A method of forming a multi-doped junction on a substrate is disclosed.
The method includes providing the substrate doped with boron, the
substrate including a first substrate surface with a first surface region
and a second surface region. The method also includes depositing a first
set of nanoparticles on the first surface region, the first set of
nanoparticles including a first dopant. The method further includes
heating the substrate in an inert ambient to a first temperature and for
a first time period creating a first densified film, and further creating
a first diffused region with a first diffusion depth in the substrate
beneath the first surface region. The method also includes exposing the
substrate to a diffusion gas including phosphorous at a second
temperature and for a second time period creating a PSG layer on the
first substrate surface and further creating a second diffused region
with a second diffusion depth in the substrate beneath the second surface
region, wherein the first diffused region is proximate to the second
diffused region. The method further includes exposing the substrate to a
oxidizing gas at a third temperature and for a third time period, wherein
a SiO2 layer is formed between the PSG layer and the substrate surface,
wherein the first diffusion depth is substantially greater than the
second diffusion depth.