Silicon Nitride with Low Carbon Concentration Deposited by Radical Beam Deposition Technique with Organic Liquid Source
Kohshi TAGUCHI, Masahiro YOSHIMOTO and Junji SARAIE
Abstract:Silicon nitride (SiNx) films have been deposited at a substrate temperature ranged from R.T. to 800Ž by a new radical-beam deposition technique. In order to reduce carbon incorporation into the film, hexamethyldisilazane was decomposed in a reaction with atomic nitrogen rather than in plasma directly in this technique. The carbon concentration of the film was estimated to be less than the order of 1019 cm-3 based on secondary ion mass spectroscopy. The density of the film estimated from Rutherford backscattering spectroscopy (RBS) increased from 2.6 to 3.2 g/cm3 with increasing substrate temperature. The resistivity and the dielectric constant of the film were evaluated to be 1013ƒ¶Ecm at 3 MV/cm and 5.7 at 300 kHz, respectively. This new technique is promising to obtain high-quality SiNx film by deposition without using SiH4. Key Words:Silicon nitride, Radical-beam deposition, Hexamethyldisilazane, Activated nitrogen atom, Carbon incorporation, Density, Resistivity