JP2835977B2 - Temperature control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control device for obtaining a constant temperature by using both heating and cooling. In particular, the present invention relates to a temperature controller for controlling a substrate temperature of a film forming apparatus and a dry etching apparatus.

[Prior Art] Conventionally, as a control device and a method for obtaining a constant temperature by using both heating and cooling, there are two types of control devices, one for (1) above room temperature and the other for (2) below room temperature. is there.
Since the material used around the sample stage (substrate) must be changed depending on the set temperature of the sample, it must be divided into at least low temperature, near room temperature, and high temperature regions.

(1) In the case of room temperature or higher, heating is performed intermittently and cooling is performed by stopping heating. There are control devices called temperature control devices or temperature regulators. No cooling has taken place.

(2) In the case where the temperature is lower than room temperature, i) control is performed by continuously cooling to a low temperature, heating to a desired temperature and maintaining the temperature at a constant temperature, and a helium refrigerator as a control device. There is a so-called cold head in which a small heater is attached in the vicinity of the tip head cooled by using the heat conduction.

ii) There is a control method in which a refrigerant is gasified to obtain a low temperature, and the temperature is raised to a desired temperature by heating, and the temperature is kept constant (for example, Taji, Denki Kagaku, 108 (12), pp. 1961-1197). (1988)).

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, since it is set up for room temperature or higher or lower than room temperature, it has the following disadvantages.

1) First, the material to be used around the sample stage (substrate) is determined according to the temperature range to be used. Therefore, the target of the control temperature should be divided into room temperature or higher and room temperature or lower. Or the temperature could not be controlled step by step.

2) When the target of the control temperature is higher than room temperature, heating is performed intermittently, and cooling is controlled by stopping heating. Therefore, it is not possible to maintain a constant temperature near a heat source or when exposed to plasma. It was possible.

3) When the target of the control temperature is lower than room temperature: i) The above-mentioned cold head has the following disadvantages.

The area where low temperature can be obtained is narrow (about ^30Φ ).

If a low temperature is to be obtained in a large area region, it is necessary to newly provide a heat transfer system, which is large.

In order to provide the heat transfer system with good electrical insulation in (1), it is necessary to use sapphire having good heat transfer at low temperatures, which is extremely expensive.

ii) In the above-described method of assembling a control system in which the refrigerant is gasified to obtain a low temperature, which is raised to a desired temperature by heating, and which maintains a constant temperature, a low temperature of 0 ° C. or less can be obtained accurately. .

However, this structure is a system that utilizes the vaporization of liquid nitrogen, so it is effective below room temperature, but it is impossible to control it continuously and / or stepwise across room temperature.

On the other hand, Japanese Unexamined Patent Publication (Kokai) No. 63-115338 discloses an apparatus for low-temperature dry etching. As shown in FIG. 1 and FIG. A system for performing heating is disclosed.
The cooling means shown in FIG. 1 of this publication is a method of cooling by utilizing the vaporization of a liquefied gas. The cooling means is in direct contact with the sample stage (substrate), and the cooling efficiency is good. But,
Since the heater is in the refrigerant sump, the capacity of the heater must be increased, and bumping of the refrigerant may cause damage to the apparatus. At the time of bumping, the original purpose of the apparatus (eg, low-temperature etching) cannot be achieved. . Conversely, in the cooling means shown in FIG. 2, the coolant reservoir and the sample stage (basic) are separated from each other, and although the heater capacity is small, the cooling efficiency is reduced.

[Means and Actions for Solving the Problems] The object of the present invention is achieved by the following means.

That is, the temperature control device of the present invention is a heating mechanism that heats the substrate to be temperature-controlled, and the refrigerant is dropped under the open to the atmosphere, and is atomized during the dropping and dispersed on the substrate to disperse the substrate. By having a cooling mechanism for cooling, it is possible to continuously and / or stepwise control a high temperature from a low temperature below room temperature to a high temperature above room temperature across the room temperature.

The greatest feature of the present invention is that the cooling refrigerant is used in the form of mist. Specifically, there are the following advantages.

Since the refrigerant is used in the form of a mist under the open atmosphere, 1) there is no bumping of the refrigerant, so that the cooling efficiency can be improved without damaging the device and the original purpose of the device can be achieved.

2) Moreover, if the number of revolutions of the rotary blades is fixed, the vaporization rate decreases with an increase in the amount of the dropped refrigerant, so that the cooling efficiency can be sharply increased.

3) Since the material used for the sample stage (substrate) does not come into direct contact with the refrigerant for a long time, the range of materials that can be used is expanded,
Even at extremely low temperatures, for example, polytetrachloroethylene can be used as an electrically insulating material, and low-temperature control at low temperatures becomes possible.

4) Uniform cooling of a large area (for example, about ^500Φ ) can be easily performed, and uniform cooling of a large area can be further achieved by providing a plurality of coolant dropping mechanisms and atomizing mechanisms.

In addition, a refrigerant such as liquid nitrogen or a combination of dry ice and ethanol can be used as the refrigerant.

Further, in the temperature control device of the present invention, since the rotating blades for controlling the heating mechanism and the cooling mechanism are separated from the heating section main body and the cooling section main body, the temperature range from low temperature below room temperature to room temperature above room temperature. It is very easy to control the high temperature continuously and / or stepwise.

That is, even if the temperature control device of the present invention is exposed to heat during the temperature control, the temperature is maintained at the set temperature by controlling the amount of the cooling refrigerant and the number of revolutions of the rotating blades.

In addition, since the cooling efficiency of the method of the present invention is extremely good, there are many examples in which the rotation speed control of the rotary blade is sufficient without changing the amount of the cooling refrigerant, and the higher the rotation speed, the higher the atomization efficiency. I have.

However, the number of rotations required to use a high-speed rotating machine is completely unnecessary, and practically, if the number of rotations of the rotating blades is determined at the time of setting the temperature, sufficient control can be performed by controlling the supply of the refrigerant.

As the shape of the rotary wing, a screw-shaped wing, a notched disk-shaped wing, a wing provided with a notched disk-shaped thing in a cylinder,
Commercially available products such as a screw-shaped notched disk-shaped wing and a rotor with a semi-disk at the tip of a rod could also be used, but the mist is evenly distributed in the shape of the rotor. It is not particularly limited as long as it is a material.

EXAMPLES Next, the present invention will be described more specifically with reference to examples.

Embodiment 1 FIG. 1 schematically shows a temperature control device having both a heating mechanism and a cooling mechanism for dropping and atomizing a refrigerant.

In order to maintain the temperature continuously and / or stepwise at each temperature below room temperature and above room temperature, it is composed of the following.

Temperature detection mechanism: composed of thermocouple 5, filter 11 Temperature control mechanism: composed of temperature regulator 4, thermocouple 5, filter 11 Heating mechanism: heater 3 Cooling mechanism for dropping and atomizing refrigerant: refrigerant 1, A refrigerant supply regulator 2, a rotary blade 6, and a rotating shaft 7 are used. Here, a commercially available PID: ON-OFF system manufactured by Chino Corporation that can control the temperature to a low temperature of room temperature or lower is used. Also,
A halogen lamp (not shown) may be used instead of the heater 3.

The temperature control device shown in FIG. 1 was used as an anode of a high frequency sputtering device.

Sputtering conditions Substrate temperature: 80 ° C., target: Si (4 ″ ^Φ ), sputtering gas: Ar, sputtering pressure: 0.01 Torr, high frequency power: 300 W. Sputtering was performed for 3 hours to obtain a 2 μm Si film. In order to set the substrate temperature to 80 ° C. during this period, the number of rotations of the rotor is switched, liquid nitrogen is used as a refrigerant, and the supply amount is adjusted. As a result, no temperature increase was observed during sputtering.

Comparative Example A water-cooled pipe was welded to the temperature control apparatus shown in FIG. 1 from which the cooling mechanism (1, 2, 6, 7) for dropping and atomizing the refrigerant was removed.

This product with a water-cooled pipe was used as an anode of a high frequency / sputtering device.

The sputtering conditions were the same as in Example 1, except that the substrate temperature was set to 80 ° C. and the cooling mechanism was changed to water cooling (23 ° C.). The substrate temperature increased to 150 ° C.

Example 2 In Example 1, only the sputtering conditions were changed as follows.

Substrate temperature: 150 ° C., target: W (4 ″ ^Φ ), sputtering gas: Ar, sputtering pressure: 0.001 Torr, high frequency power: 150 W. Sputtered for 1 hour to obtain a 1 μm W film. In order to set the substrate temperature to 150 ° C., the number of rotations of the rotor was switched and the supply amount of liquid nitrogen was adjusted. As a result, no increase in temperature was observed during sputtering.

Example 3 In Example 2, only the substrate temperature among the sputtering conditions was changed to −40 ° C.

At this time, in order to set the substrate temperature to −40 ° C., the number of rotations of the rotor was switched, and after adjusting the supply amount of liquid nitrogen, liquid nitrogen was supplied in the regulated supply mode to −40 ± 1 ° C. However, no increase in temperature was observed during sputtering.

Example 4 In Example 1, the same effect could be obtained by using a halogen lamp (not shown) instead of the heater 3.

In addition, the shape of the rotary wing only caused a deviation in the adjustment of the control conditions.

Example 5 The apparatus shown in FIG. 1 was used as a cathode of a reactive etching apparatus.

Etching conditions Substrate temperature: -25 ° C, Sample: Positive resist pattern
Etching was performed under the conditions of a / W film / Si wafer, etching gas: SF ₆ , etching pressure: 2 × 10 ⁻³ Torr, and high-frequency power: 100 W until a W pattern was formed.

During this time, in order to set the substrate temperature to −25 ° C., the number of rotations of the rotor was switched, and after adjusting the supply amount of liquid nitrogen, liquid nitrogen was supplied in the regulated supply mode and set to −25 ± 1 ° C. However, no temperature rise was observed during the etching. After completion of the etching, the temperature was returned to room temperature to remove adsorbed substances.

Example 6 In Example 5, the substrate temperature was set to −
Changed to 65 ° C.

At this time, in order to set the substrate temperature at −65 ° C., the number of rotations of the rotary blade was switched, and the supply amount of liquid nitrogen was adjusted. No increase in temperature was observed during the operation.

After completion of the etching, the temperature was returned to room temperature to remove adsorbed substances.

Embodiment 7 The heater 3 of the components shown in FIG.
FIG. 2 shows a structure separated from the above.

The temperature control device shown in FIG. 2 was used as an anode of a high frequency sputtering device.

Sputtering was performed for 3 hours under the same conditions as in Example 1 to obtain a 2 μm Si film. In the meantime, in order to maintain the substrate temperature at 80 ° C. in the same manner as in Example 1, the rotation speed of the rotor was switched and liquid was used as the refrigerant. After adjusting the supply amount using nitrogen, liquid nitrogen is supplied in a regulated supply mode, and 80 ± 0.5 ° C.
However, no temperature increase was observed during sputtering.

This method was particularly effective for -150 to 350 ° C, preferably -100 to 300 ° C.

Embodiments 1 to 7 show examples in which the present invention is applied to a sputtering apparatus used for producing a thin film and a fine particle film and a reactive ion etching (RIE) apparatus used for dry etching. It can also be used for a thin film and fine particle film manufacturing apparatus and a dry etching apparatus, and in each case, control of ± 1 ° C. was achieved.

Here, FIG. 3 schematically shows an apparatus for producing a thin film and a fine particle film provided with the temperature control apparatus of the present invention and a dry etching apparatus, for example, a sputtering apparatus, an electron beam evaporation apparatus, and an ion plating evaporation apparatus. , A resistance heating evaporation apparatus, a reactive etching apparatus, and the like. In light of the above Examples 1 to 7, the cathode of the high-frequency sputtering device or the anode of the dry etching device corresponds to 15 in FIG.

FIG. 4 schematically shows a chemical dry etching apparatus or a chemical vapor deposition apparatus equipped with the temperature control device of the present invention. It is devised according to the application.

[Effects of the Invention] The temperature control device of the present invention can have the following effects.

1. ^{1) The} heating mechanism and ^{2) The} cooling mechanism that drops the refrigerant and ³⁾ atomizes the cooling mechanism are combined. Since it is used in atomization unlike the conventional one, 1), 2) and 3) It is easy to balance and can maintain any temperature continuously.

2. A large area can be realized only by providing a plurality of 1), 2) and 3).

3. Since it is a heating source with a cooling function, it has a function of maintaining a constant temperature even when exposed to a heat source.

4. In addition, since it is a cooling source with a heating mechanism, it has the function of maintaining a constant temperature even when exposed to a cooling source.

5. Inexpensive temperature control with good controllability becomes possible.

6. Since electrical insulation can be easily achieved by using polytetrafluoroethylene, it can be used as an anode of a sputtering device to which a bias is applied or a cathode of a reactive ion etching (RIE) device.

[Brief description of the drawings]

FIG. 1 schematically shows a temperature control device according to the present invention. FIG. 2 is an example in which a part of the temperature control device of the present invention is changed, and only the changed part is shown. FIG. 3 schematically shows an apparatus for producing a thin film and a fine particle film provided with the temperature control apparatus of the present invention and a dry etching apparatus. FIG. 4 schematically shows a chemical dry etching apparatus or a chemical vapor deposition apparatus provided with the temperature control device of the present invention. 1: Refrigerant, 2: Refrigerant supply regulator 3: Heater, 4: Temperature regulator 5: Thermocouple, 6: Rotating blade 7: Rotating shaft, 8: Rotating motor 9: Substrate, 10: Substrate holding jig 11: Filter, 12: substrate support 13: flow controller, 14: temperature controller 15: counter electrode or target 16: exhaust system, 17: pressure gauge 18: means for activating gas

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-297558 (JP, A) JP-A-1-92384 (JP, A) Actually open JP-A-63-128728 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) C23C 14/00-14/58 C23F 4/00 H01L 21/302 G05D 23 / 00,23 / 19

Claims (4)

(57) [Claims] 1. A heating mechanism for heating a substrate to be temperature-controlled, and a cooling mechanism for cooling a substrate by dropping a refrigerant under open air and atomizing and dispersing the refrigerant on the substrate during the dropping. A substrate temperature control device, comprising: 2. The temperature control device according to claim 1, wherein the atomizing mechanism is a rotary wing. 3. A film forming apparatus comprising the temperature control device according to claim 1 as a temperature control device for a sample substrate. 4. A dry etching apparatus comprising the temperature control device according to claim 1 as a temperature control device for a material to be etched.