AP Cleanroom Briefing Note (V.2) 1. Cleanroom Introduction • Functions of the Cleanroom • Layout of the AP Cleanroom • Snapshots of Cleanroom 2. Regulations • Cleanroom General Regulations • Cleanroom Chemical Regulations • Special Guideline on HF Safety • Special Guideline on Lead Safety 3. Chemical Safety • Chemical storage and handling • Chemical waste storage • Classification of Chemical Waste 4. Management • Network CCTV Surveillance System • Online Booking System • iGoogle Frontpage for the Cleanroom • AP Cleanroom User Registration By Lee Fuk Kay Assistant Scientific Officer (BC601, 3400-3260, 6203-3983, [email protected]) 1 1.1 Brief Introduction to the Cleanroom A Cleanroom ( 潔淨間，超淨室) is defined by ISO14644-1 as "a room in which the concentration of airborne particles is controlled , and which is constructed and used in a manner to minimize the introduction, generation, and retention of particles inside the room and in which other relevant parameters, e.g. temperature, humidity, and pressure, are controlled as necessary." Definition of " Class "：total number of dust particles per unit volume e.g. Class-1000; Dust count = 1000 per cubic foot (particle diameter =0.5 mm³ ) Functions of the Cleanroom 1. Wafer / substrate cleaning; 2. Thin film depositions by means of sol-gel and/or sputtering; 3. Thermal treatment using rapid thermal annealing technique; 4. Photo-lithography; 5. Wet chemical etching / dry etching; 6. Microfluidic experiment; 7. Other operations that must be carried out in a very clean environment 2 1.2 Layout of the AP Cleanroom (5.75 ××× 8.85 m 2) Safety shower and eye wash Oven First Aid box Fire extinguisher and blanket Air shower Telephone Changing room ICP Aligner Class 1000 Storage cabinet Sink O2 Plasma Plant room Spin Balance Coater Fire blanket Sputterer RTP Hotplate Fume cupboard 3 1.3 Snapshots of Cleanroom ICP Oxygen plasma MilliQ Water and Storage Photoaligner Sputterer Inverted. Microscope Fume hood 4 2.1 Cleanroom General Regulations General 1. Wear the Cleanroom garments including face mask, hood, coverall, shoe cover and gloves properly. 2. Make the equipment booking in advance and plan your operation or experiment carefully , taking into consideration of the hazardous properties of material involved; 3. Do not wear jewelry and make-up . No food and drink is allowed. 4. Do not bypass interlocks for convenience; Do not work when sick . 5. Clean up your stuff after experiment. 6. Report any mistakes you or others have made. Don’t hide it . Safety 1. User must familiar with the location of fire fighting equipment, first aid kit, safety shower and eye washes, emergency alarm button, fire escape routes, safety equipment and assembly point; 2. Know the chemicals which you are using, by referring the MSDS (Material Safety Date Sheet) which provide information of physical, chemical, and toxicological properties of the chemical; 3. A buddy system should always be used when working in or near a hazardous environment, never work alone even for a minute; 4. Familiar all emergency procedures now, don’t go through those procedure in case of emergency; Operational 1. Get proper training before operating the equipments. 2. Use appropriate Personal Protective Equipment on different operation; 3. Check every operation before and after it is performed; 4. Be aware of all the potential hazards and take safety precaution when operating the equipments. 5. Don’t stay in the laboratory if not necessary . AP cleanroom is not a meeting place. 5 2.2 Cleanroom Chemical Regulations Chemical Handling 1. Never mix acid with solvent because it may cause explosion ; 2. Never use Perchloric acid in the clean room as the fume hood is not compatible with it; 3. Never mix acetone and chloroform in alkaline medium because it will cause explosion ; 4. Always use the PPE when handling the waste. 5. Don’t take any chemicals or materials away. That is theft. 6. Be aware of contamination that you may cause and others cause. Chemical Storage 1. Make sure each container is properly labeled ; ( User name, contact number, chemical identity, date ). Don’t bring your own chemicals or materials into the cleanroom unless you have approval. 2. Clean all the tools and containers you have used and place them back to where they are. 3. Don’t leave chemical bottles on the floor . 4. Label the chemicals properly with complete chemical formula or the full chemical name, User name, Contact number and the Date. Do not leave your chemicals unattended . Chemical Waste Disposal 1. Keep each container 70% of its max. capacity . When the tank is full , keep the cap loosely to prevent pressure build-up. Always keep the waste tank inside the waste cabinets ; 2. Dispose of chemicals properly in their corresponding waste bottles! Nothing but water should be poured into city water system! 6 2.3 Special Guideline on HF Safety http://www.nff.ust.hk/ Hydrofluoric acid (HF) is a very strong inorganic acid and its solution are clear, colorless liquids. HF differs from other acid because the fluoride ion readily penetrate the skin , causing destruction of the deep tissue layers including bone . Unlike other acid which are rapidly neutralized, this process may continue for days. Move victim immediately under safety shower and flush affected area with large amounts of cool running water . Remove all contaminated clothing while flushing with water. The rinsing may be limited to 5 minutes , with 2.5% calcium gluconate gel applied as soon as the rinsing is stopped. While the victim is being rinse with water, someone should alert first aid or medical personnel and arrange for subsequent treatment. Apply the gel every 15 minutes and rubs continuously until pain and /or redness disappear. It is advisable for the individual applying the gel to wear surgical gloves to prevent a possible secondary HF burn. Workers handling hydrogen fluoride should use full coverage of clothing at all times. These include the use of rubber shoes soled with neoprene or rubbers, a hat or protective head covering, a full face mask and/or chemical goggles with plastic lenses, and gauntlet-type gloves made of neoprene , plasticized polyvinyl chloride (0.028 inch think), or an equally resistant material. 2.4 Special Guideline on Lead Safety Be very careful when handling Lead (Pb) materials : Lead, especially its sol-gel solution, is very harmful! Lead causes permanent damage to human tissues! Lead is accumulative inside human body! 1. Never do Pb-ceramic sintering in the Cleanroom; 2. Always do Pb sol-gel solution preparation inside the fume hood; 3. Always do Pb-film baking and annealing inside the fume hood. 7 3.1 Chemical storage and handling http://www.esd.uga.edu/chem/chemstorage.htm Acids 1. Make sure that all acids are stored by compatibility (ex. separate inorganic from organics). 2. Store concentrated acids on lower shelves in chemical-resistant trays or in a corrosives cabinet . This will temporarily contain spills or leaks and protect shelving from residue. 3. Separate acids from incompatible materials such as bases, active metals (ex. sodium, magnesium, potassium) and from chemicals which can generate toxic gases when combined (ex. sodium cyanide and iron sulfide). Bases 1. Store bases away from acids . 2. Store concentrated bases on lower shelves in chemical-resistant trays or in a corrosives cabinet . This will temporarily contain spills or leaks and protect shelving from residue. Flammables 1. Approved flammable storage cabinets should be used for flammable liquid storage. 2. Use only explosion-proof or intrinsically safe refrigerators and freezers for storing flammable liquids. Oxidizers 1. Make sure that all oxidizers are stored by compatibility . 8 2. Store oxidizers away from flammables, combustibles, and reducing agents . 3.2 Chemical storage and handling http://www.esd.uga.edu/chem/chemstorage.htm Peroxide-Forming Chemicals 1. Peroxide-forming chemicals should be stored in airtight containers in a dark, cool, and dry place . 2. Unstable chemicals such as peroxide-formers must always be labeled with date received, date opened, and disposal/expiration date. 3. Peroxide-forming chemicals should be properly disposed of before the date of expected peroxide formation (typically 6-12 months after opening). 4. Suspicion of peroxide contamination should be immediately investigated. Contact HSEO 34008395 for procedures. Water-Reactive Chemicals 1. Water reactive chemicals should be stored in a cool, dry place . 2. Do not store water reactive chemicals under sinks or near water baths . 3. Class D fire extinguishers for the specific water reactive chemical being stored should be made available. Toxins 1. Toxic compounds should be stored according to the nature of the chemical , with appropriate security employed when necessary. 9 3.3 Chemical waste storage Dispose the chemical wastes into their corresponding waste bottles as follows: Waste Bottles for 1. Non-Halogenic Solvent (Acetone, IPA, Ethanol) 2. Acid (H 2SO 4, HCl, HAc, H3PO 4) 3. Base (NaOH, KOH, AZ400K) 4. HF Hydrofluoric Acid 5. HNO 3 Nitric Acid 6. Developer AZ 300MIF 7. Gold and Chromium etchants 8. SU-8 developer Waste Container for 1. Broken Glass and Wafers 10 3.4 Classification of Chemical Waste Chemical Disposal method In general Hydrogen peroxide Oxidizing agent waste •Non-halogenated organic solvent Sulphuric acid Inorganic acid waste •Halogenated organic solvent Nitric acid Separately from other acid waste •Inorganic acid Hydrofluoric acid and its mixture HF waste •Inorganic alkali Phosphoric acid Inorganic