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Chlorine Trifluoride Best Practices 2003-12-05
Brett Last year to better understand what can happen with releases of ClF3 we did liquid and vapor release testing on a variety of PPE, metals, Building Materials etc. I presented on this study at SESHA and the presentation can be downloaded from the website www.airproducts.com/er
We just finished testing last week for pure Fluorine and Nitorgen Trifluoride and had some interesting results. I hope to develop a presentation and paper on this as well.
Give me a call and we can discuss this further. I am only in the office for the next day and will leave for the Far East this weekend. (Cell 908-500-4907) Eugene Ngai
Sent: Thursday, December 04, 2003 4:25 PM To: SEHS Grapevine Subject: Chlorine Trifluoride Best Practices ISMT and SEMI EHS Professionals,
Can anyone share or direct me to documents describing best practices for use of and emergency response for chlorine trifluoride? I'd be particularly interested to hear from those with existing installations regarding these issues: - gas detection - automated emergency systems (e.g. a cylinder cooling jacket has been suggested) - gas cabinet construction - gas piping construction and passivation - sprinklering inside and outside of the gas cabinet - process exhaust treatment - emergency release treatment - hazardous materials response procedures and equipment - anything I've overlooked Thanks in advance for all that you can offer. Brett
Detonable Pyrophorics? 2004-01-07 Jay I agree with Roger and Dr.Fthenakis but would add the following comments
Fike conducted release testing of Phosphine for Air Products 5 years ago and determined that the autignition temperature was less than 32F. This was the lowest temperature they could go to in their chamber. We did this with very high purity Phosphine (Diphosphine <1 ppm) and lower purity Phosphine
In my exepreince with DCS leaks they have ignited under certain conditions. I have theorized that this is due to the energy given off by the water reaction forming HCL and SiO2. The SiO2 as a solid retains the heat until it reaches the autoignition temp
Hope this helps Eugene
Sent: Wednesday, January 07, 2004 11:47 AM To: SEHS Grapevine Subject: RE: Detonable Pyrophorics? SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE DCS and 15%PH3/H2 very flammable? Yes. Pyrophoric? Yes but unlike SiH4 they have an high AIT ~110F (probably unlikely to autoignite unless released in the Sahara in August). Unlike SiH4 I personally know of no evidence that either of these will result in a detonation explosion rather than a deflagration and would not base my occupancy design on them being "detonable pyrophorics". Roger
-----Original Message----- Sent: Wednesday, January 07, 2004 5:23 AM To: SEHS Grapevine Subject: Detonable Pyrophorics? SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE
Someone out there with recent Fire Code experience.....
Are Dichlorosilane and 15% Phosphine/Balance Hydrogen detonable pyrophorics?
Our MSDS's indicates that these can form explosive mixtures with air. However, NFPA rating for reactivity is "2".
Any suggestions about how to conclude whether these materials are "Detonable Pyrophorics".
This has bearing on the design of the "H" occupancy where they will be stored and used.
Diborane 2005-07-24
Al How are you? I didn't see you in the Far East this trip.
One of the problems with RFO's with Diborane is that it so readily hydrolyzes to Boric Acid and Hydrogen. The initial RFO's had porous metal filters to prevent the orifices from plugging. These unfortunately had high surface area where water would naturally adsorb onto. This was difficult to remove even with repeated purges and vacuum. The Diborane would immediately react and plug the filter when the valve was opened. RFO's for Diborane should not have a filter.
At our fill locations we have a variety of scrubbers to handle an emergency release. Regards Eugene
-----Original Message----- Sent: Sunday, July 24, 2005 3:03 PM To: SEHS Grapevine Cc: Graham Beard; John Blades Subject: Diborane SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE
Colleagues I'd be grateful for some feedback on the following questions related to Diborane and toxic gas systems.
We are particularly interested in industry practice rather than strictly what the standards recommend or require as there seems to be a wide variation in practice around the world. 1. Certain literature suggests that RFOs should not be installed on Diborane cylinders because of the potential for polymerisation of the gas. Does anyone not use RFOs and if you do use them what size do you typically use? 2. Does anyone have abatement systems installed to treat a major release from a special gas housed in a gas cabinet (for example a pressure regulator failure resulting in a discharge from the relief valve) and in particular for Diborane which has an extremely low toxic threshold level?
Regards Al
Dry Ice Disposal 2005-11-09
Just be cautious with adding the water, it can cause the dry ice to flash and throw the water back at you. Best to also have a faceshield on. Or just let it naturally warm and vaporize without water Eugene Ngai
Sent: Wednesday, November 09, 2005 1:39 PM To: SEHS Grapevine Subject: RE: Dry Ice Disposal SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE
Rosanna, The answer to your question does not need to be complicated. I imagine the amount of dry ice is fairly small and would not take long to evaporate. It could be as simple as placing the dry ice in a tub of water in a remote exterior location of your site. If you are concerned with exposure of passer-bys, you could barricade the area or post someone in the area for the 10 minutes that it would take for the reaction to occur.
Of course, the person working with the dry ice should always use the proper PPE [primarily heavy gloves] when handling the material. Hope this helps. Dennis
-----Original Message----- Sent: Wednesday, November 09, 2005 1:23 PM To: SEHS Grapevine Subject: Dry Ice Disposal SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS)GRAPEVINE
Any one out there have any experience with dry ice disposal? We will be getting a few samples of material that arrive in dry ice. Disposal methods that I've read involve allowing the ice to evaporate in a well-ventilated area. I want to eliminate the possibility of employee exposure while the ice evaporates. Any procedures/methods that have proved successful? Thanks, Rosanna
Forming Gas Percentage 2004-10-22
For flammability, mixtures are classified in the US by CGA Pamphlet P-23 and Internationally by ISO10156. A Hydrogen/Nitrogen mixture is flammable at concentrations above 5.7% based on the calculations. If the balance gas changes the concentration also changes because of the difference in thermal conductivity. Actual testing may show that this could be higher. Eugene Ngai
Sent: Friday, October 22, 2004 3:57 PM To: SEHS Grapevine Subject: RE: Forming Gas Percentage SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE
Hydrogen has a lower explosive limit of ~4% in air. As such, forming gas mixtures (H2 / N2) below 4% H2 are clearly not flammable and don't require monitoring, gas cabinet, etc. Slightly higher concentrations of forming gas (for example, 5%) are also not flammable even though the H2 concentration is above the LEL since mixing the forming gas with air upon release will dilute the hydrogen below the LEL before there is sufficient oxygen to allow combustion. Steve
-----Original Message----- Sent: Friday, October 22, 2004 11:51 AM To: SEHS Grapevine Subject: Forming Gas Percentage SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE
Apologies if this question ties to an old discussion thread, but can someone refresh my memory on forming gas percentages with respect to the fire code, and need for a gas cabinet.
I know there’s the old “it’s up to your local authority,” but I believe there is at least a rule of thumb that applies to a forming gas (H2N2) and other blends…
Any help you can provide is much appreciated. Rob
Germane Use and SOP's 2009-06-02
I tried to send this but the safetygram was too big. I would be happy to send to those that want it Eugene Ngai
Sent: Monday, June 01, 2009 10:22 PM To: 'SEMI EHS Grapevine' Subject: RE: Germane Use and SOP's Joe I was just in State College last week to see my cousin who works in the PR dept.
I would treat Germane the same as Arsine. While the toxicity is not as bad as Arsine, the toxic action and medical treament is similar. Germane also is an unstable compound, similar to Nitrous Oxide and Acetylene. Given a little energy it will decompose. This caused a cylinder rupture in Japan in 1984. As a result, the cylinder fill amount was reduced to consider the decomposition byproducts and heat. Here is the letter I wrote to CGA to describe this history. This became a UN paper which was accepted in Dec 2006.
I have also attached a AP Safetygram which I coauthored on Metal Hydride Gases Eugene Ngai Chemically Speaking LLC
Sent: Monday, June 01, 2009 9:39 PM To: SEMI EHS Grapevine Subject: Germane Use and SOP's SEMI Environmental Health & Safety Grapevine
We are currently installing 100% Germane for use in a oxy/nitride deposition tool. We have not used Germane in this particular tool before and have limited procedures developed. I am looking for any insights, experiences, or procedures that might be shared to help us further develop our safety protocols before we allow the connection and use.
We intend to have 4 points of detection and currently are set on using tape detection technology. I would like to develop some very specific procedures for when personnel have to maintain the system, especially when opening the chamber for maintenance or cleaning, or when gas bottles have to be changed.
Any information would be greatly appreciated. Thanks, Joe
Hydride as Nitride Process Byproduct? 2008-07-03 My opinion on this Calling it a Hydride Chemcassette is technically incorrect. A hydride is a molecule that has been reduced with Hydrogen, CH4, NH3, AsH3, SiH4, etc even Lithium Hydride. The chemistry of the chemcassette is most likely a reaction with a metal atom such as As, Si, P, B. Ge Technically this should be called a Metal Hydride Gas Chemcassette. This is also the reason why it will respond to molecules that contain these atoms but are not technically hydrides DCS, TBA, TBP.
Hope this helps Eugene Ngai
Sent: Thursday, July 03, 2008 7:51 AM To: SEMI EHS Grapevine Subject: RE: Hydride as Nitride Process Byproduct? SEMI Environmental Health & Safety Grapevine
The tech note for hydrides chemcassettes also says that it will NOT respond to NH3. Using hydrides chemcassette to sample for germane is probably the only exception since the sample time for germane is VERY long compared to other hydrides (8 minutes compared to 1 minute and less) giving it plenty of time to begin to stain the chemcassette.
Sent: Wednesday, July 02, 2008 1:14 PM To: SEMI EHS Grapevine Cc: sklar@safetyguru.com Subject: Re: Hydride as Nitride Process Byproduct? SEMI Environmental Health & Safety Grapevine
Jay, Although "hydride" tends to bring to mind "silane, arsine, phosphine, diborane", ammonia is also a hydride. Therefore, it's entirely possible that your detector is sensing residual NH3 from your process.
FYA: In one memorable incident, I got calls in the middle of Saturday night two weeks in a row because someone mopped the floor in front of a germane cylinder cabinet with an ammoniabased cleaner and tripped the detector. Eric
Ellingsen, Bart wrote: SEMI Environmental Health & Safety Grapevine The tech note for hydrides chemcassette says it will respond to DCS.
Sent: Wednesday, July 02, 2008 12:28 PM To: SEMI EHS Grapevine Subject: Hydride as Nitride Process Byproduct? SEMI Environmental Health & Safety Grapevine
We recently observed low level hydride concentrations on our gas detection system (CM4s). Investigation found a leak in an exhaust fitting of our Nitride system.
We use Ammonia and Dichlorosilane in our Nitride process.
Are hydrides an expected byproduct of this process?
Thanks, Jay
Hydride Gas 2006-11-07
What is the stain color? Metals in a acidic solution can generate the corresponding hydride gas Eugene Ngai
-----Original Message----- Sent: Tuesday, November 07, 2006 5:02 PM To: SEMI EHS Grapevine Subject: Hydride Gas SEMI Environmental Health & Safety Grapevine
Hey everyone, I am a graduate student at Colorado State University and am investigating a problem at a semiconductor manufacturer as a research project. The problem is that we are detecting hydride gases in filters being used to screen out ground silica from waste water. The basic process is that the wafers are ground thinner using a wet grinding process and the water and silica particles are removed as waste. The liquid waste is then filtered to remove the silica from the waste water. When the filters become clogged and are removed, we are able to detect the hydride gas; we are detecting the hydride gases using a paper-tape detection system.
My question is, are any other manufacturers having this same problem or any guesses as to what is creating it? We are trying to find out what hydride is being off-gassed and if the gas could present a health problem to workers. Any information you could provide would be appreciated. Thanks, Phil
Indium Gallium Arsenide 2009-04-21
I am sending without the articles since the grapevine will not allow larger than 100 K. Rebecca I will send this via separate e-mail Eugene From: Eugene Ngai [mailto:eugene_ngai@comcast.net] Sent: Tuesday, April 21, 2009 4:55 PM
To: 'SEMI EHS Grapevine' Subject: RE: Indium Gallium Arsenide Rebecca
There have been a few articles written on this topic which I’m trying to find.Here are some quick articles from a quick internet search Below a response to a similar grapevine posting a few years ago Eugene Ngai Chemically Speaking LLC
Rich, This comment is from Doug Reigle of our Reading, PA facility. Reading was involved in Galium Arsenide technology for a number of years.
Mark Mitchell Agere Systems Orlando, FL
"We did very little laser trimming of GaAs devices. What I recall is that we never detected any arsine outside of the laser and no significant amounts of arsenic inside the laser. It does seem likely that at least some arsine is being generated at the point of lasing (since I could get a positive response from the TLD-1 by simply rubbing a GaAs ingot across extra fine sandpaper."
-----Original Message----- Sent: Wednesday, February 25, 2004 12:42 PM To: SEHS Grapevine Subject: GaAs wafers SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE
Has anyone had experience working with Galium Arsenide wafers? Do you have any restrictions on demos or process work on GaAs wafers?
My concern is that when laser processing, you generate Laser Generated Air Contaminants. We are going to do some testing to determine the amount of fun materials such as Arsine and Phosphene will be generated during laser processing from standard wafers. I imagine the Arsine levels will be significantly higher if GaAs wafers are used. We are having discussions with a customer over the next couple of days that does a lot of SOI and GaAs wafer work. At this time, I do not believe that any of our alpha or BLT tools are equipped with process exhaust.
Let me know your thoughts. Rich Morales
Sent: Tuesday, April 21, 2009 2:34 PM To: SEMI EHS Grapevine Subject: Indium Gallium Arsenide SEMI Environmental Health & Safety Grapevine
Hello- Is anyone familiar with dicing Indium Gallium Arsenide (InGaAs) wafers? In particular, are there EHS related issues with this type of processing? How do you handle the wastewater from the process?
Thank you in advance for your help- Rebecca
Liquid Nitrogen - Dewar filling 2004-10-04
Some of you might not have gotten the attachments. Please log onto http://www.airproducts.com/Responsibility/EHS/ProductSafety/ProductSafetyInformation/Safetygrams.htm To download safetygram 7 and 16 which recap Liquid Nitrogen Safety Eugene Ngai
-----Original Message----- From: Ngai,Eugene Y. Sent: Monday, October 04, 2004 10:58 PM To: 'SEHS Grapevine' Subject: RE: Liquid Nitrogen - Dewar filling
There is no CGA standard. The closest is P-1 Safe Handling of Compressed Gases. I have attached the Air Products Safetygrams on Liquid Nitrogen and Cryogenic Liquids which may be of value Eugene Ngai
Sent: Monday, October 04, 2004 11:34 AM To: SEHS Grapevine Subject: RE: Liquid Nitrogen - Dewar filling SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE
We use face shield, cryo gloves and plastic apron. There is an O2 monitor in the area as well. Steve
-----Original Message----- From: Chouinard, Vicki (MN65) [mailto:Vicki.Chouinard@honeywell.com] Sent: Monday, October 04, 2004 6:58 AM To: SEHS Grapevine Subject: Liquid Nitrogen - Dewar filling SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE
Is there an industry/consensus standard on liquid nitrogen fill stations? I am looking for a standard that might talk about the need for oxygen monitoring, specify minimum PPE, and so forth. I checked the Compressed Gas Association website and didn't see a standard. But I'm sure you'll tell me if I missed something. Vicki
NF3 substitutes 2008-11-18
Prof Fthenakis As discussed at the IEEE conference last year I am sending to you a poster session on NF3 cleaning. The grapevine will not accept the file since it is over 100 KB. For those that want a copy, please send me an e-mail. Regards Eugene Ngai
-----Original Message----- Sent: Monday, November 17, 2008 11:30 AM To: SEMI EHS Grapevine Cc: SEMI EHS Grapevine Subject: Re: NF3 substitutes SEMI Environmental Health & Safety Grapevine
Hello Vasilis, There are several NF3 abatement options. R&D is also being done on F2 generation, particularly in Japan. I will send whatever information I have directly to your email. Please give me a couple of days to pull it together. I'm sure the abatement companies on the Grapevine will send you material directly also.
If anyone out there has experience with F2 generation, it would be helpful for you to share what you can. If you cannot share the information directly, you can send it to me at azude@semi.org and I will consolidate the information into a summary with no company names included. Thanks, Aaron
To "SEMI EHS Grapevine" sehs@ehs.semi.org 11/17/2008 07:51 Subject NF3 substitutes SEMI Environmental Health & Safety Grapevine
Dear All, I am looking to NF3 substitutes for reactor cleaning and/or NF3 abatement options, and would welcome any input related to practices or research projects that you may have on this topic. Cheers, Vasilis M. Fthenakis, Ph.D.
-----Original Message----- Sent: Monday, November 17, 2008 10:21 AM To: SEMI EHS Grapevine Subject: RE: F006 Wastes SEMI Environmental Health & Safety Grapevine
F006 only applies to electroplating operations. If you really doingchemical etching and not electroplating -- I would not use F006. Jamie
Sent: Monday, November 10, 2008 2:33 PM To: SEMI EHS Grapevine Subject: F006 Wastes SEMI Environmental Health & Safety Grapevine
Hello Everyone; New member here. Urgent need to see if anyone who is doing "chemical etching" can in a general sense conform if you categorize your waste materials as F006, or F006 precursor? If not, why not? Thanks in advance for your help
Nitrogen and Forming Gas (5%H/95%N) in clean rooms 2008-07-30
Hydrogen in Nitrogen is not flammable until 5.5%. Asphyxiation in a clean room at these flow rates are highly unlikely at the ventilation flows of most clean rooms. Hydrogen and Nitrogen when mixed will not separate without cooling them down to their boiling points which is well below -200 F Eugene Ngai
Sent: Wednesday, July 30, 2008 8:39 AM To: SEMI EHS Grapevine Subject: Nitrogen and Forming Gas (5%H/95%N) in clean rooms SEMI Environmental Health & Safety Grapevine
Hello All, I am looking for any information regarding safety considerations for the use of Forming Gas (5% Hydrogen/95% Nitrogen) and Nitrogen with flow rates in the 1 and 4 liters/minute range, respectively, in a clean room environment.
I understand that Forming gas at these concentrations is not flammable. Another consideration is the risk of asphyxiation due to Oxygen displacement by Nitrogen. There have been some concerns aired, although I believe unfounded, about the possible separation of the Hydrogen from the Forming gas mixture which could lead to a fire or explosion hazard.
What considerations/precautions/recommendations can be given in the design/specification of a clean room to ensure proper purging of any remnant gases. Which SEMI standards or other publications provide guidance in this area, etc.
Any input would be appreciated. Thanks in advance. Regards, Tony
Nitrogen Generators 2008-09-30
Here is what our Electronic’s Business Manager (John Sullivan) had to say about this question Eugene –
Essentially, the answer is in the economies of scale. Hauled-in LIN is economical for a low volume customer as there is a higher variable portion of the overall nitrogen spending for the hauled-in product itself and a lower fixed portion for the actual equipment to store and deliver the product. LIN supply becomes the most efficient at a full-trailer off load at a customer's site. After the full-trailer off load, LIN supply can't get any more efficient from the perspective of trailer usage and the marginal benefit of driving to the customer's site.
As more nitrogen is required on the site, at some point, the unit price of LIN will become more expensive than the fixed cost of equipment and power to generate GAN on-site on a monthly basis. At that point, the fixed costs of on-site production on a unit basis would become less expensive than the unit price of delivered LIN. So you are able to achieve a more economical method of nitrogen delivery than simply hauling-in more LIN product.
As nitrogen usage grows, there is another factor -- at a certain point, the logistical hurdles of finding enough trailers and LIN product to haul is stretched to the breaking point, and it is physically impossible to haul-in LIN. Of course, on-site production becomes a necessity at this usage volume as well.
Hope this answers the question Eugene Ngai
Sent: Friday, September 26, 2008 2:33 PM To: SEMI EHS Grapevine Subject: Nitrogen Generators SEMI Environmental Health & Safety Grapevine
Question regarding the use of Nitrogen Generators versus purchasing nitrogen from bulk suppliers i.e. Air Products, BOC etc. What are pro’s and cons of the nitrogen generators and on a large scale usage requiring purity of 99.999%
Thanks, George
Use of Deuterium in Annealing 2004-10-25
The hazards of D2 are the same as for H2. The only difference is a slightly higher LFL of 5% vs 4% for H2
When mixing it with H2 the concentrations are additive to calculate flammability Eugene Nagi
Sent: Monday, October 25, 2004 5:26 PM To: SEHS Grapevine Subject: Use of Deuterium in Annealing SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE
Anyone have any experience with investigating EH&S Issues regarding the use of Deuterium in Annealing furnaces? Looking at either 1-2% mixture in H2/N2. Also looking at 100% option as well.
Many thanks in advance Eric |
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