Defect creation kinetics in swift heavy ions, protons and electrons irradiated germanium

LERMAT (FRE CNRS 2149), ISMRA, 6 boulevard Maréchal Juin, 14050 Caen Cedex, France

Corresponding author: marie@labolermat.ismra.fr

Received: 8 September 2000
Revised: 18 December 2000
Accepted: 18 December 2000
Published online: 15 February 2001

Abstract

N-type lightly doped germanium has been irradiated at room temperature with different particles: swift heavy ions, protons and electrons. Hall effect measurements have been carried out versus either the temperature (at a given fluence) or the fluence (at room temperature). Using the level positions determined by DLTS results previously reported, we extract from the Hall coefficient simulation at low doses the creation kinetics of the irradiation-induced defects. These defects are typically at room temperature the A-centre, the E-centre and the divacancy complexes. At higher doses, in the case of electron irradiation, these simulations are still feasible using only the previous defects mentioned above since the material leads towards a quasi-intrinsic state. But we point out that it is necessary in the case of proton and swift heavy ion irradiations to add an acceptor level in the forbidden band probably associated with a multivacancy defect. Indeed, in these cases, the material becomes p-type. Finally, the experimental introduction rates are compared to the theoretical ones. It appears that the relative damage creation efficiency is not very different from a projectile to another, proving that there is no strong dependence on the electronic energy loss.