SILVER SCHOTTKY CONTACTS ON SI(111) - H-(1X1) SURFACES PREPARED BY WET-CHEMICAL ETCHING

Schottky contacts were prepared by evaporation of silver on H-terminat ed Si(1 1 1) surfaces at room temperature. The Si(1 1 1):H-(1 x 1) sur faces were obtained by wet-chemical etching in buffered hydrofluoric a cid. The zero-bias barrier heights and the ideality factors, which wer e determined from I/V characteristics measured with these contacts, we re found to be linearly correlated. This plot gives a zero-bias barrie r height of 0.74 eV for an ideality factor of 1.01 which is obtained f or image-force lowering of the barrier only. The barrier heights obser ved here equal the one found with Ag/Si(1 1 1)-(1 x 1) contacts. They were prepared by Ag evaporation onto clean Si(1 1 1)-(7 x 7) surfaces at room temperature and subsequent heat treatments. The present result is explained by the desorption of the hydrogen adatoms during the dep osition of Ag and the existence of a (1 x 1)-structure at the Ag/Si(1 1 1)interface.