Oxygen gettering and oxide degradation during annealing of Si/SiO[sub 2]/Si structures

Journal Article · Sun Jan 01 00:00:00 EST 1995 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.359365· OSTI ID:6738184

Devine, R A.B. ^[1]; Warren, W L ^[2]; Xu, J B; Wilson, I H ^[3]; Paillet, P; Leray, J ^[4]

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1. CNET-France Telecom, B.P. 98, 38243 Meylan (France)
2. Sandia National Laboratories, Albuquerque, New Mexico 87185-1349 (United States)
3. Department of Electrical Engineering, Chinese University, Shatin, N. T. (Hong Kong)
4. CEA, Centre d'Etudes de Bruyeres, B. P. 12, 91680 Bruyeres le Chatel (France)

The microscopic nature of the degradation of oxide layers in Si/SiO[sub 2]/Si structures induced by annealing at 1200 to 1320 C in inert or weakly oxidizing atmospheres was studied. ESR measurements were performed on unannealed and annealed samples subsequently subjected to [gamma] or [ital X] radiation or hole injection. Two oxygen-vacancy-related defect centers were observed, the monovacancy [ital E][sub [gamma]][sup [prime]] center and the multiple vacancy [ital E][sub [delta]][sup [prime]]---both were observed in substantially larger numbers in annealed oxides as compared to unannealed oxides. Etchback profiling of the paramagnetic defect distributions shows that they are distributed nonuniformly throughout the annealed oxides with the highest densities close to the two Si/SiO[sub 2] interfaces. Electrical measurements of fixed oxide charge induced by [ital X] irradiation indicate that annealing results in the creation of both positive and negative charge traps. The numbers of positive trapped charges and their radiation dose dependence are inconsistent with their origin being identified simply with the paramagnetic oxygen-vacancy centers. Infrared measurements of the O interstitial content of the float-zone Si substrates of annealed and unannealed samples reveal that the interstitial concentration increases as a function of anneal temperature/time. Atomic force microscopy measurements reveal that the SiO[sub 2]/Si substrate interfaces are roughened during high-temperature annealing. The data are interpreted in terms of a model in which oxygen is gettered from the oxide film into the over- and underlying Si. The O are incorporated into the Si as interstitials and it is their solubility limit at the anneal temperature which drives the gettering process. The oxygen-vacancy defect profiles near to both Si/SiO[sub 2] interfaces are not well predicted by the gettering model suggesting that other interface-related defect creation processes may be active.

• DOE Contract Number: AC04-94AL85000
• OSTI ID: 6738184
• Journal Information: Journal of Applied Physics; (United States), Vol. 77:1; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SILICON
INTERFACES
SILICON OXIDES
DEFECTS
ANNEALING
ELECTRON SPIN RESONANCE
GAMMA RADIATION
GETTERING
INFRARED SPECTRA
LAYERS
PHYSICAL RADIATION EFFECTS
VACANCIES
X RADIATION
CHALCOGENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTROMAGNETIC RADIATION
ELEMENTS
HEAT TREATMENTS
IONIZING RADIATIONS
MAGNETIC RESONANCE
OXIDES
OXYGEN COMPOUNDS
POINT DEFECTS
RADIATION EFFECTS
RADIATIONS
RESONANCE
SEMIMETALS
SILICON COMPOUNDS
SPECTRA
360606* - Other Materials- Physical Properties- (1992-)