Plasma Technology  

 

CNT growth
with 13 MHz plasma at 650° C
onto a 5 nm Co catalyst seed layer
70 nm diameter, 1 µm height

Plasma treatment of the catalyst
5 nm Co film after plasma treatment
The metal does not form particles at
this temperature without plasma,
particle size related to film thickness

 

Plasma treatment of Catalyst
enhances growth

No pre growth plasma treatment
thermal only growth: 190nm

With pre growth plasma treatment,
thermal only growth 1.4 um
(same process time and conditions)

Use of a plasma treatment step
before growth increases catalyst activity
(cobalt acetate catalyst used).



LF Plasma used to align CNTs

C2H2/NH3 process
thermal growth (no plasma)

Same process as thermal
with addition of 150 W LF power

LF power gives much better alignment
of CNTs. Co nanoparticle catalyst used.

 

Metal Catalysts are typically Au, Ni or Co.

C Nanotube Growth

 

Growth temperature is lowered by Plasma

Plasma enables the catalyst thin film to form islands,
which would not form without at that temperature.

Plasma treatment of catalyst provides denser,
faster growth relative to no treatment and
even over thermal treatment.

Plasma provides for Alignment plus further
diameter and density control.

Plasma growth provides selective area growth .


Equipment:
Plasmalab System 100

Technology:
Parallel Plate Reactor
Shower Head Gas inlet
temperature range: 600° - 800° C

CNTs can be grown with or without plasma.
The plasma is also used to preclean the seed
layer and to clean the process chamber.

aligned growth rate > 40 nm/ min
random growth rate ca 300 nm/ min

short brochure as PDF file (460 kB)

 

PECVD and CVD technology

 


CNT growth
with 13 MHz plasma at 450° C
onto a 1 nm Ni catalyst seed layer
40 nm diamter, 500 nm height


Carbon Nanotube Growth
1 µm high, 15 - 40 nm diameter
plasma assisted

 

 

TEM of multiwalled carbon nanotube
grown with plasma assistance

Raman spectrum of multi walled CNTs

Plasmalab System 100
("Nanofab" )

 

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