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Overview of Nanofabrication Techniques. Experimental Methods Club Monday, July 7, 2014 Evan Miyazono. Outline. Addition (deposition) Subtraction (etching, milling) Patterning. Deposition. figures of merit uniform conformal/edge coverage deposition temperature deposition material
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Overview of Nanofabrication Techniques Experimental Methods Club Monday, July 7, 2014 Evan Miyazono
Outline • Addition (deposition) • Subtraction (etching, milling) • Patterning
Deposition • figures of merit • uniform • conformal/edge coverage • deposition temperature • deposition material • lattice mismatch & / built in strain
Deposition • Thermal evaporation • e-beam evaporation • Sputtering
Other deposition • chemical vapor deposition (CVD) • vapor liquid solid (VLS) method of nanowire growth
Etching • figures of merit • isotropy/anisotropy • selectivity • redeposition? • check volatility/solubility of products
Dry Etching CAIBE • reactive ion etching (RIE) • inductively coupled plasma (ICP) • sputtering • includes FIB Ga+ milling • chemical assisted ion beam etching RIE ICP RIE FIB
Exotic Dry Etches Angled ICP Bureket al., Nano. Lett. 2012, 12, 6084-6089
Wet Etching • often more selective & isotropic • some etch along crystal planes • ion beam enhanced etching KOH etching of silicon LiNbO/YSO He+
Patterning • e-beam lithography • photolithography • patterning a uniform layer • polymer used as etch mask • patterning something hard to etch? • deposit on polymer and lift-off unwanted material
Beating patterning limitations • cheating positive feature limits with sacrificial masks & conformal deposition • cheating negative feature limits with built in stress and
Case Study: SOI Silicon on insulator Wafer bonding: plasma clean + heat + pressure
My GaAs/YSO device Fabrication photoresist GaAs Spin coat photoresist AlGaAs HF undercut GaAs Transfer to REI host e- Develop resist Dry etch Strip photoresist apply e-beam resist Strip resist Direct write