JPH04301078A - Cooling method and cooling device for film forming chamber - Google Patents

Abstract

PURPOSE:To allow the cooling of a film forming chamber to a uniform temp. by preventing the unequal temp. of a furnace wall occurring in the temp. difference between the inlet side and outlet side of the cooling water pipe relating to the method and device for cooling a film forming chamber for a device, such as CVD device, which produces thin films in a chamber. CONSTITUTION:The device which is disposed with the cooling water pipe P in the wall 1 of the film forming chamber 2 for producing the thin films therein and cools the chamber with the cooling water is constituted to alternately change over the inlet and outlet for the cooling water of the cooling water pipe P, thereby periodically reversing the direction of the cooling wager flow in the cooling water pipe P.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION This invention relates to a method and apparatus for cooling a film forming chamber with cooling water in an apparatus such as a CVD apparatus for forming thin films indoors.

0002

2. Description of the Related Art FIG. 5 is a horizontal cross-sectional view showing a cooling device in an example of a conventional CVD apparatus, and FIG. 6 is a vertical cross-sectional view of the same example. This example is an apparatus that can simultaneously form thin films on multiple substrates, and a substrate holder 5 called a susceptor is installed on a radial arm 4 fixed to a spindle 3 in a vacuum chamber 2 surrounded by a furnace wall 1. A substrate 6 is held in each substrate holder 5.

A gas mixing chamber 7 is provided on the inner wall of the vacuum chamber 2, facing each substrate holder 5, and a source gas G is supplied to each gas mixing chamber 7 from an external gas supply device 8. The treated waste gas is discharged from the exhaust port 9 at the upper end.

[0004] Outside the vacuum chamber 2, cassette chambers 10 and 11 for loading and unloading substrates and a load lock chamber 12 for transporting substrates are provided. In order to form a thin film in this apparatus, with the transfer gate TG between the cassette chambers 10 and 11 in a vacuum state and the load lock chamber 12 and the substrate loading/unloading port 13 of the vacuum chamber 2 open, The substrate 6 passes through the load lock chamber 12 and is placed on the substrate holder 5.
is supplied. For example, when a substrate is mounted on the F1 substrate holder, the spindle 3 rotates 60 degrees and the next F2
The second substrate holder moves to the substrate loading/unloading port 13, and a substrate is mounted thereon.

[0005] When the substrates are loaded on all the substrate holders in this way, the substrate loading/unloading port 13 is closed, and the source gas is supplied to each gas mixing chamber 7.
WSi or the like is formed into a film by being sprayed toward each substrate 6.

When the film formation is completed, the gas supply pipe 14 of the gas mixing chamber 7 is closed, and after several steps of purging are performed, the substrate loading/unloading port 13 is opened, and the spindle 3 is rotated intermittently to close the substrate holder. board 6 on 5
is taken out to the load lock chamber 12 side.

By the way, when the temperature of the wall surface of the furnace wall 1 of the vacuum chamber 2 is high, a film of WSi or the like is formed on the inner surface of the furnace wall, and as a result, the source gas is consumed on the wall surface, and the rate of film formation on the substrate is slowed down. Therefore, conventionally, a cold wall type furnace in which the furnace wall 1 is water-cooled has been adopted.

In the apparatus shown in the figure, cooling water pipes P1,
P2 is arranged. That is, one cooling water pipe P1
For example, the furnace wall facing the substrate holders F1, F2, and F3 is cooled, and the other cooling water pipe P2 is used to cool the furnace wall facing the substrate holders F1, F2, and F3, for example, and
By cooling the furnace wall facing the F6 substrate holder,
This ensures uniform cooling of the entire furnace wall. In this way, the furnace wall 1 of the vacuum chamber is dividedly cooled by the two cooling water pipes P1 and P2.

[0009]

[Problem to be Solved by the Invention] In this way, even if the two systems of cooling water pipes P1 and P2 share the cooling, the cooling water pipe P
1. While the cooling water moves through P2, the temperature of the cooling water increases due to the heat taken from the furnace wall 1, so the cooling water pipes P1 and P
The temperature of the cooling water in 2 becomes higher as it approaches the outlet Po. Therefore, among the three board holders, the middle F
2. The temperature of the cooling water is set so that the furnace wall position corresponding to the F5th substrate holder has the optimum cooling temperature.

However, even if the temperature is set in this way, the temperature of the furnace walls corresponding to the F1 and F6 boards near the cooling water outlet PO is too high, and conversely, the temperature of the furnace walls corresponding to the F6 boards near the cooling water inlet PO is too high.
A problem arises in that the temperature of the furnace wall corresponding to the fourth substrate is too low.

As a result, a film of WSi or the like is formed on the furnace wall near the cooling water outlet PO, and as a result, the F1 and F6th substrates lack source gas and film thickness. Also,
In the vicinity of F3 and F4 near the cooling water inlet Pi, since the furnace wall temperature is too low, condensation occurs, and there is a risk that the electrical system may short-circuit due to the condensed water.

[0012] The technical problem of the present invention is to focus on such problems and to prevent the temperature unevenness of the furnace wall caused by the temperature difference between the inlet side and the outlet side of the cooling water pipe, and to make it possible to cool the furnace wall to a uniform temperature. There is a particular thing.

[0013]

[Means for Solving the Problems] FIG. 1 is a horizontal sectional view illustrating the basic principle of a method and a cooling device for cooling a film forming chamber according to the present invention. Reference numeral 2 denotes a film forming chamber such as, for example, a CVD apparatus, and a cooling water pipe P is disposed in the chamber wall 1. P11 is one end of the cooling water pipe P, and P12 is the other end of the cooling water pipe P. In the present invention, one end P11 of the cooling water pipe P is used as the inlet Pi of the cooling water and the other end P12 is used as the outlet Po for a predetermined period of time. , the other end P12 is assumed to be an entrance Pi. Then, after a predetermined period of time has elapsed, one end P11 is again set as the inlet of the cooling water, and the other end P12 is set as the outlet of the cooling water.

A second aspect of the present invention is a means for alternately switching the inlet and outlet of the cooling water pipe in this way,
One end P11 and the other end P12 of the cooling water pipe P are connected between one end P11 and the other end P12 and the inlet 15i and outlet 15o of the cooling water cooler 15.
and a switching valve device V for alternately switching and connecting to the outlet 15o.

[0015]

[Operation] As claimed in claim 1, by alternately switching the inlet and outlet of the cooling water in the cooling water pipe P at regular intervals, the flow of cooling water in the cooling water pipe P is reversed at regular intervals. . That is, one end P11 of the cooling water pipe P is the inlet Pi,
While the other end P12 is the outlet Po, the cooling water flows through the cooling water pipe P in the direction indicated by the solid arrow a1.
Although the cooling water temperature at one end P11 side is low and the cooling water temperature at the other end P12 side is high, it takes time until the chamber wall 1 is cooled by the cooling water pipe P.

[0016] Then, before the furnace wall on the one end P11 side becomes too cold or the furnace wall temperature on the other end P12 side becomes high, the inlet Pi
and the exit Po is switched, and one end P11 is the exit (Po)
Since the other end P12 becomes the inlet (Pi), the cooling water flows through the cooling water pipe P in the direction of the broken arrow a2. In this way, the direction of the cooling water flow in the cooling water pipe P is reversed at regular intervals, so that the chamber wall 1 is connected to one end P11 of the cooling water pipe.
The problem of the side being too cold and the temperature on the other end P12 side being too high does not occur, and both the one end P11 side and the other end P12 side are cooled to the same uniform temperature as the middle part.

A second aspect of the present invention is a device for reversing the flow of cooling water in the cooling water pipe at a constant period as described above, which connects one end P11 and the other end P12 of the cooling water pipe P and the inlet 15i of the cooling water cooler 15. Since a switching valve device V is provided between the cooling water pipe P and the outlet 15o, by operating the valve device V at regular intervals, the cooling water inlet and outlet of the cooling water pipe P are alternately switched, and the film forming process is performed. The flow of cooling water in the cooling water pipe P on the chamber wall is reversed at regular intervals. In this way, just by providing the valve device, all the walls of the film forming chamber can be uniformly cooled.

[0018]

[Example] Next, how the method for cooling a film forming chamber according to the present invention is actually implemented will be explained using an example. In FIG. 1, the entire chamber wall 1 is cooled by one cooling water pipe P. According to the method of the present invention, two cooling water pipes are
Even if the furnace wall 1 is not separated, the temperature difference between one end P11 side and the other end P12 is eliminated, and the entire furnace wall 1 can be cooled uniformly. However, even when the furnace wall 1 is dividedly cooled by the two cooling water pipes P1 and P2 as shown in FIG. 5, the method of the present invention allows the cooling water to be supplied by alternately switching the inlet Pi and the outlet Po. This allows more effective and uniform cooling.

FIG. 2 shows a cooling water flow direction switching device using an on/off valve as a valve device in a cooling device.
(a) shows the normal cooling water flow direction, and (b) shows the state where the cooling water flow direction is reversed.

Reference numeral 15 denotes a cooler, which cools the furnace wall 1, cools the returning cooling water, and supplies the cooled water to the cooling water pipe P again. Between the cooling water outlet 15o and the cooling water inlet 15i of the cooler 15, one end P11 and the other end P12 of the cooling water pipe P are connected by pipes 16 and 17. However, on/off valves V1 and V2 are interposed in the middle.

Further, both pipes 16 and 17 are connected by a pipe 18, and an on/off valve V3 is connected between this connecting pipe 18 and the upstream side of the on/off valve V1 of the pipe 16. 18 and the cooling water pipe P from the on/off valve V2 of pipe 17
An on/off valve V4 is interposed between the two sides.

Further, a pipe 19 is connected to the downstream side of the on-off valve V1 of the pipe 16 via an on-off valve V5, and the other end of this connecting pipe 19 is connected to the pipe via an on-off valve V6. No. 17 is connected to the downstream side of the on/off valve V2.

In this device, as shown in (a), only the on/off valves V1 and V2 of the pipes 16 and 17 are opened;
On/off valves V3, V4, V at both ends of connections 18, 19
5. When V6 is closed, the cooling water coming out of the cooling water outlet 15o of the cooler 15 flows into the pipe 16 through the on/off valve V1 and into one end P11 of the cooling water pipe P. After cooling the furnace wall 1 while passing through the cooling water pipe P, the water returns to the inlet 15i of the cooler 15 through the on/off valve V2 from the other end P12 in the pipe 17.

After a certain period of time has elapsed, as shown in (b), only the on/off valves V1 and V2 of the pipes 16 and 17 close, and the on/off valves V3 and V4 at both ends of the connections 18 and 19 close.
, V5 and V6 open. As a result, the cooling water coming out of the cooling water outlet 15o of the cooler 15 flows into the pipe 16 → on/off valve V3 → connecting pipe 18 → on/off valve V4 → pipe 17 → the other end P12 of the cooling water pipe P. do. After cooling the furnace wall 1 while passing through the cooling water pipe P, from one end P11 to the pipe 16 → on/off valve V5 → connecting pipe 19 → on/off valve V6 → pipe 17 → cooler inlet 15i. I'll be back.

In this way, the cooling water supplied from the outlet 15o of the cooler 15 is distributed between one end P11 and the other end P11 of the cooling water pipe P.
One end P11 and the other end P12 of the cooling water pipe P are alternately connected to the inlet 15i of the cooler 15 at a certain period. The rising cooling water always flows to the inlet 15 of the cooler 15.
Come back to i.

This example was applied to a cooling device using two cooling water pipes as shown in FIG. 5, and the cycle of on/off operation of each on/off valve was set to 10 minutes, and the set temperature of the cooler was set to 10°C. In this case, the temperature near one end P11 of the cooling water pipe on the furnace wall 1 was 11.8°C, and the temperature near the other end P12 of the cooling water pipe was 11.9°C, and the temperature difference between the two was 0.1°C. In the conventional device shown in FIG. 5, when the set temperature of the cooler is 10°C, the temperature near one end P11 of the cooling water pipe on the furnace wall 1 is 11.5°C, and the temperature near the other end P12 of the cooling water pipe is 12.4°C, and both Compared to the fact that the temperature difference was as much as 0.9°C, the effects of the present invention are clearly visible.

FIG. 3 shows an example of a switching valve, (a
) When the spool 20 is moved to the left, ports 21 and 22 are in communication and port 23 is closed. However, when the spool 20 is moved to the right as shown in (b), ports 21 and 22 are connected. 23 is in communication and port 22 is closed.

FIG. 4 shows an embodiment using such switching valves, and switching valves V7 to V10 all have the switching valve structure as shown in FIG. The switching valve V7 has its port 21 connected to the outlet 15o of the cooler, and the switching valve V8 has its port 21 connected to one end P11 of the cooling water pipe P.
It is connected to the. Ports 22 and 22 of both switching valves V7 and V8 are connected by a pipe 24.

[0029] Also, the switching valve V9 has its port 21
is connected to the inlet 15i of the cooler, and the port 21 of the switching valve V10 is connected to the other end P12 of the cooling water pipe P. And port 2 of both switching valves V9 and V10
2 and 22 are connected by a pipe 25.

Further, ports 23 and 23 of the switching valves V7 and V10 are connected by a pipe 26, and ports 23 and 23 of the switching valves V8 and V9 are connected by a pipe 27.

In this device, as shown in FIG. 4(a), when the spools of the switching valves V7 to V10 are moving in the direction in which port 22 is open and port 23 is closed, water is supplied from the outlet 15o of the cooler. Cooling water is supplied by switching valve V.
Port 22 of 7 → Piping 24 → Port 2 of switching valve V8
2 → One end P11 of the cooling water pipe P → The cooling water pipe P flows. After cooling the furnace wall 1 while passing through the cooling water pipe P,
Other end P12 → Port 22 of switching valve V10 → Piping 25
→ Port 22 of switching valve V9 → Flows to inlet 15i of the cooler.

As shown in FIG. 4(b), each switching valve V7
~V10 spool, port 22 closed, port 23
is moving in the opening direction, the cooling water supplied from the outlet 15o of the cooler is transferred from port 23 of switching valve V7 → piping 26 → port 23 of switching valve V10 → other end P12 of cooling water pipe P → cooling water pipe Flows with P. And the cooling water pipe P
After cooling the furnace wall 1 when passing through, it flows from one end P11 → port 23 of switching valve V8 → piping 27 → port 23 of switching valve V9 → inlet 15i of the cooler.

[0033] The above cooling method and apparatus are
This method is applicable not only to the D device but also to all devices that require cooling of the film forming chamber wall.

[0034]

As described above, according to the present invention, the inlet 15i and the outlet 15o of the cooling water pipe P in the film forming chamber wall are alternately switched by operating the valve device, and the cooling water flow in the cooling water pipe P is controlled. It is designed to reverse at a predetermined period. Therefore,
One end P11 and the other end P12 of the cooling water pipe P serve as an inlet Pi and an outlet Po of the cooling water at predetermined intervals. As a result, as long as the cycle of reversal is not too long, the film forming chamber wall is cooled to a uniform temperature near one end P11 of the cooling water pipe P and the other end P12. Problems such as film formation and dew condensation are solved.

[Brief explanation of drawings]

FIG. 1 is a horizontal cross-sectional view illustrating the basic principle of a cooling method and a cooling device for a film forming chamber according to the present invention.

FIG. 2 is a piping diagram illustrating a cooling water flow switching device using an on-off valve.

FIG. 3 is a cross-sectional view illustrating a switching valve.

FIG. 4 is a piping diagram illustrating a cooling water flow switching device using a switching valve.

FIG. 5 is a horizontal sectional view showing a cooling device in a conventional CVD apparatus.

6 is a longitudinal sectional view of the CVD apparatus of FIG. 5. FIG.

[Explanation of symbols]

1 Furnace wall (chamber wall) 2 Vacuum chamber (film formation chamber) 3 Spindle 4 Radial arm 5 Substrate holder (susceptor) 6 Board 7 Gas mixing chamber 8 Gas supply device G Source gas 9 Exhaust port 10,11 Cassette chamber 12 Load lock chamber 13 Board entry/exit 14 Gas supply pipe P1, P2, P Cooling water pipe P11 One end of the cooling water pipe P12 Other end of cooling water pipe 15 Cooling machine 15o Cooling water outlet 15i Cooling water inlet 16,17 Piping 18,19 Connecting pipe V Switching valve device V1...V6 On/off valve 20 Spool 24...27 Piping V7...V10 switching valve

Claims (2)

[Claims] [Claim 1] A film forming chamber (2) for producing a thin film inside.
In a device in which a cooling water pipe (P) is installed in the chamber wall (1) and the cooling water is used for cooling, the cooling water inlet and outlet of the cooling water pipe (P) are alternately switched at regular intervals. , a cooling method for a film forming chamber characterized by periodically reversing the direction of a cooling water flow in a cooling water pipe (P). [Claim 2] A film forming chamber (2) for producing a thin film inside.
A cooling water pipe (P) is disposed in a chamber wall (1) of a room, and in a device for cooling with cooling water, one end (P11) and the other end (P12) of the cooling water pipe (P) and a cooling water cooler are installed. One end (P11) and the other end (P12) of the cooling water pipe (P) are connected between the inlet (15i) and the outlet (15o) of the cooler (15).
and an outlet (15o).