Title :
Time resolved reflectivity measurements of Al alloys during excimer laser planarization
Author :
Woratschek, B. ; Carey, P. ; Bachmann, F.
Author_Institution :
Siemens AG, Munchen, West Germany
Abstract :
Time-resolved reflectivity measurements have been made in situ during XeCl (λ=308 nm) excimer laser planarization of Al, AlSi(1%), and AlSi(1%)Cu(0.5%) at 25, 250, and 400°C. The reflectivity change observed when using a HeNe (λ=632.8 nm) probe beam is assumed to indicate layer melting. Metal melt times have been determined as a function of laser energy fluence, substrate temperature, and oxide thickness. The results show that metal melt times increase with laser energy fluence and substrate temperature, the pure Al melts for shorter times and needs higher laser energy fluences than the corresponding alloys, and little difference is seen in the melting characteristics of the alloys. The best conditions for insuring complete planarization (long melt times) would thus be for conditions in which the wafer is heated
Keywords :
aluminium; aluminium alloys; copper alloys; laser beam effects; melting; metallic thin films; metallisation; reflectivity; silicon alloys; time resolved spectra; 25 degC; 250 degC; 308 nm; 400 degC; Al; AlSi; AlSiCu; HeNe probe beam; XeCl excimer laser; complete planarization; excimer laser planarization; laser energy fluence; layer melting; metal melt times; oxide thickness; substrate temperature; time resolved reflectivity; Aluminum alloys; Heating; Laser beams; Optical pulses; Planarization; Probes; Reflectivity; Silicon; Temperature; Time measurement;
Conference_Titel :
VLSI Multilevel Interconnection Conference, 1990. Proceedings., Seventh International IEEE
Conference_Location :
Santa Clara, CA
DOI :
10.1109/VMIC.1990.127848