Abstract:
The present invention provides a metal organic chemical vapor deposition device and a temperature control method therefor. The device comprises: a chamber; a susceptor which is installed inside the chamber to allow rotation therein, wherein at least one substrate is settled thereon; a plurality of heaters which heat the susceptor, wherein the temperature is independently controlled; a gas sprayer which is positioned in the upper part of the susceptor, and sprays gases of group III and V toward the susceptor; a plurality of temperature detection sensors which are positioned in the upper part of the susceptor, and measure the temperature of heating regions heated by each heater; and a controller which retains temperature setting values necessary for the heating regions, and controls the temperature of the heating regions by comparing sensing temperature values detected by each temperature detection sensor with the setting values necessary for the heating regions. According to the present invention, the metal organic chemical vapor deposition device and the temperature control method therefor can uniformly apply necessary temperature ramping to the entire substrates during process by effectively adjusting the temperature conditions essential for every epitaxial process in the metal organic chemical vapor deposition device, which carries out the process by changing the temperature up to 1200° C. from room temperature. Therefore, the invention improves process efficiency and deposition uniformity.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a metal organic chemical vapor deposition device and a temperature control method therefore and, more particularly, to a metal organic chemical vapor deposition device and a temperature control method therefor, which are capable of controlling a temperature of a plurality of divided heating regions. 
     2. Background of the Related Art 
     A nitride material has been most well known as materials for fabricating light-emitting devices. The light-emitting device using the nitride material chiefly has a structure in which a buffer layer made of GaN crystals, an n type doping layer made of n type GaN crystals, an active layer made of InGaN, and a p type doping layer made of p type GaN are sequentially stacked over a substrate, such as a sapphire. Furthermore, the layers are sequentially stacked in one metal organic chemical vapor deposition device chamber. 
     However, temperature conditions for growing each of the layers are different, and the temperature conditions must be effectively controlled whenever each layer is grown in order to satisfy the temperature conditions. Moreover, if a plurality of wafers is seated on a susceptor and a process is performed, temperature uniformity in the entire area of the susceptor has a great effect on process efficiency. For example, if a temperature for forming an n type doping layer is 1200° C., a temperature for forming an active layer may be 700° C. to 900° C. Furthermore, in case of multiple active layers, a process temperature is repeatedly changed in 700° C. and 900° C. 
     SUMMARY OF THE INVENTION 
     Temperature control in a metal organic chemical vapor deposition device is the most important technology for effectively performing the process and obtaining a high quality light-emitting device. If this temperature control is effectively performed, a high efficiency light-emitting device can be obtained. Accordingly, an object of the present invention is to perform temperature control of a metal organic chemical vapor deposition device more effectively. 
     The present invention provides a metal organic chemical vapor deposition device and a temperature control method therefor, wherein a temperature of a susceptor can be effectively controlled in each epitaxial process in the metal organic chemical vapor deposition device. 
     An metal organic chemical vapor deposition device according to the present invention includes a chamber; susceptors rotatably installed within the chamber and configured to have at least one substrate seated therein; a plurality of heaters configured to heat the susceptors and to have their temperatures independently controlled; gas sprayers placed over the susceptors and configured to spray group III gas and group V gas toward the susceptors; a plurality of temperature detection sensors placed on one side of the susceptors and configured to measure temperatures of heating regions heated by the respective heaters; and a controller configured to store temperature setting values necessary for the respective heating regions and to control the temperatures of the heating regions by comparing the detected temperature values, detected by the respective temperature detection sensors, with the respective temperature setting values necessary for the heating regions. 
     The heating regions may include individual heaters individually controlled, the temperature controller may include individual controllers for controlling the respective heaters, and individual power sources for independently supplying electric power to the respective heaters may be connected to the respective heaters. 
     The temperature controller may include individual controllers for controlling the respective heating regions, store a temperature setting value for any one of the heating regions as a representative temperature setting value, and control the temperatures of the heating regions based on the representative temperature setting value. 
     The temperature controller may control a temperature of a representative heating region, selected from among the heating regions, based on the representative temperature setting value and control the temperatures of the remaining heating regions other than the representative heating region based on the detected temperature value detected by a temperature detection sensor for detecting the temperature of the representative heating region, from among the temperature detection sensors. 
     The temperature controller may measure a temperature ramping tendency detected by the representative heating region and perform control so that the remaining heating regions other than the representative heating region comply with the temperature ramping tendency of the representative heating region. 
     The temperature ramping tendency may be a temperature ramping speed of the representative heating region. 
     The temperature controller may store individual temperature setting values necessary for the respective heating regions and control the temperatures of the respective heating regions using the individual temperature setting values. 
     The temperature controller may measure a temperature ramping tendency detected in each of the heating regions and perform control so that the heating regions have the temperature ramping tendency. 
     The temperature ramping tendency may be the temperature ramping speed of each of the heating regions. 
     The temperature ramping tendency may be a temperature variation in each of the temperature setting values of the heating regions. 
     The temperature controller may calculate the mean value of temperatures detected while the susceptors are rotated by specific number of times and control the temperatures of the heating regions by comparing the mean value with each of the temperature setting values. 
     The temperatures of the heating regions detected by the temperature detection sensors may be temperatures for the susceptors. 
     The temperatures of the heating regions detected by the temperature detection sensors may be a temperature for the substrate. 
     The temperatures of the heating regions detected by the temperature detection sensors may be temperatures for the susceptors and the substrate. 
     A method of controlling temperatures of a plurality of heating regions for a metal organic chemical vapor deposition device according to the present invention includes detecting the temperatures of the heating regions by using respective temperature detection sensors; and comparing temperature values, detected by the temperature detection sensors, with respective temperature setting values and controlling the heating regions based on the temperature setting values by using a temperature controller for storing the temperature setting values necessary for the respective heating regions. 
     The heating regions may include individual heaters individually controlled, the temperature controller may include individual controllers for controlling the respective heaters, and individual power sources for independently supplying electric power to the respective heaters may be connected to the respective heaters. 
     The temperature controller may include individual controllers for controlling the respective heating regions, store a temperature setting value for any one of the heating regions as a representative temperature setting value, and control the temperatures of the heating regions based on the representative temperature setting value. 
     The temperature controller may control a temperature of a representative heating region, selected from among the heating regions, based on the representative temperature setting value and control the temperatures of the remaining heating regions other than the representative heating region based on the detected temperature value detected by a temperature detection sensor for detecting the temperature of the representative heating region, from among the temperature detection sensors. 
     The temperature controller may measure a temperature ramping tendency detected by the representative heating region and perform control so that the remaining heating regions other than the representative heating region comply with the temperature ramping tendency of the representative heating region. 
     The temperature ramping tendency may be a temperature ramping speed of the representative heating region. 
     The temperature controller may store individual temperature setting values necessary for the respective heating regions and control the temperatures of the respective heating regions using the individual temperature setting values. 
     The temperature controller may measure a temperature ramping tendency detected in each of the heating regions and perform control so that the heating regions have the temperature ramping tendency. 
     The temperature ramping tendency may be the temperature ramping speed of each of the heating regions. 
     The temperature ramping tendency may be a temperature variation in each of the temperature setting values of the heating regions. 
     The temperature controller may calculate the mean value of temperatures detected while the susceptors are rotated by specific number of times and control the temperatures of the heating regions by comparing the mean value with each of the temperature setting values. 
     The temperatures of the heating regions detected by the temperature detection sensors may be temperatures for the susceptors. 
     The temperatures of the heating regions detected by the temperature detection sensors may be a temperature for the substrate. 
     The temperatures of the heating regions detected by the temperature detection sensors may be temperatures for the susceptors and the substrate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing an embodiment of a metal organic chemical vapor deposition device. 
         FIG. 2  is a diagram showing a first embodiment of the temperature control construction of the metal organic chemical vapor deposition device. 
         FIG. 3  is a flowchart illustrating a first control method using the temperature control construction of the metal organic chemical vapor deposition device according to the embodiment of  FIG. 2 . 
         FIG. 4  is a flowchart illustrating a second control method using the temperature control construction of the metal organic chemical vapor deposition device according to the embodiment of  FIG. 2 . 
         FIG. 5  is a graph illustrating a temperature ramping tendency in each temperature control region. 
         FIG. 6  is a diagram showing a second embodiment of the temperature control construction of the metal organic chemical vapor deposition device. 
         FIG. 7  is a flowchart illustrating a control method using the temperature control construction of the metal organic chemical vapor deposition device according to the embodiment of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     A metal organic chemical vapor deposition device and temperature control methods therefor according to the embodiment are described methods. 
       FIG. 1  is a diagram showing an embodiment of the metal organic chemical vapor deposition device. 
     As shown in  FIG. 1 , the metal organic chemical vapor deposition device includes a reaction chamber  100  and gas sprayers  101  for spraying a process gas from an upper part to a lower part within the reaction chamber  100 . The gas sprayers  101  may include showerheads, nozzles, etc. for spraying group III gas and group V gas. Furthermore, a plurality of viewpoints  101   a  having their bottoms opened is formed in the respective gas sprayers so that temperature detection sensors to be described later can detect temperature. 
     Furthermore, subsectors  102  in which a substrate  103 , such as at least one sheet of a sapphire substrate  103 , is seated is installed under the gas sprayers  101 . In  FIG. 1 , the substrate  103  may be a satellite susceptor which has the at least one substrate  103  seated therein and which may be deviated from the susceptors  102  and drawn externally. 
     The satellite susceptor may be configured to revolve around the rotating shaft  104  of the susceptors  102  by means of the rotation of the susceptors  102  and also to revolute and rotate by rotation itself. To this end, a motor  105  is installed under the susceptor  102 , and the center of the susceptors  102  is coupled to the rotating shaft  104  of the motor  105 . Furthermore, for the rotation of the satellite susceptor, the satellite susceptor may be configured to be rotated by air pressure or a mechanical operation, although not shown. 
     Furthermore, a plurality of heaters  200 ,  201 ,  202 , and  203  for heating the susceptors  102  to a high temperature is installed under the susceptors  102 . The heater may be formed of a tungsten heater, a ceramic heater, an RF heater or the like. The heaters include a first heater  200 , a second heater  201 , a third heater  202 , and a fourth heater  203 . The first heater  200  heats a portion near the center which is the most inner side of the susceptors  102 . 
     In the present embodiment, a region heated by the first heater  200  is called a first heating region. Furthermore, the second heater  201 , the third heater  202 , and the fourth heater  203  are sequentially placed outside the first heater  200 , and regions corresponding to the second heater  201 , the third heater  202 , and the fourth heater  203  are sequentially divided into a second heating region, a third heating region, and a fourth heating region. Furthermore, the first heater  200 , the second heater  201 , the third heater  202 , and the fourth heater  203  include a first temperature detection sensor  240  for detecting a temperature of the first heating region heated by the first heater  200 , a second temperature detection sensor  241  for detecting a temperature of the second heating region, a third temperature detection sensor  242  for detecting a temperature of the third heating region, and a fourth temperature detection sensor  243  for detecting a temperature of the fourth heating region. The heating regions detected by the respective temperature detection sensors  240 ,  241 ,  242 , and  243  may be the positions of the susceptors  102 , may become regions where temperatures of the substrates  103  (i.e., wafers) are detected, or may be regions where temperatures of both the substrate  103  and the wafer are detected while the susceptors  102  are rotated. 
     Meanwhile, in another embodiment, the temperature detection sensors may be placed under the susceptors  102 . Here, the temperature detection sensor may be a thermo couple or a pyrometer. If the pyrometer is used, the viewpoints may be formed under the heaters, such as RF heaters. 
       FIG. 2  is a diagram showing a first embodiment of the temperature control construction of the metal organic chemical vapor deposition device. 
     As shown in  FIG. 2 , in the temperature control construction of the metal organic chemical vapor deposition device, power sources and controllers are connected to the respective heaters. First, a first power source  210  for supplying electric power to the first heater  200  is connected to the first heater  200 . The first power source  210  is equipped with a first individual controller  220  for controlling the first power source  210 . Furthermore, a second power source  211  for supplying electric power to the second heater  201  is connected to the second heater  201 . The second power source  211  is equipped with a second individual controller  221  for controlling the second power source  211 . Furthermore, a third power source  212  for supplying electric power to the third heater  202  is connected to the third heater  202 . The third power source  212  is equipped with a third individual controller  222  for controlling the third power source  212 . Furthermore, a fourth power source  213  for supplying electric power to the fourth heater  203  is connected to the fourth heater  203 . The fourth power source  213  is equipped with a fourth individual controller  223  for controlling the fourth power source  213 . 
     Furthermore, a main controller  230  for controlling the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223  is also provided. Furthermore, each of the individual controllers  220 ,  221 ,  222 , and  223  calculates a mean value of temperatures detected while the susceptors  102  are rotated by one or more times and determines the mean value as a detected temperature value. That is, temperature control for each heating region may be performed by comparing a temperature mean value and a temperature setting value. 
       FIG. 3  is a flowchart illustrating a first control method using the temperature control construction of the metal organic chemical vapor deposition device according to the embodiment of  FIG. 2 . 
     As shown in  FIG. 3 , the same first-step temperature setting value may be designated to the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223  (S 10 ). The temperature setting value may be a ramping temperature which is a target in each region. The reason why the ramping temperature is set as the same temperature setting value (or setting point) is to uniformly deposit a metal organic substance all over the substrate  103  by maintaining all the susceptors  102  at the same temperature. 
     For example, in an epitaxial process for fabricating a Light-Emitting Device (LED), assuming that 1,200° C. that is a temperature for heat treatment and cleaning the substrate  103  under a first hydrogen atmosphere on the substrate  103  is a target temperature, the target temperature detected by the temperature detection sensor may become the temperature setting value. 
     Furthermore, if the same first-step temperature setting value is designated to the individual controllers  220 ,  221 ,  222 , and  223 , the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223  apply the same temperature setting value to the first, the second, the third, and the fourth power sources  210 ,  211 ,  212 , and  213 . Accordingly, the first, the second, the third, and the fourth heaters  200 ,  201 ,  202 , and  203  heat the respective susceptors  102  to the same temperature setting value (S 11 ). Here, the susceptor  102  is rotated at a specific rotating speed. 
     Meanwhile, the first, the second, the third, and the fourth temperature detection sensors  240 ,  241 ,  242 , and  243  detect temperatures for the susceptors  102  in the respective heating regions and transfer the detected temperature values to the individual controllers  220 ,  221 ,  222 , and  223  (S 12 ). Furthermore, when the detected temperature reaches the first-step temperature setting value, each of the heaters  200 ,  201 ,  202 , and  203  maintains a relevant temperature within an acceptable error range of the first-step temperature setting value. The acceptable error range may be within 3% of a setting temperature. 
     While the temperature is ramped on the first-step temperature setting value, the temperature detection sensor  240 ,  241 ,  242 , and  243  analyzes and determines a temperature ramping tendency (i.e., a temperature rise tendency or a temperature fall tendency) of the first heating region (S 13 ). The temperature ramping tendency may be a temperature ramping time versus a temperature value (i.e., a temperature rise speed or a temperature fall speed). 
     The temperature ramping tendency is related to deposition uniformity and deposition quality for a wafer in the epitaxial process. If the temperature ramping tendency is different in each of heating regions, it is difficult to obtain the result of a high quality epitaxial process because deposition quality is deteriorated. Accordingly, if the same or most similar temperature ramping tendency is maintained in the heating regions, the improvement of the epitaxial quality may be expected. Control of the temperature ramping tendency is described in more detail with reference to  FIG. 5 . 
     Temperature ramping is performed by adjusting the temperature ramping tendency so that the first, the second, the third, and the fourth heating regions have the same or most similar temperature ramping tendency (S 14 ). If each of temperatures of the first, the second, the third, and the fourth heating regions reaches the temperature setting value, a desired epitaxial process is performed (S 15 ). 
     It is then determined whether the relevant process has been completed (S 16 ). If, as a result of the determination, the main controller  230  determines that a next process needs to be performed, a temperature setting value different from the first-step temperature setting value is inputted (S 17 ). For example, the main controller  230  may provide a second-step temperature setting value (i.e., an (1+n)-step, wherein n is a natural number) to the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223  as the temperature setting value. Accordingly, the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223  perform control so that temperature ramping is performed based on a next-step temperature setting value in the heaters  200 ,  201 ,  202 , and  203  through the power sources  210 ,  211 ,  212 , and  213 . Likewise, the temperature ramping tendency is maintained. 
     Furthermore, temperature setting for a plurality of different temperature setting values may be applied when a plurality of epitaxial processes with different conditions is performed in one reaction chamber  100 . Since one epitaxial process may be performed in one reaction chamber  100 , temperature setting may be modified in various ways depending on process operating conditions of the reaction chamber  100 . 
     Meanwhile, in another embodiment, temperature ramping may be performed by inputting different and unique temperature setting values to the heaters  200 ,  201 ,  202 , and  203 . In this case, if a large number of the substrates  103  are seated in the large-sized susceptors  102 , temperature ramping may be performed when it is difficult to control a temperature over a very wide area using the same temperature setting value or may be performed when a process target has a different temperature ramping value in each heating region for epitaxial uniformity, but process efficiency is good. In yet another example, temperature ramping may be performed when temperature ramping needs to be controlled more actively, such as the case in which a different process is required in each position on the susceptor  102 . 
     A method for the embodiment is shown in  FIG. 4 .  FIG. 4  is a flowchart illustrating a second control method using the temperature control construction of the metal organic chemical vapor deposition device according to the embodiment of  FIG. 2 . 
     As shown in  FIG. 4 , the main controller  230  designates unique temperature setting values to the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223  (S 20 ). Each of the unique temperature setting values may be a ramping temperature which is independently a target in each heating region. 
     When the unique temperature setting values are designated to the individual controllers  220 ,  221 ,  222 , and  223 , the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223  supply unique temperature setting values to the first, the second, the third, and the fourth power sources  210 ,  211 ,  212 , and  213 . Accordingly, the first, the second, the third, and the fourth heaters  200 ,  201 ,  202 , and  203  heat the respective susceptors  102  based on the unique temperature setting values (S 21 ). Here, the susceptors  102  are rotated at a specific rotating speed. 
     Next, the first, the second, the third, and the fourth temperature detection sensors  240 ,  241 ,  242 , and  243  detect temperatures of the respective heating regions and transfer the detected temperatures to the individual controllers  220 ,  221 ,  222 , and  223  (S 22 ). When the detected temperatures reach the respective unique temperature setting values, each of the heaters  200 ,  201 ,  202 , and  203  maintains the relevant temperature within an acceptable error range of the preset unique temperature setting value. The acceptable error range may be within  3 % of the setting temperature. 
     While the temperature is ramped on the unique temperature setting value, the first temperature detection sensor  240  determines a temperature ramping tendency of the first heating region (a temperature rise tendency or a temperature fall tendency). The characteristic of the temperature ramping tendency is the same as that of the first method. 
     When the temperature of each of the first, second, third, and the fourth heating regions reaches the preset unique temperature setting value in the state in which the first, the second, the third, and the fourth heating regions are adjusted to have the same or very similar temperature ramping tendency, a desired epitaxial process is performed (S 24 , S 25 ). 
     It is then determined whether the relevant process has been completed (S 26 ). If, as a result of the determination, the main controller  230  determines that a next process needs to be performed, the main controller  230  input second new and unique temperature setting values different from the first unique temperature setting values as temperature setting values (S 27 ). Accordingly, the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223  perform control so that temperature ramping is performed based on the unique temperature setting values of a next step in the heaters  200 ,  201 ,  202 , and  203  through the respective power sources. Likewise, the temperature ramping tendency is maintained. 
     Meanwhile,  FIG. 5  is a graph illustrating a temperature ramping tendency in temperature control regions. In  FIG. 5 , a process of maintaining a temperature ramping tendency in each heater or region is described by taking the epitaxial process of an LED as an example. 
     As shown in  FIG. 5 , in order to perform the epitaxial process, the plurality of substrates  103 , such as sapphires, is seated on the susceptors  102  within the reaction chamber  100 . Next, the inside of the reaction chamber  100  is blocked from the outside, and preparations for starting the process are made. During the preparation time for starting the process, the first, the second, the third, and the fourth temperature detection sensors  240 ,  241 ,  242 , and  243  measure temperatures of the relevant heating regions and transfer the detected results to the individual controllers  220 ,  221 ,  222 , and  223 . 
     The process is performed according to a necessary process sequence. The first process is a cleaning process for cleaning the substrates  103  through heat treatment. For the cleaning process, temperature setting values are set to 1000° C. to 1200° C., and the inside of the reaction chamber  100  becomes a hydrogen atmosphere. 
     If the temperature setting values are identically set, the main controller  230  transfer the same temperature setting value to the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223 . If different temperature setting values for process uniformity are set in the heating regions, the main controller  230  transfer unique temperature setting value to the individual controllers  220 ,  221 ,  222 , and  223 . In either case, a temperature required in an heat treatment process is 1000° C. to 1200° C. within an acceptable error range. 
     If the temperature setting values are set as described above, the heaters perform temperature ramping based on the temperature setting values. In the heat treatment process, temperature ramping conditions are to raise a temperature up to the temperature setting values. At this time, a temperature ramping tendency (i.e., a temperature-rise speed) in the first heating region is detected. In other words, the temperature-rise speed is detected based on a temperature for the consumption time, and each of temperature-rise speeds in the second, third, and fourth heating regions are then compared with the temperature-rise speed in the first heating region. If heating regions having temperature-rise speeds different from the temperature-rise speed in the first heating region are detected, the individual controllers  220 ,  221 ,  222 , and  223  for controlling the respective heaters  200 ,  201 ,  202 , and  203  control the temperature-rise speeds in the respective heating regions so that the temperature-rise speeds are uniformly performed in the respective heating regions. 
     When each of the temperatures of the first, the second, the third, and the fourth heating regions reaches the temperature setting value within an acceptable error range, the substrates  103  are heated and annealed to temperatures corresponding to the relevant temperature setting values for 10 to 20 minutes. The heat treatment process is a cleaning process for removing an alien substance layer, such as an oxide film on the substrate  103 . Here, the inside of the reaction chamber  100  becomes a hydrogen gas atmosphere. 
     When the heat treatment process is finished, a process of depositing a GaN buffer layer is performed. The process of depositing the GaN buffer layer is a process of depositing a GaN layer having a thickness of about 100 nm at 450° C. to 600° C. For the heat treatment process, a temperature in each heating region whose temperature has risen must be decreased to 450° C. to 600° C. The temperature at this time becomes a second temperature setting value. 
     Accordingly, when the main controller  230  transfer the second temperature setting values to the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223 , the individual controllers  220 ,  221 ,  222 , and  223  control the first, the second, the third, and the fourth heater  200 ,  201 ,  202 , and  203 , respectively, so that the temperatures are decreased to the second temperature setting values. The first, the second, the third, and the fourth temperature detection sensors  240 ,  241 ,  242 , and  243  continue to detect the temperature-fall states and transfer the detected temperatures to the first, the second, the third, and the fourth individual controllers  220 ,  221 ,  222 , and  223 . Furthermore, the main controller  230  checks a temperature ramping tendency received from the first individual controller  220  and performs control so that the second, the third, and the fourth heaters  201 ,  202 , and  203  are operated according to the checked temperature ramping tendency and thus the temperature falls of the first, the second, the third, and the fourth heating regions have the same temperature ramping tendency. 
     If the buffer layer is grown to a thickness of about  100  nm, an undoped GaN layer is deposited. The undoped GaN layer is deposited to a temperature of 1000° C. to 1100° C. for about 60 minutes. 
     To this end, temperatures are raised again. Furthermore, a process is performed in the state in which the temperature rises have the same temperature ramping tendency in the heating regions as described above. Furthermore, a process of depositing an active layer and a p-GaN layer is performed while performing temperature ramping. In this case, the heating regions have the same temperature ramping tendency. If the same temperature ramping tendency is maintained in the layers as described above, there is an advantage in that the layers deposited using the epitaxial process have a very uniform crystalline growth quality in the substrates  103  of all the susceptors  102 . 
     Furthermore, the temperature ramping tendency may be a temperature ramping speed (i.e., a temperature-rise speed or a temperature-fall speed) or a temperature variation for a temperature setting value. If the temperature ramping speed and the temperature variation is controlled identically or similarly, the epitaxial process can be performed with higher efficiency. 
     Meanwhile, in the metal organic chemical vapor deposition device of the present embodiment, the temperature control construction may be modified and implemented differently.  FIG. 6  is a diagram showing a second embodiment of the temperature control construction of the metal organic chemical vapor deposition device, and  FIG. 7  is a flowchart illustrating control method using the temperature control construction of the metal organic chemical vapor deposition device according to the embodiment of  FIG. 6 . 
     In the temperature control construction according to the second embodiment, as shown in  FIG. 6 , a first power source  210  for supplying electric power to the first heater  200  is connected to the first heater  200 . The first power source  210  is equipped with a first individual controller  220  for controlling the first power source  210 . Furthermore, a second power source  211  for supplying electric power to the second heater  201  is connected to the second heater  201 . The second power source  211  is equipped with a second individual controller  221  for controlling the second power source  211 . Furthermore, a third power source  212  for supplying electric power to the third heater  202  is connected to the third heater  202 . The third power source  212  is equipped with a third individual controller  222  for controlling the third power source  212 . Furthermore, a fourth power source  213  for supplying electric power to the fourth heater  203  is connected to the fourth heater  203 . The fourth power source  213  is equipped with a fourth individual controller  223  for controlling the fourth power source  213 . Furthermore, a main controller  230  for controlling the first individual controller  220  is provided. 
     Furthermore, unlike in the first embodiment, the main controller  230  is connected to the first individual controller  220 , and it supplies a temperature setting value to only the first individual controller  220 . That is, the main controller  230  supplies a representative temperature setting value to the first individual controller  220 , but does not supply additional temperature setting values to the remaining individual controllers  221 ,  222 , and  223 . Furthermore, while the susceptors  102  are rotated by one or more times, the individual controllers  220 ,  221 ,  222 , and  223  calculate the mean values of respective detected temperatures and determine the mean values as detected temperature values. Meanwhile, temperature control may be performed by using the temperature mean values and temperature values detected at specific positions. 
     Furthermore, temperatures detected by the temperature detection sensors  240 ,  241 ,  242 , and  243  may be temperatures of the susceptors  102 , may be temperatures of the substrates  103  (i.e., wafers), or may be temperatures of both the substrates  103  and the wafers which are detected while the susceptors  102  are rotated. 
       FIG. 7  is a flowchart illustrating a first control method using the temperature control construction of the metal organic chemical vapor deposition device according to the embodiment of  FIG. 6 . 
     As shown in  FIG. 7 , a representative temperature setting value (i.e., a first-step temperature setting value) may be designated to the first individual controller  220  (S 30 ). The representative temperature setting value may be a ramping temperature that is a target in each region. After the first-step representative temperature setting value is designated to the first individual controller  220 , the first temperature detection sensor  240 ,  241 ,  242 , and  243  detects a temperature of the first heating region and transfers the detected temperature value to the first individual controller  220  (S 31 ). 
     That is, the first heating region becomes a representative heating region. Furthermore, the first individual controller  220  transfers the temperature of the first heating region to the second, the third, and the fourth individual controllers  221 ,  222 , and  223 . Accordingly, the second, the third, and the fourth individual controllers  221 ,  222 , and  223  start heating based on the detected temperature of the first heating region (S 32 ). At this time, the susceptors  102  are rotated at a specific rotating speed. 
     Furthermore, while temperatures are ramped on the representative temperature setting value, the first temperature detection sensor  240  analyzes and determines a temperature ramping tendency (i.e., a temperature-rise tendency or a temperature-fall tendency) of the first heating region (S 33 ). Next, the second, the third, and the fourth heaters  201 ,  202 , and  203  are controlled so that respective temperature tendencies become adjusted (S 34 ). 
     In the state in which the first, the second, the third, and the fourth heating regions have been adjusted to have the same or similar temperature ramping tendency as described above, a desired epitaxial process is performed based on the temperatures of the first, the second, the third, and the fourth heating regions (S 35 ). 
     Next, if the first individual controller  220  determines that the temperatures have been ramped on the first-step representative temperature setting value, the first individual controller  220  controls the first heater  200  so that the ramped temperature is maintained. At this time, the second, the third, and the fourth individual controllers  221 ,  222 , and  223  continue to control the respective heaters  200 ,  201 ,  202 , and  203  based on a temperature value detected by the first temperature detection sensor  240 ,  241 ,  242 , and  243  in real time and reported to the first individual controller  220  so that temperatures of the respective heating regions are controlled within an acceptable error range identical with or similar to the temperature of the first heating region (S 33 , S 34 ). Next, whether a next process will be performed is determined (S 37 ). If, as a result of the determination, the next process needs to be performed, the process is performed when the first heater  200  starts heating at an (1+n)-step (n is a natural number) temperature setting value (S 38 ). 
     Meanwhile, in a second embodiment, the second, the third, and the fourth heaters  201 ,  202 , and  203  are controlled so that they track the temperature of the first heating region. Accordingly, the first, the second, the third, and the fourth heaters  220 ,  221 ,  222 , and  223  may automatically maintain the same or similar temperature ramping tendency with a time lag without additional control. Furthermore, even though a next process is performed, a temperature ramping tendency and temperature uniformity can be secured because ramping conditions of the first heater  200  are different from those of the second, the third, and the fourth heaters  201 ,  202 , and  203 . 
     Furthermore, if a temperature value of the first heating region provided from the first individual controller  220  to the second, the third, and the fourth individual controllers  221 ,  222 , and  223  is consistently provided at short time intervals if possible, temperature uniformity and a temperature ramping tendency may be controlled more accurately. 
     According to the metal organic chemical vapor deposition device and the temperature control methods therefor according to the present invention, in the metal organic chemical vapor deposition device on which processes are performed while a temperature is changed from normal temperature to 1200° C., temperature conditions necessary for the epitaxial process are effectively controlled so that temperature ramping necessary during the process is uniformly performed in all the substrates. Accordingly, there are advantages in that deposition uniformity and process efficiency can be improved.