From mcvittie at cis.Stanford.EDU Mon Jun 5 18:44:43 2006 From: mcvittie at cis.Stanford.EDU (Jim McVittie) Date: Mon, 5 Jun 2006 18:44:43 -0700 (PDT) Subject: Cl2 Flow Problem Message-ID: PQusers, Over the weekend, several users reported that they could not get the Cl2 flow to go below 2.5 sccm. This is a problem since the standard GaAs etch process runs with a Cl2 flow of 1.5 sccm. I traced the problem to the Cl2 pressure regular, which was at 25 psi rather than the standard 10 psi. The pressure was reduced to 10 psi but it creeped back to 25+ psi after a short time. This is a typical problem from for a contaminated Cl2 line. I suspect insufficent purging was done at some point when the Cl2 cylinder was changed. The solution is to replace the regulator and to increase the number purges during cylinder changes. Ted Berg said that a new regulator could take 3 wks to come in. It is possible that the Cl2 line may have to be shut down until the new regulator is installed. Jim -------------------------------------------------------------- Jim McVittie, Ph.D. Senior Research Scientist Allen Center for Integrated Systems Electrical Engineering Stanford University jmcvittie at stanford.edu Rm. 336, 330 Serra Mall Fax: (650) 723-4659 Stanford, CA 94305-4075 Tel: (650) 725-3640 From mcvittie at cis.Stanford.EDU Tue Jun 13 13:05:01 2006 From: mcvittie at cis.Stanford.EDU (Jim McVittie) Date: Tue, 13 Jun 2006 13:05:01 -0700 (PDT) Subject: Sapphire Etching in PQuest Message-ID: PQuest Users, I have a user, who wants to etch a dense arrays of 1 um and 0.5 um diameter holes 0.5um deep into 2 " diameter sapphire (Al2O3) wafers using a BCl3/Cl2/Ar process in the PQuest. About a 1/3 of the area surface area or about 3.2 sq cm is to be etched. He will be using a resist mask. There is no new material involve being here since Al etch always involve etching some Al2O3, and I belief some sapphire etching has been attempted in the past. But clearly there will be much more Al2O3 and resist by-products than we usually see. If you have a concern about letting the user do this process in the PQ, please reply. My understanding is that this is a one time need. Thanks, Jim -- -------------------------------------------------------------- Jim McVittie, Ph.D. Senior Research Scientist Allen Center for Integrated Systems Electrical Engineering Stanford University jmcvittie at stanford.edu Rm. 336, 330 Serra Mall Fax: (650) 723-4659 Stanford, CA 94305-4075 Tel: (650) 725-3640 From edmyers at stanford.edu Tue Jun 13 13:08:46 2006 From: edmyers at stanford.edu (Ed Myers) Date: Tue, 13 Jun 2006 13:08:46 -0700 Subject: Sapphire Etching in PQuest In-Reply-To: References: Message-ID: <6.2.5.6.2.20060613130749.0274e7d0@stanford.edu> Secondly, Can this be done during the Cl weeks or does it need to be done during the fluorine week? At 01:05 PM 6/13/2006, Jim McVittie wrote: >PQuest Users, > >I have a user, who wants to etch a dense arrays of 1 um and 0.5 um >diameter holes 0.5um deep into 2 " diameter sapphire (Al2O3) wafers using >a BCl3/Cl2/Ar process in the PQuest. About a 1/3 of the area surface area >or about 3.2 sq cm is to be etched. He will be using a resist mask. There >is no new material involve being here since Al etch always involve etching >some Al2O3, and I belief some sapphire etching has been attempted in the >past. But clearly there will be much more Al2O3 and resist by-products >than we usually see. If you have a concern about letting the user do this >process in the PQ, please reply. My understanding is that this is a one >time need. > >Thanks, Jim > > >-- >-------------------------------------------------------------- >Jim McVittie, Ph.D. Senior Research Scientist >Allen Center for Integrated Systems Electrical Engineering >Stanford University jmcvittie at stanford.edu >Rm. 336, 330 Serra Mall Fax: (650) 723-4659 >Stanford, CA 94305-4075 Tel: (650) 725-3640 From mwiemer at stanford.edu Tue Jun 13 13:48:14 2006 From: mwiemer at stanford.edu (Michael Wiemer) Date: Tue, 13 Jun 2006 13:48:14 -0700 Subject: Sapphire Etching in PQuest In-Reply-To: <6.2.5.6.2.20060613130749.0274e7d0@stanford.edu> Message-ID: <000101c68f2a$b0c114c0$766140ab@longmorn> Sounds fine to me. And it is a Cl process so I don't see why any of this would be a problem during Cl etch times. My 2 cents, -Mike > -----Original Message----- > From: Ed Myers [mailto:edmyers at stanford.edu] > Sent: Tuesday, June 13, 2006 1:09 PM > To: Jim McVittie; pquest at snf.Stanford.EDU > Subject: Re: Sapphire Etching in PQuest > > > > Secondly, Can this be done during the Cl weeks or does it need to be > done during the fluorine week? > > At 01:05 PM 6/13/2006, Jim McVittie wrote: > >PQuest Users, > > > >I have a user, who wants to etch a dense arrays of 1 um and 0.5 um > >diameter holes 0.5um deep into 2 " diameter sapphire (Al2O3) > wafers using > >a BCl3/Cl2/Ar process in the PQuest. About a 1/3 of the area > surface area > >or about 3.2 sq cm is to be etched. He will be using a > resist mask. There > >is no new material involve being here since Al etch always > involve etching > >some Al2O3, and I belief some sapphire etching has been > attempted in the > >past. But clearly there will be much more Al2O3 and resist > by-products > >than we usually see. If you have a concern about letting > the user do this > >process in the PQ, please reply. My understanding is that > this is a one > >time need. > > > >Thanks, Jim > > > > > >-- > >-------------------------------------------------------------- > >Jim McVittie, Ph.D. Senior Research Scientist > >Allen Center for Integrated Systems Electrical Engineering > >Stanford University jmcvittie at stanford.edu > >Rm. 336, 330 Serra Mall Fax: (650) 723-4659 > >Stanford, CA 94305-4075 Tel: (650) 725-3640 > > > >