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Al2O3/Si0.7Ge0.3(001) & HfO2/Si0.7Ge0.3(001) interface trap state reduction via in-situ N2/H2 RF downstream plasma passivation
- Source :
- Applied Surface Science. 478:1065-1073
- Publication Year :
- 2019
- Publisher :
- Elsevier BV, 2019.
-
Abstract
- A novel method for passivating the interface between Si0.7Ge0.3 using an in-situ downstream RF plasma consisting of a nitrogen-rich mixture of H2 and N2 gases at 250 °C prior to atomic layer deposition (ALD) of Al2O3 and HfO2 was demonstrated. XPS spectra of the interface with Al2O3 indicated the presence of a nitride layer enriched in SiONx and depleted in Ge relative to the substrate. The electrical properties of this interface were characterized using I-V and variable frequency C-V measurements of MOS capacitors. The N2/H2 plasma passivation process produced a reduced density of interface trap states (Dit) and lower gate leakage compared with ex-situ HF clean and sulfur passivation for Al2O3 gate oxides. The lowered leakage current and Dit observed compared with HF(aq) or sulfur-passivated surfaces were consistent with enhanced oxide nucleation due to N2/H2 plasma passivation lowering carbon surface contamination and dangling bonds. TEM/EELS analysis of the interface was consistent with the presence of a thin interfacial nitride layer suppressing the formation of Ge O bonds at the interface to form an SiOx-rich interlayer (IL).
- Subjects :
- Materials science
Passivation
Nucleation
Oxide
Dangling bond
Analytical chemistry
General Physics and Astronomy
02 engineering and technology
Surfaces and Interfaces
General Chemistry
Nitride
010402 general chemistry
021001 nanoscience & nanotechnology
Condensed Matter Physics
01 natural sciences
0104 chemical sciences
Surfaces, Coatings and Films
chemistry.chemical_compound
Atomic layer deposition
chemistry
Gate oxide
0210 nano-technology
Leakage (electronics)
Subjects
Details
- ISSN :
- 01694332
- Volume :
- 478
- Database :
- OpenAIRE
- Journal :
- Applied Surface Science
- Accession number :
- edsair.doi...........bfcc6e9c3ac6881330598efdadcae894
- Full Text :
- https://doi.org/10.1016/j.apsusc.2019.01.216