The merits of high landing energy for E-beam inspection

Abstract

E-beam inspection has become one of the most important tools for rapid yield ramp in the semiconductor industry, due to its ability to detect a wide range of defects in-line soon after their formation. This role expansion is due to the increasing difficulty in detecting defects in-line with other traditional methods as well as the continuing evolution of e-beam capability. In the last five years, the role of e-beam inspection has expanded from detection of electrically active, buried defects using voltage contrast inspection to also detection of many challenging physical defect types as well as systematic patterning defects. This paper reports on the impact of an important recent improvement in E-beam inspection tool capability, the availability of dramatically higher landing energies, and the benefits this improvement provides. These include detection of buried defects, a sharper image for detection of surface physical defects, and minimization of wafer charge enabling much longer inspections. These advantages are illustrated through a number of examples. High landing energy can damage certain wafer surfaces and these concerns are also discussed. Overall, high landing energy is a powerful new tool in the E-beam inspection tool box which should be aggressively adopted.