Carbon deposition-etch-ash gap fill process

摘要

Techniques, systems, and apparatuses for performing carbon gap-fill in semiconductor wafers are provided. The techniques may include performing deposition-etching operations in a cyclic fashion to fill a gap feature with carbon. A plurality of such deposition-etching cycles may be performed, resulting in a localized build-up of carbon film on the top surface of the semiconductor wafer near the gap feature. An ashing operation may then be performed to preferentially remove the built-up material from the top surface of the semiconductor wafer. Further groups of deposition-etching cycles may then be performed, interspersed with further ashing cycles.

主权项

1. A semiconductor processing tool comprising:
a process chamber; one or more gas inlets into the process chamber and associated flow-control hardware; a low-frequency radio-frequency (LFRF) generator; a high-frequency radio-frequency (H FRF) generator; and a controller having at least one processor and a memory, wherein: the at least one processor and the memory are communicatively connected with one another, the at least one processor is at least operatively connected with the flow-control hardware, the HFRF generator, and the LFRF generator, and the memory stores computer-executable instructions for controlling the at least one processor to at least control the process chamber, the flow-control hardware, the HFRF generator, and the LFRF generator to: a) perform a deposition process on receiving a substrate within the process chamber, the substrate having a top surface and at least one gap feature with a gap entry width where the at least one gap feature intersects the top surface; b) perform a deposition process to deposit a carbon film layer on the substrate and on exposed surfaces of the at least one gap feature, wherein the deposition process is performed at least until the deposited carbon film layer causes the gap entry width to be reduced; c) perform an anisotropic etch process on the substrate with a dominant anisotropic axis substantially perpendicular to the substrate at least until the gap entry width increases from the gap entry width at the conclusion of (b); d) perform X additional cycles of (b) and (c), wherein X is a positive integer; and e) perform an ashing process to remove localized build-up of carbon film on the top surface of the substrate adjacent to the at least one gap feature produced as a result of (b) through (d).