Study on the formation of silicide phase by deposition erbium on (001)Si

Abstract

Solid-state reactions on a 35nm erbium film deposited on a (001)Si substrate prepared by using different base pressures in the sputtering deposition, which resulted in different oxygen content in the samplesi??have been studied. It is found that the formation of ErSi2 is influenced both by the presence of oxygen in as-deposited Er (incorporated during sputtering deposition) and by the attack by the residual oxygen in the N2 ambient during the annealing. Besides, a possible solution to the oxygen contamination problem proposed is to deposit a Ti film as a capping layer after the sputtering deposition of Er film. Ti capping layer has been demonstrated to have a beneficial influence on the erbium silicide films as it decreases the temperature of ErSi2 formation; it broadens the process window of ErSi2 formation and also improves the film quality.