Please use this identifier to cite or link to this item: https://scholarbank.nus.edu.sg/handle/10635/153901
DC FieldValue
dc.titlePATTERNING OF HAFNIUM ALUMINIUM OXIDE/POLY-SI GATE STACK FOR ADVANCED CMOS APPLICATIONS
dc.contributor.authorARDIANTO WIRASENTANA
dc.date.accessioned2019-05-09T05:30:32Z
dc.date.available2019-05-09T05:30:32Z
dc.date.issued2003
dc.identifier.citationARDIANTO WIRASENTANA (2003). PATTERNING OF HAFNIUM ALUMINIUM OXIDE/POLY-SI GATE STACK FOR ADVANCED CMOS APPLICATIONS. ScholarBank@NUS Repository.
dc.identifier.urihttps://scholarbank.nus.edu.sg/handle/10635/153901
dc.description.abstractThe patterning of hafnium aluminium oxide/PolySi (HfAlO/polySi) gate stack was investigated. To etch polySi with high etch rate, high RF power of 400W and Cl-based plasma(s) were incorporated into the polySi recipe. HBr-based plasma together with He-O₂ gases showed best selectivity for etching HfAlO films compared to Cl-based plasma. AFM scans showed that Root Mean Square (RMS) roughness of HfAlO film etched by H-2 recipe was quite low and lower than that of etched-HfO₂ films by Pearton's group [24]. The final gate stack, consisting of 80Ǻ HfAlO and 2000 Ǻ polySi film, was dry etched using photoresist mask. It showed relatively a good fidelity transfer with straight sidewalls and good resist integrity during HBr plasma etch as no facet formation was observed. Etch artifacts such as microtrenching, facet formation and undercutting, were not observed on the pattern. However, polymer film was found on the pattern from cross section SEM. The presence of the polymer film was in good agreement with Auger Electron Spectroscopy (AES) spectra, which was able to detect the significant carbon concentration on three different regions, namely region near the sidewalls of the gate stack, region between the pattern and region on the pattern. This polymer film was shown to aid in the formation of straight sidewalls as this passivation layer is etch resistant in HBr plasma. This film was found by cross section SEM to be 20 nm thick. Sidewall bowing was minimal, hence, no microtrenching was observed. Further work needs to be performed for polymer film removal employing NH₄OH and H₂O₂ chemical solution. A relatively straight sidewall profiles developed during the HBr etching explain the nonoccurrence of microtrenches. The absence of microtrenching is probably associated with the absence or the minimum sidewall bowing near the bottom of the gate stack. The microtrenching is probably associated with two mechanisms: ion scattering from tapered sidewalls and the focusing of directional ions by bowed sidewalls onto the feature bottom.
dc.sourceSMA BATCHLOAD 20190422
dc.subjectHigh-κ
dc.subjectDielectrics
dc.subjectHfAlO
dc.subjectCMOS
dc.subjectEtching
dc.subjectSelectivity
dc.subjectTaN
dc.subjectSidewall bowing
dc.subjectMicrotrenching
dc.subjectPolymer film
dc.typeThesis
dc.contributor.departmentSINGAPORE-MIT ALLIANCE
dc.contributor.supervisorSHAJAN MATHEW
dc.contributor.supervisorCHIM WAI KIN
dc.description.degreeMaster's
dc.description.degreeconferredMASTER OF SCIENCE IN ADVANCED MATERIALS FOR MICRO- & NANO- SYSTEMS
dc.description.otherDissertation Advisors: 1. Shajan Mathew, Senior Research Engineer, SPT Lab., IME. 2. Assoc. Prof. Chim Wai Kin, SMA Fellow, NUS.
Appears in Collections:Master's Theses (Restricted)

Show simple item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
Ardianto Wirasentana_THESIS.pdf3.09 MBAdobe PDF

RESTRICTED

NoneLog In

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.