The physics goals at the future e+e- linear collider require high performance
vertexing and impact parameter resolution. Two possible technologies for the
vertex detector of an experimental apparatus are outlined in the paper: an
evolution of the Hybrid Pixel Sensors already used in high energy physics
experiments and a new detector concept based on the monolithic CMOS sensors.Comment: 8 pages, to appear on the Proceedings of the International Workshop
on Linear Colliders LCWS99, Sitges (Spain), April 28 - May 5, 199
