Etching for Failure Analysis

Polyimide Etch

process gases: CF₄/O₂

etch rate:  80  - 200 nm/ min

very high selectivity to SiN with O₂

PE for low damage isotropic etch

RIE for anisotropic interlayer dielectric etching
(ICP for low ion energies)

SiN Etching

process gases: CF₄/O₂

etch rate 70 - 200 nm/ min

uniformity < ± 7% (300 mm)

PE for low damage isotropic etch

SiO₂ RIE

process gases: CHF₃/Ar

etch rate: 30 - 50 nm/ min

selectivity  > 7: 1 to polySi and W

uniformity < ± 5% (300 mm)

RIE for anisotropic interlayer dielectric etching
(ICP for low ion energies)

passivation to be removed isotropically

passivation to be removed isotropically

ILD to be etched over polySi

OPT application lab:
residue free fotoimide etch

OPT application lab:
isotropic SiN etch

OPT application lab;
anisotropic SiO₂ etch

Other processes of interest:

Metal Etching:

Al etching
Cu etching

Plasma Deposition:

PECVD of Si₃N₄ (and SiO₂) passivations

Equipment:

Plasmalab 80 Plus
for up to 200 mm wafers and packaged devices

Plasmalab 800 Plus
for up to 300 mm wafers and packaged devices

Plasmalab System 100
with vacuum loadlock
for up to 200 mm wafers and packaged devices

Plasmalab System 133
with vacuum loadlock
for up to 300 mm wafers and packaged devices

Options:

Laser Interferometer for end point detection and in situ rate measurement
(integrated in PC 3000 control) on chips and wafers (SiGe RIE with laser)
Optical Emission for end point detection over wafers

Technologies:

RIE/ PE mode for failure analysis

Failure Analysis Etching with laser interferometry

Inductive Coupled Plasma Sources (ICP) for low damage etching