Papers by Author: Jeffrey M. Lauerhaas

Abstract: Selective nitride etching in semiconductor manufacturing is currently performed in wet benches using hot orthophosphoric acid at 160-180C. This process requires silica seasoning to achieve the desired selectivity to silicon oxide. Silica seasoning in wet benches is achieved by etching blanket silicon nitride wafers prior to running productions runs. While, this method of selective silicon nitride etching has been successful in the past, particle requirements at advanced nodes [1] are driving the need for a new solution. Single wafer wet processing is proposed as a way to meet these challenging new particle specifications.

Abstract: Selective etching of silicon nitride films has been an important process step in integrated circuit manufacturing for many years [1-. In the past, this process has been mainly used to remove the silicon nitride mask which protects the transistor active area during the formation of oxide isolation. Recently, this process has also been used to remove silicon nitride spacers after source and drain formation for better management of the strained channel [. Advanced device integration continues to add more steps in which the selective removal of silicon nitride is needed.