Novel in-situ Ion Bombardment Process for A Thermally Stable (> 800 °C) Plasma Deposited Dielectric

ABSTRACTWe demonstrated an in-situ dielectric film passivation technique by dividing a thick film deposition into many thin film (<40Å) depositions and incorporating the ion bombardment between the depositions. N2 was used for the plasma treatment to passivate the SiNx film and a well passivated and thermally stable SiNx was achieved with this process. The refractive index of N2 treated SiNx film only changed 0.3% when the SiNx film was heated up to 1000 °C and the film with a continuous deposition showed a 2.5% change. From the results of SIMS analysis, the N2 treated SiNx film showed a excellent thermal stability after heat up to 1000 °C. The etch rates of passivated SiNx film in BOE and diluted HF are ≤40 Å/min which is much slower than that of un-treated SiNx (135 Å/min).