Trench isolation means and method.

摘要

A means and method is described for forming dielectric filled isolation trench (18) in semiconductor substrate (10) in which a differentially etchable etch-stop layer (14) is provided above the surface (11) of the substrate (10) during the trench filling process so that the height of the trench filling (22) relative to the surface (11) of the substrate (10) may be adjusted for optimum overall results during subsequent fabrication steps and so that the substrate surface (11) may be protected from contact with the etching reagents used during planarization of the trench filling material (22, 36). This avoids damage to the substrate surface (11) and permits improved surface planarity.