Calibrated work function mapping by Kelvin probe force microscopy

Pablo Fernández Garrillo (1) , Benjamin Grevin (2, 3) , Nicolas Chevalier (1) , Lukasz Borowik (1)

1 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
2 SYMMES - SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé
3 INAC - Institut Nanosciences et Cryogénie

We propose and demonstrate the implementation of an alternative work function tip calibration procedure for Kelvin probe force microscopy under ultrahigh vacuum, using monocrystalline metallic materials with known crystallographic orientation as reference samples, instead of the often used highly oriented pyrolytic graphite calibration sample. The implementation of this protocol allows the acquisition of absolute and reproducible work function values, with an improved uncertainty with respect to unprepared highly oriented pyrolytic graphite-based protocols. The developed protocol allows the local investigation of absolute work function values over nanostructured samples and can be implemented in electronic structures and devices characterization as demonstrated over a nanostructured semiconductor sample presenting Al0.7Ga0.3As and GaAs layers with variable thickness. Additionally, using our protocol we find that the work function of annealed highly oriented pyrolytic graphite is equal to 4.6 ± 0.03 eV.

Domaines: Physique [physics]; Matière Condensée [cond-mat]

Pablo Fernández Garrillo, Benjamin Grevin, Nicolas Chevalier, Lukasz Borowik. Calibrated work function mapping by Kelvin probe force microscopy. Review of Scientific Instruments, 2018, 89 (4), pp.043702. ⟨10.1063/1.5007619⟩. ⟨hal-02277068⟩