JPH0534102Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention relates to an atmospheric pressure CVD device, and in particular to a device for smoothly and accurately shortening the time for cooling down the susceptor when replacing the susceptor. It is something.

(Prior art) Figure 4 shows a conventional atmospheric pressure CVD device.
A heater block 4 made of aluminum alloy is installed on a base plate 3 made of stainless steel or the like that is attached to the fixed plate 1 via a height adjustment device 2, and a susceptor 5 also made of aluminum alloy is placed on top of it. Then, a wafer 6 is placed on this susceptor 5.
The cartridge heater 7 embedded in the heater block 4 heats the wafer 6 by approximately 450 mm.
The reactant gas is heated to about 10°C and blown out from the gas nozzle 8 that faces the surface of the wafer 6 and moves along the surface, and is exhausted from the nozzle cover 9 and exhaust duct 10 around it to apply CVD onto the surface of the wafer 6.
It began to form a film. Note that 11 is a heat insulating material.

In this atmospheric pressure CVD apparatus, after CVD is performed several times, a CVD film gradually accumulates on the surface of the susceptor 5, so that the susceptor 5 must be replaced. When replacing the susceptor 5, since the susceptor 5 is made of an aluminum alloy and has low high-temperature strength, it is necessary to lower the temperature to about 50°C.

(Problem to be solved by the invention) By the way, in the past, the susceptor 5 was
was causing the temperature to drop. However, as the diameter of the wafer 6 has recently increased, the susceptor 5, heater block 4, and base plate 3 have also become larger and have a larger heat capacity. As shown in FIG. 5, it takes as long as 7 hours. In order to shorten the cooling time, active cooling is effective, but it is difficult to cool down the aluminum alloy heater block 4 and susceptor 5, which are heated to about 450°C, smoothly and accurately in a short period of time. It was hot.

The present invention smoothly and accurately cools the heater block and susceptor of the atmospheric pressure CVD equipment in a short period of time, minimizes the negative effects of this cooling, reduces the time required to replace the susceptor, and increases the operating efficiency of the equipment. The aim is to improve.

[Structure of the idea]

(Means for Solving the Problems) The present invention to achieve the above-mentioned object is a conventional method in which a wafer is placed on a susceptor placed on a heater block, and a reactive gas is blown onto the wafer surface. In a pressure CVD device, a cooling pipe is embedded in a heater block or a cooling block provided in contact with the heater block, and a refrigerant is used to selectively supply cooling gas and cooling liquid to the cooling pipe using a switching valve. The switching valve is configured to detect the temperature of at least one of the supply means, the susceptor, the heater block, and the cooling block, and to switch the refrigerant supplied to the cooling pipe from cooling gas to cooling liquid when the temperature falls to a set value. It is equipped with a control section for operation, and a heater block and a cooling block are installed on a base plate made of heat-resistant ceramics.

(Function) Since the susceptor, heater block, and cooling block are in contact with each other, they are at approximately the same temperature during CVD. When replacing the susceptor, stop heating the heater block and flow cooling gas into the cooling pipe to first cool the susceptor with the gas. Cooling with this cooling gas is possible from high temperatures such as CVD temperatures of about 450°C.
The process is continued until the temperature drops to a set temperature of 350°C to 150°C, and when the set temperature is reached, the cooling liquid is switched to, and the cooling liquid is used to cool down to about 50°C.

In this way, by using cooling gas and cooling liquid together and switching them depending on the temperature,
The susceptor and heater block, which are at a high temperature of approximately 450°C, can be cooled smoothly and accurately, making it possible to cool down in a short time while minimizing the negative effects of cooling.Furthermore, the heater block and cooling block are supported on a base plate made of heat-resistant ceramics. Therefore, even if forced cooling as described above is repeated, the flatness will be maintained in the high temperature conditions where CVD is performed, and CVD will not be adversely affected.

(Embodiments) Examples of the present invention will be described below with reference to FIGS. 1 to 3. Note that in FIG. 1, the same parts as in FIG. 4 are designated by the same reference numerals, and their explanation will be omitted. The base plate 3a is made of quartz glass in order to suppress thermal deformation, and a cooling block 12 made of aluminum alloy is installed thereon.
In the cooling block 12, as shown in FIG.
The cooling pipe 13 is buried in a meandering manner. One end of the cooling pipe 13 is selectively connected to a cooling gas supply pipe 15 such as an air pressure source and a cooling liquid supply pipe 16 such as a water pipe via a switching valve 14, and the other end is connected to a tank 17. It is connected to the.

The switching of the switching valve 14 is controlled by the control unit 18, and the output of the temperature detector 19 that detects the surface temperature of the susceptor 5 is controlled by the control unit 18.
When the temperature is higher than the temperature set in the setting section 18a, the cooling pipe 13 is switched to the cooling gas supply pipe 15.
and when the temperature is low, the cooling liquid supply pipe 16
In addition to being connected to the system, it is also possible to supply and stop the supply according to commands.

Above the cooling block 12 is a heater block 4.
The heater block 4 and above are the same as the conventional device shown in FIG. 4.

Next, the operation of this device will be explained. CVD
When performing CVD, the switching valve 14 is closed and power is supplied to the cartridge heater 7 of the heater block 4, and CVD is performed in the same manner as in the conventional apparatus.

When replacing the susceptor 5, the power supply to the cartridge heater 7 is stopped, a command is given to the control section 18, and the switching valve 14 is opened. At this time, the surface temperature of the susceptor 5 is about 450°C, so the temperature detector 1
The output of No. 9 is higher than the set temperature of the setting section 18a. Therefore, when the switching valve 14 is opened as described above, cooling gas is supplied to the cooling pipe 13 from the cooling gas supply pipe 15 to cool the cooling block 12, thereby cooling the heater block 4 and the susceptor 5. Since this initial cooling is performed by gas, it is relatively slow, as shown in FIG. 3, but unlike the case of using liquid such as water, which boils when exposed to high temperatures, it is performed safely and smoothly.

In this way, the cooling block 12, the heater block 4, and the susceptor 5 are cooled, and the surface temperature of the susceptor 5 is set to the set temperature of the setting section 17a, for example.
When the temperature drops to 230°C, the control unit 18 switches the switching valve 14 to supply cooling liquid from the cooling liquid supply pipe 16 to the cooling pipe 13 instead of the cooling gas, and cools the cooling block 12 with the cooling liquid. do. At this time, the temperature of the cooling block 12 has dropped to approximately 230°C as described above, so even if water is used as the cooling liquid, the amount of heat received is relatively small, and the cooling liquid is flowing, so it will not boil. Safe and accurate cooling is performed. As shown in FIG. 3, cooling by this cooling liquid is performed relatively rapidly, and the temperature can be lowered to 50° C. in about 1 hour and 30 minutes in total, including cooling by cooling gas. Note that this cooling time shows one example, and can be further shortened by increasing the heat exchange capacity of the cooling pipe 13 or increasing the flow rates of cooling gas and cooling liquid.

It was thought that by actively cooling the base plate 3a, the heater block 4, and the susceptor 5, it would have a negative effect on CVD. For example, if they are made of a material such as heat-resistant ceramics, the aluminum alloy cooling block 12, heater block 4, and susceptor 5 will not cause any problems because they will follow the top surface of the base plate 3a at a CVD temperature of about 450°C. .

In the above-mentioned embodiment, the cooling pipe 13 is buried in the cooling block 12 which is placed in close contact with the heater block 4.
may be buried in the heater block 4, and
The temperature detector 19 for switching the switching valve 13 is not limited to detecting the surface temperature of the susceptor 5, but may also detect the temperature of the heater block 4 or the cooling block 12. Furthermore, it is preferable to set the temperature at which cooling gas is switched to cooling liquid as high as possible without boiling depending on the type of cooling liquid used and the supply flow rate, etc. Even when using tap water,
The temperature can be raised up to about 350℃.

[Effect of idea]

As described above, according to the present invention, atmospheric pressure CVD
The temperature of the susceptor of the device can be lowered smoothly and accurately in a short time, and the operating rate of the device can be improved.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view showing an embodiment of the present invention, FIG. 2 is a schematic diagram of the main parts of the present invention, and FIG. 3 is a diagram showing the drop in susceptor surface temperature according to the present invention.
FIG. 4 is a partially cutaway side view of a conventional device, and FIG. 5 is a diagram showing a decrease in susceptor surface temperature due to conventional natural cooling. 3, 3a... Base plate, 4... Heater block, 5... Susceptor, 6... Wafer, 8...
Gas nozzle, 12... Cooling block, 13... Cooling pipe, 14... Switching valve, 15... Cooling gas supply pipe, 16... Cooling liquid supply pipe, 18...
...control section, 18a...setting section, 19...temperature detector.

Claims (1)

[Scope of utility model registration request] In an atmospheric pressure CVD apparatus in which a wafer is placed on a susceptor placed on a heater block and a reaction gas is sprayed onto the surface of the wafer, the heater block or a cooling block provided in contact therewith is used. a cooling pipe buried therein; a refrigerant supply means for selectively supplying cooling gas and cooling liquid to the cooling pipe by a switching valve; and at least one of the susceptor, the heater block, and the cooling block. a control unit for detecting one temperature and operating the switching valve to switch the refrigerant supplied to the cooling pipe from cooling gas to cooling liquid when the temperature falls to a set value; An atmospheric pressure CVD device characterized in that a block and a cooling block are installed on a base plate made of heat-resistant ceramics.