RFバイアススパッタリングによるシリコン酸化膜

概要

論文の詳細を見る
Silicon oxide films have been formed by a RF bias sputter-deposition system using a quartz target in Ar or Ar/O2 sputtering gas. Substrate bias voltage Vb was varied from 0 to-200 V, at the total power of 1.9 W/cm2. In order to evaluate the planarization effect, the step coverage of the film on AlSi patterns was examined by SEM and compared with the computer simulated profiles using the Lehmanns method, and a good agreement was obtained. Further, we have applied this planarization technology to a 6-level metallization and realized the good step coverage. The properties of the silicon-oxide films were also studied. In the case of the Ar gas sputtering, the leakage current and the compressive stress in the film increase with increasing Vb. It is found that the Ar/O2 gas sputtering improves the film properties of both the inner stress and leakage current. Auger analysis indicates that the films deposited in Ar/O2 gas have O/Si ratio of about 2, but O/Si ratio of the films deposited in Ar gas is less than 2. From these data, the improvement of the properties of the films can be explained as following; oxygen in Si-O network in the films is removed by Ar ion bombardment during bias sputtering, and damaged bond is compensated by oxygen addition.
日本真空協会の論文