Rinsing in acid processing of substrates

Abstract

In a chemical processing system for processing substrates or wafers in the production of electronic devices or integrated circuit chips, a rinsing step of simultaneously thoroughly rinsing the substrate in the processing chamber while the chemical supply lines and chemical spray posts are also being thoroughly rinsed with rinse water directed down a drain and without spraying into the processing chamber by controlling the pressure or rate of flow of rinsing water through the liquid chemical supply lines and chemical spray post passages and orifices so that most of the rinsing water will flow through an open drain valve and down the drain and only a trickle of water is permitted to flow outwardly through the spray orifices of the chemical spray post so that none of the rinsing water with dilute traces of chemical is sprayed onto the substrates in the processing chamber. A separate and dedicated rinsing water spray post or head is provided for directing rinsing water atomized by inert gas such as nitrogen to instantaneously commence rinsing of the wafers in the processing chamber. The liquid chemical spray posts are provided with pipe connections to the chemical supply passages within the spray post to accommodate rinsing water flow through the passage and out through the drain ducts and through an openable drain valve to a drain so that rinsing water may freely flow through the chemical supply lines and chemical supply passages in the chemical spray heads simultaneously with the application of rinsing water from the dedicated rinsing water spray post on the chamber wall.