Method for homogenizing device parameters through photoresist planarization

Abstract

In a fabrication process, photoresist is disposed over a semiconductor substrate ( ), covering a front surface ( ) of the substrate ( ) and filling trenches ( ) therein. The photoresist is planarized in chemical mechanical polishing to achieve a uniform thickness throughout the substrate ( ). An anisotropic etching process partially removes the photoresist in the trenches ( ), thereby creating recesses in the trenches ( ). Because the thickness of the photoresist is uniform throughout the substrate ( ) before the etching process, the depths of the recesses in different trenches ( ) are substantially equal to each other. A uniform recess depth throughout the substrate ( ) is thereby achieved. The uniform recess depth facilitates in ensuring the semiconductor devices fabricated on the substrate ( ) to have consistent parameters, characteristics, and performances.