Nuclear reaction analysis of hydrogen in the buried SiO2 layer of Si/SiO2/Si structures

The concentration of hydrogen introduced by a heat treatment into the buried oxide (BOX) layer of Si/SiO2/Si structures (SIMOX and unibond) was determined by nuclear reaction technique. The areal density of H atoms is of the order of 1014/cm2, regardless whether the top Si layer was removed or not. This value is much less than the reported density of mobile protons in these structures prepared in a similar manner. Thus, it is unlikely that the increased density of mobile protons near the edges of patterned top Si layer is due to the enhanced diffusion of H atoms there.