Concepedia

Progress in Surface Passivation of Heavily Doped n-Type and p-Type Silicon by Plasma-Deposited AlO $_{\bm x}$/SiN$_{\bm x}$ Dielectric Stacks

Shubham Duttagupta, Fa‐Jun Ma, Serena Fen Lin, Thomas Mueller, Armin G. Aberle, Bram Hoex

IEEE Journal of Photovoltaics · 2013 · 24 citations · 36 references

Abstract

We report an outstanding level of surface passivation for both n + and p + silicon by AlO x /SiN x dielectric stacks deposited in an inline plasma-enhanced chemical vapor deposition (PECVD) reactor for a wide range of sheet resistances. Extremely low emitter saturation current densities (J 0e ) of 12 and 200 fA/cm 2 are obtained on 165 and 25 Ω/sq n + emitters, respectively, and 8 and 45 fA/cm 2 on 170 and 30 Ω/sq p + emitters, respectively. Using contactless corona-voltage measurements and device simulations, we demonstrate that the surface passivation mechanism on both n + and p + silicon is primarily due to a relatively low interface defect density of <;10 11 eV -1 cm -2 in combination with a moderate fixed negative charge density of (1-2) × 10 12 cm -2 . From advanced modeling, the fundamental surface recombination velocity parameter is shown to be in the order of 10 4 cm/s for PECVD AlO x /SiN x passivated heavily doped n + and p + silicon surfaces.