SC7640 Auto/Manual High Resolution Sputter Coater Operating ...

OM-SC7640 Description
4.4.1 Operational Description
The SC7640 operates at a potential of up to 3000 Volts dc.
An HV voltage is applied between the Target (cathode) and Baseplate (anode) which is at earth
potential. A pressure interlock ensures that the HV supply cannot be activated until vacuum
chamber pressure is reduced to 10 -1 mbar or better. Low pressure gas (argon is preferred) is
leaked into the vacuum chamber to provide a medium for ionisation. Figure 4.2 shows the principles
of operation of the SC7640.
Electrons emitted by the cathode, concentrated in the vicinity of the target by the magnetic field,
collide with the gas molecules, producing positive ions (due to secondary electron emission).
Positive ions attracted by the negative potential of the cathode, bombard the target, causing erosion
of the target material. The dislodged target atoms falling toward the sample follow multiple paths
due to collisions with the ionized gas, coating the sample on all exposed faces.
A gas discharge glow centered about the cathode is visible.
4.4.2 Pumping Requirements
Figure 4.2 Sputter Coater Operation
The work chamber has to be evacuated to