Optimized in situ rinsing for HF last processes

In order to optimize HF last processing in situ rinsing is frequently discussed to avoid the transition through the air liquid interface. In this work a special tank design for high efficient rinsing post HF wafer treatment was designed, characterized by laser interferometric flow measurements and verified by studies on the etch characteristics of thermal oxide wafers in diluted hydrofluoric acid. An in situ rinse process featuring only 45 seconds of process time and less than 15 gal/batch Di water consumption at uniformities comparable to sequential processing is presented and discussed.