Material request: ZnS

[Jim McVittie]

Hi Ben,

I need to correct what I said about etching ZnCdS in the MRC. I contacted 
the user whom I thought had etched this material. She informed me that 
none of her devices required etching of the ZnCdS. Regarding our photronic 
device people. Some years ago, one of them approached me about plasma 
etching ZnSe or ZnSSe. At the time, I looked into the issue and found out 
about the methane process, which we were not set up to do. Later, I learn 
from James Conway that they went to UCSB to etch their material. Last 
March at an etch workshop, I met the guy who is in charge of the UCSB 
etchers. He said the methane process is set up in a RIE tool and is mainly 
used for InP related materials. I did not ask him about the Zn compounds.  
There are a number of papers in the literature about the methane process. 
It can be used for ZnTe, ZnSe, CdTe, ZnS, CdS in addition to the In 
compounds.  

	Jim 


On Thu, 7 Sep 2006, Ben Chui wrote:

> Jim,
> 
>    That's a good piece of information to know.  Thanks!
> 
> Ben
> 
> 
> On 07/09/06, Jim McVittie <mcvittie at cis.stanford.edu> wrote:
> > Ben,
> >
> > The students here work with films < 500 A thick. You will not be able to
> > sputter etch a 1 um thick ZnS in any of our tools. UCSB has a RIE tool
> > which is set up with the methane process. Our optics people here go there
> > for etching materials which need that process.
> >
> >        Jim
> >
> > On Thu, 7 Sep 2006, Ben Chui wrote:
> >
> > > Jim,
> > >
> > >      We have to etch an optical stack which includes an alternating
> > > Ge/ZnS/Ge/ZnS.... structure (each layer on the order of 1 micron
> > > thick, i.e. the total stack will be multiple microns tall).  If we
> > > can't etch ZnS in-house, we might have to send it outside, or it might
> > > be easier anyway to do a thick liftoff process to avoid dry-etching
> > > altogether (since a dry-etch would involve continually switching
> > > between Ge etch and ZnS etch).  What do you recommend?
> > >
> > > Ben
> > >
> > >
> > > On 07/09/06, Jim McVittie <mcvittie at cis.stanford.edu> wrote:
> > > > Ben,
> > > >
> > > > Some of the students already work with ZnCdS, so ZnS is not new to the
> > > > lab. I think they have done some sputter etching of their material in the
> > > > MRC. I will have to check on this point.  What materials do you want to
> > > > etch? To plasma etch ZnS, you need a CH4/H2/Ar process, which we do not
> > > > have.
> > > >
> > > >        Jim
> > > >
> > > > On Thu, 7 Sep 2006, Ben Chui wrote:
> > > >
> > > > > Hello specmat committee,
> > > > >
> > > > >      On behalf of A.M.Fitzgerald and Associates, I'd like to submit a
> > > > > material request for ZnS.  This material will be deposited at an
> > > > > external vendor and we'd like to bring it into SNF for dry etching
> > > > > only.
> > > > >
> > > > >      To our knowledge, this material has been used at the Univ of
> > > > > Minnesota clean room for optical MEMS.
> > > > >
> > > > >      Please advice us as to whether this material is allowed in SNF
> > > > > and  if so in which machines.
> > > > >
> > > > > Thanks,
> > > > >
> > > > > Ben Chui
> > > > >
> > > >
> > > > --
> > > > --------------------------------------------------------------
> > > > Jim McVittie, Ph.D.                     Senior Research Scientist
> > > > Allen Center for Integrated Systems     Electrical Engineering
> > > > Stanford University                     jmcvittie at stanford.edu
> > > > Rm. 336, 330 Serra Mall                 Fax: (650) 723-4659
> > > > Stanford, CA 94305-4075                 Tel: (650) 725-3640
> > > >
> > > >
> > > >
> > >
> >
> > --
> > --------------------------------------------------------------
> > Jim McVittie, Ph.D.                     Senior Research Scientist
> > Allen Center for Integrated Systems     Electrical Engineering
> > Stanford University                     jmcvittie at stanford.edu
> > Rm. 336, 330 Serra Mall                 Fax: (650) 723-4659
> > Stanford, CA 94305-4075                 Tel: (650) 725-3640
> >
> >
> >
> 

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