The n-type Si growth is enabled by doing singlewafer CVD deposition of Si:P on Si substrate. The substrate has a small Boron doping, from the manufacturer, in the range of ~ 10 15 /cm 3 . Epitaxial growth allows one to create films that have high activated doping, by virtue of substitutional doping. In epitaxial deposition, the depositing film templates on top of a crystalline material. Furthermore, the inherent high crystallinity of the films ensure that they exhibit superior material and transport properties such as: high mobility, low impurity/defect scattering and high thermal stability . Another key advantage of epitaxial growth is the ability to do selective growth on top of templating surface. This allows epitaxy to be used for deeptrench, bottom-up growth .