos. 6,319,553, 5,882,417, and 5,679,405, has been used to increase the productivity of a deposition system in a CVD process.  
         [0005]      FIG. 1  illustrates a conventional arrangement of a CVD system having a multi-station processing chamber.  
         [0006]     Referring to  FIG. 1 , a plurality of processing gases  31 ,  32  and  33  are supplied through a plurality of gas supply conduits  61 ,  62 ,  63  and  64  into a reaction chamber  20  having several stations. Gas supply valves  41 ,  42 ,  43  and  44 , filters  51 ,  52 ,  53  and  54 , and mass flow controllers (MFCs)  55 ,  56 ,  57  and  58  are installed at the gas supply conduits  61 ,  62 ,  63  and  64 , respectively. The gas supply conduits  61  and  62  may be joined together at a predetermined point, and the gas supply conduits  63  and  64  may be joined together at another predetermined point. Then, the gas supply conduits  61 ,  62 ,  63  and  64  joined together at the predetermined points are connected to the reaction chamber  20 . Main supply valves  45  and  46  are installed at the joined conduits to control flows of processing gases  31 ,  32  and  33 .  
         [0007]     After performing a predetermined process, the processing gases supplied into the reaction chamber  20  are exhausted to the outside of the system  10  by means of an exhausting pump  26 . The exhausting pump  26  is connected with the gas supply conduits  61 ,  62 ,  63  and  64  by means of exhausting conduits  65  and  66 . Exhausting valves  47  and  48  are installed at the exhausting conduits  65  and  66 , respectively, to control flowing paths of the processing gases  31 ,  32  and  33 . The main supply valves  45  and  46  also take part in this control of gas flow.  
         [0008]     The reaction chamber  20  is connected to a load-lock chamber  22 . A deposition process comprises steps of loading wafers into the reaction chamber  20  and supplying the processing gases  31 ,  32  and  33  into the reaction chamber  20 . In detail, in the loading step, the wafers contained in a wafer cassette are loaded from the outside of system  10  into the inside of load-lock chamber  22 .  
         [0009]     Meanwhile, during the deposition process, the reaction chamber  20  is maintained at the almost same pressure as the load-lock chamber  22 . Thus, an additional step for controlling the pressure during a process of loading the wafers into the reaction chamber  20  is not required. As a result, such isobaric CVD system has by far a higher productivity than other type CVD systems where the pressure in the reaction chamber  20  is different from the load-lock chamber  22 . However, A conventional isobaric CVD system, such as the one described above, may needlessly consume processing gases.  
         [0010]      FIG. 2  is a timing diagram for explaining the consumption of processing gases occurring in the isobaric CVD system.  
         [0011]     Referring  FIGS. 1 and 2 , a reaction of processing gases and a resultant deposition of a material layer occur at the second step when the processing gases are supplied with a radio-frequency (RF) power on.  
         [0012]     In forth and fifth steps, the RF power is off during the process of loading a new wafer into the reaction chamber  20 . The main supply valves  45  and  46  are closed and the exhausting valves  47  and  48  are opened so that the processing gases are not supplied into the reaction chamber  20  in forth and fifth steps. Thus, the processing gases are directly exhausted through the exhausting pump  26 . Since such unnecessary consumption of processing gases reduces an exchanging period of gas bottles as the source of processing gases, a cost for fabricating the semiconductor devices may be increased and an efficiency of equipment may be decreased. Thus, it is necessary to provide a reaction chamber system capable of minimizing an unnecessary consumption of processing gases.  
       SUMMARY OF THE INVENTION  
       [0013]     In general, exemplary embodiments of the present invention include reaction chamber systems capable of minimizing an unnecessary consumption of processing gases. Furthermore, exemplary embodiments of the present invention include reaction chamber systems comprising gas supply apparatus for replacing a reaction gas with another gas.  
         [0014]     More specifically, in one exemplary embodiment, a reaction chamber system comprises a reaction chamber, a plurality of gas supplies, and a plurality of gas supply conduits connecting the reaction chamber with the gas supplies. Gas supply valves are installed at each of the gas supply conduits, and a substitute gas supply conduit having a substitute gas supply valve is connected to at least one of the gas supply conduits. The substitute gas supply conduit is connected to the gas supply conduit between the reaction chamber and at least one of the gas supply valves.  
         [0015]     According to another exemplary embodiment of the present invention, a gas-blocking valve is further installed at the gas supply conduit where the substitute gas supply conduit is connected. The gas-blocking valve is installed between the gas supply and the position where the substitute gas supply conduit and the gas supply conduit are joined together. Preferably, the gas supply valve and the substitute gas supply valve are a normal close type valve and the gas-blocking valve is a normal open type valve. The substitute gas supply valve and the gas-blocking valve may be a valve selected from a group consisting of solenoid valves, hydraulic valves, and pneumatic valves. And, the gas supply valve may be a valve selected from a group consisting of solenoid valves, hydraulic valves, and pneumatic valves.  
         [0016]     According to another exemplary embodiment of the present invention, the system comprises a controller for controlling an opening state of the gas-blocking valve and the substitute gas supply valve. Preferably, the gas-blocking valve is closed by a signal of the controller and the substitute gas supply valve is opened by the same signal of the controller. Here, the gas-blocking valve and the substitute gas supply valve are preferably interlocked via a signal of a controller and simultaneously respond to the signal of the controller.  
         [0017]     According to another exemplary embodiment of the present invention, a load-lock chamber is further disposed at one side of the reaction chamber. Here, the load-lock chamber is an isobaric type that is maintained at substantially the same pressure as the reaction chamber. Preferably, the pressure of the reaction chamber is lower than that of the load-lock chamber. More preferably, the pressure of the reaction chamber is about 1 to about 20% lower than the pressure of the load-lock chamber.  
         [0018]     According to another exemplary embodiment of the present invention, filters and mass flow controllers may be disposed between the gas supply valves and the reaction chamber.  
         [0019]     According to another exemplary embodiment of the present invention, the system comprises a pump for exhausting reaction gases supplied into the reaction chamber and an exhausting conduit connecting the pump with the reaction chamber. And, other exhausting conduits having exhausting valves may be installed between the pump and the gas supply conduits.  
         [0020]     According to another exemplary embodiment, a radio-frequency power for activating the gases supplied into the reaction chamber may be connected to the reaction chamber. Preferably, the gas-blocking valve and the substitute gas supply valve are interlocked with the radio-frequency power via a controller.  
         [0021]     According to another exemplary embodiment of the present invention, the substitute gas supply conduit may be connected to gas supplies for supplying nitrogen gas and argon gas.  
         [0022]     These and other exemplary embodiments, features, aspects, and advantages of the present invention will be described and become apparent from the following detailed description of exemplary embodiments when read in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]      FIG. 1  illustrates a reaction chamber system having conventional gas supplying arrangements.  
         [0024]      FIG. 2  is a timing diagram for explaining an operation of a reaction chamber system having conventional gas supplying arrangements as illustrated in  FIG. 1 .  
         [0025]     FIGS.  3  to  6  illustrate reaction chamber systems according to exemplary embodiments of the present invention.  
         [0026]     FIGS.  7  to  10  are timing diagrams for explaining methods of operating reaction chamber systems according to exemplary embodiments of the present invention.  
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0027]     The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout the specification.  
         [0028]      FIG. 3  illustrates a reaction chamber system according to one exemplary embodiment of the present invention, and  FIG. 7  is a timing diagram for explaining a method of operating the reaction chamber system illustrated in  FIG. 3 , according to an exemplary embodiment of the present invention.  
         [0029]     Referring to  FIGS. 3 and 7 , a reaction chamber system  100  according to one exemplary embodiment of the present invention comprises a reaction chamber  120  connected to a load-lock chamber  122 . Preferably, to increase the production efficiency of system  100 , the reaction chamber  120  comprises a multi-station processing chamber and a spindle that can be moved up and down.  
         [0030]     It is desirable that the reaction chamber system  100  has an isobaric structure. In other words, it is necessary that a pressure difference between the reaction chamber  120  and the load-lock chamber  122  is maintained and that the pressure difference does not exceed a predetermined magnitude, e.g., about 20%. In particular, the pressure of the reaction chamber  120  is about 1 to about 20% lower than the pressure of the load-lock chamber  122  to prevent processing gases from leaking out of the reaction chamber  120 .  
         [0031]     According to another exemplary embodiment of the present invention, internal pressures of the reaction chamber  120  and the load-lock chamber  122  are about 2.2 Torr and about 2.5 Torr, respectively. The reaction chamber  120  is connected to a plurality of gas supplies including a first gas supply  131 , a second gas supply  132 , and a third gas supply  133 . In order to make this connection to the reaction chamber  120 , a plurality of gas supply conduits are placed between the reaction chamber  120  and the gas supplies  131 ,  132  and  133 . For example, a first, second, and third gas supply conduits  161 ,  162  and  163  are attached to the first, second, and third gas supplies  131 ,  132  and  133 , respectively.  
         [0032]     According to this exemplary embodiment of the present invention, a fourth gas supply conduit  164  is further displaced between the reaction chamber  120  and the third gas supply  133 . Here, the first gas supply conduit  161  and the third gas supply conduit  163  are joined together at a first position  191 , and then connected to the reaction chamber  120 . In addition, the second gas supply conduit  162  and the fourth gas supply conduit  164  are also joined together at a second position  192 , and then connected to the reaction chamber  120 . A first main supply valve  145  is installed between the first position  191  and the reaction chamber  120 , and a second main supply valve  146  is installed between the second position  192  and the reaction chamber  120 .  
         [0033]     According to this exemplary embodiment of the present invention, the first, second and third gas supplies  131 ,  132  and  133  may be used for containing an oxygen-containing gas (e.g., nitrous oxide (N 2 O)), a silicon-containing gas (e.g., silane (SiH 4 )), and one of nitrogen gas (N 2 ) or inert gases including argon, neon or helium, respectively. Here, the fourth gas supply conduit  164  may be connected to an additional gas supply (not shown) instead of the third gas supply  133 .  
         [0034]     Gas supply valves  141 ,  142 ,  143  and  144 , filters  151 ,  152 ,  153  and  154 , and MFCs  155 ,  156 ,  157  and  158  are respectively installed at the gas supply conduits  161 ,  162 ,  163  and  164  in regular sequence. The gas supply valves  141 ,  142 ,  143  and  144  may be a normal close type. normal close type valves are closed until reception of a predetermined signal that causes the valve to open.  
         [0035]     The reaction chamber  120  is connected to a radio frequency power  124  for activating the supplied processing gases and an exhausting pump  126  for exhausting the processing gases from the reaction chamber  120 . The exhausting pump  126  is connected to the reaction chamber  120  through a chamber exhausting conduit  167 . In addition, the exhausting pump  126  is connected to the first and second positions  191  and  192  through first and second exhausting conduits  165  and  166 , respectively. A first exhausting valve  148  and a second exhausting valve  147  are installed at the first and second exhausting conduits  165  and  166 , respectively. Preferably, the first and second exhausting valves  147  and  148  are of the normal close type.  
         [0036]     A first substitute gas supply conduit  168  is installed between the first gas supply conduit  161  and the third gas supply  133 . One endpoint of the first substitute gas supply conduit  168  is connected to a third position  193 , which is a position between the first gas supply valve  141  and the first position  191 , and other endpoint is connected to the third gas supply  133 . A first substitute gas supply valve  172  is installed at the first substitute supply conduit  168 , and a first gas-blocking valve  170  is installed at the first gas supply conduit  161 . The first gas-blocking valve  170  is installed between the third position  193  and the first gas supply  131  and interlocked via a signal with the first substitute gas supply valve  172 . Additionally, a controller  180  is connected to both the first gas-blocking valve  170  and the first substitute gas supply valve  172  to control operations of the valves. It is desirable that the controller  180  is electronically connected with the first gas-blocking valve  170  and the first substitute gas supply valve  172 . And, the controller  180  may be used for monitoring and controlling operations of the radio frequency power  124 .  
         [0037]     The first gas-blocking valve  170  and the first substitute gas supply valve  172  are of the normal open type and a normal close type, respectively. In other words, the first gas-blocking valve is open and the first substitute gas supply valve  172  is closed until reception of a predetermined signal, which simultaneously causes the first gas-blocking valve to close and the first substitute gas supply valve  172  to open. The first gas-blocking valve  170  and/or the first substitute gas supply valve  172  are a valve selected from a group consisting of solenoid valves, hydraulic valves, and pneumatic valves. As aforementioned, the first gas-blocking valve  170  and the first substitute gas supply valve  172  are interlocked via a signal such that the first gas-blocking valve  170  and the first substitute gas supply valve  172  simultaneously respond to a signal of the controller  180 .  
         [0038]     Referring to  FIG. 7 , when the RF power  124  stops, the controller  180  transmits an operating signal to the interlocked valves  170  and  172  (S 4 ). The operating signal simultaneously causes the first gas-blocking valve  170  to close and the first substitute gas supply valve  172  to open. Thus, during steps S 4  and S 5  of substituting wafers, a substitute gas, e.g., nitrogen gas contained in the third gas supply  133 , can substitute for processing gases contained in the first gas supply  131 , to prevent an unnecessary consumption of the processing gases. In addition, the substitute gas may be supplied from not only the third gas supply  133 , but also an additional gas supply, not shown, containing other gases.  
         [0039]     Next, when the RF power  124  starts again (S 1 ), the operating signal of the controller  180  disappears so that the interlocked valves  170  and  172  are, respectively, restored to the ordinary states. In other words, the first gas-blocking valve  170  is opened while the first substitute gas supply valve  172  is closed. Thus, during operating of the RF power  124 , the processing gas contained in the processing gas supply  131  (and not the substitute gas) is supplied into the reaction chamber  120  through the first main supply valve  145 . In the meantime, the operating signal for restoring the interlocked valves  170  and  172  may be generated in a form of pulse.  
         [0040]      FIG. 4  illustrates a reaction chamber system according to another exemplary embodiment of the present invention, and  FIG. 8  is a timing diagram for explaining a method of operating the reaction chamber system illustrated in  FIG. 4 , according to another exemplary embodiment. The exemplary reaction chamber illustrated in  FIG. 4  has many similar parts as the exemplary embodiment explained by means of  FIGS. 3 and 7 , and parts where the exemplary embodiments differ are described below.  
         [0041]     Referring to  FIG. 4 , one endpoint of a second substitute gas supply conduit  169  is connected to a fourth position  194 , which is located at the second gas supply conduit  162 . Particularly, the fourth position  194  is located between the second gas supply valve  142  and the second position  192 . More particularly, the fourth position  194  is located between the second filter  152  and the second MFC  156 . Other endpoint of the second substitute gas supply conduit  169  is connected to the third gas supply  133 , but may be connected to another gas supply as stated above.  
         [0042]     A second substitute gas supply valve  177  and filter  178  are installed at the second substitute gas supply conduit  169 . In addition, a second gas-blocking valve  175  is installed at the second gas supply conduit  162 , and the second gas-blocking valve  175  is interlocked via a signal with the second substitute gas supply valve  177 . The second gas-blocking valve  175  is installed between the second gas supply  132  and the second gas supply valve  142 . In structure and operation, a relation between the second gas-blocking valve  175  and the second substitute gas supply valve  177  is identical to that between the first gas-blocking valve  170  and the first substitute gas supply valve  172 . Similarly, the second substitute gas supply valve  177  and the second gas-blocking valve  175  are interlocked via the signal. Simultaneously, the second substitute gas supply valve  177  and the second gas-blocking valve  175  respond to an operating signal transmitted from the controller  180 .  
         [0043]     Referring to  FIG. 8 , when the RF power  124  stops, the controller  180  transmits an operating signal to the interlocked valves  170 ,  172 ,  175  and  177  (S 4 ). Simultaneously, the operating signal causes the first and second gas-blocking valves  170  and  175  to close and the first and second substitute gas supply valves  172  and  177  to open. Thus, during steps S 4  and S 5  of substituting wafers, a substitute gas, e.g., nitrogen gas contained in the third gas supply  133 , can substitute for processing gases contained in the first and second gas supplies  131  and  132 , to prevent an unnecessary consumption of them.  
         [0044]     According to another exemplary embodiment of the present invention, a first valve  210  may be used instead of the first gas supply valve  141  and the first gas-blocking valve  170 , as shown in  FIG. 5 . Similar to the exemplary embodiment as shown in  FIG. 3 , the first valve  210  is interlocked via a signal with the first substitute gas supply valve  172 . The first valve  210  is closed for steps S 4  and S 5  of substituting wafers, and is opened for other period, i.e., steps S 1 , S 2  and S 3 , as shown in  FIG. 9 . The first substitute gas supply valve  172  is opened, when the first valve  210  is closed.  
         [0045]     According to another exemplary embodiment of the present invention, in addition to the first valve  210 , a second valve  220  may be installed to substitute for the second gas supply valve  142  and the second gas-blocking valve  175 , as shown in  FIG. 6 . The second valve  220  is interlocked with the second substitute gas supply valve  177 . The first and second valves  210  and  220  are closed for steps S 4  and S 5  of substituting wafers, to prevent an unnecessary consumption of the processing gases, as shown in  FIG. 10 . Further, the first and second substitute gas supply valves  172  and  177  are opened, when the first and second valves  210  and  220  are closed.  
         [0046]     As stated above, during interchanging of wafers, the substitute gas, such as, nitrogen gas and so forth, is supplied into the reaction chamber system in substitution for the processing gases. Thus, the unnecessary consumption of processing gases can be minimized, and then extend an interchange period of the gas bottles. As a result, the system can be utilized effectively, and then it is possible to increase the productivity in the process for fabricating semiconductor devices.