Low Specific Contact Resistivity to n-Ge and Weil-Behaved Ge n~+/p Diode Achieved by Implantation and Excimer Laser Annealing

摘要

Excimer laser annealing of phosphorus-implanted p-type germanium substrate with various laser energy densities for n+/p junction were investigated. The effects of laser energy density on the redistribution of dopant, surface morphology, and recrystallization of the amorphous Ge induced by ion implantation were characterized. A low specific contact resistivity of 1.61 ×10~(-6) Ω·cm~2 was achieved from Al-Ge ohmic contact, in which phosphorus-implanted Ge was annealed at a laser energy density of 250mJ/cm~2, tAlloring a small phosphorus diffusion length, high activation level, and low dopant loss. A well-behaved Ge n~+/p diode with a rectification ratio up to 1.99 × 10~5 was demonstrated.