Multi-step methods for chemical mechanical polishing silicon dioxide and silicon nitride

Polishing silica (S1) and silicon nitride on a semiconductor, comprises: planarizing (S1) with a first aqueous composition (I) comprising e.g. carboxylic acid polymers (P1), an abrasive (P3), polyvinylpyrrolidone (P5), a cationic compound (P7) and phthalic acid (P4) or its salt; detecting the end point of planarization; and releasing silica with a second aqueous composition (II) comprising e.g. ammonium quaternary compound. Polishing silica (S1) and silicon nitride on a semiconductor, comprises: planarizing (S1) with a first aqueous composition (I) comprising carboxylic acid polymers (P1) (0.01-5 wt.%), an abrasive (P3) (0.02-6 wt.%), polyvinylpyrrolidone (P5) (0.01-10 wt.%) (molecular mass of 100-1000000 g/mol), a cationic compound (P7) (0-5 wt.%), phthalic acid (P4) (0-1 wt.%) or its salts, a zwitterionic compound (0-5 wt.%) and water for complementing; detecting the end point of planarization; and releasing silica with a second aqueous composition (II) comprising ammonium quaternary compound (0.001-1 wt.%), (P4) (0.001-1 wt.%), (P1) (0.01-5 wt.%), (P3) (0.01-5 wt.%) and water for complementing. An independent claim is also included for a process comprising planarizing (S1) with an inhibiting suspension, detecting first end point, stopping planerization, releasing (S1) with a selective suspension and detecting second end point and stopping the release.