In:
Journal of Applied Physics, AIP Publishing, Vol. 98, No. 2 ( 2005-07-15)
Abstract:
This study investigates the stability of surface hydride layers passivating silicon-germanium alloys against contamination in ambient conditions after treatment in dilute hydrofluoric acid (HF), which is of central importance to the fabrication of SiGe-based semiconductor devices. We report quantitative hydrogen coverages on HF-etched Si(1−x)Gex surfaces (x=0,0.30,0.60,0.82), determined after air-to-vacuum transfer by H-specific H1(N15,αγ)C12 nuclear reaction analysis. Combination of this coverage information with analysis of the zero-point vibrational properties and N15-ion-induced desorption kinetics of the surface H atoms enables the distinction of well-passivated SiGe surfaces terminated exclusively by hydrides of Si and Ge from those partially covered by contaminating adsorbates. It is found that the resistance of HF-etched Si(1−x)Gex alloys against recontamination is drastically reduced at increasing Ge contents. Pure Si(100)–H is stably passivated at least up to 1week in air by a layer of 1.3±0.1 monolayer total H coverage. Si0.70Ge0.30 initially resembles H-passivated Si(100) but shows indications of moderate contamination after 1week in air. The HF treatment does not produce stable passivation layers on Ge-rich alloys (x⩾0.60), which suffer heavy recontamination within minutes after removal from the HF solution.
Type of Medium:
Online Resource
ISSN:
0021-8979
,
1089-7550
Language:
English
Publisher:
AIP Publishing
Publication Date:
2005
detail.hit.zdb_id:
220641-9
detail.hit.zdb_id:
3112-4
detail.hit.zdb_id:
1476463-5
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