18466613. TUNABLE PATTERNED SURFACE UNIFORMITY USING DIRECT CURRENT BIAS (Tokyo Electron Limited)
TUNABLE PATTERNED SURFACE UNIFORMITY USING DIRECT CURRENT BIAS
Organization Name
Inventor(s)
Pingshan Luan of Albany NY (US)
TUNABLE PATTERNED SURFACE UNIFORMITY USING DIRECT CURRENT BIAS
This abstract first appeared for US patent application 18466613 titled 'TUNABLE PATTERNED SURFACE UNIFORMITY USING DIRECT CURRENT BIAS
Original Abstract Submitted
A high aspect ratio etching method includes generating plasma in a chamber containing a substrate including a patterned surface such as a hardmask, and etching one or more underlying layers through openings in the patterned surface by coupling a periodic sequence including direct current bias waveforms to the substrate. Each bias waveform has voltage ranging from a reference voltage to a peak voltage. The periodic sequence has a duty cycle greater than 20%. The bias waveforms may include a non-vertical voltage transition. The one or more underlying layers may be a dielectric and the method may be a high aspect ratio contact etch. The etching may form features having an aspect ratio of at least about 100:1 and a critical dimension less than about 100 nm. The periodic sequence may have a frequency between about 100 kHz and about 3 MHz.