Structure of laminated-layer reinforced type wiring layer and manufacture thereof

Abstract

Abstract PURPOSE:To obtain a wiring layer, which is resistant to electromigration and stress and characterized by few faults, by forming an aluminum wiring, whose diameter of a crystal grain is mostly larger than the width of a wiring on a substrate, and laminating an aluminum wiring, whose diameter of a crystal grain is mostly smaller than 1/2 the width of the wiring so that double layers are obtained. CONSTITUTION:In order to laminate a first wiring layer 3, sputtering is performed by using an alloy material of Al and about 1% Si. The temperature of a substrate is heated to 200-300 deg.C. Thus the diameter of an average crystal grain is several mum, and a wiring layer having the large diameter of the crystal grain is obtained. Then, under the state the temperature of the substrate is maintained at 100 deg.C or less, an alloy, in which 1% Si and a small amount of 1% or less of any metal of Ti, Zr and Mo are added in Al, is laminated. Thus a second wiring layer 4 is formed. In the second wiring layer, the diameter of the crystal grain is very small. The diameter of the grain is several 100Angstrom -1,000Angstrom . This is the very small diameter of the crystal grain in comparison with the width of the wiring. A sufficient buffer function is provided against stress yielded at a step part and stress caused by the difference is expansion coefficients of the Al wiring, the basis material and a cover film.

Inventors

• 👤 Kenji Nishida
• 👤 健治 西田

Bibliographic Details