Forming sacrificial endpoint layer for deep STI recess

A method of forming a semiconductor structure, the method comprising:

• forming a plurality of fins over a substrate;
• forming at least one shallow isolation trench (STI) structure;
• forming polysilicon spacers adjacent sidewalls of the plurality of fins and adjacent the at least one STI structure;
• filling the at least one STI structure with an STI oxide;
• and
• alternately recessing, in a continuous manner, the STI oxide and the polysilicon spacers adjacent the plurality of fins, multiple times, in a stepwise manner until the STI oxide is completely removed such that an entirety of each of the plurality of fins remains intact.

A semiconductor structure, comprising:

• a plurality of fins formed over a substrate;
• one or more shallow isolation trench (STI) structures defining a first region and a second region;
• a liner dielectric;
• spacers adjacent sidewalls of the plurality of fins and adjacent the one or more STI structures;
• and
• an oxide layer for filling the one or more STI structures;
• wherein the oxide layer and the spacers adjacent the plurality of fins are incrementally recessed multiple times in an alternating and continuous manner until the oxide layer is completely removed such that an entirety of each of the plurality of fins remains intact.