Low-energy hydrogen ion implantation in Schottky barrier control

The use of a shallow dopant implant at the semiconductor surface is a well entrenched technique for Schottky barrier height modification. The essential thermal annealing step following implantation has the undesirable effect of redistributing the dopant atoms and thus reducing the efficacy of barrier height control. It is shown here that a low-energy (∼0.4 keV) hydrogen ion implant in silicon following the dopant implant lowers the necessary annealing temperature from about 850 to less than 600°C. The role of atomic hydrogen is believed to be twofold: passivation of dopant ion beam induced damage in Si as well as activation of dopant atoms by enabling a low-temperature solid phase epitaxial regrowth.