masked ion beam lithography
DESCRIPTION
TRANSCRIPT
MASKED ION BEAM LITHOGRAPHY
ARUNBALAJI.S
MIBL - INTRODUCTION
• Successing technology of Ion Beam Lithography• New approach for Biomaterial Patterning• It allows selected Ion beam to be allowed to fall
on the mask• Ions of Ca,Mg,Na,P are used as Sources• Technique of implanting the dopants in the
manufacturing process of semiconductors.
MIBL- Setup
Techniques in Ion Beam Lithography
• Hydrogen and helium ion beams a extracted from the suitable ion source.
• M X B mass separation unit is included.• Proper electrostatic setup is arranged to get the
parallel ion beam• The Mask is made up of Silicon, copper.• Ion Beam Induced heating on the mask is avoided
by arrangement of cooling setup for mask
MAJOR TYPES OF ION SOURCES
Liquid metal ion sources Gas field ion sources Volume Plasma sources
Liquid metal ion source
GAS FIELD ION SOURCE
Volume plasma Source• Mostly used in ion implanters, ion milling
machines and other ion accelerators• Sources of desired ions are introduced as gas.• Electron bombardment is used to ionize it.
Importance of ion beam over other
techniques• Nanofabrication without multistep process.• When a focused beam of ions is traced over a
surface, it removes material to form a trench approximately equal to the beam diameter.
• rewire integrated circuits by cutting or depositing metal film conductors.
• useful in the pre-production development phase to alter a circuit that may not be working because of a design or fabrication error
Advantages of using ions over electrons
Ions are larger than electrons, so less change in chemical nature of substrate,no x- ray emissions in the sample.
Ions are heavier than electrons . So ions gain high momentum.
Ion beam milling depends on the how much ions needed to remove the material, it is independent of the material’s chemical nature and material strength.
Material deposition on the specific sites of the circuit.
MIBL - ADVANTAGES• This method overcomes the problems of beam
dispersion and diffraction in the Optical and X-ray lithographic systems
• It reduces the multiple steps like film casting, exposure, developing and etching process as in photolithography.
• The surface chemistry of substrate is tailored better compared to photolithography.
• PMMA surface modification by calcium and phosphorous ions are used to create microwells for biomems devices
•
MIBL -APPLICATIONS• High Volume gate level printing of Field emitter
Displays(FED).• Fabrication of surface acousting wave and
microoptic devices.• Deep trenching reactive ion beam etching in
MEMS and in particular for silicon Microsystems
THANK YOU