High-barrier Schottky diodes on p-type silicon due to dry-etching damage

Abstract

It is known that the barrier height of Schottky diodes made to dry-etched silicon surfaces deviate from the barrier height values obtained for diodes fabricated on wet chemically etched or cleaved silicon. This effect, in cases where neither a substantial residue layer nor a surface film is formed, can be exploited to yield diodes on p-type Si that display barrier enhancement together with excellent diode ideality factors. It is shown that the barrier heights produced on p-type Si, by exploiting this effect of dry etching, can achieve a value of ∼0.75 eV which is ∼0.15 eV better than the best value reported for wet chemically etched or cleaved p-Si. When this barrier height value is attained, it is found to be independent of metallization. The same barrier height is achieved by two very different dry etching techniques: Ar+ion-beam etching (IBE) and CCl4reactive ion etching (RIE).