Title :
Development of a magnetron-enhanced plasma process for tungsten etchback with response-surface methodology
Author :
Riley, Paul E. ; Chang, Mei ; Ghanayem, Steve G. ; Mak, Alfred
Author_Institution :
Digital Equipment Corp., Hudson, MA, USA
fDate :
8/1/1990 12:00:00 AM
Abstract :
A two-step etchback process to form tungsten plugs in submicron contacts and vias has been developed. the process uses an Applied Materials Inc., P5000 WCVD magnetron-enhanced, single-wafer system with an experimental design and response-surface methodology. Tungsten is first etched with an Ar/SF6 mixture until excited N2 molecules from the underlying TiN adhesion layer are detected in the plasma. Residual TiN is then etched for a fixed time with an Ar/Cl 2 plasma. Both steps employ a rotating 0.5-Hz magnetic field. Although the use of the magnetic field has no pronounced effect on the etch rate of either film, it provides broad regions of high etch uniformity. In addition, the DC-bias voltage measured as part of the TiN study decreases with increasing magnetic field strength without reducing the etch rate of the film
Keywords :
integrated circuit technology; metallisation; sputter etching; tungsten; 0.5 Hz; Ar-Cl2 plasma; Ar-SF6 gas mixture; DC-bias voltage; TiN adhesion layer; W plugs formation; etch rate; etch uniformity; magnetron-enhanced plasma process; response-surface methodology; rotating magnetic field; single-wafer system; submicron contacts; submicron vias; two-step etchback process; Argon; Etching; Magnetic field measurement; Magnetic films; Magnetic materials; Plasma applications; Plasma materials processing; Plasma measurements; Tin; Tungsten;
Journal_Title :
Semiconductor Manufacturing, IEEE Transactions on