Laser processing of solar cells with anti-reflective coating

摘要

Contact holes of solar cells are formed by laser ablation to accommodate various solar cell designs. Use of a laser to form the contact holes is facilitated by replacing films formed on the diffusion regions with a film that has substantially uniform thickness. Contact holes may be formed to deep diffusion regions to increase the laser ablation process margins. The laser configuration may be tailored to form contact holes through dielectric films of varying thicknesses.

主权项

1. A process of fabricating a solar cell, the process comprising:
forming an anti-reflective coating over an interlayer dielectric on a backside of a solar cell, the anti-reflective coating together with the interlayer dielectric being configured to have a breakdown voltage that is greater than 1×107 V/cm; using a laser to form a contact hole through the interlayer dielectric and the anti-reflective coating to expose an underlying diffusion region of the solar cell; and forming a metal contact in the contact hole to electrically connect to the diffusion region, wherein the anti-reflective coating comprises a layer of amorphous silicon and a layer of silicon nitride.