Effects of in situ N{sub 2} plasma treatment on etch of HfO{sub 2} in inductively coupled Cl{sub 2}/N{sub 2} plasmas

Journal Article · Tue May 15 04:00:00 EDT 2007 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.2731361· OSTI ID:20979374

Chaung, Lin; Leou, K -C; Fan, Y -C; Li, T -C; Chang, K -H; Lee, L -S; Tzeng, P -J ^[1]

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1. Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30043, Taiwan (China)

The etch selectivity of HfO{sub 2} to Si reported to date is poor. To improve the selectivity, one needs to either increase the etch rate of HfO{sub 2} or decrease the etch rate of Si. In this work, the authors investigate the etch selectivity of HfO{sub 2} in Cl{sub 2}/N{sub 2} plasmas. In particular, the effects of in situ N{sub 2} plasma treatment of HfO{sub 2} and Si were investigated. The silicon substrate was exposed to nitrogen plasma and was nitrided, which was confirmed by x-ray photoelectron spectroscopy. The nitrided Si etching was suppressed in Cl{sub 2}/N{sub 2} plasmas. The effectiveness of nitridation was studied with varying the plasma power, bias power, pressure, and N{sub 2} plasma exposure time. The results show that the etch resistance increased with increased power and decreased pressure. A minimum exposure time was required to obtain etch resistant property. The applied bias power increased the etch rate of Si substrate, so it should not be used during N{sub 2} plasma treatment. Fortunately, the etch rate of HfO{sub 2} was increased by the nitridation process. Therefore, HfO{sub 2}/Si selectivity can be improved by nitridation and became higher than 5 under proper exposure condition.

• OSTI ID: 20979374
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 3 Vol. 25; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHLORINE
DIELECTRIC MATERIALS
ETCHING
HAFNIUM OXIDES
NITRIDATION
NITROGEN
PLASMA
SEMICONDUCTOR MATERIALS
SILICON
SUBSTRATES
THIN FILMS
X-RAY PHOTOELECTRON SPECTROSCOPY