CVD of nitride layer onto organosilicate glass

Mary Tang mtang at
Fri Jun 6 09:34:10 PDT 2008

Hi Andrew --

There are a couple of different flavors of nitride available.  Please 
consult with Jeannie Perez, the process staff person in charge of this 
machine for more information.  It would probably be most helpful, if you 
are planning to perform similar processing to what previous Dauskardt 
group members have done, to have the recipe settings and desired film 
properties (thickness, uniformity, refractive index, and stress, if 
appropriate) on hand before consulting with her.

Jeannie is also the person you should contact to become trained and 
qualified on this system.

Let us know if you have further questions --


Andrew Thiel wrote:
> Yeah, I guess there certainly was some confusion.  Now that we're all 
> clear, would it be possible for someone at SNF to perform this nitride 
> deposition for me?  I'd like a film of silicon nitride thin enough to 
> be transparent deposited onto three of my organosilicate glass 
> specimens.  Please let me know how this may be arranged.
> Thank you,
> Andrew
> Quoting Mary Tang <mtang at>:
>> Hi Andrew --
>> After consulting with Maurice, I think there was some confusion about
>> the equipment choice.  I believe Maurice thought you were asking about
>> the LPCVD Tylan nitride system.  This is a high temperature-activated
>> CVD deposition for CMOS clean wafers.  The temperature is 750-850C --
>> typically, organosilicate glasses aren't subject to those temperatures
>> -- and generally these glasses are restricted to the metal and
>> post-metal processing of devices (i.e., "semiclean" at SNF).  The LPCVD
>> furnace is question is restricted to pre-metal CMOS (i,e,m "clean" at
>> SNF.)  Thus, his concern.
>> Looking through the Coral history, it looks like the Dauskardt group
>> has not used the LPCVD nitride system.  Several group members have,
>> however, used the sts PECVD system.  This system uses plasma to
>> activate the deposition process -- and so, the deposition is at about
>> 300-350 C, typically.  This would be consistent with use of
>> organosilicate materials. SpecMat approval is not required for sts dep
>> -- The sts is a "gold-contaminated" tool.and organosilicate glasses are
>> OK'ed for processing in this class of tools.  I believe this
>> information is on the website, but I'd be first to admit that it may
>> not be easy to find (and as webmaster, I should know.)  As we're in the
>> process of redesigning it, your suggestions and advice on how to
>> improve it would be appreciated.
>> Mary
>> Andrew Thiel wrote:
>>> Hello,
>>> I'm a graduate student in materials science interested in using CVD 
>>>  at SNF.  I have a silicon wafer topped with a thin film of an  
>>> organosilicate glass, and I'd simply like a silicon nitride film  
>>> deposited onto it.  My research group (Dauskardt in MSE) has  
>>> actually done this exact deposition at SNF several times over the  
>>> past couple years without any issues, but the current manager of  
>>> CVD at SNF (Maurice Stevens) is reluctant to allow an  
>>> organosilicate glass into any chamber without the permission of  
>>> SpecMat.
>>> The specific organosilicate glass I would be introducing into the  
>>> CVD chamber is DiEthoxyMethylSilane (DEMS).  My research group has  
>>> conducted thermal studies and found this material to stable up to  
>>> temperatures of at least 400 C.
>>> Please let me know of any other additional information you may need.
>>> Thanks,
>>> Andrew

Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
CIS Room 136, Mail Code 4070
Stanford, CA  94305
mtang at

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