Deposit ITO (indium doped tin oxide) with Metalica.

Jim McVittie mcvittie at cis.Stanford.EDU
Fri Sep 8 16:25:43 PDT 2006


Let me make some comments about ITO deposition.

1. Particles -- It has been stated that we want to stay away from sputter
deposited dielectrics because they generate lots of particles. We have
been depositing all types oxides with the AJA sputtering system in the
Nishi lab. We are finding SiO2 sputtering does indeed generate lots of
small particles so one has to be very careful not to spread these
particles. For this reason, I strongly agree with keeping SiO2 sputtering
out of the SCT and the Metallica. But we are not seeing the same problem
with the other oxides (TiO, GeOx, WO, NiO, and Al2O3). The other oxides
show flaking, which is much easier to cleanup and control than the SiO2
particles. So far, my experience has been that the metal oxides do flake
much more than a metal like Al but they are no where as bad as a high
stress metal like Ni, where we have had a major flaking problem. The
bottom line is I expect ITO will be no worst that many of the metals you
are already putting down in the Metallica.

2. RF or DC sputtering - ITO is conductive and can be deposited using
either RF or DC. Dc is much easier to use so it is the way to go.

3. Ar-O2 mixtures -- ITO sputtering yields its lowest resistivity when 
sputtered with about 0.5% O2 in the Ar. I suggest that Ying start with no 
O2 added. If she needs the O2 addition, there is a tank of Ar with 1% O2 
and an second MFC already installed on the Metallica. I believe the MFC 
has been disconnected but it is fairly easy to re-hookup. There is a multi 
MFC controller at the top of the Metallica rake, which is setup for 
controlling a master (Ar) gas and a slave (Ar/1%O2), so that mixtures 
between 0.25 and 1% O2 can be flowed into the Metallica.

4. Why not use the AJA for ITO - We already have a 1" ITO target for the 
Metallica and it is already set up for ITO in that it has Ar/1% O2 mix 
installed. We do not have a 2" target for the AJA, it is not set up for 
running 0.5% O2 and Ying's project is not part of the project which 
purchased the AJA. This last point is not a show stopper for her since she 
is a Nishi student.


On Fri, 8 Sep 2006, Ying Chen wrote:

> To whom it may concern,
> I would like to request the approval to use ITO (indium doped tin oxide)
> target in Metalica in the snf clean room. I've talked to Jim McVittie and
> Jeannie Perez both of whom agreed that the process is feasible and will
> need only the approval from SpecMat.
> Thanks a lot!
> Best regards,
> Ying Chen
> EE PhD Candidate
> Professor Nishi's Group

Jim McVittie, Ph.D.    			Senior Research Scientist 
Allen Center for Integrated Systems     Electrical Engineering
Stanford University             	jmcvittie at
Rm. 336, 330 Serra Mall			Fax: (650) 723-4659
Stanford, CA 94305-4075			Tel: (650) 725-3640

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