PPP-EFM

PointProbe® Plus Electrostatic Force Microscopy - PtIr5 Coating

The new PointProbe® Plus (PPP) combines the well-known features of the proven PointProbe® series such as high application versatility and compatibility with most commercial SPMs with a more reproducible tip radius as well as a more defined tip shape. The minimized variation in tip shape provides more reproducible images.
The PPP-EFM probe is offered for electrostatic force microscopy. An overall metallic coating (PtIr5) on both sides of the cantilever increasing the electrical conductivity of the tip. The force constant of this type is specially tailored for the electrostatic force microscopy yielding very high force sensitivity while simultaneously enabling tapping mode and lift mode operation.

The probe offers unique features:

metallic conductivity of the tip

radius of curvature better than 25 nm

tip height 10 - 15 µm

high mechanical Q-factor for high sensitivity

alignment grooves on backside of silicon holder chip

precise alignment of the cantilever position (within +/- 2 µm) when used with the Alignment Chip

compatible with PointProbe® Plus XY-Alignment Series

Please note: Wear at the tip can occur if operating in contact-, friction- or force modulation mode.

Although this is possible, it is not recommended to use PtIr5 coated tips for electrical contacting in applications where it is necessary to conduct high current. The very thin layer of PtIr5 is unable to support much current.

The PtIr5 coating is an approximately 25 nm thick double layer of chromium and platinum iridium5 on both sides of the cantilever. The tip side coating enhances the conductivity of the tip and allows electrical contacts. The detector side coating enhances the reflectivity of the laser beam by a factor of about 2 and prevents light from interfering within the cantilever. The coating process is optimized for stress compensation and wear resistance. The bending of the cantilever due to stress is less than 3.5% of the cantilever length.

Cantilever Specifications
Spring k (N/m	2.8 (0.5 - 9.5)
Freq (kHz)	75 (45 - 115)
Length (µm)	225 (215 - 235)
Width (µm)	28 (20 - 35)
Thickness (µm)	3.0 (2.0 - 4.0)
Shape	rectangular
Material	Silicon
Reflex Coating (nm)	Cr/PtIr (5/25)

Tip Specifications
Tip radius (nm)	25
Tip height (µm)	12.5 +/- 2.5
Front angle (°)	25 +/- 2
Back angle (°)	15 +/- 2
Side angle (°)	22.5 +/- 2
Tip shape	4-sided
Tip material	Silicon
Tip coating (nm)	Cr/PtIr (5/25)