processing request, semicleanB Ni-Ti

Michael Deal mdeal at
Wed Apr 6 12:25:01 PDT 2005

      The specmat committee has decided that your Ni-Ti samples can be 
considered semicleanB materials, and hence can go into the LTO 
(tylanbpsg).   The guidelines for semicleanB materials is:

- Semiclean B class wafers (i.e. those deposited in the SCT system) can be 
processed in all semiclean equipment (i.e. tylanbpsg, tylanfga, etc.) as 
well as the litho equipment, with the following IMPORTANT restrictions:
         a. Semiclean B class wafers can only be cleaned or wet-etched at 
wbgeneral in dedicated clean beakers. (exception: WBmetal - Semiclean A and 
B metals and Ge can be cleaned here, but only in the PRS-1000 pot.)
         b. Dry-etching of these films will be allowed on a case-by-case 
basis.  (Etching oxide down to these SCT metals will be allowed in oxide 
etchers in the semiclean equipment set, ie. AMTetcher and P5000.)
         c. When annealing semiclean B class wafers in the AG4108 RTA, the 
silicide tray must be used, which from now on will be referred to as the 
"semiclean tray".  (Once the AG4100 comes on line, it will be classified as 
a semiclean tool and will be used for all semiclean materials including SCT 
metals and Ge.  The AG4108 will be dedicated to clean materials only.)
         d. Semiclean B materials (as with semiclean A materials) should 
use the metal-side of tylanfga.


At 01:15 PM 4/5/2005, Ankur Jain wrote:
>Hello SpecMat members,
>  Following my request to allow processing of my wafers containing a Ni-Ti
>film in the LTO furnace, I had a brief meeting with Mike discussing my
>process flow. TiNi Alloy Company, the vendor that sputters these Ni-Ti
>films for me uses a Perkin-Elmer 4450 sputterer that is used exclusively
>for depositing Ni-Ti, and no other metals. They have done Auger
>spectroscopy on their films in the past and the only significant surface
>contamination observed was elemental carbon, which they say is normal for
>anything exposed to air.
>  Following my discussion with Mike, who agreed in principle to let me use
>the LTO tube, I am sending this email to SpecMat with a request to kindly
>expedite a final decision on my request. I would appreciate it very much
>if I can get started on my microfabrication soon.
>On Mon, 4 Apr 2005, Michael Deal wrote:
> > LTO is semicleanB, so it's okay to put Ni and Ti in there as long as the Ni
> > and Ta are not contaminated from somewhere else.  (We allow Ni and Ta
> > deposited in the new SCT sputterer to go into semiclean tools now, for
> > example.)     Ankur, where was the NiTi deposited and how clean is
> > it?   (Was it deposited in a system that also does gold or iron?)
> >                                                  0mike
> >
> >
> > At 01:13 PM 4/4/2005, Ankur Jain wrote:
> > >Hello SpecMat members,
> > >  I have six 4-inch Si wafers. It has a sandwich of 2 micron thermal oxide
> > >and 2 micron layer of Nickel-Titanium alloy on one side. The other side
> > >has only 2 micron thermal oxide. I would like to deposit about 0.5 microns
> > >of LTO on the Nickel-Titanium side. I understand that Ni is not one of the
> > >standard metals allowed on the metal side of the LTO tube.  However,
> > >Maurice suggested that I write to SpecMat and find out if it might be
> > >possible to do a one-time deposition just before the LTO tube is scheduled
> > >for pull and clean. Please let me know if that would be possible.
> > >  If you have any other suggestions for depositing an electrically
> > >passivating layer that will still let my wafers be processed in clean
> > >equipment after deposition, I would welcome them.
> > >
> > >thanks,
> > >
> > >Ankur.
> > >
> > >*************************************************************************
> > >Graduate Student
> > >Microscale Heat Transfer Laboratories         Residence:
> > >Room 201, Building 530                        126 Blackwelder Ct, Apt 902
> > >Stanford, CA-94305                            Stanford, CA - 94305
> > >Ph: 650-736-0044                              Cell Ph: 650-799-8986
> > >
> >
>Graduate Student
>Microscale Heat Transfer Laboratories         Residence:
>Room 201, Building 530                        126 Blackwelder Ct, Apt 902
>Stanford, CA-94305                            Stanford, CA - 94305
>Ph: 650-736-0044                              Cell Ph: 650-799-8986

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