A few years back I built some thin film superconducting transformers.  After
depositing and patterning the metal for the first coil, I deposited and
patterned a layer if PECVD silicon oxynitride. I then deposited and
patterned a 2nd layer of metal which provided a connection from the center
of the coil to the outer region. This process was repeated to build the 2nd
inductor.

The selection of dielectric wasn't particularly critical, except that it
must have good step coverage and be pinhole free.  Before switching to SiON
I tried PECVD SiO2 using Silane.  This material had terrible step coverage
which resulted in poor conductivity where the 2nd metal passed over each
turn of the underlying coil.

Roger Shile

-----Original Message-----

Hi everyone-

I am attempting to create an integrated inductor (just a few coils on my
substrate), and I was curious if anyone had experience with this or
something similar.  My main problem is how to get the wire back out from
the middle of the coil.  I was thinking I could make a line of metal to
the center of my coil, and then cover it with some material allowing the
next metallization to just go over that part.  I just don't know what
material would be best suited for this.  Please let me know if you have
any suggestions.

Thanks,
Tony Homan