MICROMACHINING
Two major fabrication strategies
Bulk Micromachining
Mechanical features are formed by etching deeply into the silicon substrate.
Surface Micromachining
Structures are built layer by layer on the wafer surface.
Surface: build structures above the substrate.
BULK MICROMACHINING
Remove material from the wafer.
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Bulk micromachining creates mechanical features by etching into the silicon substrate.
Cavities, trenches, membranes, channels, and other structures can be produced this way.
SURFACE MICROMACHINING
Build structures layer by layer.
Surface micromachining builds thin-film structures on top of the wafer.
Sacrificial layers can later be removed from beneath structural layers to create free-standing mechanical structures.
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Sacrificial layer: is intentionally removed.
UNIT 9 STUDY COMPLETE
Ready for the Fab Challenge?
You've covered Bulk vs. Surface Micromachining.