OPT application lab:
anisotropic ICP etch 400 nm PZT/
120 nm Pt /30 nm Ti, then etching
to a specified depth in LTO layer
(PR mask not removed)

Plasmalab System 100
with ICP 380 source

ICP - RIE technology

Plasmalab 80 Plus

RIE technology

RIE:
anisotropic etch
ca 20 nm/ min
selectivity to photoresist mask > 1 : 1
selectivity to underlying Pt > 50 : 1
uniformity ± 3 % (100 mm wafer)

ICP - RIE:
anisotropic etch
60 - 180 nm/ min
selectivity to photoresist mask > 0.5
uniformity ± 3 %(100 mm wafer)

A multi step process can be used to achieve vertical walls and about constant etch rates during an etch process through PZT and Pt. For stopping on Pt the PZT process can be optimised to achieve high selectivities to Pt (> 50 : 1). Endpoint detection by optical emission or laser interferometry is possible.

OPT application lab:
anisotropic RIE etch of 1 µm PZT
(PR mask removed)

OPT application lab:
anisotropic RIE etch of 1 µm PZT
(PR mask not removed)