Applied Physics A

, Volume 78, Issue 8, pp 1181–1186

Charge-storage effects in a metal-insulator-semi-conductor structure containing germanium nano-crystals formed by rapid thermal annealing of an electron-beam evaporated germanium layer

Rapid communication

DOI: 10.1007/s00339-003-2482-0

Cite this article as:
Heng, C., Tjiu, W. & Finstad, T. Appl. Phys. A (2004) 78: 1181. doi:10.1007/s00339-003-2482-0


Charge-storage effects in a metal-insulator-semi-conductor device containing germanium (Ge) nano-crystals were investigated. The Ge nano-crystals were formed by rapid thermal annealing (RTA) of an evaporated, ultra-thin Ge layer at 1000 °C in argon. Capacitance–voltage measurements shows that the amount of electrical charge which can be stored in the device varies with the duration of the RTA treatment. The charge shows a maximum value for 200 s RTA treatment, and then decreases with longer annealing time up to 400 s. Atomic force microscopy analysis indicates that there is a correlation between the density of Ge nano-crystals in the devices, and the amount of electrical charge stored. For an RTA treatment of 300 s, capacitance–time measurements show a time dependence, which indicates a dispersive carrier relaxation. The retention time is dependent on the applied bias, and a maximum retention time of ∼115 s was observed at -7 V. The value of the stored electrical charges in the device decreases with increasing ambient temperature. A possible charging/discharging mechanism for the device was discussed to explain the capacitance–time measurements and the temperature stored charge results.

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  1. 1.Department of PhysicsUniversity of OsloNorway
  2. 2.Singapore-MIT AllianceSingaporeSingapore
  3. 3.Institute of Materials Research and EngineeringSingaporeSingapore