InP Etching

RIE

process gases: CH₄/H₂

etch rates: 50  - 100 nm/ min

higher rates by Cl addition possible

mask: Photoresist or SiO₂

aspect ratio > 5 : 1

OPT Application lab
InP RIE: 0.2 µm width for DFB Laser

OPT Application lab
80 µm diameter InP Lens

ICP - RIE

Chlorine based processes

etch rates: 50 nm/ min - 1.5 µm/ min

low damage by low ion energies

selectivity to SiO₂:10 - 25 : 1

selectivity to PR: > 500 : 1 possible

OPT Application lab
Anisotropic InP ICP Etch

OPT Application lab
Anisotropic InP ICP Etch

RIBE/ CAIBE

Chlorine and CH₄/H₂ based process

etch rates: up to 300 nm/ min

adjustable wall angle

mask: Photoresist (SEM) or SiO₂

CAIBE or RIBE possible with RF sources

OPT Application lab
Anisotropic InP RIBE

Courtesy of NRC Canada
5 µm deep InP/ InGaAsP/ InP CAIBE