ラジカル反応を応用したZrN_x膜の低温作製

摘要

Recently, an increase in the integration density of the Si-ULSI system is realized in the 3-D packaging technology. A through-silicon-via (TSV) is an important constituent technology to realize the 3D integration. This requires a deposition process of diffusion barriers at low temperatures if we choose a promising 'via last process'. We have developed a new deposition method of preparing metal-nitrides at low temperatures, which consists of sputter-deposition of a metal film and subsequent nitride formation assisted by radical species generated by catalytic cracking of NH_3 molecules with a heated W-wire. In this study, we successfully prepared ZrN_x films by the proposed method without substrate heating at a temperature as low as 200 ℃ or less. The characteristics of the obtained ZrN_x film are good as comparable to those by reactive-sputtering. A high performance of prepared ZrN_x diffusion barrier is also demonstrated.%3次元実装によるSi－ULSIの集積度の向上に必要なSi貫通ビア配線に適用可能な低温での拡散バリヤの新たな成膜手法として，スパッタ法にラジカル反応を応用した新たな手法を提案してきた．本研究では，その手法を用いて基板加熱なしの200℃以下の低温プロセスで，ZrN_x膜を作製し，その特性を評価した．その結果ZrN_x膜は反応性スパッタ法により得たZrN_x膜に遜色ない良好な特性と有効なバリヤ特性が得られることが知られた．