Abstract:
An apparatus includes a reaction chamber installed in a reaction furnace; a discharge port for removing from the reaction chamber reaction byproducts formed during producing of the semiconductor device; a heater for generating heat to the reaction chamber; and a hot fluid supply unit for introducing heat from the heater and the reaction chamber into the discharge port. The hot fluid supply unit further comprises a fluid container for receiving a heat transfer fluid. The apparatus includes a hot fluid generator adjacent the reaction chamber in the reaction furnace. The hot fluid generator defines a fluid channel for conveying the heat transfer fluid and transfers heat generated from the heater and the reaction chamber to the heat transfer fluid supplied from the fluid container. The apparatus also includes a heat transfer element for transferring heat to the discharge port using the heat transfer fluid supplied from the hot fluid generator.

Description:
BACKGROUND OF THE INVENTION 
   This application claims priority from Korean Patent Application No. 2003-7157, filed on Feb. 5, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
   1. Field of the Invention 
   The present invention relates to an apparatus and method for producing a semiconductor device, and more particularly, to an apparatus and method for producing a semiconductor device including a system capable of controlling certain byproducts formed during the semiconductor production process. 
   2. Description of the Related Art 
   In the chemical vapor deposition process (CVD) employed in semiconductor device fabrication, various reaction gases are used according to the reaction condition and the types of treatment gases. 
   Accordingly, various byproducts are formed by chemical reaction of these reaction gases some of which are undesirable. For example, when NH 3  and dichlorosilane (DCS) are the gases that react with each other in a reaction chamber, at a relatively high temperature of 650° C. or more and a pressure of 10 −2  torr, a desired silicon nitride film (Si 3 N 4 ) is deposited. 
   However, at the same time, ammonium chloride (NH 4 Cl) is generated as a byproduct. NH 4 Cl is a white, odorless, crystalline substance formed by the reaction of gaseous ammonia (NH 3 ) and hydrochloric acid (HCl). It is mainly formed at the outlet portion of a reaction chamber or a vacuum pipe, which has a relatively low temperature. 
   Therefore, as the deposition process proceeds, powdery NH 4 Cl is accumulated at the outlet portion of the reaction chamber or the vacuum pipe. As the deposition process continues, the outlet portion of the reaction chamber and the vacuum pipe become clogged. 
   As a result, the accumulated NH 4 Cl flows backward into the reaction chamber. As the amount of the accumulated NH 4 Cl increases in the reaction chamber, the effective inner diameter of the outlet portion of the reaction chamber and the vacuum pipe decreases. Then, the volume of the exhaust gas changes. As a result of these differences caused by the presence of excess NH 4 Cl, a pressure change takes place within the reaction chamber. 
   Conventionally, in the deposition of a silicon nitride film, the reaction chamber and the vacuum pipe are periodically cleaned to remove the NH 4 Cl byproduct. However, if the use of equipment for cleaning the reaction chamber is circumvented, an increase of production loss and working expense is incurred. 
   In attempts to overcome this problem, there have been methods of preventing the generation of NH 4 Cl, channeling the generated NH 4 Cl toward an area away from a reaction chamber, and exhausting the generated NH 4 Cl through the back side of a vacuum pump. 
     FIGS. 1 and 2  are illustrative views of an apparatus for manufacturing a semiconductor device having a construction capable of preventing the generation of NH 4 Cl according to an example of the prior art.  FIG. 2  is an enlarged view of the part of “A” of  FIG. 1 . 
   Referring to  FIGS. 1 and 2 , the deposition of a silicon nitride film is performed using DCS and NH 3  in a reaction chamber  12  installed in a vertical-type reaction furnace  10 . During the deposition, in order to prevent the accumulation of a NH 4 Cl byproduct in the outlet portion of the reaction chamber  12  and in the discharge port  14 , a heating jacket  70  or a heating coil (not shown) is installed around sections in which a temperature drastically drops, i.e., the “A” part surrounding the discharge port  14 , the “B” part between the discharge port  14  and a vacuum pipe  20  connected to a vacuum pump  60 , and the “C” part surrounding the vacuum pipe  20 . 
   Such a heating jacket or heating coil serves to maintain the above sections at a temperature of about 150° C. In  FIG. 1 , a reference numeral  16  denotes a heater for heating the reaction chamber  12  to a temperature required for the deposition and a reference numeral  50  denotes a utility box. 
   In a method using such a heating jacket  70 , as shown in  FIG. 2 , an external heat is applied to the outer surfaces of the discharge port  14  and the vacuum pipe  20 . Therefore, the outlet portion of the reaction chamber  12 , the inner portion of the discharge port  14 , and the inner portion of the vacuum pipe  20  are indirectly heated and kept warm. 
   As a result, NH 4 Cl 4  can be prevented from being accumulated in the reaction chamber  12  and the discharge port  14 . However, because the heating jacket  70  generates heat using a heating coil inserted in an outer insulating shell made of asbestos or a flexible synthetic silicon material, a high manufacturing cost is incurred. 
   In addition, various problems such as breakage of the heating coil during use and degradation due to the presence of water during the cleaning operation may occur. Therefore, an average life span of the heating jacket  70  is about a year. In addition, because overheating may cause a fire hazard, installation and management of separate fire safety equipment are required. 
   As a direct heating method, there is adopted a method for supplying a hot N 2  gas into a discharge port of a reaction chamber to prevent the accumulation of a byproduct in a vacuum pipe.  FIG. 3  is an illustrative view of an apparatus for manufacturing a semiconductor device having a construction capable of preventing the generation of NH 4 Cl by supplying a hot N 2  gas according to another example of the prior art. In  FIG. 3 , the same reference numerals as in  FIGS. 1 and 2  denotes the same constitutional elements. 
   Referring to  FIG. 3 , a hot N 2  generator  80  as a separate heating unit is installed outside deposition equipment. When a room temperature N 2  gas passes through the hot N 2  generator  80 , a hot N 2  gas with a temperature of 50° C. or more is generated. The generated hot N 2  gas is supplied into the outlet portion of the reaction chamber  12  or the discharge port  14 , which has a lower temperature. According to this method, the inner portions of the vacuous reaction chamber  12  and discharge port  14  are heated by the hot N 2  gas, and thus, NH 4 Cl is prevented from being accumulated in the reaction chamber  12  and the discharge port  14 . 
   However, the hot N 2  generator  80  is very expensive. Also, in order to separately install such a heating unit outside the deposition equipment, additional costs such as a high installation cost and working expense are required, in addition to the limitation of the available installation space. 
   In such conventional semiconductor device manufacturing apparatuses as described above with reference to  FIGS. 1 through 3 , a separate expensive unit such as a heating jacket and a hot N 2  generator for heating the outlet portion of a reaction chamber, a discharge port, or a vacuum pipe is required. In addition, together with a separate space for installation of such a unit, additional cost for separate electric equipment installation and working expense are required. 
   SUMMARY OF THE INVENTION 
   According to an aspect of the present invention, an apparatus for manufacturing a semiconductor device comprises a reaction chamber installed in a reaction furnace; a discharge port for removing from the reaction chamber reaction byproducts formed during producing of the semiconductor device; a heater for applying heat to the reaction chamber; and a hot fluid supply unit for supplying heat generated from the heater and the reaction chamber to the discharge port. The hot fluid supply unit includes a fluid container for receiving a heat transfer fluid. The apparatus further comprises a hot fluid generator installed near the reaction chamber in the reaction furnace. The hot fluid generator may be formed of a fluid channel for conveying the heat transfer fluid. The hot fluid generator transfers heat generated from the heater and the reaction chamber to the heat transfer fluid supplied from the fluid container. The apparatus also includes a heat transfer element for transferring heat to the discharge port, using the heat transfer fluid supplied from the hot fluid generator. 
   The hot fluid generator may be formed of multiple fluid channels, each of which has an on/off valve for opening or closing a passage of the heat transferfluid. 
   The hot fluid generator may be installed at an upper portion or a side portion of the reaction chamber in the reactionfurnace. 
   When the heat transfer fluid is a gas, the heat transfer element may comprise nozzles for supplying the heat transfer fluid to the discharge port and the vacuum pipe. 
   The apparatus may further comprise a utility box containing the fluid container. The first pipe may comprise a flow control element for controlling a flow rate of the heat transfer fluid. The flow control element may be a mass flow controller (MFC) or a flow meter. 
   The apparatus may comprise a thermocouple for sensing and monitoring the temperature of the heat transfer fluid from the hot fluid generator. 
   The apparatus may comprise a main controller for opening or closing an on/off valve formed at the multiple fluid channels based on temperature of the heat transfer fluid which is sensed by the thermocouple. 
   The semiconductor device manufacturing apparatus of the present invention can prevent the generation of byproducts during a thin film deposition process, using the heat generated in the reaction chamber, without external heat supply, in an inexpensive and efficient manner. Therefore, a thin film with high quality can be deposited on a wafer and deposition efficiency can be increased. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
       FIG. 1  is a schematic diagram of an apparatus for manufacturing a semiconductor device according to a prior art method; 
       FIG. 2  is an enlarged view of a part of “A” of  FIG. 1 ; 
       FIG. 3  is a schematic diagram of an apparatus for manufacturing a semiconductor device according to another prior art method; 
       FIG. 4  is a schematic diagram of an apparatus for producing a semiconductor device according to an embodiment of the present invention; 
       FIG. 5  is a schematic diagram of a hot fluid generator in an apparatus for producing a semiconductor device according to another embodiment of the present invention; 
       FIG. 6  is a longitudinal sectional view of a heat transfer element in an apparatus for producing a semiconductor device according to yet another embodiment of the present invention; 
       FIG. 7  is a longitudinal sectional view of another heat transfer element according to still another embodiment of the present invention; and 
       FIG. 8  is a cross sectional view a heat transfer element according to an embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIG. 4 , an apparatus for producing a semiconductor device according to an embodiment of the present invention is depicted. The subject apparatus comprises a reaction furnace such as a vertical-type reaction furnace  110 , and a reaction chamber  112  that is contained in the reaction furnace  110 . In the reaction chamber  112 , a silicon nitride film is deposited on a wafer using, for example, dichlorosilane, SiH 2 Cl 2  (DCS), and ammonia (NH 3 ). The lower portion of the reaction chamber  112  is formed with a discharge port  114 , which is connected to a vacuum pump  160  via a vacuum pipe  120 , for the ventilation of the reaction chamber  112 . A heater  116  is installed around the reaction chamber  112  to introduce heat required for the deposition process in the reaction chamber  112 . Heat from the heater  116  is supplied to the reaction chamber  112  during the deposition. Before heat from the heater  116  and the reaction chamber  112  is discharged, all or a portion of the heat passes through a hot fluid supply unit  130  and is then transferred to the discharge port  114  of the reaction chamber  112 , the vacuum pipe  120 , and the vacuum pump  160 . 
   The hot fluid supply unit  130  includes a fluid container  132  for receiving a heat transfer fluid  102 , a hot fluid generator  134  for transferring heat generated from the heater  116  and the reaction chamber  112  to the heat transfer fluid  102 , heat transfer elements  154 ,  156 , and  158  for transferring heat to the discharge port  114 , the vacuum pipe  120 , and the vacuum pump  160 , respectively, using the hot heat transfer fluid  102  supplied from the hot fluid generator  134 . The heat transfer fluid  102  may be a gas or liquid. Preferably, the heat transfer fluid  102  is N 2  gas, He gas, Ar gas, or H 2 O. The fluid container  132  is installed in a utility box  150 , which is contained in conventional semiconductor manufacture equipment. 
   The hot fluid generator  134  serves to transfer heat generated from the heater  116  and the reaction chamber  112  to the heat transfer fluid  102  supplied via a first pipe  142  from the fluid container  132 . The hot fluid generator  134  is installed near the reaction chamber  112  in the reaction furnace  110 . 
   Referring to  FIG. 5 , the hot fluid generator  134  may be formed of multiple fluid channels  134   a,    134   b,  and  134   c  in pipe shapes for passing the heat transfer fluid  102 . The multiple fluid channels  134   a,    134   b,  and  134   c  are formed with respective on/off valves  135   a,    135   b,  and  135   c  for opening or closing a passage of the heat transfer fluid  102 . Although there are three of each in the fluid channels ( 134   a,    134   b,  and  134   c ) and the on/off valves ( 135   a,    135   b,  and  135   c ) as shown in  FIG. 5 , the present invention is not limited thereto. As needed, the number of the fluid channels and on/off valves may vary. 
   Generally, the temperature of the hot fluid generator  134  varies depending on the temperature of the reaction chamber  112 . However, the temperature of the hot fluid generator  134  can be separately controlled by varying the length and material of the pipes or the piping configuration. 
   Alternatively, the temperature of the hot fluid generator  134  can be controlled by varying the surface area of the hot fluid generator  134  through which the fluid passes. In the method of varying the surface area of hot fluid generator  134 , control of the opening and closing operation of the on/off valves  135   a,    135   b,  and  135   c  may be used for this purpose. That is, the temperature of the fluid can be varied depending on opening and closing of the on/off valves  135   a,    135   b,  and  135   c.  For example, closing one or two of the on/off valves  135   a,    135   b,  and  135   c  allows the heat transfer fluid  102 , which passes through the hot fluid generator  134 , to have a lower temperature, when compared to opening all the on/off valves  135   a,    135   b,  and  135   c.    
   In another method regarding the temperature control of the heat transfer fluid by varying a surface area of the hot fluid generator  134  through which the fluid passes. In that instance, a heated fluid is allowed to pass through a separate cooler prior to passing the discharge port  114 , the vacuum pipe  120 , and the vacuum pump  160 . 
   Although the hot fluid generator  134  as shown in  FIG. 5  are formed of pipes, the present invention is not limited thereto. That is, the hot fluid generator  134  may be formed of multiple panel members for passing the heat transfer fluid  102 . Passages for passing the heat transfer fluid  102  may be arrayed in series, in parallel, or in combination. 
   The hot fluid generator  134  may be installed near the reaction chamber  112  in the reaction furnace  110 , for example, at the upper portion, lower portion, or side portion of the reaction chamber  112 . Preferably, the hot fluid generator  134  is installed at the upper or side portion of the reaction chamber  112  in the reaction furnace  110 . More preferably, in order to achieve an optimum heat capacity and thermal stability of the reaction chamber, the reaction chamber  112 , a cooler  118 , and the hot fluid generator  134  can be sequentially arrayed from the bottom to the top of the reaction furnace  110 , as shown in  FIG. 4 . Alternatively, the reaction chamber  112 , the hot fluid generator  134 , and the cooler  118  can also be sequentially arrayed from the bottom to the top of the reaction furnace  110 . The heat transfer fluid  102  discharged from the hot fluid generator  134  may be supplied to only one portion of a semiconductor device manufacturing apparatus. However, it is preferable to supply the heat transfer fluid  102  to all of the relevant portions, i.e., the discharge port  114  of the reaction chamber  112 , the vacuum pipe  120 , and the vacuum pump  160 . 
   The heat transfer fluid  102  from the hot fluid generator  134  is transferred to the discharge port  114  and the vacuum pipe  120  via second pipes  144  and  146 , and to the vacuum pump  160  via a third pipe  148 . The heat transfer elements  154 ,  156 , and  158  transfer heat to the discharge port  114 , the vacuum pipe  120 , and the vacuum pump  160 , respectively, using the heat transfer fluid  102  supplied via the second pipes  144  and  146 , and the third pipe  148  from the hot fluid generator  134 . 
     FIG. 6  is a longitudinal sectional view of an example of the heat transfer element  156 . Although  FIG. 6  illustrates only heat transfer element  156 , a similar structure may be employed for the heat transfer element  154 . That is, the heat transfer elements  154  and  156  have diameters larger than those of the discharge port  114  and the vacuum pipe  120 , respectively, and form dual pipe structures with the discharge port  114  and the vacuum pipe  120 , respectively. For example, the heat transfer element  154  or  156  can be formed of a fluid tube in a pipe shape, which extends along the same axis as the discharge port  114  or the vacuum pipe  120 . In this case, the heat transfer fluid  102  flows through a space defined between the outer wall of the discharge port  114  or the vacuum pipe  120  and the inner wall of the heat transfer element  154  or  156 . 
   Although  FIG. 7  illustrates heat transfer element  156 . However, a similar structure may be used for the heat transfer element  154 . That is, the heat transfer elements  154  and  156  are formed of coiled fluid tubes, which are wound around the discharge port  114  and the vacuum pipe  120 , respectively. In this case, the heat transfer fluid  102  flows inside the coiled fluid tubes. The cross sections of the fluid tubes may be circular, oval, or polygonal in construction. 
   Referring to  FIG. 8 , a space defined between the vacuum pipe  120  and the heat transfer element  156  may be filled with a heat transfer substance  170  to facilitate the heat transfer operation. Preferably, the heat transfer substance  170  is a metal. Although not shown, a space defined between the discharge port  114  and the heat transfer element  154  may also be filled with a heat transfer substance to facilitate a heat transfer. According to the construction of the heat transfer element  156  of  FIGS. 6 and 7 , the vacuum pipe  120  is heated by the heat transfer fluid  102 , which passes through the outer wall of the vacuum pipe  120 . 
   There can be alternative structures of the heat transfer elements  154  and  156  which supply the heat transfer fluid  102  in a gaseous phase directly to inside the discharge pipe  114  and the vacuum pipe  120 , respectively. In such gaseous heat transfer fluid supply designs, the contact surface area of the gaseous fluid is determined according to the supply location and flow rate of the gaseous fluid. In this regard, nozzles are used to ensure uniform contact of the gaseous fluid. The number of the nozzles is determined according to the shape of the discharge port  114  or vacuum pipe  120 , and the degree of deposition of byproducts. The nozzles may be installed symmetrically to the left and right or to be spaced 90 or 45 degrees apart, with respect to the vacuum pipe  120 , for example. Alternatively, the nozzles may be installed in the vacuum pipe  120 , spaced apart from each other, and extending about central axis  120   a  at a predetermined radial distance within a 360 degrees range. In practice, manner of installation of the nozzles is determined according to the use of the nozzles. In addition, in order to prevent the gaseous heat transfer fluid  102  from being sprayed unevenly, diffusers may be installed at the ends of the nozzles. 
   As shown in  FIG. 4 , the first pipe  142  may comprise a flow control element  138  for controlling a flow rate of the heat transfer fluid  102 , which passes through the first pipe  142 . The flow control element  138  may be a mass flow controller (MFC) or a flow meter. The flow control element  138  is installed at the front side of the hot fluid generator  134 , but the location thereof is not limited thereto. Therefore, the flow control element  138  may be installed at the rear side of the hot fluid generator  134 . However, it is preferable to position the flow control element  138  at the front side of the hot fluid generator  134  in which the room-temperature heat transfer fluid  102  flows. The number of the flow control elements  138  may be selected based on factors such as the cost incurred and the ultimate end use. In addition, because the flow control element  138  may undergo substantial changes in the flow rate when switched from a closed mode to an opened mode, it is preferable to use a flow control element  138  which can be set at a slower initial flow rate. Then, the actual operating flow rate can be set for the particular end use. 
   The second pipes  144  and  146  and the third pipe  148 , which transfer the heat transfer fluid  102  from the hot fluid generator  134  to the respective discharge port  114 , vacuum pipe  102 , and vacuum pump  160 , include respective on/off valves  194 ,  196 , and  198  for opening and closing a passage of the heat transfer fluid  102 . The flow of the fluid, which passes through the second pipes  144  and  146 , and the third pipe  148 , can be controlled by on/off operation of the on/off valves  194 ,  196 , and  198 . In addition, the second pipes  144  and  146 , and the third pipe  148  may include respective thermocouples  184 ,  186 , and  188  for sensing and monitoring the temperature of the heat transfer fluid  102 , which passes through these pipes  144 ,  146 , and  148 . 
   The apparatus of the present invention may further comprise a main controller for opening or closing multiple on/off valves  135   a,    135   b,  and  135   c  formed at the multiple fluid pipes  134   a,    134   b,  and  134   c  according to temperature data of the heat transfer fluid  102  sensed by the thermocouples  184 ,  186 , and  188 . That is, when the temperature data of the heat transfer fluid  102  sensed by the thermocouples  184 ,  186 , and  188  are transmitted to the main controller, the on/off valves  135   a,    135   b,  and  135   c  are opened or closed by a signal emitted from the main controller. In this way the flow rate and temperature, the gaseous or liquid heat transfer fluid  102  is supplied in a controlled manner to the discharge port  114 , the vacuum pipe  120 , and the vacuum pump  160 . 
   As apparent from the above descriptions, in the semiconductor device manufacture apparatus of the present invention for carrying out a deposition process on a wafer, preferably using a vertical-type reaction furnace, all or a portion of the heat generated from the reaction chamber can be transferred to a discharge port of the reaction chamber, a vacuum pipe, and/or a vacuum pump using a heat transfer fluid, before the heat is discharged out of the furnace. Therefore, generation of undesirable byproducts can be prevented, for example, at a low temperature area. 
   More specifically, the semiconductor device manufacturing apparatus of the present invention can prevent the generation of, for example, ammonium chloride using all or a portion of the heat generated in the reaction chamber, without the use of an external heat supply, in an inexpensive and efficient manner. Therefore, a thin film with high quality can be deposited on a wafer and deposition efficiency can be increased. 
   While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.