TIN PREPARED BY PLASMA SOURCE ION IMPLANTATION OF NITROGEN INTO TI AS A DIFFUSION BARRIER FOR SI/CU METALLIZATION

A method of forming TiN films for Si/Cu metallization by using plasma source ion implantation (PSII) of nitrogen into Ti is described. The PSII process utilizes a dose of 1 × 1017 ions/cm2 and peak voltages of –10, –15, and –20 kV. The properties of such TiN films as diffusion barriers between Cu and Si were investigated by annealing Cu(2000 A)/TiN/Ti/Si films in vacuum from 500 °C to 700 °C, and by analyzing with four-point probe sheet resistance measurements, Rutherford backscattering spectrometry (RBS), and Auger electron spectroscopy (AES). The TiN films made at peak voltages of –15 and –20 kV were stable barriers against Cu diffusion after annealing at temperatures higher than 600 °C.