From mtang at snf.stanford.edu  Fri Jan 17 19:03:05 2003
From: mtang at snf.stanford.edu (Mary Tang)
Date: Fri, 17 Jan 2003 19:03:05 -0800
Subject: [Fwd: Drytek4]
Message-ID: <3E28C3E9.E9D7FA55@snf.stanford.edu>



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

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Subject: Drytek4
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From mcvittie at snf.stanford.edu  Tue Jan 21 11:36:46 2003
From: mcvittie at snf.stanford.edu (Jim McVittie)
Date: Tue, 21 Jan 2003 11:36:46 -0800
Subject: Nitride Etch Problem in Drytek4
Message-ID: <3E2DA14E.B25E0A8B@snf.stanford.edu>

Vijit,

Over the weekend I checked out Drytek4 and could not find any problems.
In particular,
I looked at the base pressure, the leak rate, the rf power, the rf
voltage
waveform, the dc bias, the matching, a SF6 plasma and an Ar plasma. Note

that the bias I measured for the SF6, 150mt, 150W was only -23V, but
such
low values are common for SF6. Under the same conditions for an Ar
plasma,
the bias was well over -100V. My -23V at 150W is significantly lower
than
your previous -30V at 120W.

I agree with Henry and Casar that your problem may well be solved by a
long chamber
season using your nitride etch process. However, I would like point out
that there have been a number of recent papers showing that the presence
of  NO in plasma is very imnportant in the etching of Si Nidride. For
example see Kastenmeier et al, "Remove plasma etching of si nidride and
si oxide using NF3/O2 mixtures", JVST A, 16(4), 2047, 1998.

In Dec, Ben Chui was able to a get enhancement in his SF6 nitride
etching by adding a small amount of O2. I did his etching on either
Drytek1 or Drytek4.

    Jim McVittie
------------------------
Subject:  re: nitride etch
   Date:  Tue, 03 Dec 2002 09:10:05 -0800
   From: "Benjamin Chui" <bchui at california.com>
     To:   Jim McVittie <mcvittie at snf.stanford.edu>

Jim,     I tried the SF6 with a little bit of added O2 and it worked
wonders!  The nitride etch rate went from 50 Ang/min (without O2) to
something like 1000 Ang/min (with O2).
      Thanks for the suggestion!
    Ben





From scaccag at stanford.edu  Tue Jan 21 13:26:40 2003
From: scaccag at stanford.edu (Luigi Scaccabarozzi)
Date: Tue, 21 Jan 2003 13:26:40 -0800 (PST)
Subject: Nitride Etch Problem in Drytek4
In-Reply-To: <3E2DA14E.B25E0A8B@snf.stanford.edu>
Message-ID: <Pine.LNX.4.44.0301211318200.17631-100000@cardinal5.Stanford.EDU>

HI all,
sorry if this email turns out to be useless (I think I missed the first
part of the problem), but I thought my data can be useful to someone.
I used dryteck4 a few days ago and found AT LEAST the same etchrate I had
last September: I cleared 1800A of SiN in 1'25",  which means an etch rate
>=1270 A/min.
I used SF6 (flow 100) with pressure 100 mTorr, Power~120W (-48 V DC).
Gigi

On Tue, 21 Jan 2003, Jim McVittie wrote:

> Vijit,
>
> Over the weekend I checked out Drytek4 and could not find any problems.
> In particular,
> I looked at the base pressure, the leak rate, the rf power, the rf
> voltage
> waveform, the dc bias, the matching, a SF6 plasma and an Ar plasma. Note
>
> that the bias I measured for the SF6, 150mt, 150W was only -23V, but
> such
> low values are common for SF6. Under the same conditions for an Ar
> plasma,
> the bias was well over -100V. My -23V at 150W is significantly lower
> than
> your previous -30V at 120W.
>
> I agree with Henry and Casar that your problem may well be solved by a
> long chamber
> season using your nitride etch process. However, I would like point out
> that there have been a number of recent papers showing that the presence
> of  NO in plasma is very imnportant in the etching of Si Nidride. For
> example see Kastenmeier et al, "Remove plasma etching of si nidride and
> si oxide using NF3/O2 mixtures", JVST A, 16(4), 2047, 1998.
>
> In Dec, Ben Chui was able to a get enhancement in his SF6 nitride
> etching by adding a small amount of O2. I did his etching on either
> Drytek1 or Drytek4.
>
>     Jim McVittie
> ------------------------
> Subject:  re: nitride etch
>    Date:  Tue, 03 Dec 2002 09:10:05 -0800
>    From: "Benjamin Chui" <bchui at california.com>
>      To:   Jim McVittie <mcvittie at snf.stanford.edu>
>
> Jim,     I tried the SF6 with a little bit of added O2 and it worked
> wonders!  The nitride etch rate went from 50 Ang/min (without O2) to
> something like 1000 Ang/min (with O2).
>       Thanks for the suggestion!
>     Ben
>
>
>