Cornell Center for Materials Research

Varian Thermal Bell Jar Evaporator

Clark Hall D21

 

 

Jonathan Shu
Office (607) 255-9833
Cell (607) 227-8154
jbs24@cornell.edu
BD-22 Clark Hall

Bell Jar evaporator
Varian

This system is a thermal evaporator. The system has a diffusion pump. Typically source materials are melted in "dimpled" flat tungsten boats. These include: Al, Ag, Au, Au/Ge, Au/Pd, Au/Zn, Cr, Mn, Ni, SiO and Zn. Cr is evaporated (sublimed) from a pre-coated rod and SiO from a special baffle heater. Evaporation rates are manually controlled by varying the output voltage of a variac which feed various transformer taps (and feedthroughs) allowing for currents up to 200 amps. Rates are monitored with a standard 6 mHz crystal oscillator. Samples typically are piece parts or quarters of 3 inch wafers, and are clipped onto a removable metal plate which sits at approximate 12 inches from the sources? At present 2 inch wafers would be the maximum sample size for 100% coverage. Substrate heating is possible to 300C. Deposition cycling time from pumpdown to deposition to system venting is two hours.
 
Edited on: 26 May 2009 5:38 pm