Figured it out... Doesn't depend on the machine, but on what elementary metal we deposit on top of the silicon... Ok. I think I change the process to gate-first with silicides and go through the pain of dimensioning the temperature and time for the silicide formation... Aaand updating the equations for the threshold calculation for accounting for the changed gate potential....
Cheers David
On Wednesday, 7 March 2018 7:22:08 PM HKT David Lanzendörfer wrote:
Hi These rapid thermal process machines AW610 RTP (DIF-R2) and AW610 RTP (DIF-R3) can both deposite silicides: http://www.nff.ust.hk/en/equipment-and-process/equipment-list/thermal-diffu sion-and-ion-implantation-module.html
I will check which materials are available. -> "Is it WSi2 or AlSi2?" plays into the threshold equation!
I'll keep you updated!
Cheers David
On Wednesday, 7 March 2018 6:45:15 PM HKT David Lanzendörfer wrote:
Hi What I'm taling about in indeed a mix between our metal and polysilicon as described here in these lecture slides: https://web.stanford.edu/class/ee311/NOTES/Silicides%20&%20Metal%20gate %20Slides.pdf
This polycrystal resulting from this process step would be resistant against the temperatures during annealing after implantation.
However. Getting the reaction of Aluminum and Polysilicon right will be very very tricky.
Anyone experience with this step, or knows someone who does, who could assist me with setting the parameters for time and temperature and atmosphere?
Otherwise I would have to experiment around a few times until I get it right with orientation numbers I find with Googling ^^'
Cheers
David
On Wednesday, 7 March 2018 5:04:05 PM HKT Staf Verhaegen wrote:
(Now send to the list.)
R. Timothy Edwards schreef op di 06-03-2018 om 16:48 [-0500]:
Hello Staf,
Could you summarize again what the problem is with poly gate? In the industry polysilicon has been the gate for all technologies I know from 1um up to at least 65nm.
What is commonly drawn as a poly gate is actually a "salicide", or poly coated with a thin layer of metal. This is what David is referring to. The difference between a poly salicide and plain polysilicon is a few ohms per square vs. a hundred ohms per square.
AFAIK, David is talking about aluminum gates. Silicidation or salidication is indeed a step done after poly formation to decrease sheet resistance of the poly. AFAIR also the diffusion regions are silicided but I think you need spacers then.
greets, Staf.