PL showed that the pitting appeared after diffusion, which was greatly reduced after etching and cleaning, and the proportion of pitting after oxidation increased significantly, reaching more than 95%.

Suspicions:

1. Oxidation will amplify the pitting produced in the front section;

2. Pockmarks are generated from pollution from after etching to before ALD;

Oxidation amplifies pitting in the anterior segment

1.Dusting before diffusion (EL no black spots)

2. The appearance of the dots on the back of the etching is abnormal (the position of the EL black dots cannot correspond)

pollution from the environment

After etching, it is placed in the environment of dust particles at 10W+ for 2H; Proportion: 15%After etching, it is placed in an environment with dust particles below 1000 for 2H; Proportion: 8%0.01% of normal cycle time production

Debris on the belt of the oxidizer may be lifted due to air purging

The defects of the black spots are improved