H2 annealing for metallic contaminant reduction in BCD-SOI process: Benefits and drawbacks

Contaminant reduction is a key issue for SOI substrate which cannot make use of back-side gettering. H₂ annealing has been proven to be effective in Si reconstruction, influencing diffusion by breaking strained Si bonds and generating cavities for contaminant gettering. These properties could help in reducing contaminants in BCD-SOI process. Unfortunately, H₂ annealing integration can be highly critical and the process optimization has to take into account 3-D morphology evolution and contaminant reduction efficiency. Aim of this work is to understand the physical mechanisms behind Si surface reconstruction and metallic contaminants reduction.