Simple back contact polysilicon emitter solar cell

The present invention relates to the formation of the contact portion of the solar cell. According to one embodiment, the design of the back comb electrodes (IBC) cell according to the present invention, to form the comb junction (whereas in other designs it is necessary twice) requires only one patterning step to. According to another embodiment, back contact structure includes a tunnel dielectric that silicon nitride or nitride. Since this acts as a diffusion barrier, properties of the tunnel dielectric can be maintained during the high temperature process steps, it is possible to prevent the boron from diffusing through the tunnel dielectric. According to yet another embodiment, the process for forming a back contact, does not require a deep drive-in diffusion.