Unexpectedly High Minority‐Carrier Lifetimes Exceeding 20 ms Measured on 1.4‐Ω cmn‐Type Silicon Wafers

We measure very high minority‐carrier lifetimes exceeding 20 ms on 1.4‐Ω cm n ‐type Czochralski silicon wafers passivated using plasma‐assisted atomic‐layer‐deposited Al 2 O 3 on both wafer surfaces. The measured maximum effective lifetimes are surprisingly high as they significantly exceed the intrinsic lifetime limit previously reported in the literature. We are able to measure such high lifetimes by realizing an exceptionally homogeneous Al 2 O 3 surface passivation on large‐area samples (12.5 × 12.5 cm 2 ). The importance of the homogeneous passivation is demonstrated by comparison with samples of locally reduced passivation quality.