SEM investigation of surface defects arising at the formation of a buried nitrogen-containing layer in silicon

摘要

The main goal of this work is to demonstrate the correlation between the density and type of surface defects arising during the formation of a buried nitrogen-containing layer in Si wafers, and the number of buried defects formed by different dose hydrogen preimplantation. Standard commercial 12 Ω·cm boron-doped and 4.5 Ω·cm phosphorous-doped Cz Si wafers were subjected to hydrogen ion implantation at room temperature with the energy 100 keV and doses 1-10~(15) - 4·10~(16) at/cm~2. Then nitrogen was introduced into silicon from a DC plasma source at a temperature of 300℃. Finally, all samples were subjected to 2 h vacuum annealing at 900℃. The experiments have shown that the density and type of the surface defects depend significantly on the dose of hydrogen implantation, parameters of N~+-plasma treatment, and conductivity type of silicon. Optimization of the above-mentioned parameters makes it possible to create the substrates containing a buried dielectric Si_xN_y layer and having a practically defect-free surface.