Method of generating uniformly aligned well and isolation regions in a substrate and resulting structure
View Patent ↗A solution for alleviating variable parasitic bipolar leakages in scaled semiconductor technologies is described herein. Placement variation is eliminated for edges of implants under shallow trench isolation (STI) areas by creating a barrier to shield areas from implantation more precisely than with only a standard photolithographic mask. An annealing process expands the implanted regions such their boundaries align within a predetermined distance from the edge of a trench. The distances are proportionate for each trench and each adjacent isolation region.
1. A method comprising:
depositing a thin oxide on a substrate;
depositing a Polysilicon adjacent to the thin oxide;
performing photolithography using a reticle;
performing an etch;
implanting the Polysilicon;
annealing the substrate;
depositing nitride;
performing a CMP process;
removing the Polysilicon;
performing an RIE step on the exposed oxide and silicon;
depositing the oxide;
performing the CMP process; and
removing the nitride.
2. The method of claim 1 further comprising one or more implanting steps.
3. A method comprising:
layering a first substrate ( 510 ) and a first film ( 505 ) to form a layered substrate;
forming a trench in the layered substrate, the trench having at least one edge;
implanting a first region coupled to a first portion of the trench;
annealing the first region;
depositing a second film ( 610 ) on the layered substrate;
performing a first planarizing process;
removing at least a portion of the first film;
performing a reactive ion etching process;
depositing a structure ( 910 );
performing a second planarizing process; and
removing a portion of the second film ( 610 ).