Study of UV Cure Effect on Peald Sinx WER in 3D Architecture

We investigated the effects of different ultraviolet (UV) cure time 1 min/5min/10min and output power 75%/85%/95% on PEALD SiN<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> (with H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) film thickness (THK) and dilute HF @30:1 wet etch rate (WER). With the increase of UV cure time, the transmission electron microscope (TEM) THK of PEALD SiN<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> film showed little change for both NPW (non-pattern wafer) & PW (pattern wafer). Though WER also no obviously changes for the NPW, it shows trend down for nearly all locations in the 3D architecture. Especially for UV cure 10 min, the PEALD SiN<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> film WER shows evident decrease, pocket lateral maximum optimizes ~70%, changes from 21.4 nm/min to 6.3 nm/min on average for 6 Tiers. Due to the limited transmission of UV wavelengths, the effect of UV cure on PEALD SiN<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> film WER reduction weakens as depth increases. Also we found the UV lamp power has a positive effect on lowering the WER. Next we can merge the long UV cure time and large UV lamp power for the WER further reduction.