MATERIAL PROPERTIES OF ZRN FILM ON SILICON PREPARED BY LOW-ENERGY ION-ASSISTED DEPOSITION

We investigated the crystalline quality and the resistivity of a ZrN film on an Si(100) substrate, prepared by an ion-assisted deposition method. With this method, metallic Zr is deposited by electron beam evaporation, while simultaneously bombarding the film with nitrogen ions of low ion energy E(i) (100-700 eV). The crystalline quality was improved and the resistivity was decreased by lowering the ion energy to 150 eV. However, the quality of the film prepared at E(i) = 100 eV became poorer than those at E(i) = 150 and 200 eV. The optimum arrival rate ratio N/Zr for the film quality depends slightly on the ion energy, and is about 1.2-1.5 for E(i) = 150 and 200 eV. Increasing the substrate temperature to 820-degrees-C improves the crystalline quality of the ZrN film and decreases the resistivity. However, at 850-degrees-C, a solid phase reaction between Si and Zr occurred, and Zr silicide was sometimes formed. With the optimum deposition conditions, we can obtain a (100)-oriented ZrN film on Si with a resistivity as low as 11.4 muOMEGA cm.