A method of planarizing a microelectronic substrate assembly, comprising:
- removing material from the substrate assembly by pressing the substrate assembly against a planarizing surface of a polishing pad and moving at least one of the substrate assembly or the polishing pad in a planarizing plane;
- monitoring a lateral drag force between the substrate assembly and the planarizing surface by sensing lateral forces between a moveable primary support member supporting either the polishing pad or the substrate assembly and a secondary support member holding the primary support member;
- and
- terminating removal of material from the substrate assembly when the sensed lateral drag force reaches a predetermined endpoint force.