A Photoelectron Spectroscopy Study of  CF 4 /  H 2 Reactive Ion Etching Residue on Tantalum Disilicide

X‐ray photoelectron spectroscopy has been used to characterize reactive ion etching residue on the tantalum disilicide surface after removing 100 nm of silicon dioxide. This was done to simulate the structure of multilevel metallization presently being encountered in integrated circuit manufacture. At a pressure of 80 millitorr and a power density of 1 W/cm 2 , the residue layer formed consists chemically of a mixed tantalum and silicon fluoride and oxide‐like film. This layer is complex and does not appear to contain polymeric fluorocarbon as has been observed on silicon at slightly higher hydrogen concentrations in the glow discharge. Its thickness is estimated to be 3 nm based on electron escape depths. The presence of causes the surface residue layer to be more oxygen rich in comparison with the uncoated tantalum disilicide surface. Sputtering does occur at a self‐bias of 300V and results in preferentially removing silicon. Core‐level binding energies are reported for tantalum disilicide, the etch residue, the native oxide on the disilicide, and some related materials for reference purposes.