OPT application lab:
TEOS PECVD in a 100 µm deep
hole with 10 : 1 aspect ratio
top surface: 1.88 µm
bottom surface: 0.83 µm
bottom sidewall: 0.49 µm

0.5 µm SiO₂ deposited over a
90° step with excellent step coverage

OPT application lab:
170 nm TEOS SiO2 over a 1 µm step

Plasmalab System 133
(with vacuum loadlock)

The (blue) TEOS bubbler is attached to the side.

see the ALD bubbler for more details

tetraethoxysilane or tetraethyl orthosilicate

Dr. Wöhl uses his Plasmalab System 100 for depositing SiO2
and TEOS SiO2 for the fabrication of Si and SiGe high
frequency and optoelectronic devices.
The TEOS results were achieved in cooperation
between Uni Stuttgart, Inst. fuer Halbleitertechnik, and OPT.

Process Chemistry : TEOS, O2, Ar or He
Deposition Rate : 30 - 100 nm/min
Uniformity: < ± 3%
Refractive Index : 1.44 - 1.46
Uniformity: < ± 0.001
Repeatability: < ± 0.001
Step coverage: > 75 %, up to 90%
no voids or "nano slits"
Low N-H content for low loss films at 1550 nm
Low stress (< 50 MPa) for > 50 µm thick films
BHF etch rate 10 - 40 x thermal SiO2 at 13 MHz
                       1.5 x thermal SiO2 at kHz

download TEOS system brochure (PDF file, 1.2 MB)

1.1 µm SiO₂ deposited over a
500 nm 80° step at 73 nm/ min

The process can be made "directional" !
("poor" step coverage)

PECVD technology

OPT application lab:
1 µm TEOS SiO2 over a 1 µm step

OPT application lab:
400 nm TEOS SiO2 over a 1 µm step
with 84 % step coverage