Recently, it has been shown that the investigation of minority carrier traps (traps) is a useful method to study defects in silicon wafers. In this paper, we report the presence of traps in p-type multicrystalline silicon with a photoconductance decay time constant of 1.9 ± 0.4 s (at 30 °C). It is shown that the density of traps is significantly reduced after firing. However, this reduction in trap density is metastable, and it recovers by short dark annealing at 100 °C or after several days of storage at room temperature. In contrast, laser annealing is shown to eliminate the traps in fired wafers, while no change in the trap density is observed for wafers that have not been fired. Further dark annealing of those wafers does not recover the traps, suggesting that this trap annihilation is not reversible.

最近，研究表明少数载流子陷阱（陷阱）是研究硅晶片缺陷的有用方法。在本文中，我们报告了 p 型多晶硅中存在陷阱，其光电导衰减时间常数为 1.9 ± 0.4 s（30 °C）。结果表明，发射后陷阱的密度显着降低。然而，陷阱密度的这种降低是亚稳态的，它可以通过在 100 °C 下进行短暂的暗退火或在室温下储存几天后恢复。相比之下，显示激光退火消除了烧制晶片中的陷阱，而未观察到未烧制晶片的陷阱密度没有变化。这些晶片的进一步暗退火不会恢复陷阱，表明这种陷阱湮灭是不可逆的。