JPH0499178A - Cvd device - Google Patents

Abstract

PURPOSE:To easily hold the entire raw material feed pipe at a specified temp. with a simple structure, to prevent the condensation and thermal decomposition of the raw material and to form a good-quality thin film in the CVD device in which plural solid materials are heated and vaporized to obtain the raw gas by housing the raw material feed pipe in an insulated box and specifying the temp. in the box. CONSTITUTION:Four kinds of raw materials, for example, are supplied to a reaction furnace 2, and a specified thin film is formed in the furnace 2. Four sets of the container 4 for the solid material, thermostatic oven 5 for heating the container 4 to a specified temp. and raw material feed pipe 6 for feeding the vaporized raw gas entrained by a carrier gas to the furnace 2 are provided as the raw material feed circuit 3. Meanwhile, a pipeline extending from a raw gas outlet pipe 8 to the furnace 2 via a feed pipe 6 is housed in an insulated box 15 provided with a heating source and a temp. control part 15a consisting of an air agitating means and a temp. controller for keeping the box at a specified temp. by controlling the heat generated from the heating source. The box 15 is heated at a temp. higher than that of any bath 5 and lower than the thermal decomposition temp. of the plural solid materials.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a CVD apparatus, such as a CVD apparatus that forms a superconducting thin film on a substrate, in which a plurality of homogeneous raw materials are heated and vaporized to form a raw material gas. Regarding CVD equipment.

[Conventional technology]

In the superconducting thin film CVD (chemical paper deposition) device, Sr, Ca, Cu, B
β-diketone metal complexes such as a, Pb, B i (C
Solid raw materials such as 6H4) are used, but these are generally 1
It is heated and vaporized in a temperature range of 20 to 250°C and used as a raw material gas. In addition, since each solid raw material is a thermally decomposed product, it is necessary to set the temperature appropriately and use it. For this reason, in the conventional apparatus, as shown in FIG.
The material gas is heated to a predetermined temperature and vaporized.
The mixture is sent to the mixer 24 through the respective raw material supply pipes 23 and 23 together with a predetermined carrier gas supplied from the carrier gas introduction pipe 22, mixed evenly, and supplied to the reactor 25, where the substrate is heated under predetermined conditions. A thin film is formed on top.

Note that the concentration of the raw material gas supplied to the reactor 25 is 1'! 2L 2] temperature control, if the raw material container 20 and raw material supply pipe 23 are placed in a single constant temperature bath, the raw material concentration cannot be adjusted.
It becomes impossible to form a desired thin film.

Further, when creating a superconducting thin film, in order to make each of the above elements into oxides, a predetermined amount of oxygen at a predetermined temperature is supplied to the reactor 25 from a pipe (not shown).

Then, in order to prevent the vaporized raw materials from condensing or thermally decomposing within the raw material supply pipes 23, heater wires 26 and 26 are wound around each raw material supply pipe 23 and 23, and further heat insulation treatment (not shown) is performed to individually maintain a predetermined temperature. It was heated to.

[Problem to be solved by the invention]

However, winding the heater wire around the raw material supply pipe is time-consuming, and when maintaining the raw material supply pipe or thermostatic chamber, it must be attached and detached each time, and the wire may break at that time. There was also.

Furthermore, if there is variation in the winding density of the heater wire wound around the raw material supply pipe, temperature unevenness will occur within the raw material supply pipe.
The raw material condenses in a part of the raw material supply pipe, resulting in a change in the raw material concentration in the carrier gas, or the raw material thermally decomposes and changes into a different substance, which may adversely affect the formation of a thin film. In order to prevent this, it is necessary to measure and adjust the temperature over the entire length of the raw material supply pipe, but it is almost impossible to adjust the entire length of the raw material supply pipe.

Therefore, an object of the present invention is to provide a CVD apparatus that has a simple configuration, can easily maintain the entire raw material supply pipe at a predetermined temperature, prevents condensation and thermal decomposition of the raw material, and forms a high-quality thin film. The purpose is

[Means to solve the problem]

In order to achieve the above object, the CVD apparatus of the present invention vaporizes a plurality of solid raw materials by heating each of them to a predetermined temperature in a constant temperature bath, and supplies the solid raw materials onto a substrate in a reactor via a raw material supply pipe. In the CVD apparatus for forming a thin film on the substrate, the raw material supply pipe is equipped with a heating source, an air stirring means, and a temperature controller that controls the amount of heat generated by the heating source and sets it to a predetermined temperature. The material is housed in an insulated box, and the temperature in the insulated box is set higher than the highest temperature of any one of the constant temperature baths and lower than any of the thermal decomposition temperatures of the plurality of solid raw materials. It is said that

Furthermore, the present invention is characterized in that the raw material supply pipe between the thermostatic oven and the heat insulating box is covered with a pipe communicating with the thermostatic oven and the heat insulating box to form double piping.

[For production]

As mentioned above, by storing the entire raw material supply pipe in an insulated box set at a predetermined temperature, the labor of winding the heater wire around the raw material supply pipe can be saved, and the work during equipment manufacturing and maintenance can be simplified. It can be significantly reduced. Further, by setting the inside of the heat insulating box within the above temperature range, it is possible to prevent the raw material from condensing or thermally decomposing.

Furthermore, by forming the raw material supply pipe between the thermostatic chamber and the heat insulating box into a double pipe, it is possible to prevent the raw material from condensing or thermally decomposing in this part.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on embodiments shown in the drawings.

First, in FIG. 1, this CVD apparatus 1 is configured to supply four types of raw materials to a reactor 2 at the same time or by switching them as appropriate, and to form a predetermined thin film within the reactor 2. The raw material supply circuit 3 includes a raw material container 4 containing each homogeneous raw material, a constant temperature bath 5 that heats the raw material container 4 to a predetermined temperature, and a reactor 2 in which the vaporized raw material gas is entrained with a predetermined carrier gas. Raw material supply pipe 6 to be supplied to 4
A set is provided.

A carrier gas inlet pipe 7 and a raw material gas outlet pipe 8 are connected to each raw material container 4, and by appropriately opening and closing valves 9.9 provided in each pipe line, a predetermined raw material gas is supplied to the reactor. It is formed so that it can be supplied to 2. That is, the carrier gas for supplying the raw material gas, for example argon gas, is branched from the carrier gas main pipe 10 to each branch pipe 11, adjusted to a predetermined flow rate by the flow rate regulator 12, and then passed from the carrier gas introduction pipe 7 to the preheater. The raw material gas is introduced into the raw material container 4 via the raw material container 13, and is led out to the raw material gas outlet pipe 8 together with the raw material gas vaporized in the raw material container 4. The raw material gas entrained in the carrier gas passes through the raw material gas outlet pipe 8, the raw material supply pipe 6, and the mixer 14 where it is uniformly mixed, and then transferred to the reactor 2.
will be introduced in

In the present invention, the piping system from the raw material gas outlet pipe 8 to the reactor 2 via the raw material supply pipe 6 is set to a predetermined temperature by controlling the heating source, the air stirring means, and the calorific value of the heating source. The plurality of solids are housed in an insulating box 15 equipped with a temperature controller 15a consisting of a temperature regulator, and the temperature in the insulating box 15 is higher than the highest temperature of any of the thermostatic chambers 5, and the plurality of solids are The temperature is set lower than any of the thermal decomposition temperatures of the raw materials.

The heat source in the temperature control section 15a may be, for example, a heater provided in the heat insulating box 15, or introducing and circulating hot air or steam into the heat insulating box 15. An appropriate heating source can be used depending on the conditions such as the volume and set temperature. Further, the air stirring means is for stirring the air in the heat insulating mls with a fan or the like to prevent temperature unevenness in the heat insulating box 15 as much as possible, and the temperature regulator is a temperature sensor and a heat generating amount of the heater. Alternatively, it is configured by an electric circuit, an air volume control mechanism, etc. that controls the amount of hot air or steam introduced, or the temperature thereof. Similar to the above, these can also be implemented with appropriate configurations depending on conditions such as the volume of the heat insulating box 15 and the set temperature.

For example, the temperature of each constant temperature bath 5 is T, , T2 . T.

T41, T4>T, , T2. T, the lowest temperature TL in the insulation box 15 is set to TL>T4, and the highest temperature T□ in the insulation box 15 is set to a temperature at which the raw material does not thermally decompose. Ru. In addition, when using a raw material that decomposes at temperature T', store the raw material supply pipe that supplies this raw material in a separate insulated box, set the inside of the insulated box to an appropriate temperature, and turn off the mixer 14. They may be formed so that they merge just before.

Also, a raw material supply pipe 8 between the thermostatic chamber 5 and the insulation box 15
Although the section a is a short section, it is exposed to the outside air and is cooled by the outside air, so a heater is wrapped around this section to heat it to a predetermined temperature range, and the section is appropriately covered with a heat insulating material. Further, a pipe 16 having a larger diameter than the raw material supply pipe 8a and communicating with both the thermostatic chamber 5 and the heat insulating box 15 may be provided in this portion to accommodate the raw material supply pipe 8a.

In this way, by covering the raw material supply pipe 8a with a pipe 16 of an appropriate diameter, making this part a double pipe structure, and further covering it with a heat insulating material as necessary, the inside of the pipe 16 can be connected to the thermostatic chamber 5. Due to the action of the heated air inside the heat insulating box 15, the temperature is maintained at an intermediate temperature between the constant temperature bath 5 and the heat insulating box 15, making it possible to maintain the raw material supply pipe 8a at an appropriate temperature.

Therefore, there is no need to wrap heater wires around individual pipes.
The entire piping system from the thermostatic chamber 5 to the reactor 2 is kept uniformly at a temperature that does not cause condensation or thermal decomposition of the raw materials, eliminating the need for winding heater wires and making it easy to use during equipment manufacturing and maintenance. In addition to greatly reducing work, reactor 2
The raw materials can be supplied in a desirable manner, and high-quality young films can be produced.

Further, in FIG. 2, each of the raw material gas outlet pipes 8 is connected to one raw material supply pipe 18 so that each raw material gas is supplied to the reactor 2 at once. In this case as well, by setting the inside of the heat insulating box 15 at a temperature higher than the highest temperature of each constant temperature bath 5 and lower than any of the thermal decomposition temperatures of the plurality of solid raw materials, as described above, This eliminates the need for heater wires, greatly reducing work during equipment manufacturing and maintenance, and prevents condensation and decomposition of raw materials within the piping system.

Incidentally, when the raw material gas outlet pipe 8 is connected to one raw material supply pipe 18 as shown in FIG. 2, there is no need to provide a mixer upstream of the reactor 2. Further, in FIG. 2, the same components as those shown in FIG. 1 are given the same reference numerals and detailed explanations will be omitted.

〔Effect of the invention〕

As explained above, in the CVD apparatus of the present invention, the raw material supply pipe is housed in a heat insulating box, and the temperature in the heat insulating box is set higher than the highest temperature of a plurality of thermostats for vaporizing solid raw materials. Since the thermal decomposition temperature is set high and lower than any of the thermal decomposition temperatures of multiple solid raw materials, it eliminates the hassle of winding heater wires around each raw material supply pipe, greatly reducing work during equipment manufacturing and maintenance. In addition, it is possible to reduce the manufacturing cost and operating cost of the device, improve the operating efficiency of the device, and easily manage the temperature of the piping system.

Furthermore, by setting the temperature inside the insulation box within a predetermined range, it is possible to prevent condensation and thermal decomposition of the raw materials in the piping system from the thermostatic chamber to the reactor. It is possible to obtain a film having a similar composition with good reproducibility, and it is possible to significantly improve the crystallinity of the thin film.

Furthermore, by forming the raw material supply pipe between the thermostatic chamber and the heat insulating box into a double pipe, it is possible to prevent the raw material from condensing or thermally decomposing in this part.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a CVD apparatus showing an embodiment of the present invention;
FIG. 2 is a system diagram of a CVD apparatus showing another embodiment of the present invention, and FIG. 3 is a system diagram showing an example of a conventional CVD apparatus. 1...CVD apparatus 2...Reactor 3...Raw material supply circuit 4...Raw material container 5...Thermostat
6. Raw material supply pipe 15...insulation box

Claims (2)

[Claims] 1. In a CVD apparatus, a plurality of solid raw materials are heated to a predetermined temperature in a constant temperature bath, vaporized, and supplied onto a substrate in a reactor via a raw material supply pipe to form a thin film on the substrate. a supply pipe, a heating source, an air agitation means,
The heating source is housed in an insulated box equipped with a temperature regulator that controls the calorific value of the heat source and sets it at a predetermined temperature, and the temperature in the insulated box is set higher than the highest temperature of either of the thermostatic ovens. , and is set lower than any of the thermal decomposition temperatures of the plurality of solid raw materials. 2. 2. The CVD apparatus according to claim 1, wherein a raw material supply pipe between the thermostatic chamber and the insulation box is covered with a pipe communicating with the thermostatic chamber and the insulation box to form double piping.