The formation of narrow nanocluster bands in Ge-implanted SiO2-layers

The paper describes the formation of Ge nanocrystals in thin thermally grown SiO2-layers (d(ox) less than or equal to 100 nm) using implantation of 10(15)-2 x 10(16) Ge+/cm(2) and subsequent annealing, Although the implanted Ge depth profile is distributed over almost the whole SiO2 layer, a very narrow band (typical width 5 nm) of Ge nanoclusters very close but well-separated to the Si/SiO2-interface is formed by self-organization under specified annealing conditions. A possible mechanisms for this self-organization process is discussed including nucleation phenomena, Ostwald ripening and defect-stimulated interface processes, Simple MOS-structures were prepared and the effect of charge storage inside the dusters has been derived from C-V characteristics. (C) 1999 Elsevier Science Ltd, All rights reserved.