硅光电二极管钝化膜的抗辐射性能研究

为了研究硅光电二极管钝化膜的抗辐射性能,采取了0.8M eV电子在4个辐照剂量(1013cm-2~1014cm-2)分别辐照3种不同厚度二氧化硅钝化的光电二极管的方法,比较了光电二极管光电流变化率和暗电流变化率,得到了3种钝化厚度的光电二极管的性能参数有不同程度衰减的结果。辐照后光电二极管的光电流衰减强烈依赖入射光波长,在短波和长波阶段衰减明显,而在中波阶段(600nm~800nm)基本不衰减。另外,暗电流变化率随着辐照剂量迅速增加,当辐照剂量达到1×1014cm-2时,短波光电流仅为辐照前的80%,暗电流为辐照前的40倍。实验中还发现,薄钝化的二极管的光电流衰减最小,其暗电流增加最显著。结果表明,钝化膜的辐射特性与器件结构和钝化膜工艺密切相关。

Radiation hardness study of passivation film on Si photodiode

With 0.8MeV electron irradiating the passivation film with three different thickness of SiO2 at 4 radiation dosages(1013cm－2～1014cm－2),the radiation hardness of the passivation film was studied through comparing the photocurrent and dark current of the photodiode. It is found after radiation,the characteristics of the photodiodes degrade to some extent. The photocurrent decreases at short and long wavelength,never decrease at middle wavelength(600nm～800nm). On the other hand,the dark current increases with radiation dosage. When the radiation is 1×1014cm－2,the photocurrent is only 80% of that before radiation and the dark current is 40 times of that before radiation. In addition,for photodiodes passivated with thin SiO2,photocurrent decreases slightly,however dark current increases remarkably. Results show that the radiation effect has a relationship with device structure and technics of the film.