Fig. 1. The schematic of characteristic shift

Fig. 2. Abnormal bright spot with light on

Fig. 3. The abnormal spot of semiconductor and FIB analysis

Fig. 4. Acid resistance test of SiO₂：Corrosion status of Cu film after acid soaking

Fig. 5. Relations between the etching rate and WER

Fig. 6. Relationship between factor of deposition and deposition rate

Fig. 7. Variation curves of SiO₂ film deposition rate and related factors

Fig. 8. Two‑step deposition of SiO₂ and the comparison results of acid resistance

Fig. 9. Effect diagram of adverse improvement