From nbelov at nanochip.com  Sat Oct  1 15:50:05 2005
From: nbelov at nanochip.com (Nickolai Belov)
Date: Sat, 1 Oct 2005 15:50:05 -0700
Subject: PQuest
Message-ID: <EF96B3FAFF9EDB41A7FCB23D5F067E4228EE58@ex2k.nanochip.com>

Hello Michael,

Yes, I can come over to SNF Tuesday (October 4) at 4 p.m.

I think it makes sense to invite to the meeting all PQuest users not
only to opponents of fluorine etch. Would you, please, do this when time
and place of the meeting is finalized.

With respect

Nickolai Belov

-----Original Message-----
From: Michael Wiemer [mailto:mwiemer at stanford.edu] 
Sent: Thursday, September 29, 2005 8:58 PM
To: Nickolai Belov
Subject: Re: PQuest

Hi Nickolai,

Im trying to see if some of the main opponents to the etch are available

next Tuesday at 4:00pm. They have not yet replied to my email I sent
them 
about this date/time so this is a very tentative date/time. Would you be

available then if they are as well?

Ill keep you posted. Hopefully we can settle on a date tomorrow
(Friday).

Thanks,

-Mike


----- Original Message ----- 
From: "Nickolai Belov" <nbelov at nanochip.com>
To: "Michael Wiemer" <mwiemer at stanford.edu>
Cc: <pquest at snf.stanford.edu>
Sent: Thursday, September 29, 2005 2:50 PM
Subject: RE: PQuest


Hello Michael,

Thank you for your response.

I'll be happy to meet and discuss the proposed "no CF4 without O2" rule.

Process/tools related restrictions usually require either executive
decision or have to be proven experimentally.

You are trying to solve the CF4 etching issue using executive decision.
If the decision will be made then I'll follow it.

I believe that experimental comparison of results of Cl2 etching versus
(CF4 etching - oxygen cleaning - Cl2 etching) should be the main
argument in the discussion. It is likely that we'll be able to find a
"common ground".

Please, suggest meeting time and I'll try to be there. I hope that some
other PQuest users will join us as well.

I'll be out of area this Friday (09/30).
I have several regular meetings in my schedule (Monday 1 p.m. - 3 p.m.;
Wednesday, Friday 9-10 a.m.).

With respect

Nickolai Belov
Tel: (510)-770-2516

-----Original Message-----
From: Michael Wiemer [mailto:mwiemer at stanford.edu]
Sent: Thursday, September 29, 2005 1:54 PM
To: Nickolai Belov
Cc: 'Rafael Aldaz'
Subject: PQuest

Hi Nickolai,

First, I am sorry this has taken so long. And second, I brought up the
issue
of testing the CF4 etching in the Pquest with other GaAs users. As you
can
see below, it did was not met with much enthusiasm. I am sure you do not
like this proposal (see below). So perhaps the best thing at this point
is
to get you together with some of the strongest opponents to this etch,
along
with Jim McVittie, and we can discuss.  If you are interested, when are
you
going to be on Campus?

Please read below. This was sent out to the Pquest list. Im not sure if
you
are on the pquest list and I wanted to make sure this got to you.

Pquest Users,

Over the last couple of weeks GaAs users - mostly Harris group people
who
are by far the group with the most people using the tool - have
discussed
the question of opening the tool for CF4 etching. The question was
basically, "Should CF4 etching of SiO2 and other materials widely used
in
the lab be allowed in the Pquest and if so, under what circumstances".
Nickolai Belov proposed a test to investigate the effects of CF4 on GaAs
etching to help answer this question. In the end, little support was
voiced
for the tests proposed by Nickolai Belov (test CF4 effect on GaAs
etching),
or for Flourine etching in the Pquest in general. I will try to
summarize
the main points which came out in the discussion in this email.

Currently, O2 with small amounts of CF4 is used to clean the chamber as
well
as etch some polymers (BCB for example). No one really had a problem
with
this as it is a necessary cleaning procedure, nor with the BCB etch,
being
so similar to the clean.

The issues, as well as I can summarize them here, follow below. While
reading, keep in mind that this is not a "etch anything" tool. It is the
only III-V etch tool in the lab and its integrity as a III-V etch tool
must
be maintained. This can only be done with good policy (I fully recognize
that policy on this tool has not always been stellar). And any good
policy
is simple, so here we go....

1.) CF4 polymerization

Instead of using an oxygen rich plasma like the CF4/O2 clean, the
proposed
etching would involve little to *no* O2 and 100% CF4. With this kind of
etch, there is the concern that this etch will deposit/build up a
teflon-like polymer film in the chamber.

2.) F affects the GaAs (and, more dramatically, the AlGaAs) etch rate.

This this is well documented. There is no desire among the users to
re-prove
this. Conditioning the chamber after a F etch can return the chamber to
good
Cl2/BCl3 GaAs etching condition. The question is what kind of
conditioning
and how long should the conditioning be. However, there was little
desire to
put the effort into researching this. Just like tests which may address
problem 1 above, the test to address this problem is time consuming and
may
ultimately be inconclusive. And any test only tests 1 particular
condition -
other CF4 users in the future would surely want to alter the process a
little and then we can be faced with the same problems all over again -
this
leads to the next problem....

3.) What about other people and the future?

One of the biggest problems which came out during the discussion is that
etching of SiO2 opens the door to more SiO2 etching. 90% of the lab
users
are Silicon people and if the word gets out that the Pquest can be used
for
SiO2 etching, there would probably be significantly more interest in the
future. Considering there are at least 6 SiO2 etch tools in the fab, why
do
we have to make the Pquest another one? People do not want to open this
tool
to SiO2 (Fluorine) etching and then deal with these issues above
continually
as the next and then the next person decides that Pquest is their
best-bet
tool for their Fluorine etch. If we make an exception here, or there, we
will CONSTANTLY have to deal with issues of process compatibility. The
tool
must be maintained as a III-V etch tool. Why do these questions never
come
up with the P5000? Answer: because there is a strong policy on that tool
about what gases/materials can be run in each chamber.

Proposal:
We propose that CF4 etching is eliminated from the "list" of possible
Pquest
etches. High O2-low CF4 flow etches will still be OK. And the week will
stay
split: GaAs etching Wed-Sat, non-GaAs etching Sun-Tues. If you want to
use
CF4 in the Pquest and are unhappy by this, perhaps the best way to
communicate is to get together (email is so difficult and time
consuming).
Contact people: Rafael Aldaz (aldaz at stanford.edu) and Mike Wiemer
(mwiemer at stanford.edu). We are in contact with other GaAs users.












From mwiemer at stanford.edu  Mon Oct  3 16:27:56 2005
From: mwiemer at stanford.edu (Michael Wiemer)
Date: Mon, 3 Oct 2005 16:27:56 -0700
Subject: PQuest
In-Reply-To: <EF96B3FAFF9EDB41A7FCB23D5F067E4228EE58@ex2k.nanochip.com>
Message-ID: <000c01c5c872$16545660$766140ab@longmorn>

Pquest-

4:00pm Tomorrow (Tuesday) CISX Conference room 316 (on the 3rd floor).
Anyone interested in CF4 etching restrictions in the Pquest is welcome.

-Mike


> -----Original Message-----
> From: Nickolai Belov [mailto:nbelov at nanochip.com] 
> Sent: Saturday, October 01, 2005 3:50 PM
> To: Michael Wiemer
> Cc: pquest at snf.stanford.edu
> Subject: RE: PQuest
> 
> 
> Hello Michael,
> 
> Yes, I can come over to SNF Tuesday (October 4) at 4 p.m.
> 
> I think it makes sense to invite to the meeting all PQuest users not
> only to opponents of fluorine etch. Would you, please, do 
> this when time
> and place of the meeting is finalized.
> 
> With respect
> 
> Nickolai Belov
> 
> -----Original Message-----
> From: Michael Wiemer [mailto:mwiemer at stanford.edu] 
> Sent: Thursday, September 29, 2005 8:58 PM
> To: Nickolai Belov
> Subject: Re: PQuest
> 
> Hi Nickolai,
> 
> Im trying to see if some of the main opponents to the etch 
> are available
> 
> next Tuesday at 4:00pm. They have not yet replied to my email I sent
> them 
> about this date/time so this is a very tentative date/time. 
> Would you be
> 
> available then if they are as well?
> 
> Ill keep you posted. Hopefully we can settle on a date tomorrow
> (Friday).
> 
> Thanks,
> 
> -Mike
> 
> 
> ----- Original Message ----- 
> From: "Nickolai Belov" <nbelov at nanochip.com>
> To: "Michael Wiemer" <mwiemer at stanford.edu>
> Cc: <pquest at snf.stanford.edu>
> Sent: Thursday, September 29, 2005 2:50 PM
> Subject: RE: PQuest
> 
> 
> Hello Michael,
> 
> Thank you for your response.
> 
> I'll be happy to meet and discuss the proposed "no CF4 
> without O2" rule.
> 
> Process/tools related restrictions usually require either executive
> decision or have to be proven experimentally.
> 
> You are trying to solve the CF4 etching issue using executive 
> decision.
> If the decision will be made then I'll follow it.
> 
> I believe that experimental comparison of results of Cl2 
> etching versus
> (CF4 etching - oxygen cleaning - Cl2 etching) should be the main
> argument in the discussion. It is likely that we'll be able to find a
> "common ground".
> 
> Please, suggest meeting time and I'll try to be there. I hope 
> that some
> other PQuest users will join us as well.
> 
> I'll be out of area this Friday (09/30).
> I have several regular meetings in my schedule (Monday 1 p.m. 
> - 3 p.m.;
> Wednesday, Friday 9-10 a.m.).
> 
> With respect
> 
> Nickolai Belov
> Tel: (510)-770-2516
> 
> -----Original Message-----
> From: Michael Wiemer [mailto:mwiemer at stanford.edu]
> Sent: Thursday, September 29, 2005 1:54 PM
> To: Nickolai Belov
> Cc: 'Rafael Aldaz'
> Subject: PQuest
> 
> Hi Nickolai,
> 
> First, I am sorry this has taken so long. And second, I brought up the
> issue
> of testing the CF4 etching in the Pquest with other GaAs users. As you
> can
> see below, it did was not met with much enthusiasm. I am sure 
> you do not
> like this proposal (see below). So perhaps the best thing at 
> this point
> is
> to get you together with some of the strongest opponents to this etch,
> along
> with Jim McVittie, and we can discuss.  If you are 
> interested, when are
> you
> going to be on Campus?
> 
> Please read below. This was sent out to the Pquest list. Im 
> not sure if
> you
> are on the pquest list and I wanted to make sure this got to you.
> 
> Pquest Users,
> 
> Over the last couple of weeks GaAs users - mostly Harris group people
> who
> are by far the group with the most people using the tool - have
> discussed
> the question of opening the tool for CF4 etching. The question was
> basically, "Should CF4 etching of SiO2 and other materials widely used
> in
> the lab be allowed in the Pquest and if so, under what circumstances".
> Nickolai Belov proposed a test to investigate the effects of 
> CF4 on GaAs
> etching to help answer this question. In the end, little support was
> voiced
> for the tests proposed by Nickolai Belov (test CF4 effect on GaAs
> etching),
> or for Flourine etching in the Pquest in general. I will try to
> summarize
> the main points which came out in the discussion in this email.
> 
> Currently, O2 with small amounts of CF4 is used to clean the 
> chamber as
> well
> as etch some polymers (BCB for example). No one really had a problem
> with
> this as it is a necessary cleaning procedure, nor with the BCB etch,
> being
> so similar to the clean.
> 
> The issues, as well as I can summarize them here, follow below. While
> reading, keep in mind that this is not a "etch anything" 
> tool. It is the
> only III-V etch tool in the lab and its integrity as a III-V etch tool
> must
> be maintained. This can only be done with good policy (I 
> fully recognize
> that policy on this tool has not always been stellar). And any good
> policy
> is simple, so here we go....
> 
> 1.) CF4 polymerization
> 
> Instead of using an oxygen rich plasma like the CF4/O2 clean, the
> proposed
> etching would involve little to *no* O2 and 100% CF4. With 
> this kind of
> etch, there is the concern that this etch will deposit/build up a
> teflon-like polymer film in the chamber.
> 
> 2.) F affects the GaAs (and, more dramatically, the AlGaAs) etch rate.
> 
> This this is well documented. There is no desire among the users to
> re-prove
> this. Conditioning the chamber after a F etch can return the 
> chamber to
> good
> Cl2/BCl3 GaAs etching condition. The question is what kind of
> conditioning
> and how long should the conditioning be. However, there was little
> desire to
> put the effort into researching this. Just like tests which 
> may address
> problem 1 above, the test to address this problem is time 
> consuming and
> may
> ultimately be inconclusive. And any test only tests 1 particular
> condition -
> other CF4 users in the future would surely want to alter the process a
> little and then we can be faced with the same problems all 
> over again -
> this
> leads to the next problem....
> 
> 3.) What about other people and the future?
> 
> One of the biggest problems which came out during the 
> discussion is that
> etching of SiO2 opens the door to more SiO2 etching. 90% of the lab
> users
> are Silicon people and if the word gets out that the Pquest 
> can be used
> for
> SiO2 etching, there would probably be significantly more 
> interest in the
> future. Considering there are at least 6 SiO2 etch tools in 
> the fab, why
> do
> we have to make the Pquest another one? People do not want to 
> open this
> tool
> to SiO2 (Fluorine) etching and then deal with these issues above
> continually
> as the next and then the next person decides that Pquest is their
> best-bet
> tool for their Fluorine etch. If we make an exception here, 
> or there, we
> will CONSTANTLY have to deal with issues of process compatibility. The
> tool
> must be maintained as a III-V etch tool. Why do these questions never
> come
> up with the P5000? Answer: because there is a strong policy 
> on that tool
> about what gases/materials can be run in each chamber.
> 
> Proposal:
> We propose that CF4 etching is eliminated from the "list" of possible
> Pquest
> etches. High O2-low CF4 flow etches will still be OK. And the 
> week will
> stay
> split: GaAs etching Wed-Sat, non-GaAs etching Sun-Tues. If you want to
> use
> CF4 in the Pquest and are unhappy by this, perhaps the best way to
> communicate is to get together (email is so difficult and time
> consuming).
> Contact people: Rafael Aldaz (aldaz at stanford.edu) and Mike Wiemer
> (mwiemer at stanford.edu). We are in contact with other GaAs users.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 



From wistey at snowmass.stanford.edu  Tue Oct  4 19:12:59 2005
From: wistey at snowmass.stanford.edu (Mark Wistey)
Date: Tue, 4 Oct 2005 19:12:59 -0700
Subject: Allowed processes
Message-ID: <p06110406bf68cbe44195@[171.64.98.179]>

There seems to be some confusion for new users of the PlasmaQuest as 
to the usage of new processes on the machine.  We apologize that the 
old process policy apparently never make it to the PQuest Processes 
web page, and apparently new trainees are not being made aware that 
they need to get prior approval for any new process or recipe.  The 
policy can also be found in the PQuest mailing list archive (July 
2003):
http://snf.stanford.edu/cgi-bin/ezmlm-cgi/870
We will make sure the current operating policy is posted to the web 
page, and included in PQuest training, and that SpecMat is aware of 
the restrictions on the machine.  If our more explicit policy (from 
Mike's email last week) is approved, it will be posted as well.

Without further ado, here is the operating policy as of 2003:

>Date: Wed, 09 Jul 2003 09:55:29 -0700
>From: Jim McVittie <mcvittie at snf.stanford.edu>
>Organization: Stanford Nanofabrication Facility
>To: pquest at snf.stanford.edu
>Subject: Deleting Old Processes on PQuest
>
>PQuest Users,
>
>Thanks for senting me your PQuest processes. Now that I have all the
>current processes, I am going to start deleting all the old processes
>that are no longer being used. Any process that has not been sent to me
>by THIS FRIDAY ( 5pm July 11) will be considered a new process and will
>need to get my approval being able to be run on the PQuest. Only
>processes that I have recieved will be kept on the PQuest. Over the
>weekend, I will send out a list of all the current approved processes.
>Running unproved processes will be ground for being removed from the
>PQuest user list.
>
>     Thanks,  Jim McVittie

The form to request a new process OR recipe is here:
http://snf.stanford.edu/cgi-bin/ezmlm-cgi?870:mss:109:200307:fahiihjcobiobfcemdnn

And here's the start of the split by days of the week.  As Seth 
pointed out during today's meeting, setting aside Sun-Tues for 
"dirty" silicon processes does not mean "any" silicon process.  In 
other words, even existing processes may be restricted in the future 
if they are found to interfere with the primary purpose of the 
machine (GaAs/AlGaAs etching), even if they're performed Sun-Tues.

>Date: Mon, 30 Jun 2003 13:36:26 -0700
>From: Jim McVittie <mcvittie at snf.stanford.edu>
>To: pquest at snf.stanford.edu
>Subject: PQuest Time Split
>
>Pquest Users,
>
>Here is where things stand on slitting the use of the Pquest over the
>week. We will start out with a 4/3 split and see how well it works. The
>III-V users will get Wed-Sat and other users will have
>Sun-Tues. Since it is already on Monday, I propose we start the III-V
>period on Thursday of this week with them only getting 3 days on their
>first period.
>
>     Thanks,  Jim McVittie

Jim McVittie also posted a nice summary of process separation from 
Applied Materials.  Today's meeting seemed to have some confusion 
about the difference between polymerizing (low-oxygen) and 
nonpolymerizing (high-oxygen) plasmas.
http://snf.stanford.edu/cgi-bin/ezmlm-cgi?870:mss:111:200307:milghaonmllgibblleie

I would encourage all users of the PQuest--particularly new users who 
may not be aware of the machine's history--to read through the email 
list archive from time to time.  Sometimes new users run into a 
problem which was identified and solved by another user years ago. 
Or it may just be helpful to understand the reasoning behind the way 
things are today.
					 - Mark


From patricklu at gmail.com  Sun Oct 16 22:24:01 2005
From: patricklu at gmail.com (Patrick Lu)
Date: Sun, 16 Oct 2005 22:24:01 -0700
Subject: 1st time user requesting help
Message-ID: <5ef4413c0510162224w4175893bq8c012c7a3609ab8f@mail.gmail.com>

Hey,

I'm making my first etch ever on this machine at 1pm tomorrow (monday). Is
anyone available to watch me to make sure I'm not doing anything stupid?

Lemme know,
Patrick
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