Wafer flatness control using backside compensation structure

A method for forming a semiconductor structure, comprising:

• forming a plurality of semiconductor structures on a front side of a wafer;
• depositing a film on a backside opposite to the front side of the wafer;
• patterning the deposited film on the backside of the wafer to form a compensation structure partially covering the backside of the wafer, such that a flatness difference of the wafer between a first direction and a second direction is reduced;
• and
• removing at least part of the compensation structure from the backside of the wafer.

A semiconductor structure, comprising:

• a wafer having a front side and a backside opposite to the front side;
• a plurality of semiconductor devices on the front side of the wafer;
• and
• a compensation structure partially covering the backside of the wafer and configured to reduce a flatness difference of the wafer between a first direction and a second direction,
• wherein a layout of the compensation structure comprises at least one of parallel wave lines, radial strips, or lattice.