FW: Gold

Mary Tang mtang at stanford.edu
Wed Jan 13 16:49:24 PST 2010


Hey Ed --


Good test case.  We've talked about this for long enough.  I suggest we 
approve one of our furnaces for this purpose, with a few, key caveats.  
Thermcopoly1?  We'll need to inform the few people who use this system.  
Caveats might be: 


- substrates with noble metals allowed
- no substrates containing materials that will react at process 
temperatures with Cl-


Alternatively, we can start conservatively and define "trace" metals at 
concentrations typical for catalytic nanowire growth.  Trace metals 
we've seen (that I know of) for nanowires include iron and silver -- I 
think there are concerns about the volatility of iron chlorides at 
thermal oxidation temperatures, but don't know about poly LPCVD 
temperatures.  So, I don't know if we want to be more specific about 
what acceptable "trace" metals are.  Trace noble metals only?  I don't 
know, I think I favor allowing noble metals.


Should we be concerned if the nanoporous alumina substrate has any other 
major components other than alumina?


Mary




Ed Myers wrote:
> All,
>
> Here is a request from an anxious prospective lab member to convert 
> one of our doped poly furnaces to gold contaminated.  They are under a 
> SBIR deadline, so they are anxious to have a resolution.
>
> Ed
>
>
>> x-cr-puzzleid: {028F3430-F240-4D74-87CE-CA49A4A1876C}
>> x-cr-hashedpuzzle: AUex AzNj BTV9 ED3A ESpk FqN2 GbDh HjbJ HmqB Hx/A 
>> IRYW IVcD I+Hu JBjW Kkrg 
>> L6h2;1;ZQBkAG0AeQBlAHIAcwBAAHMAdABhAG4AZgBvAHIAZAAuAGUAZAB1AA==;Sosha1_v1;7;{028F3430-F240-4D74-87CE-CA49A4A1876C};dABoAHUAbABhAHMAaQBkAGgAYQByAGEAbgAuAGcAYQBuAGQAaABpAEAAZAB4AHIAYQB5AC4AYwBvAG0A;Wed, 
>> 13 Jan 2010 21:22:48 GMT;RgBXADoAIABHAG8AbABkAA==
>> Subject: FW: Gold
>> Date: Wed, 13 Jan 2010 13:22:48 -0800
>> X-MS-Has-Attach: yes
>> X-MS-TNEF-Correlator:
>> Thread-Topic: Gold
>> Thread-Index: AcqTCLmLOumGV0zxQ22RekcwmIFejAAAPdLQAGMrzvA=
>> From: "Thulasidharan Gandhi" <thulasidharan.gandhi at dxray.com>
>> To: "Ed Myers" <edmyers at stanford.edu>
>>
>> Dear Ed,
>>
>> This is the package which I sent to specmat group. Can you let me know
>> if you need anything else.
>>
>> Thanks
>>
>> Thulasi Gandhi
>>
>>
>>
>> To SpecMat Committee:
>>
>> We would like to grow Si nanowires using a template process using
>> Stanford Nanofabrication facility. The template which we will be using
>> is nanoporous alumina template with few nanometers of gold
>> electrodeposited into the pores which will act as a catalyst for growth
>> of Si nanowires. Since gold is a contamination I would like to request
>> you permission to assign a poly furnace for growth of Si nanowires under
>> the gold contamination equipment set. I have attached a paper which
>> shows the growth process of Si nanowires using a template process using
>> gold as a catalyst. If you need any other information, I will be ready
>> to provide you.
>>
>> Thanks
>>
>> Thulasi Gandhi
>>
>> 1) Contact Information:
>>
>> DxRay Inc
>> 19355 Business Center Drive, Suite 10, Northridge, CA-91324 Contact
>> Person: Thulasi Gandhi Ph no: 8182800177 ext107 email:tgandhi at dxray.com
>>
>> 2)Material: The Material which we are proposing to use is gold.
>>
>> 3)Process: The process which we will be developing is CVD growth of Si
>> nanowires onto a nanoporus alumina template using gold as a catalyst.
>>
>> 4)Quantity: The substrate size is around 1/2" in diameter
>>
>> 5)Storage: There won't be any storage of the substrates at SNF.
>>
>> 6)Disposal: There won't be any disposal of the substrates at SNF.
>>
>>
>>
>> -----Original Message-----
>> From: Ed Myers [mailto:edmyers at stanford.edu]
>> Sent: Monday, January 11, 2010 1:55 PM
>> To: Thulasidharan Gandhi
>> Subject: RE: Visit to See Silane Setup on 01/06/09
>>
>> Thulasi Gandhi,
>>
>> The link is a couple of pages deeper
>>
>> http://snf.stanford.edu/Materials/NewMatProc.html
>>
>> Ed
>>
>> At 01:50 PM 1/11/2010, you wrote:
>> >Dear Ed,
>> >
>> >I checked for the paperwork at the spectmat group, but could not find
>> >one. Should I send an email and request them? We want to make sure we
>> >get an approval from them before signing in for the training and making
>>
>> >a open purchase order for using the facility. Can you guide me through
>> >on this.
>> >
>> >Thanks
>> >
>> >Thulasi Gandhi
>> >
>> >-----Original Message-----
>> >From: Ed Myers [mailto:edmyers at stanford.edu]
>> >Sent: Monday, January 11, 2010 1:21 PM
>> >To: Thulasidharan Gandhi
>> >Cc: specmat at snf.stanford.edu; maurice stevens
>> >Subject: RE: Visit to See Silane Setup on 01/06/09
>> >
>> >Thulasi Gandhi,
>> >
>> >Yes, we have a poly-silicon furnace plumbed with both dopants.  Right
>> >now it is for clean samples, where your sample would be considered gold
>>
>> >contaminated.  I have copied the specmat group which is responsible for
>>
>> >any changes to our cleanliness or contamination levels.  To run what
>> >you ask, does require this group to assign a poly furnace to the gold
>> >contaminated equipment set.  If you want to make this change, you will
>> >need to fill out the paperwork starting at
>> >http://snf.stanford.edu/Materials/Materials.html
>> >
>> >Also, there will be a memory effect as you switch dopant gases.  This
>> >should be factored in to your process planning.  If you don't remove or
>>
>> >seal the dopants, you will get a lot of compensated doping and not
>> >sharp dopant transitions.
>> >
>> >Regards,
>> >Ed
>> >
>> >
>> >At 11:01 AM 1/11/2010, Thulasidharan Gandhi wrote:
>> > >Dear Ed Myers,
>> > >
>> > >It was nice meeting you the other day and knowing about the research
>> > >capabilities you have. We have one final question before we go ahead
>> > >with the application for training and using your facility.
>> > >
>> > >This is what we are planning to do: We are planning to grow Si
>> >nanowires
>> > >onto alumina template.
>> > >
>> > >We will have gold deposited into the alumina template and grow the Si
>>
>> > >nanowires using silane at around 500C. In the growth of Si nanowires
>> > >we want to dope phosphor and boron alternatively to grow PN Si
>> nanowires.
>> > >The other day you told us that your system is capable of doping
>> >phosphor
>> > >and boron. We want to once again make sure whether it can be done by
>> > >switching the gas supply.
>> > >
>> > >Thanks
>> > >
>> > >Thulasi Gandhi
>> > >
>> > >-----Original Message-----
>> > >From: Ed Myers [mailto:edmyers at stanford.edu]
>> > >Sent: Wednesday, January 06, 2010 7:43 AM
>> > >To: Thulasidharan Gandhi
>> > >Subject: RE: Visit to See Silane Setup on 01/06/09
>> > >
>> > >Thulasi Gandhi,
>> > >
>> > >Yes, I do have to make a change.  Last night I was not by my calendar
>>
>> > >and I forgot about a 1:30-3pm training I have to provide today.  Can
>> > >we meet after 3pm?
>> > >
>> > >Regards,
>> > >Ed
>> > >
>> > >
>> > >At 07:47 PM 1/5/2010, you wrote:
>> > > >Dear Ed Myers,
>> > > >
>> > > >Thats ok. I am not sure whether we can make it before 10 am. So i
>> > > >think 1-3 pm should be ok with us. I will meet you tomorrow at 1pm.
>> > > >Let me know if there is any changes.
>> > > >
>> > > >Thanks
>> > > >
>> > > >Thulasi Gandhi
>> > > >
>> > > >
>> > > >----------
>> > > >From: Ed Myers [mailto:edmyers at stanford.edu]
>> > > >Sent: Tue 1/5/2010 7:12 PM
>> > > >To: Thulasidharan Gandhi
>> > > >Subject: Re: Visit to See Silane Setup on 01/06/09
>> > > >
>> > > >Thulasi Gandhi,
>> > > >
>> > > >I found out late today, I have to participate in a phone conference
>>
>> > > >at 11am on Wednesday.  On Wednesday, I have time before 10am or
>> > > >between 1-3pm.  Sorry for the late change, but please let me know
>> > > >if either of these times will work for you.
>> > > >
>> > > >Regards,
>> > > >Ed
>> > > >
>> > > >
>> > > >At 02:51 PM 1/4/2010, you wrote:
>> > > > >Dear Edward Myers,
>> > > > >
>> > > > >I just spoke to you over the phone about visiting your lab on
>> > > > >Wednesday (01/06/09) at 11am. You can email me back the
>> directions.
>> > > > >
>> > > > >Thanks for your help.
>> > > > >
>> > > > >Regards,
>> > > > >
>> > > > >Thulasi Gandhi
>> > > >
>>
>>
>>


-- 
Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
CIS Room 136, Mail Code 4070
Stanford, CA  94305
(650)723-9980
mtang at stanford.edu
http://snf.stanford.edu




More information about the specmat mailing list