Lift-off (microtechnology)

– Process:
– Preparation of the substrate
– Deposition of the sacrificial stencil layer
– Patterning the sacrificial layer (e.g., etching), creating an inverse pattern
– Deposition of the target material
– Washing out the sacrificial layer together with the target material on its surface

– Advantages:
– Applied when direct etching of structural material would have undesirable effects on the layer below
– A cost-effective alternative to etching in a research context
– Permits a slower turn-around time
– Useful when there is no access to an etching tool with appropriate gases

– Disadvantages:
– Retention: Unwanted parts of the metal layer may remain on the wafer
– Ears: Metal deposition covering resist sidewalls may form standing or falling ears
– Risk of unwanted connections if ears remain on the surface
– Redeposition: Metal particles may reattach to the surface during the process
– Difficulty in removing reattached metal particles after drying

– Use:
– Lift-off process mainly used to create metallic interconnections
– Different types of lift-off processes can achieve various outcomes
– EBL allows for very fine structures
– Multiple layers of different resist types can be used for specific shapes
– Useful in preventing side walls of the resist from being covered in the metal deposition stage

– External Links:
– Link: https://www.mems-exchange.org/catalog/lift_off/
– Retrieved from: https://en.wikipedia.org/w/index.php?title=Lift-off_(microtechnology)&oldid=1207824218
– Categories: Microtechnology, Semiconductor device fabrication
– Hidden categories: Articles needing additional references from June 2011, All articles needing additional references