Patent ID: 6884317

Claim:
An installation for etching a substrate by simultaneous exposure to two etching gases, the two etching gases forming a corrosive mixture, the installation, comprising: an etching chamber for a substrate, the etching chamber having an opening; a piping system coupled to the opening and providing for at least a first fluid feed and a second fluid feed, wherein the first fluid feed is connected at a source end to a source of a first etching gas, wherein the second fluid feed is connected at a source end to a source of a second etching gas, and wherein the first and second fluid feeds are configured to separately provide the first and second etching gases to the etching chamber via the piping system; an auxiliary chamber positioned within the piping system and having an inlet and an outlet, wherein the inlet includes a first controllable shut-off valve and is in communication with the first fluid feed, wherein the outlet includes a second controllable shut-off valve and is in communication with the etching chamber, and wherein said first and second shut-off valves are configured to be open only one at a time; and a third controllable shut-off valve positioned in the piping system in the second fluid feed, wherein the third shut-off valve and the second shut-off valve are configured to be open only one at a time, wherein the walls of auxiliary chamber and the walls of piping system upstream of the auxiliary chamber are each formed of different materials.