Study of the Cluster Ion for Gate Oxide Nitrogen Measurement by TOF-SIMS

Measurement of the nitrogen in ultrathin gate oxide is important for the precise control of gate oxide quality in the FEOL manufacturing process. TOF-SIMS is one of the most capable analysis tools for the nitrogen distribution in the bulk of gate oxide and substrate interface, nitrogen concentration as well as dose measurement. However, there are many cluster ions formed during primary ion bombardment and subsequently captured in the mass spectrometry. Some discrepancy during data analysis was possibly observed for certain cluster ions. In this paper, the ion cluster for the characterization of nitrogen in the gate oxide will be discussed and demonstrated in one of the actual applications in manufacturing control process.