Electrical and Structural Analysis of Crystal Defects After High-Temperature Rapid Thermal Annealing of Highly Boron Ion-Implanted Emitters

Ion implantation of boron is a promising technique for the preparation of p-type emitters in n-type cells. We use rapid thermal annealing with temperatures up to 1250 °C and annealing durations between 6 s and 20 min to anneal the implant-induced crystal defects. Experimental
$J_{0e}$
is compared with simulated and measured defect densities. Perfect dislocation loops are identified to be the dominating defect species after rapid thermal annealing (RTA) above 1000 °C. Even for emitters with
$J_{0e}$
values around 40 fA/cm
²
, defects are present within the valleys of the textured surfaces after annealing. On textured Al
₂
O
₃
-passivated boron emitters, we measure
$J_{0e}$
of 38 fA/cm
²
for a sheet resistance around 80 Ω/□ after very short annealing processes (1 min at 1200 °C).