Highly reliable one-micron-rule interconnection utilizing TiN barrier metal

A lum-rule interconnection structure is described especially in terms of contact characteristics of Al-Si to BF2⁺-implanted Si.(1-5) It is found that contact resistance of Al-Si to BF2⁺-implanted Si increases more drastically than those to B⁺- and As⁺-implanted Si, as contact hole size is reduced down to around lum². With SEM and TEM analyses, a model that Si solid phase epitaxial growth take place on contact surface, where crystalline defect induced by BF2⁺implantation act as the seed, and thus effective metal contact area to Si is drastically reduced, is established. As a solution for this problem, a new metallization system with a TiN barrier metal is proposed and its feasibility is confirmed.