STUDY ON DETERMINING FACTORS OF LOW CONTACT RESISTIVITY IN TRANSITION-METAL SILICON SYSTEMS

We have made a systematic study of electrical properties and crystallographic structures of transition metal (the group of IVa and Va)/Si(100) interfaces. In the case of Zr and Hf/n+-Si contacts, extremely low contact resistivities of (4-8) x 10(-8) OMEGA.cm2 can be obtained by annealing at 400-500-degrees-C, under the condition of which an amorphous layer and crystallites are formed at the interfaces. It can be found that the contact resistivity for n+-Si has a large dependence on the Schottky barrier height. On the other hand, the contact resistivity for p+-Si is more than an order of magnitude larger than that for n+-Si. These results can be explained by formation of a thin dielectric layer at the interface.