JP2002198315A - Temperature control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature control system for highly accurately controling a temperature of a fluid for a temperature control being used in semiconductor manufacturing equipment. SOLUTION: A tank T is provided with a fluid for the temperature control for the semiconductor manufacturing equipment, a reservoir room 19 to keep the fluid for the temperature control, a heat exchanger 20 for circulating the fluid for the temperature control between the reservoir room 19 and the heat exchanger 20, circulation routes 21, 22 for connecting between the reservoir room 19 and the heat exchanger 20, a pump 23 at the circulation routes 21, 22 to circulate the fluid a sensor 10 for measuring the temperature of the fluid in the reservoir room 19, and a temperature controller 25 for connecting the sensor 10 and the heat exchanger 20 electrically. The temperature controller 25 controls the heat exchanger 20 corresponding to the temperature of the sensor 10 and heats up or cools down the fluid to keep the temperature of the fluid fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control system for maintaining a constant temperature of a temperature control fluid used in a semiconductor manufacturing apparatus such as an epitaxial growth or a CVD process.

[0002]

FIG. 3 is a view showing an epitaxial growth apparatus 1. As shown in FIG. This epitaxial growth apparatus 1 is an apparatus for growing a silicon crystal on the surface of a semiconductor substrate 2.
In a tank 3 of this apparatus, trichlorosilane as a raw material for growing a silicon crystal on the surface of the semiconductor substrate 2 is stored in a liquid state. And this tank 3
Is connected to the reaction chamber 4 via the supply passage 5,
A regulator 6 and a mass flow controller 7 are connected in series to the supply passage 5. The regulator 6 is for keeping the pressure of the fluid supplied from the tank 3 to the reaction chamber 4 constant. The mass flow controller 7 is for keeping the flow rate of the fluid supplied from the tank 3 to the reaction chamber 4 constant. That is, the regulator 6 and the mass flow controller 7 keep the supply pressure and the supply flow rate of the fluid supplied to the reaction chamber 4 constant.

[0003] Reference numeral 14 in the figure denotes a hydrogen introduction path for supplying hydrogen as a carrier gas for trichlorosilane. This hydrogen is supplied in gaseous form to the tank 3 from a cylinder not shown. Reference numeral 15 in the figure denotes the tank 3
This is a trichlorosilane introduction path for replenishing trichlorosilane in accordance with the consumption of trichlorosilane in the inside.
Then, the supplied hydrogen and trichlorosilane are stored in the tank 3
It may be supplied with a temperature difference of ± several degrees with respect to the liquid trichlorosilane inside. Under such a situation, the supply of hydrogen or trichlorosilane causes a temperature change in the tank 3.

When the temperature of the liquid trichlorosilane in the tank 3 changes, the reaction chamber 4 changes in accordance with the temperature change.
The temperature of the gaseous trichlorosilane sent to the reactor also changes. On the other hand, to stably grow the silicon crystal in the reaction chamber 4, the temperature of the gaseous trichlorosilane to be sent to the reaction chamber 4 must be kept constant. Therefore, conventionally, a temperature control system for keeping the temperature of the liquid trichlorosilane in the tank 3 constant has been configured as follows. A heater 8 is provided on the outer periphery of the tank 3 as described above.
And the outside thereof is covered with a heat insulating material 9. The heater 8 is for heating trichlorosilane in the tank 3. Then, the heat insulating material 9 is for preventing heat radiation from the trichlorosilane in the tank 3 at the set temperature. In order to measure the temperature of the trichlorosilane heated as described above, a temperature sensor 10 is attached to the tank 3 and the temperature sensor 10
Is connected to a temperature controller 12 via a wiring 11.
The temperature controller 12 configured as described above turns on / off the power of the heater 8 in accordance with the temperature signal from the temperature sensor 10 and maintains the temperature of trichlorosilane in the tank 3 at the set temperature. Further, the set temperature of trichlorosilane is input to the temperature controller 12 in advance.

[0005] The temperature controller 12 controls the temperature of the trichlorosilane in the tank 3 in the following manner. If the supplied hydrogen or trichlorosilane is lower than the set temperature, the temperature of trichlorosilane in the tank 3 becomes lower than the set temperature. If the temperature of trichlorosilane in the tank 3 becomes lower than the set temperature, the temperature sensor 10
Detects this temperature, and the temperature controller 12 turns on the power of the heater 8 and warms the tank 3 so that the temperature of trichlorosilane becomes the set temperature. When the temperature of the trichlorosilane in the tank 3 reaches the set temperature, the temperature controller 12 turns off the power of the heater 8.

On the other hand, if the supplied hydrogen or trichlorosilane is higher than the set temperature or the heating is excessive, the temperature of trichlorosilane in the tank 3 becomes higher than the set temperature. When the temperature of the trichlorosilane in the tank 3 becomes higher than the set temperature, the temperature sensor 10 detects this temperature, and the temperature controller 12 turns off the power of the heater 8 and turns off the trichlorosilane in the tank 3. Dissipate heat naturally until the temperature reaches the set temperature. In this way, the power of the heater 8 is repeatedly turned on and off to heat the outer periphery of the tank 3 and radiate heat from the outer periphery of the tank 3 so as to control the temperature of trichlorosilane in the tank 3 to be constant. .

[0007] The trichlorosilane gas kept at a constant temperature as described above is sent into the reaction chamber 4 together with hydrogen through the supply passage 5, via the regulator 6 and the mass flow controller 7. The semiconductor substrate 2 is placed on the susceptor 16 in the reaction chamber 4 in advance.
Then, the trichlorosilane introduced into the reaction chamber 4 and the hydrogen are caused to react with each other by the high frequency from the coil 17 outside the reaction chamber 4 to form a silicon single crystal on the surface of the semiconductor substrate 2. Unnecessary gas generated by the above reaction is exhausted from the exhaust passage 18.

[0008]

In the conventional system as described above, the temperature of trichlorosilane in the tank 3 is changed while heating and natural heat radiation are repeated in response to a temperature change due to the supplied hydrogen or trichlorosilane. Was controlled to be constant, but there were the following problems.
As mentioned above, the supplied hydrogen and trichlorosilane are
The liquid trichlorosilane in the tank 3 may be supplied with a temperature difference of ± several degrees. Under these circumstances, the supplied hydrogen and trichlorosilane
A temperature change will occur in the tank 3.

However, when the amount of trichlorosilane in the tank 3 is sufficiently larger than the amount of hydrogen or the like to be supplied, the trichlorosilane in the tank 3 absorbs almost the temperature change, and as a whole a very small temperature. Keep to change. That is, when the ratio of the amount of hydrogen or the like supplied to the amount of trichlorosilane in the tank 3 is sufficiently small,
Most of the temperature change due to the supplied hydrogen or the like is absorbed by the trichlorosilane in the tank 3, and the temperature change becomes very small. Even in the case where the temperature change is minute as described above, in the above system, the error from the set temperature is made as small as possible because the temperature of the trichlorosilane in the tank 3 approaches the set temperature by natural heat radiation and heating by the heater 8. I was trying. On the other hand, in order to improve the response of the control to the temperature change, it is necessary to increase the capacity of the heater 8 to some extent. If the heater 8 having such a high capacity is used, even when the temperature of the trichlorosilane in the tank 3 becomes lower than the set temperature, the temperature of the trichlorosilane quickly rises to the set temperature.

However, when the heater 8 having a high capacity is used, the trichlorosilane in the tank 3 may be overheated when the temperature change is small as described above. If the trichlorosilane is overheated, the temperature must be lowered. However, since the surroundings of the tank 3 are covered with the heat insulating material 9, the natural heat radiation does not immediately lower the temperature, and it takes time to reach the set temperature. I was In addition, if overheating and natural heat radiation are repeated, a problem that the set temperature is not easily converged may occur. And
As the temperature control system satisfies both characteristics of preventing overheating and good control responsiveness,
It was difficult to select a heater and design the tank 3.

Further, when cooling by the natural heat radiation as described above, the temperature of the tank 3 itself may become lower even though the trichlorosilane in the tank 3 maintains the set temperature. That is, under this situation, a small temperature difference occurs between trichlorosilane in the tank 3 and the tank 3 around the trichlorosilane. For this reason, after the temperature of the trichlorosilane reaches the set temperature, heat is transferred, and the temperature of the trichlorosilane drops slightly from the set temperature. When heating is applied to this temperature change, natural heat radiation and heating are repeated, and the same problem as described above may occur. In the control in which the heating and the natural heat radiation are repeated as described above, it has been difficult to keep the temperature of trichlorosilane constant with a high degree of accuracy even for a minute temperature change.

If the temperature of trichlorosilane cannot be kept constant with high precision as described above, the temperature of trichlorosilane to be supplied will vary during the epitaxial growth process in the reaction chamber 4, and a uniform growth process will be obtained. There was another problem. An object of the present invention is to provide a temperature control system for controlling the temperature of a temperature control fluid used in a semiconductor manufacturing apparatus with high accuracy.

[0013]

According to a first aspect of the present invention, a tank is provided with a temperature control fluid used in a semiconductor manufacturing apparatus and a storage chamber for storing the temperature control fluid, while the tank is provided with a storage chamber for storing the temperature control fluid. A heat exchange device through which a temperature control fluid circulates, a circulation passage connecting the heat exchange device and the storage chamber, a pump in the circulation passage for circulating the temperature control fluid, and a storage chamber A sensor for measuring the temperature of the temperature control fluid, and a temperature controller electrically connected to the sensor and the heat exchange device, wherein the temperature controller is adapted to the heat exchange device according to the temperature of the sensor. Is controlled so that the temperature control fluid is heated or cooled, and the temperature of the temperature control fluid is kept constant.

The second invention is characterized in that the heat exchange device is provided with a Peltier element while premising on the first invention.

The third invention is based on the premise of the above invention,
It is characterized in that the temperature control fluid is trichlorosilane.

A fourth invention is based on the premise of the above invention,
An introduction path for supplying a supply fluid such as a carrier gas to the tank is provided, a heat exchanger provided in the introduction path, and a supply fluid heat exchange device for controlling the heat exchanger are provided. While controlling the temperature of the supply fluid with the heat exchanger, the temperature controller controls the heat exchange device according to the temperature of the sensor provided in the storage chamber to heat the temperature control fluid including the supply fluid. Alternatively, it is characterized in that it is configured to cool and keep the temperature of the temperature control fluid constant.

[0017]

FIG. 1 shows a first embodiment of the present invention. The outside of a tank T is covered with a heat insulating material 9. The above-described tank T is provided with the hydrogen introduction path 14 and the trichlorosilane introduction path 15 which is the temperature control fluid of the present invention, and the fluid in the storage chamber 19 in the tank T is not shown. A supply path 5 leading to the epitaxial device is provided.

The storage chamber 19 stores trichlorosilane, and the storage chamber 19 is connected to a heat exchange device 20 via a circulation passage. That is, the storage room 19
Is connected to an upstream circulation passage 21 and a downstream circulation passage 22, and the heat exchange device 20 is connected between the circulation passages 21 and 22. Reference numeral 23 in the figure denotes a pump provided in the upstream circulation passage 21 for forcibly circulating the trichlorosilane in the storage chamber 19.

The heat exchanger 20 directly heats or cools trichlorosilane in the storage chamber 19 using a Peltier device. In other words, the Peltier element generates heat or absorbs heat at the junction of dissimilar metals according to the direction of the current. When one of the junctions absorbs heat from trichlorosilane, the other joint generates heat. I do. The heat exchange device 20 heats or cools trichlorosilane by utilizing the action of heat generation and heat absorption of the Peltier element, which will be described later. The heat exchange device 20 is provided with a passage 24 for circulating cooling water. The cooling water is used to cool the other heated joint and promote the heat absorbing effect of the one joint. ing.

A temperature controller 25 is connected to the heat exchanger 20 as described above via a wiring 27. The temperature controller 25 is electrically connected to the temperature sensor 10 for measuring the temperature in the tank T via a wiring 26.
The temperature controller 25 monitors the temperature of trichlorosilane in the tank T from the temperature sensor 10. In addition, the temperature controller 25 has a function of controlling the heat exchange device 20 according to the temperature of the temperature sensor 10.

Hereinafter, a specific operation for maintaining the temperature of trichlorosilane at the set temperature will be described. First, the set temperature of trichlorosilane is input to the temperature controller 25.
Then, the pump 23 is driven to forcibly circulate the trichlorosilane in the storage chamber 19 via the heat exchange device 20. The temperature of trichlorosilane in the tank T at this time is detected by the temperature sensor 10 and the temperature controller 25
Will be fed back.

If the temperature of the trichlorosilane is lower than the set temperature, the temperature controller 25
A current is caused to flow through the Peltier element to generate heat at one of the junctions and heat the trichlorosilane. The trichlorosilane heated in this manner is stored in the storage chamber 19 and the heat exchange device 2.
Cycles between zero. Therefore, the temperature of the circulating trichlorosilane increases, and the temperature of the trichlorosilane in the tank T also increases due to the heat. Thus, when the trichlorosilane rises to the set temperature,
Since the temperature is fed back to the temperature controller 25, the temperature controller 25 stops the current value to the Peltier element of the heat exchange device 20 or reduces the current value.

Contrary to the above, if the temperature of trichlorosilane is higher than the set temperature, the temperature controller 25 supplies a current in the opposite direction to the case of the above-mentioned heat generation, cools one of the joints, and Cool the chlorosilane. The trichlorosilane thus cooled circulates between the storage chamber 19 and the heat exchange device 20. Therefore, the circulating trichlorosilane is cooled and the trichlorosilane in the tank 3 is also cooled. In this manner, when the trichlorosilane is cooled to the set temperature, the temperature is fed back to the temperature controller 25, and the temperature controller 25 stops the current value to the Peltier element of the heat exchange device 20. Or reduce its value.

When one of the joints of the Peltier element is being cooled, the other joint is cooled by the cooling water from the passage 24 as described above, so that the heat absorbing effect of one of the joints is promoted. Will be.

In the first embodiment, even if the temperature in the tank T is slightly changed by the supplied hydrogen or trichlorosilane, etc., the temperature of the trichlorosilane in the storage chamber 19 is directly controlled. Can be controlled so as to keep the temperature constant with high accuracy. As described above, since the temperature of trichlorosilane can be kept constant with high accuracy, a uniform silicon growth film can be formed with little variation in the temperature of trichlorosilane during the epitaxial growth process. In addition, since the trichlorosilane can be directly cooled by the cooling function of the heat exchange device provided with the Peltier element, the temperature can be lowered faster than the conventional natural heat radiation. Therefore, temperature control with good responsiveness to a temperature change can be performed.

FIG. 2 shows a block diagram of the temperature control system of the second embodiment. As shown in FIG. 2, the second embodiment includes:
In the temperature control system of the first embodiment, a supply fluid such as hydrogen as a carrier gas is supplied to the tank T via the first heat exchanger 28 after the temperature is made constant. Next, the configuration of the supply fluid heat exchange device 29 including the first heat exchanger 28 will be described. The first heat exchanger 28 is connected to the second heat exchanger 30 via a circulation passage. That is, the first heat exchanger 28 is connected with the upstream circulation passage 31 and the downstream circulation passage 32, and the second heat exchanger 30 is connected between the circulation passages 31 and 32. . In the figure, reference numeral 33 denotes the upstream circulation passage 3.
The pump provided in 1 forcibly circulates the inert liquid between the first heat exchanger 28 and the second heat exchanger 30.

The second heat exchanger 30 directly heats or cools the inert liquid circulating in the circulation passages 31 and 32 by using a Peltier element. The Peltier device generates heat and absorbs heat similarly to the heat exchange device 20 described in the first embodiment. The second heat exchanger 30 is provided with a passage 34 for circulating cooling water. The cooling water cools the heat-generating side of the Peltier element and promotes the effect of the heat-absorbing side. I have.

Further, as shown in FIG. 2, the supply fluid heat exchange device 29 is provided with a supply fluid temperature controller 35. The supply fluid temperature controller 35 is electrically connected to the second heat exchanger 30 via a wiring 36. Reference numeral 37 in the figure denotes a temperature sensor provided in the upstream circulation passage 31 for monitoring the temperature of the circulating inert liquid. This temperature sensor 37 is electrically connected to a supply fluid temperature controller 35 via a wiring 38. Moreover, the supply fluid temperature controller 35 has a function of controlling the temperature of the supplied hydrogen according to the temperature of the temperature sensor 37. Reference numeral 39 in the figure denotes a hydrogen introduction passage, which is connected to the first passage of the supply fluid heat exchange device 29.
It is connected to the tank T via a heat exchanger 28.

The temperature of the hydrogen gas supplied into the tank T is controlled by the supply fluid heat exchange device 29 as follows. First, a set temperature of hydrogen supplied to the supply fluid temperature controller 35 is input. Then, the pump 33 is driven to circulate the inert liquid. If the temperature of the circulating inert liquid is lower than the temperature set in the supply fluid temperature controller 35, the supply fluid temperature controller 35 supplies a current to the Peltier element of the second heat exchanger 30 to generate heat, and Heat the active liquid. The inert liquid thus heated circulates between the first heat exchanger 28 and the second heat exchanger 30. Therefore, as the temperature of the inert liquid increases, the temperature of hydrogen supplied by the heat also increases. In this way, when the inert liquid rises to the set temperature, the temperature is fed back to the supply fluid temperature controller 35,
The supply fluid temperature controller 35 stops the current value to the Peltier element of the second heat exchanger 30 or reduces the current value.

On the contrary, if the temperature of the circulating inert liquid is higher than the temperature set in the supply fluid temperature controller 35, the supply fluid temperature controller 35
A current is caused to flow through the 0 Peltier element in a direction opposite to that in the case of the heat generation. The inert liquid is cooled by passing a current through the Peltier element in a direction opposite to that of the heating. The inert liquid thus cooled circulates between the first heat exchanger 28 and the second heat exchanger 30. Therefore, the temperature of the circulating inert liquid is cooled, and the supplied hydrogen is also cooled. In this way, when the inert liquid is cooled to the set temperature, the temperature is fed back to the supply fluid temperature controller 35, so that the supply fluid temperature controller 35
Stops the current value to the Peltier element of the second heat exchanger 30 or reduces the value.

When the inert liquid is cooled by the Peltier element, heat is generated on the side opposite to the cooling side. However, since the heat generation side is cooled by the cooling water from the passage 34, the heat absorbing effect on the cooling side is obtained. Will be promoted.

In the second embodiment, the supply gas heat exchange device 29 is used to control the hydrogen gas supplied to the tank T so that the temperature approaches the set temperature before the hydrogen gas is supplied to the tank T. . Therefore, even if hydrogen is contained in the liquid trichlorosilane in the tank T, the tank T
The effect of the trichlorosilane stored in the first embodiment on the temperature is smaller than that in the first embodiment. Therefore, the temperature of trichlorosilane in the tank T can be controlled with higher accuracy.

[0033]

According to the first and second aspects of the present invention, the inert solution is filled in the jacket covering the storage chamber storing the temperature control fluid, and the temperature of the inert solution is directly controlled. . Therefore, even for a minute temperature change in the tank, the temperature of the inert liquid in the jacket can be directly controlled, so that the temperature of the temperature control fluid can be controlled with high accuracy.

According to the third aspect, since the temperature of trichlorosilane is directly controlled, it is possible to control the temperature of trichlorosilane to be constant with high accuracy. Therefore, during the epitaxial growth process, there is almost no variation in the temperature of trichlorosilane, and a uniform silicon growth film can be formed.

According to the fourth aspect, the temperature of the supplied fluid is controlled. Therefore, the influence on the temperature of the fluid such as trichlorosilane and hydrogen stored in the tank in advance can be further reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a temperature control system according to a first embodiment.

FIG. 2 is a block diagram illustrating a temperature control system according to a second embodiment.

FIG. 3 is a diagram showing an epitaxial growth apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Temperature sensor 19 Storage room 20 Heat exchange apparatus 21 Circulation path (upstream side) 22 Circulation path (downstream side) 23 Pump 25 Temperature controller 28 1st heat exchanger 29 Supply fluid heat exchange apparatus 39 Hydrogen introduction path T tank

Claims (4)

[Claims] The tank includes a temperature control fluid used in a semiconductor manufacturing apparatus and a storage chamber for storing the temperature control fluid, and heat exchange in which the temperature control fluid circulates between the tank and the storage chamber. A device, a circulation passage connecting between the heat exchange device and the storage chamber, a pump in the circulation passage for circulating the temperature control fluid, and measuring a temperature of a temperature control fluid in the storage chamber. A sensor, and a temperature controller electrically connected to the sensor and the heat exchange device, wherein the temperature controller controls the heat exchange device according to the temperature of the sensor, and the temperature control fluid A temperature control system configured to heat or cool the fluid to keep the temperature of the temperature control fluid constant. 2. The temperature control system according to claim 1, wherein the heat exchange device includes a Peltier element. 3. The temperature control system according to claim 1, wherein the temperature control fluid is trichlorosilane. 4. A supply path for supplying a supply fluid such as a carrier gas to a tank is provided, a heat exchanger provided on the introduction path, and a supply fluid heat exchange device for controlling the heat exchanger. While the fluid heat exchange device controls the temperature of the supply fluid with the heat exchanger, the temperature controller controls the heat exchange device according to the temperature of the sensor provided in the storage chamber,
The temperature control system according to any one of claims 1 to 3, wherein the temperature control fluid is heated or cooled to maintain a constant temperature of the temperature control fluid containing the supply fluid. .