Source roughness of hydrogen ion cut low temperature bonded thin film layers

We have observed that wafer splitting from hydrogen ion implantation into s ilicon after low temperature direct bonding creates an expunged film with a surface roughness that is similar to 1 nm (RMS). This result is an order o f magnitude smoother than the previous work (similar to 10 nm RMS). The key improvement is the use of low temperature bond in our work resulting in a strong bond far below the cut temperature. The smooth as-split surfaces pro duced using a:low temperature bond are very important for creation of very thin (<50 nm) silicon-on-insulator (SOI), three-dimensional bonded structur es and nanostructures that are split after processing.