Divergence of the patterned depth

Symptoms

  • Patterned depth diverging from target depth.
  • Force vs target depth curve with strong oscillations.
trbl_diverging_depths

Figure 32 Patterned depth diverges from target depth (continuous gradient).

trbl_diverging_forces

Figure 33 Force map with fast variations and non-monotone.

Cause

These are typical symptoms of incorrect Write-Read Alignment and/or too thin Feedback Mask.

Solution

Compensate the shift (CLL Offsets Tab) and/or adjust the feedback mask (Depth Feedback Mask Tab).