Reducing yield impact at ion implant process due to particles using in situ particle measurement at sub 0.13 μ geometries

Ion implant is one of the most common process steps in the manufacture of semiconductor devices. The process is a batch style operation where thirteen wafers are mounted on a rotating disk which revolves at speeds of up to 1200 rpm. On the sub 0.15 micron geometries, device structures are more fragile and vulnerable to the ballistic forces of the particles emanating from the beam line and the high speed spinning disc. A particular phenomenon where a complete batch of 13 wafers is scrapped after being impinged by these particles is described as the "tornado effect". This paper describes the investigation of particles in a batch ion implanter using a HYT in situ particle monitor to optimize the particle levels within the tool, optimize the PM intervals and also capture the tornado effect in real time preventing the die loss normally experienced.