SIMULATION AND EXPERIMENTAL-ANALYSIS OF PLANARIZATION OF REFRACTORY-METALS USING A MULTISTEP SPUTTER SPUTTER ETCH PROCESS/

In this paper, we will present both experimental and simulated results showing the use of successive sputter deposition and sputter etching of refractory metal films deposited into trenches. A layer of 0.5 mu m thick film was deposited using a magnetron sputtering source and then etched back to 0.25 mu m using radio frequency sputter etching. A mul tilayer film was built up by repetition of this process. Both the step coverage and planarization of the films improved relative to one-step sputter deposited films. The SIMulation by BAllistic Deposition (SIMB AD) simulation program was extended to allow for the modeling of multi layer films. SIMBAD was successful in modeling the sputter/sputter etc h process and accurately modeled the microstructure of the films depos ited. Particular emphasis in the paper is put on evaluating the perfor mance of SIMBAD in predicting the microstructure of the film. This mic rostructure was found to be substantially altered if the vacuum system was vented between layer deposition.