H. Ito et al., THE PRECISION-IMPLANT-9500 PLASMA FLOOD SYSTEM - THE ADVANCED SOLUTION TO WAFER CHARGING, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 96(1-2), 1995, pp. 30-33
An advanced wafer charge neutralization system based on plasma flood t
echnique has been developed to achieve an ideal voltage control on the
wafer surface during implantation. The system makes use of the ''self
-regulating'' characteristics of low energy plasma electrons that clam
p the surface potential within a few volts. Low energy electrons are g
enerated in an are discharge plasma chamber combined with an accel/dec
el extraction mechanism and are transported to wafers through a guide
tube that confines a dense plasma by using a combination of electrosta
tic suppression and a magnetic cusp field. The system has been equippe
d as standard on the Precision Implant 9500 and shown full yield on va
rious charge sensitive devices.