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

Deposition tricks

Etching figures of merit – isotropy/anisotropy – selectivity – redeposition? check volatility/solubility of products

Dry Etching reactive ion etching (RIE) inductively coupled plasma (ICP) sputtering – includes FIB Ga+ milling chemical assisted ion beam etching ICP RIERIE FIB CAIBE

Exotic Dry Etches Burek et al., Nano. Lett. 2012, 12, Angled ICP

Wet Etching often more selective & isotropic – some etch along crystal planes ion beam enhanced etching KOH etching of silicon He + LiNbO/YSO

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

Dry etch Develop resist Strip resist Spin coat photoresist HF undercut Transfer to REI host photoresist My GaAs/YSO device Fabrication AlGaAs GaAs Strip photoresist apply e-beam resist Direct write e-e-