Reduction of black silicon in semiconductor manufacture

Abstract

Reduction of black silicon is achieved by providing a protective device layer in the bead region and sides of the wafer before the formation of a hard etch mask.

Description

technical field [0001] The present invention relates generally to semiconductor manufacturing, and more particularly to reducing the formation of black silicon. Background technique [0002] In the manufacture of integrated circuits (ICs) or chips, vias or trenches are typically formed in substrates such as silicon wafers for various purposes. Vias or trenches are formed by etching into the substrate. Deep trenches (DTs), for example, function as trench capacitors for memory cell arrays. [0003] Typically, DTs are formed by first providing a substrate stack on the wafer surface. The base stack includes, for example, successive layers of base oxide 112 and base nitride 114 . On top of the substrate stack is a hard mask layer 116 comprising, for example, TEOS. The hard mask layer functions as a hard etch mask for forming DTs. [0004] A photoresist layer is deposited on the hard mask layer and patterned to selectively expose areas where DTs are to be formed. Typically, ...

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However, the use of clamp rings creates finger shielding, which can affect lithograph

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