Gas supply unit, substrate processing apparatus, and supply gas setting method

Abstract

A gas supply unit, for supplying a gas into a processing chamber in which a substrate is processed, includes a plurality of gas supply sources, a mixing line for mixing a plurality of gases supplied from the gas supply sources to make a gaseous mixture, a multiplicity of branch lines for branching the gaseous mixture to be supplied to a multiplicity of places in the processing chamber, and an additional gas supply unit for supplying a specified additional gas to a gaseous mixture flowing in at least one branch line. The gas supply unit also includes pressure gauges and valves for adjusting gas flow rates in the branch lines, respectively, and a pressure ratio controller for controlling that gaseous mixtures branched into the branch lines to have a specified pressure ratio by adjusting opening degrees of the valves based on measurement results obtained by using the pressure gauges.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS: [0001] This document claims priority to Japanese Patent Application Number 2004-357292, filed Dec. 9, 2004 and U.S. Provisional Application No. 60 / 639,795, filed Dec. 29, 2004, the entire content of which are hereby incorporated by reference.FIELD OF THE INVENTION [0002] The present invention relates to a gas supply unit for supplying a gas to a processing chamber, a substrate processing apparatus connected to the gas supply unit and a supply gas setting method. BACKGROUND OF THE INVENTION [0003] In a manufacturing process of an electric device such as a semiconductor device or a liquid crystal display device, there are performed a film forming process for forming a conductive film or an insulating film on the surface of a substrate, an etching process for etching a film formed on the substrate and the like. [0004] For example, a plasma etching apparatus is widely employed in the etching process, wherein the plasma etching apparatus includes ...

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Benefits of technology

[0009] The present invention has been conceived from the above drawbacks; and it is, therefore, an object of the present invention to provide a gas supply unit capable of realizing a simple piping configuration when supplying optional gaseous mixtures to a plurality of places in a processing chamber in a substrate processing apparatus such as an etching apparatus, a substrate processing apparatus including a processing chamber connected to the gas supply unit and a supply gas setting method employing the gas supply unit.

[0011] In accordance with the present invention, gases from a plurality of the gas supply sources are mixed in the mixing line to be branched into a multiplicity of the branch lines. Further, a specified additional gas is added to a specific branch line to adjust components or their flow rates in the gaseous mixture. In a branch line without being supplied with the additional gas, the gaseous mixture from the mixing line is supplied to the processing chamber as it is. In this case, a gaseous mixture containing common components is produced in, e.g., the mixing line and components and their flow rates in the gaseous mixture are adjusted in each branch line when necessary. Thus, the number of lines needed is minimized. As a result, optional gaseous mixtures are supplied to a plurality of places in the processing chamber by a simple piping configuration.

[0012] The gas supply unit may include pressure gauges and valves for adjusting gas flow rates in the branch lines, respectively, and a pressure ratio controller for controlling that gaseous mixtures branched into the branch lines to have a specified pressure ratio by adjusting opening degrees of the valves based on measurement results obtained by using the pressure gauges. In this case, since the flow rate in the branch line is controlled on the basis of a pressure ratio (partial pressure ratio), for example, even though a pressure in the branch line is low, the flow rate in the branch line can be adequately controlled.

[0015] In accordance with the present invention, a piping space and a cost of controlling flow rates can be reduced by a simple piping configuration.

Problems solved by technology

Further, conventionally, it has been a major challenge to improve a uniformity of etching in the surface of the substrate by making the etching characteristics uniform on the surface of the substrate.

Thus, a piping structure of a gas supply system becomes complicated and a control of gas flow rate is also complicated in each line.

Therefore, for example, a large piping space is required, which in turn increases the expense of an apparatus control system.

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