Semiconductor device fabricating system and semiconductor device fabricating method

Abstract

Shutoff valves are placed in parts of the process gas supply lines at positions near the processing vessel. A main purge gas supply line branches into branch purge gas supply lines, each of which is provided with an orifice called sonic nozzle. The branch purge gas supply lines are connected to parts of the process gas supply lines extending between the shutoff valves and the processing vessel. The ratio P1 / P2, where P1 is primary pressure on the primary side of the orifice and P2 is secondary pressure on the secondary side of the orifice, is controlled to be not less than a predetermined value, for example, two, thereby, the purge gas can always be supplied at equal flow rates into the process gas supply lines. The total flow rate of the purge gas is controlled by a mass flow controller placed in the main purge gas supply line.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a semiconductor device fabricating method of processing a substrate on which semiconductor devices are to be fabricated in a processing vessel by supplying a process gas into the processing vessel and a semiconductor fabricating system for carrying out the semiconductor device fabricating method. [0003] 2. Description of the Related Art [0004] Some semiconductor device fabricating methods carry out predetermined processes continuously to process a substrate in a processing vessel and a cleaning process for cleaning the interior of the processing vessel by selectively supplying process gases and cleaning gases through a plurality of gas supply lines connected to the processing vessel. If a process gas supplied through the open gas supply line into the processing vessel flows into the other closed gas supply lines not supplying the gases, it is possible that a product is deposited in t...

AI Technical Summary

Benefits of technology

[0013] The present invention has been made in view of the foregoing problems and it is therefore an object of the present invention to provide a semiconductor device fabricating method capable of accurately controlling the flow of a purge gas in a process gas supply pipes connected to a processing vessel, and a semiconductor conductor fabricating system for carrying out the semiconductor device fabricating method.

[0014] Another object of the present invention is to provide a semiconductor device fabricating method capable of quickly purging a process gas remaining in a process gas supply pipe, and a semiconductor device fabricating system for carrying out the semiconductor device fabricating method.

[0017] The flow controller may be a mass flow controller. In this case, the total flow rate of the purge gas can be controlled accurately.

[0022] According to the present invention, the shutoff valves are placed in parts of the process gas supply lines close to the processing vessel, and the purge gas is supplied to parts of the process gas supply lines each extending between the shutoff valve and the processing vessel. Therefore, only the process gas remaining in the short parts of the process gas supply line extending below the shutoff valve needs to be purged in changing the process, and the residual process gas can be quickly purged. Since the orifice controls the flow of the purge gas flowing through each branch purge gas supply line accurately, the flow controller needs to be placed only in the main purge gas supply line, the total flow rate of the purge gas equal to the sum of the flow rates of the purge gas flowing through the branch purge gas supply lines can be accurately controlled and the process can be stably carried out.

Problems solved by technology

If a process gas supplied through the open gas supply line into the processing vessel flows into the other closed gas supply lines not supplying the gases, it is possible that a product is deposited in the closed gas supply lines causing contamination with particles or the gas supply lines are corroded.

Consequently, it is difficult to adjust the flow rate of the inert gas to values in a desired flow rate range and accurate flow rate control cannot be achieved.

Therefore, the total purge gas flow rate cannot be accurately controlled, the process gas concentration varies and, consequently, it is possible that the process becomes unstable.

Since all the branch lines 107 are provided with the mass flow controllers 106, this piping system is costly.

Therefore, the process gases remaining in the lines extending between the processing vessel 100 and the valves V in a gas box remote from the processing vessel 100 need to be purged, which needs a long time and increases tact time.

Images