JPH0541546Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vacuum processing apparatus capable of drying objects to be processed before carrying them into a vacuum chamber for processing semiconductor substrates, mask substrates, etc.

In the manufacture of semiconductor devices, there are an extremely large number of processes for processing semiconductor substrates, mask substrates, etc. in vacuum, such as etching, exposure, ion implantation, sputtering, and vapor deposition.

Furthermore, in addition to the above-mentioned substrates, semi-finished products or finished products may be subjected to vacuum treatment in some cases.

When performing such vacuum processing, the object to be processed is placed in a vacuum chamber and evacuated to a predetermined degree of vacuum for each process, so if evacuation takes too long, the loss of time in the process will increase, so generally The object to be processed is dried before being placed in the vacuum chamber.

If moisture is adsorbed on the object to be processed, as the degree of vacuum improves during evacuation, the rate of desorption will slow down, and it will take a long time to reach a predetermined degree of vacuum.

For this reason, various methods of drying the object to be processed before transporting it into a vacuum chamber have been studied.

[Conventional technology]

FIG. 3 is a sectional view of an apparatus illustrating a conventional method of drying an object to be processed.

In the figure, an object to be processed 1 is placed on a conveyor belt 3 provided in a nitrogen chamber 2. Dry nitrogen is flowed into the nitrogen chamber 2 at a rate of about 10 to 20/min.

After the object 1 to be processed is sufficiently dried, the gate valve 4 is opened and the object 1 is sent to the vacuum load lock chamber 5.

Then, the gate valve 4 is closed and the vacuum load lock chamber 5 is evacuated. In such a case, compared to the case where the object to be processed 1 is introduced directly from the atmosphere, the exhaust time is reduced as the surface area of the object to be processed becomes larger.

After the vacuum load lock chamber 5 reaches a predetermined degree of vacuum, the gate valve 6 is opened and the object to be processed 1 is sent to the vacuum chamber 7 which has already been evacuated to a predetermined degree of vacuum. Then, the gate valve 6 is closed and the object 1 to be processed is processed.

When an object with a large surface area, such as a holder for a mask substrate, is transported directly from the atmosphere into the vacuum load lock chamber 5 as the object to be processed 1, the evacuation time is particularly long because moisture in the atmosphere adheres to the holder surface. Therefore, the effect of pre-drying is large.

[Problem that the invention attempts to solve]

By providing the nitrogen chamber 2 as described above, the exhaust time is shortened, but the nitrogen chamber 2 with the built-in conveyor belt 3 becomes larger and has the disadvantage that the amount of dry gas such as nitrogen used is also large. .

[Means for solving problems]

The solution to the above problem is to provide a vacuum processing chamber, a loadlock chamber connected to the vacuum processing chamber via a Gale valve, a transfer device for carrying the object to be processed into the loadlock chamber from the atmosphere, and the transfer device. It is equipped with a dry gas outlet provided around the
This is achieved by the vacuum processing apparatus according to the present invention, which performs a drying process on the object to be processed in the atmosphere immediately before transporting the object to the load lock chamber.

[Effect]

The inventor of the present invention discovered that when drying the object by blowing dry gas onto it before transporting the object into the vacuum chamber, by selecting the nozzle and the flow rate of the gas, the evacuation speed of the vacuum load lock chamber can be reduced compared to conventional methods. It was found that the same effect as when the object to be processed was carried in via a nitrogen chamber was obtained, and the amount of drying gas consumed was also small.

Whether or not the drying effect appeared was determined as follows.

Now, the time it takes for the object to be processed 1 to pass through the shower 8 cannot be increased too much in order to maintain the processing throughput, so if it is kept constant as in the past, the drying conditions are set by changing the nozzle and gas flow rate as described above. Select and set. Once the shape and arrangement of the nozzles of the shower are determined, the flow rate depends on the flow rate and temperature of the gas supplied to the shower, and the flow rate is set to a value that saturates and reaches the minimum value in the time it takes to reach the target vacuum level in the load lock chamber. Set.

Furthermore, if the drying gas is blown only when the object to be processed enters the vacuum load lock chamber,
Drying gas consumption can be further reduced.

〔Example〕

FIG. 1 is a cross-sectional view of an apparatus for explaining the method of drying objects to be processed according to the present invention.

In the figure, the object to be processed 1 is placed on a conveyor belt 3, and after being thoroughly dried by a shower 8 having a group of nozzles that blow out dry nitrogen from above and below, the object 1 is sent to a vacuum load lock chamber 5 by opening a gate valve 4.

In order for the drying effect to appear, the flow rate of the gas supplied to the shower must be set to a value such that the time required to reach the target degree of vacuum in the load lock chamber saturates and reaches the minimum value.

Conditions of the shower 8 in this embodiment are as follows.

Shower hole diameter...0.5mm Number of shower holes...200 Flow rate...4 m/sec Total gas flow rate...10/min Passage time...approximately 5 seconds Then, gate valve 4 is closed and vacuum load lock chamber 5 is evacuated. . In this case, as in the conventional example, the evacuation time is shortened compared to the case where the object to be processed 1 is introduced directly from the atmosphere.

For example, in the case of a workpiece left in the atmosphere for about 10 minutes, the evacuation time was reduced by about 30% compared to when it was placed directly into the load lock chamber from the atmosphere.

After the vacuum load lock chamber 5 reaches a predetermined degree of vacuum, the gate valve 6 is opened and the object to be processed 1 is sent to the vacuum chamber 7 which has already been evacuated to a predetermined degree of vacuum. Then, the gate valve 6 is closed and the object 1 to be processed is processed.

In the embodiment, the showers 8 are provided above and below the object 1 to be processed, but depending on the shape of the object 1 to be processed, it may be necessary to provide them at the top, bottom, left and right.

FIG. 2 is a side sectional view of the conveyor belt 3 showing an example of this.

[Effect of idea]

As explained above, according to the present invention, the exhaust time is shortened, the apparatus does not need to be enlarged unlike the conventional example in which a nitrogen chamber with a built-in conveyor belt is provided, and the amount of drying gas consumed can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an apparatus for explaining a method of drying objects to be processed according to the present invention, Fig. 2 is a side sectional view of a conveyor belt and a shower, and Fig. 3 is an illustration of a conventional method for drying objects to be processed. FIG. 2 is a cross-sectional view of the device. In the figure, 1 is an object to be processed, 2 is a nitrogen chamber, 3 is a conveyor belt, 4 and 6 are gate valves, 5 is a vacuum load lock chamber, 7 is a vacuum chamber, and 8 is a shower.

Claims (1)

[Scope of utility model registration request] A vacuum processing chamber, a loadlock chamber coupled to the vacuum processing chamber via a gate valve, a transfer device for transporting the object to be processed from the atmosphere into the loadlock chamber, and a transfer device for transporting the object to be processed into the loadlock chamber. 1. A vacuum processing apparatus comprising: a shower having a nozzle group for spraying dry gas onto the object to be processed immediately before transporting the object.