Clean Room Facility for MEMS Siddharth G.G. Applied Electronics and Instrumentation College of Engineering, Trivandrum April 28, 2015 Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 1 / 24
What is a Clean Room? A clean room is an enclosed space in which airborne particulates, contaminants, and pollutants are kept within strict limits. Sources of contamination 1 Particulates in air 2 Paint and coatings 3 lubricants and emissions 4 Aluminium particles and quartz flakes 5 Cleaning chemicals Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 2 / 24
Classifications of a Clean Room Cleanrooms are classified according to the number and size of particles permitted per volume of air. Class 100 or Class 1000 denotes the number of particles of size 0.5 m or larger permitted per cubic foot of air. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 3 / 24
Classifications of a Clean Room(Contd...) Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 4 / 24
General Clean Room Regulations Personal items such as keys, wallets etc. are not allowed inside a cleanroom. Eating, smoking or gum chewing are not allowed inside the cleanroom. Do not use cosmetics or hair spray while entering a cleanroom. Only approved cleanroom paper and ball point pen are allowed. Only approved garments, gloves, finger cots, pliers, tweezers are allowed. Writing on garments or equipments are not allowed. Tools should not be allowed to rest on the surface of the bench or table. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 5 / 24
General Clean Room Regulations (Contd...) Ill persons are not allowed inside the clean room. Running, walking fast etc. are not allowed. Clean or change shoes on the way in. Hair cover is necessary. Wearing the cleanroom garment outside the clean room is prohibited. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 6 / 24
Cost of Running a Clean Room Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 7 / 24
Clean Room Facility - IISc, Bangalore Consists of a comprehensive 14,000 sq. ft. clean-room facility. Major processe are: Laser writer and Electron beam lithography. LPCVD, ALCVD, RF sputtering. Pulsed laser deposition, RIE, DRIE. Semi automatic wire bonder with ball and wedge bonding capabiliity. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 8 / 24
Clean Room Facility - IIT, Bombay Houses 1000 sq. ft. of class 1000 clean room and semi-clean room primarily for MEMS or sensors related activity. Also houses 1000 sq. ft. of class 10,000 clean room primarily for material characterization and 1000 sq. ft. of class 1000 clean room dedicated to advanced process tools. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 9 / 24
Clean Room Facility - IIT, Bombay(Contd...) Major process done here are: Electron Beam Lithography-Raith 150 TWO Molecular Beam Epitaxy (MBE) Laser Writer Pulsed LASER Deposition 3 target Metal Sputtering System - Nordiko CNT Chemical Vapor Deposition STS RIE Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 10 / 24
Clean Room Facility - IIT, Madras It houses Class-100 and Class-1000 clean rooms. Major facilities provided are: Double-sided lithography facility LPCVD for polysilicon deposition PECVD for dielectrics e-beam metallization unit and RIE for dry etching Wire and die bonder Mask writer DC/RF sputtering Electron beam evaporation DRIE-Bosch process Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 11 / 24
Clean Room Facility - IIT, Delhi IIT Delhi consists of a class 1000 clean room facility of 6000 sq.ft. area. The main features in the facility are: Electron beam lithography Nano-imprinting Plasma deposition and plasma etching Wafer bonding Electronic circuits CAD tools Scanning Electrochemical microscopy Electrochemical Quartz crystal Microbalance Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 12 / 24
Clean Room Facility - Stanford University Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 13 / 24
Clean Room Facility - Stanford University(Contd...) Lab and its infrastructure extend over three floors. Houses a class 100 cleanroom which is 10,500 sq.ft. in area. The main specialities are: 1 Facility is vibration-isolated from the rest of the building. 2 Air handlers and head exchangers are located in the floor above the cleanroom. 3 Chilled water, vacuum pumps, air compressors, and acid waste neutralizers, are remotely located in the basement. 4 Corrosive and toxic gases are located in a monitored gas pad, away from the main laboratory. 5 Liquid gas storage tanks, and emergency power generators are located in an outdoor area. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 14 / 24
CLEAN ROOM EQUIPMENTS Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 15 / 24
E-beam Lithography It is the practice of scanning a focused beam of electrons to draw custom shapes on a surface covered with an electron-sensitive film called a resist. It can draw custom patterns with sub-10 nm resolution. eg: Raith 150 two Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 16 / 24
Anneal/Oxidation system It is a way to produce a layer of oxide on the surface of a wafer. Modern oxidation systems can deal with 1000-2000 wafers per hour. eg: Tempress anneal/oxidation system Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 17 / 24
Plasma Enhanced Chemical Vapour Deposition It is a process used to deposit thin films from a gas state to a solid state on a substrate. Plasma is created in the process which helps in the chemical reaction. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 18 / 24
Low Pressure Chemical Vapour Deposition In LPCVD, the wafer is exposed to one or more volatile precursors, which react or decompose on the substrate surface to produce the desired deposit. The process is done at low pressure. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 19 / 24
Deep Reactive Ion Etching DRIE is a highly anisotropic etch process used to create steep-sided holes and trenches in substrates, typically with high aspect ratios. It is used in advanced 3D wafer level packaging technology. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 20 / 24
Sputtering Sputtering is a process whereby atoms are ejected from a solid target material due to bombardment of the target by energetic particles. It can be DC or RF sputtering. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 21 / 24
E-beam Evaporation In this process, a source material is heated above its boiling temperature and evaporated to form a film on the surface. Here the heating is done by sweeping the substrate with high density electron beam. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 22 / 24
Electron Microscope An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. It has high resolving power. Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 23 / 24
The End Siddharth G.G. (AEI) Clean Room Facility for MEMS April 28, 2015 24 / 24