Process for forming schottky rectifier with PtNi silicide schottky barrier

摘要

A process for forming a Schottky barrier to silicon to a barrier height selected at a value between 640 meV and 840 meV employs the deposition of a platinum or nickel film atop the silicon surface followed by the deposition of the other of a platinum or nickel film atop the first film. The two films are then exposed to anneal steps at suitable temperatures to cause their interdiffusion and an ultimate formation of Ni2Si and Pt2Si contacts to the silicon surface. The final silicide has a barrier height between that of the Pt and Ni, and will depend on the initial thicknesses of the Pt and Ni films and annealing temperature and time. Oxygen is injected into the system to form an SiO2 passivation layer to improve the self aligned process.

主权项

1. A process of forming a Pt/Ni Schottky barrier, comprising the steps of:
depositing one of a Pt or Ni film of given thickness atop a silicon wafer surface; then depositing the other of a Pt or Ni film of given thickness atop the first deposited film; thereafter annealing said films to cause the inter diffusion of Pt and Ni, and the growth of areas of nickel and platinum silicides at the silicon surface to define a Schottky junction barrier in the range of 640 meV to 840 meV; forming a SiO2 passivation layer atop said silicide after said annealing; and removing said SiO2 passivation layer to expose the top surface of said silicide and thereafter applying a layer of TiW atop said silicide.