Quantitative Analysis of Transition Metals Penetrating Silicon Substrate through SiN Film by Dopant Ion Implantation and Annealing

Abstract

Metallic contamination on silicon surfaces has a detrimental impact on the performance and yield of ULSI devices. Surface metal impurities degrade the gate oxide integrity while metal impurities dissolved in silicon cause recombination centers and this results in junction leakage. The diffusion behavior of these metal impurities in silicon is well-known [1]. On the other hand, these metal impurities often penetrate the silicon through the silicon oxide or silicon nitride films in ULSI processing. The surface metal impurities penetrate the silicon by colliding with the dopant during ion implantation and are also diffused in silicon by subsequent annealing [2]. While the diffusion behavior of the metal impurities penetrating silicon substrates through the silicon oxide films has been reported [3], little work has been reported on the diffusion behavior of the metal impurities penetrating silicon nitride films. We demonstrated the diffusion behavior of the metal impurities penetrating silicon substrates through a CVD SiN film due to the collision with dopant during ion implantation.