Direct observation of electron-beam-induced nucleation and growth in amorphous GaAs

In situ observation of the nucleation and growth stimulated by an electron beam in amorphous GaAs was performed using a high-resolution electron microscopy. The results showed that the crystallization was closely related to the current density of the electron beam. Crystallization could not take place when the current density was 50 pA/cm(2), nanocrystals with the random orientation formed under the 74 pA/cm(2) electron beam, large grains and twining structure formed during the crystallization induced by the 93 pA/cm(2) electron beam. Ionization process and electron-beam heating were suggested to be the possible mechanisms for the irradiation-induced crystallization. (C) 2004 Elsevier Ltd. All rights reserved.