Contact hole etch scaling toward 0.1 /spl mu/m

Abstract

Non-linear relation between contact etching depth and contact diameter has long been studied concerning with etching mechanism. Recently, McNevin et al. reported a linear relation between etched depth (D) and 1//spl phi/ (/spl phi/=contact diameter) for deep sub-micron contact hole etching. However, their proposed relation is not enough to access some mechanism of high-aspect ratio contact etching. Almost 10 years ago, we proposed a very simple relation for etching depth dependence on pattern width in a silicon trench etching. In the relation, 1/D linearly depended upon l/w (w=pattern width) with strong correlation. In this paper, we will propose a new simple relation between D and /spl phi/ with a small modification of our proposed relation for silicon trench, which can be expanded into deep quarter micron contact hole etching down to 0.1 /spl mu/m.