Method for horizontal gap filling in semiconductor manufacturing

Abstract

Aspects of the present disclosure provide a method for filling a horizontal gap of a semiconductor structure. For example, the method can include providing a workpiece that includes a stack of alternating first layers and second layers that are parallel with each other. At least one of the second layers can be recessed with respect to vertical sidewalls of two neighboring first layers that sandwich the second layer. A horizontal gap can be formed between the recessed second layer and the two neighboring first layers. The method can further include depositing a gap-filling material to cover the sidewalls of the first layers and fill the horizontal gap, etching back a portion of the gap-filling material that is deposited on the sidewalls of the first layers in an ion bombardment process, and forming a gap filler that includes a remaining portion of the gap-filling material that fills the horizontal gap.

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