New sample preparation method using room-temperature direct bonding in backside SIMS analysis

Secondary ion mass spectrometry (SIMS) is one of the tools to investigate the dopant or impurity profiles of the semiconductor materials. In particular, the backside SIMS is a useful technique to examine the diffusion of dopant at the surface while minimizing knock-on effect. However, it is very difficult to prevent insulating samples from charging when O₂⁺ source is used for positive secondary ion detection in magnetic sector SIMS. In order to overcome the problem, the authors have employed a new sample preparation method using a room-temperature direct bonding (RTDB). The authors investigated the depth profiling of insulating samples, which were stacked on a dielectric silicon dioxide films with silicon wafer as a magnetic sector SIMS instrument. The samples treated with and without RTDB were compared, and the results show that the depth profiles of RTDB-treated sample could be obtained no sign of charge-up in the backside SIMS analysis.