USE OF SIBN AND SIBON FILMS PREPARED BY PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION FROM BORAZINE AS INTERCONNECTION DIELECTRICS

Thin films of silicon boron nitride (SiBN) of typical composition Si0. 09B0.39N0.51 and silicon boron oxynitride (SiBON) of typical compositi on Si0.16B0.29O0.41N0.14 were prepared by plasma enhanced chemical vap or deposition and the properties of these films were evaluated with re spect to their suitability as interconnection dielectrics in microelec tronic fabrication. Films were deposited on 125 mm silicon substrates in a parallel-plate reactor at a substrate temperature of 400 degrees C and a plasma power of 0.5 W/cm(2). Boron nitride, for comparison of electrical properties, was deposited from borazine (B3N3H6); silicon b oron nitride was deposited from borazine, disilane (Si2H6), and ammoni a (NH3); silicon boron oxynitride was deposited from borazine, disilan e, ammonia, and nitrous oxide (N2O). Metal-insulator-metal capacitors were fabricated and electrical measurements indicated that all three f ilms had excellent dielectric proper-ties with dielectric constants of 4.1, 4.7, and 3.9 for BN, SiBN, and SiBON, respectively. Tests of con formality indicated that deposition into trenches with an aspect ratio of 4:1 gave conformality greater than 70%. Silicon boron oxynitride w as shown to be an excellent barrier to the diffusion of copper. A plan ar, single level metal-insulator structure was constructed using a SiB N/SiBON insulator with copper metallization.