Instruction manual

Cantilever Preparation
Silicon Nitride Cantilever Substrates
Rev. B MultiMode SPM Instruction Manual 67/(66 Blank)
Figure 4.2e Silicon Nitride Cantilevers—Sidewall Profile Effect
Two types of silicon nitride cantilever probes are available: standard and oxide-sharpened tip
processes. The standard devices have the nitride deposited directly into the etched silicon mold pit
formed by the intersecting <111> planes, and have points that are slightly rounded with respect to
the tips produced using the oxidation sharpening process.
The oxide-sharpened silicon nitride probes have a thermally grown silicon dioxide film deposited in
the mold pit used to shape the nitride tip, prior to silicon nitride film deposition. The oxide has two
effects: it shapes the inner contours of the pyramidal pit so that there is a slight cusp formed at the
point of the pyramid, and the oxide protects the tip from excessive exposure to a long duration wet
silicon etch used to free the cantilevers from the silicon substrate. The result is a noticeably sharper
point at the end of the pyramid. Regrettably, along with the increased sharpness of the tip comes a
slight increase in double tip effect experienced with the oxide sharpened process.
65.0°
Scanning Profile
45.0°
10.0°
11˚