METAL-ASSISTED CHEMICAL ETCHING OF A SEMICONDUCTIVE SUBSTRATE WITH HIGH ASPECT RATIO, HIGH GEOMETIC UNIFORMITY, AND CONTROLLED 3D PROFILES

摘要

An embodiment of a method for metal-assisted chemical etching of a semiconductive substrate comprises forming a patterned coating on a top surface of a substrate layer of a silicon wafer; applying a noble metal layer over the patterned coating such that a portion of the noble metal layer is in contact with the top surface of the substrate layer; and immersing the silicon wafer in a wet etching solution to form a trench under the portion of the noble metal layer that is contact with the top surface of the substrate layer. Further, the trench may be filled with copper material to form a through silicon via structure. Such embodiments provide etching techniques that enable etched formations that are deep (e.g., high-aspect-ratio) and uniform as opposed to shallow etchings (i.e., low-aspect-ratio) or non-uniform deep etchings.

主权项

1. A method for forming semiconductor structures comprising:
forming a patterned coating on a top surface of a substrate layer of a silicon wafer; applying a noble metal layer over the patterned coating such that a portion of the noble metal layer is in contact with the top surface of the substrate layer; and immersing the silicon wafer in a wet etching solution to form a trench under the portion of the noble metal layer that is contact with the top surface of the substrate layer, wherein an etching profile of the trench is rationally determined by controlling at least one of a thickness of the noble metal layer, a morphology of the noble metal layer, or a composition of the wet etching solution.