AMORPHOUS GAAS1-XNX THIN-FILMS ON CRYSTALLINE SI SUBSTRATES - GROWTH AND CHARACTERIZATIONS

This work deals with the growth and study of a new nitride in thin fil ms: GaAs1-xNx. The material is deposited in its amorphous form on crys talline Si substrates by means of RF sputtering of a GaAs target in an atmosphere of argon and ammonia. Raman spectroscopy used to study the physicochemical properties of the film structure pointed out that GaA s1-xNx is a wide gap material which is formed by the substitution of a rsenic by nitrogen in the GaAs network (J. Bandet, K. Aguir, D. Lollma n, A. Fennouh, H. Carchano, Jpn. J. Appl. Phys., 36 (1997) 11. In orde r to investigate the electrical properties of GaAs1-xNx in view of pot ential applications in optoelectronic systems, J-V and C-V characteris tics have been performed. J-V results show that the heterostructures e xhibit a drastic increase in resistivity with nitrogen incorporation. The conduction passes from a diode-type one for x=0 to an approximatel y symmetrical one with nitridation, i.e, for x>0. The films present co nvenient high resistivity values for insulating character consideratio n. Furthermore, C-V results obtained present a manifest MIS-like behav iour with however the existence of a flat-band voltage (V-FB). (C) 199 7 Elsevier Science S.A.