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bob
Posted: Fri Jul 25, 2003 3:19 pm
Guest
Quote:
Have you done SIMS analysis on your diamond? I find some difficulty in the
sputtering energetics of a 2.4GHz uwave deposition technique with hydrogen
to
reduce the silica to silicon due to your tube. Is your tube a quartz tube
or
some other glass? What are your (gas)?sources for deposition? Would you
reference the silicon contamination claim?

not yet, thusfar all i have done is optical spectroscopy as thats the limit
of my inhouse ability. the si conclusion came from data on a line in
zaitsev's 'optical properties of diamond'. I dont have my notes infront of
me. i'll ahve to dig them up to provide any additional details..

I'm using an astex ax7610 as a reactor:
http://www.mksinst.com/pdf/ASTEXax7610DS.pdf
the tube is quartz
I'm using uhp argon with an saes filter for a carrier gas (ppb level purity)
and uhp h2 and methane from my gas supplier (4 1/2 nines)
boer
Posted: Mon Jul 28, 2003 8:14 am
Guest
bob wrote:

Quote:
Have you done SIMS analysis on your diamond? I find some difficulty in the
sputtering energetics of a 2.4GHz uwave deposition technique with hydrogen
to
reduce the silica to silicon due to your tube. Is your tube a quartz tube
or
some other glass? What are your (gas)?sources for deposition? Would you
reference the silicon contamination claim?

not yet, thusfar all i have done is optical spectroscopy as thats the limit
of my inhouse ability. the si conclusion came from data on a line in
zaitsev's 'optical properties of diamond'. I dont have my notes infront of
me. i'll ahve to dig them up to provide any additional details..

I'm using an astex ax7610 as a reactor:
http://www.mksinst.com/pdf/ASTEXax7610DS.pdf
the tube is quartz
I'm using uhp argon with an saes filter for a carrier gas (ppb level purity)
and uhp h2 and methane from my gas supplier (4 1/2 nines)

Looks to me like you are doing your homework. I am interested in a potential
sputtering yield of silica then a reduction to silicon as your working premise.

Bob
boer
Posted: Mon Jul 28, 2003 11:46 am
Guest
boer wrote:

Quote:
bob wrote:

Have you done SIMS analysis on your diamond? I find some difficulty in the
sputtering energetics of a 2.4GHz uwave deposition technique with hydrogen
to
reduce the silica to silicon due to your tube. Is your tube a quartz tube
or
some other glass? What are your (gas)?sources for deposition? Would you
reference the silicon contamination claim?

not yet, thusfar all i have done is optical spectroscopy as thats the limit
of my inhouse ability. the si conclusion came from data on a line in
zaitsev's 'optical properties of diamond'. I dont have my notes infront of
me. i'll ahve to dig them up to provide any additional details..

I'm using an astex ax7610 as a reactor:
http://www.mksinst.com/pdf/ASTEXax7610DS.pdf
the tube is quartz
I'm using uhp argon with an saes filter for a carrier gas (ppb level purity)
and uhp h2 and methane from my gas supplier (4 1/2 nines)

Looks to me like you are doing your homework. I am interested in a potential
sputtering yield of silica then a reduction to silicon as your working premise.

Bob

I re-read your last post again. UHP argon might give you the energetics needed to
sputter silica from the tube. However, I'm still stumped on the silica being
reduced to silicon.

Bob
Uncle Al
Posted: Mon Jul 28, 2003 12:18 pm
Guest
boer wrote:
Quote:

boer wrote:

bob wrote:

Have you done SIMS analysis on your diamond? I find some difficulty in the
sputtering energetics of a 2.4GHz uwave deposition technique with hydrogen
to
reduce the silica to silicon due to your tube. Is your tube a quartz tube
or
some other glass? What are your (gas)?sources for deposition? Would you
reference the silicon contamination claim?

not yet, thusfar all i have done is optical spectroscopy as thats the limit
of my inhouse ability. the si conclusion came from data on a line in
zaitsev's 'optical properties of diamond'. I dont have my notes infront of
me. i'll ahve to dig them up to provide any additional details..

I'm using an astex ax7610 as a reactor:
http://www.mksinst.com/pdf/ASTEXax7610DS.pdf
the tube is quartz
I'm using uhp argon with an saes filter for a carrier gas (ppb level purity)
and uhp h2 and methane from my gas supplier (4 1/2 nines)

Looks to me like you are doing your homework. I am interested in a potential
sputtering yield of silica then a reduction to silicon as your working premise.

Bob

I re-read your last post again. UHP argon might give you the energetics needed to
sputter silica from the tube. However, I'm still stumped on the silica being
reduced to silicon.

The plasma is argon/hydrogen/methane 100~200 torr. Silicon carbide
(Moissanite) is an energtically deep, chemically inert, and refractory
hole. Silicon alloys with diamond. Physical or chemical erosion of
the fused silica tube will contaminate the diamond deposit. One
therefore posits that a more refractory tube and heavy atoms that
don't fit into the diamond lattice are good things. Zirconia, thoria,
or yttria suggest themselves. Lantern mantles survive a lot of grief
in hot reducing atmospheres. With microwave excitation he is pretty
much stuck with a dielectric liner unless he wants to redesign with a
deposition waveguide rather than chamber. That gets potentially messy
with impedence matching and radiation containment. It then looks like
a job for iridium inner plating or CVD. Or CVD diamond coat the
containment tube - with the isotopic enrichment. Differential
coefficient of thermal expansion. Diamond has a CTE like invar.
Invar is a ferrous alloy and incompatible with hot diamond.

He can't go bigger and get fancy with wall boundary layers. Energy
density is the CVD diamond coin of the realm. 10X the dimensions is
1000X the power. Kilowatts become megawatts. You pay to input
electricity and you pay to dump heat. Using an extreme isotopically
enriched feed screams for small dimensions, even if your apparatus is
snugged to ISOTEC.

The application requires bleeding edge purity of the diamond layer,
compositionally and isotopically, in a production environment.
Whatever the eventual answer, we all know the rule of thumb: If you
need PhDs on your production line, you don't have a production line.
Scientists to create it, engineers to build it and make it work,
illegal aliens or White trash to run it at minimum wage. Oversight is
a managerial prerogative and not bound by objective reality.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!
res1aah7
Posted: Wed Jul 30, 2003 12:17 am
Guest
Quote:
The application requires bleeding edge purity of the diamond layer,
compositionally and isotopically, in a production environment.
Whatever the eventual answer, we all know the rule of thumb: If you
need PhDs on your production line, you don't have a production line.
Scientists to create it, engineers to build it and make it work,
illegal aliens or White trash to run it at minimum wage. Oversight is
a managerial prerogative and not bound by objective reality.


lol
all i have is me, myself, and i to build it, make it work, and operate it,
although the latter will probably be eventually set up for computer
controlled operation... watching a cvd reactor for a 2000 hr deposition run
isnt exactly my idea of a fun time...
 
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