Meint de Boer uses his Plasmalab System 100 System for
etching Si using an SF6/ O2 process at low temperature.
He has chosen Oxfords wide temperate range substrate
electrode (- 150° C - + 300° C) and Helium backside
cooling to establish an excellent thermal contact.

The advantages of the low temperature etching are the
very high rates and selectivities as the process does not
use and polymer formation step to achieve the excellent
anisotropy.

with kind permission of:
  TU Twente
  Meint de Boer, Henri Jansen 

ICP technology

Plasmalab System 100
with ICP180 and loadlock

very low substrate bias for high selectivities

Selectivity to the Photoresist Mask: 75 - 1.000 : 1

Selectivity to SiO₂ Mask: 150 - 1.500 : 1

1 µm/ min for high aspect ratio vias using ICP180
Rates up to 10 µm/ min are possible
with the larger ICP 380 source.

Uniformity  < ± 3  % over one wafer

Left 2 SEM'S:
Control over the profile by adjusting the temperature and the O2 flow

right SEM:
via holes though Si wafers