GaN sputtering

Jim McVittie mcvittie at snf.stanford.edu
Fri Feb 24 09:47:09 PST 2006


All,

All,

I take full responsibility for letting Jia Feng deposit GaN in the Metalica. It started with him asking me if we could RF sputter GaN in the tool. I told him it should work. Since he already had the target, I set up a time to try it out. Since GaN is
non-toxic and has a low vapor pressure, I just did not think about getting a Specmat approval. I apologise not delaying the work and asking Jia to submit a Spacmat request.

       Jim

Jia Feng wrote:

> Ed:
>
> I regret to know the potential hazard that GaN may bring to us. I talked to Dr. Jim McVittie before I did the sputtering. Both Jim and Zheng were just so kind to help me do it. Could you please let me know how I could fix, or minimize, this problem?
>
> Thanks,
> Jia
>
> ----- Original Message -----
> From: "Ed Myers" <edmyers at stanford.edu>
> To: <fengj at stanford.edu>; <wangz at stanford.edu>
> Cc: <specmat at snf.stanford.edu>; "Jeannie Perez" <jperez at snf.stanford.edu>; <nishiy at stanford.edu>
> Sent: Thursday, February 23, 2006 4:39 PM
> Subject: Fw: GaN sputtering
>
> > Zheng, Jia
> >
> > It appears you have ran an unauthorized process in the metalica.  I was not
> > able to find any indication of GaN in the specmat database.  This is extra
> > frustrating considering the issues we encountered last year with the
> > unauthorized use of RF depositions in the metalica.
> >
> > DO NOT RUN THIS PROCESS WITHOUT SPECMAT APPROVAL.
> >
> > In case you never looked at the MSDS sheet for GaN, I've enclosed the
> > health effects you have exposed your fellow users to without their knowledge.
> >
> > Ed
> >
> >
> > Acute Effects:
> > Inhalation: May cause irritation to the nose, throat & mucous membranes.
> > Ingestion: May cause nausea, vomiting and anorexia.
> > Skin: May cause irritation.
> > Eye: May cause irritation.
> >
> > Chronic Effects:
> > Inhalation: May cause depression of bone marrow function.
> > Ingestion: No chronic health effects recorded.
> > Skin: May cause dermatitis & depression of bone marrow function.
> > Eye: No chronic health effects recorded.
> > Routes of Entry: Inhalation, Skin, Eyes, Ingestion,
> > Target Organs: No target organs recorded.
> >
> > Carcinogenicity: None
> >
> > Medical Conditions Generally Aggravated by Exposure: Pre-existing
> > respiratory disorders.
> >
> > Signs and Symptoms of Exposure:
> > Inhalation: May cause a red, dry throat, sneezing, coughing and difficulty
> > breathing.
> > Ingestion: May cause behavioral changes such as sleepiness and loss of
> > appetite may be noted. Other symptoms may include nausea, vomiting,
> > metallic taste in mouth general itching and sweating.
> > Skin: May cause redness and itching.
> > Eye: May cause redness, itching and watering.
> >
> >
> >
> > >X-Sieve: CMU Sieve 2.2
> > >Delivered-To: Emyers at snf.stanford.edu
> > >X-Mailer: QUALCOMM Windows Eudora Version 6.2.5.6
> > >Date: Thu, 23 Feb 2006 15:31:13 -0800
> > >To: Emyers at snf.stanford.edu
> > >From: Jeannie Perez <nperez at stanford.edu>
> > >Subject: Fw: GaN sputtering
> > >
> > >  Hi Ed,
> > >Would you please read the message below and let me know if I should change
> > >parts again. I just changed them last week.
> > >Jeannie
> > >
> > >>X-Sieve: CMU Sieve 2.2
> > >>Delivered-To: jperez at snf.stanford.edu
> > >>From: "Jia Feng" <fengj at stanford.edu>
> > >>To: "Jeannie Perez" <jperez at snf.stanford.edu>
> > >>Subject: Fw: GaN sputtering
> > >>Date: Wed, 22 Feb 2006 00:32:23 -0800
> > >>X-Mailer: Microsoft Outlook Express 6.00.2800.1506
> > >>
> > >>
> > >>----- Original Message -----
> > >>From: "Jia Feng" <fengj at stanford.edu>
> > >>To: "Jim McVittie" <mcvittie at cis.Stanford.EDU>
> > >>Sent: Wednesday, February 22, 2006 12:29 AM
> > >>Subject: Re: GaN sputtering
> > >>
> > >>
> > >> > Jim:
> > >> >
> > >> > Zheng helped me do the GaN sputtering with Metalica in the afternoon.
> > >> The plasma was ignited and GaN was successfully sputtered onto my
> > >> wafers. But unfortunately, the chimney was not well fastened and thus
> > >> was tilted a little bit during the sputtering. There might be some GaN
> > >> sputtered onto the bottom of the chamber and onto the anode (we can see
> > >> a blue corlor). I did the sputtering at 25 W RF power, 10 mTorr
> > >> pressure, and 30 sccm Ar flow. The time was 10 min for one dummy wafer
> > >> and 30 min for two real wafers. I am wondering if I should clean the
> > >> chamber and the anode. If so, how can I do it? Should I better have my
> > >> own dedicated anode in the future?
> > >> >
> > >> > Thanks,
> > >> > Jia
> >
> >




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