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Title: Investigating wet chemical oxidation methods to form SiO2 interlayers for self-aligned Pt-HfO2-Si gate stacks
Self-aligned metal-oxide-semiconductor (MOS) capacitors are studied with several low-temperature, wet chemical silicon dioxide (SiO2) interlayers to understand their impact on electrical performance. Self-aligned MOS capacitors are fabricated with a bottom-up patterning technique that uses a poly(methyl methacrylate) brush and dopant-selective KOH etch combined with area-selective atomic layer deposition of hafnium dioxide (HfO2) and Pt. The wet chemical pretreatments used to form the SiO2 interlayer include hydrofluoric acid (HF) etch, 80 °C H2O, and SC-2. Capacitance-voltage measurements of these area-selective capacitors exhibit a HfO2 dielectric constant of ∼19, irrespective of pretreatment. After a forming gas anneal, the average interface state density decreased between 1.8 and 7.5 times. The minimum observed Dit is 1 × 1011 eV−1 cm−2 for the HF-last treatment. X-ray photoelectron spectroscopy shows an increase in stoichiometric SiO2 in the interfacial layer after the anneal. Additional carbon is also observed; however, comparison with capacitors fabricated in a nonselective process reveals minimal impact on performance.  more » « less
Award ID(s):
1916953
NSF-PAR ID:
10486600
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
AIP
Date Published:
Journal Name:
Journal of Vacuum Science & Technology A
Volume:
41
Issue:
5
ISSN:
0734-2101
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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