Comparative Study of Hydrogen Diffusion in Hot-Wire and Glow-Discharge-Deposited a-Si:H

1999 ◽  
Vol 557 ◽  
Author(s):  
J. Shinar ◽  
R. Shinar ◽  
K. E. Junge ◽  
E. Iwaniczko ◽  
A. H. Mahan ◽  
...  
Keyword(s):  
Glow Discharge ◽  
Hydrogen Diffusion ◽  
Secondary Ion Mass Spectrometry ◽  
Error Function ◽  
Interface Layer ◽  
Hot Wire ◽  
Release Times ◽  
Multiple Trapping ◽  
Complementary Error Function ◽  
Secondary Ion

AbstractLong-range atomic H motion in hot-wire deposited (HW) a-Si:H is compared directly to that in glow-discharge deposited (GD) a-Si:H by monitoring the deuterium secondary ion mass spectrometry (DSLMS) profiles in [GD a-Si:H]/[GD a-Si:(H,D)]/[HW a-Si:H] multilayers vs annealing temperature and time. While the profiles in the GD layer are in excellent agreement with complementary error-function behavior and previous studies, the profiles in the HW layer suggest that the multiple-trapping motion of the H and D atoms is much slower, possibly due to an interface layer of defects. However, an exponential “tail” of D atoms extends deep into the HW layer, probably due to a long diffusion length of mobile D atoms, consistent with the established release times of H and D from the GD layer and H loss typical during growth of HW films. The results are also discussed in terms of the H exchange model and compared to previous NMIR studies of HW a-Si:H, which suggest that most of the hydrogen in the HW layer is concentrated in H-rich clusters dispersed in a network of very low H content.

IR and Sims Study of Hydrogen Diffusion in RF Sputter Deposited Boron Doped a-Si:H and Undoped a-Ge:H

1989 ◽  
Vol 149 ◽  
Author(s):  
S. Mitra ◽  
X.-L. Wu ◽  
R. Shinar ◽  
J. Shinar
Keyword(s):  
Hydrogen Diffusion ◽  
Secondary Ion Mass Spectrometry ◽  
Stretch Vibration Band ◽  
Vibration Band ◽  
Boron Doped ◽  
Multiple Trapping ◽  
Stretch Vibration ◽  
Order Of Magnitude ◽  
Sputter Deposited ◽  
Secondary Ion

ABSTRACTSecondary ion mass spectrometry (SIMS) and IR measurements of long range deuterium motion in rf sputter deposited (rf sp) p-doped a-Si:H and undoped a-Ge:H are compared to recently published results on undoped rf sp a-Si:H, which exhibited strongly power-law time dependent diffusion constants (exponent α= 0.75±0.1) in films of as-deposited content of di-H and tri-H bonds (usually associated with microvoids) Ndo –4–5 at.%. In pdoped a-Si:H samples where Ndo-l.8–3.8at.%, the diffusion is much faster, but the exponent is similar. In undoped a-Ge:H exhibiting a stretch vibration band indicative of mono-H bonding only, the diffusion is about one order of magnitude faster than in undoped a-Si:H, and α = 0.23. The results are discussed in relation to both the multiple trapping (dispersive) and defect mediated diffusion models.

Hydrogen Dynamics and Tee Distribution of H Sites in Undoped a-Si:H and a-Ge:H

1991 ◽  
Vol 219 ◽  
Author(s):  
R. Shinar ◽  
X.-L. Wu ◽  
S. Mitra ◽  
J. Shinar
Keyword(s):  
Mass Spectrometry ◽  
Activation Energy ◽  
Long Range ◽  
Secondary Ion Mass Spectrometry ◽  
Ir Studies ◽  
Multiple Trapping ◽  
Ion Mass Spectrometry ◽  
Secondary Ion ◽  
Trapping Sites

ABSTRACTSecondary ion mass spectrometry and IR studies of long-range hydrogen motion in undoped a-Si:H and a-Ge:H of varying H content and microstructure are reviewed and discussed. In particular, their relation to the multiple trapping (MT) model, the role of microvoids, the significance of the Meyer-Neldel relation (MNR), and the nature of H sites is addressed. It is suggested that while the MT mechanism may be significant in a-Si:H of low H content Cfj, it is largely marginal in films where CH ≥ 10 at.% H and in a-Ge:H. Mono Si-H bonds on microvoid surfaces are apparently deep H trapping sites up to ∼ 400°C, but H is desorbed from such sites in a-Ge:H above 180°C. The MNR between the diffusional activation energy and prefactor is observed among the various a-Si:H and a-Ge:H, but its significance is questionable, and may be due to the MT mechanism only in low H content a-Si:H. The nature of the distribution of H sites is also discussed.

A study of hydrogen diffusion in crystalline silicon by secondary-ion mass spectrometry

1989 ◽  
Vol 67 (4) ◽  
pp. 379-383 ◽  
Author(s):  
B. Y. Tong ◽  
X. W. Wu ◽  
G. R. Yang ◽  
S. K. Wong
Keyword(s):  
Mass Spectrometry ◽  
Diffusion Coefficient ◽  
Mass Spectroscopy ◽  
Hydrogen Diffusion ◽  
Secondary Ion Mass Spectrometry ◽  
Crystalline Silicon ◽  
Nuclear Resonance ◽  
Secondary Ion Mass Spectroscopy ◽  
Flux Model ◽  
Secondary Ion

The diffusion coefficient of hydrogen in crystalline silicon, obtained from recent profiling experiments such as nuclear resonance retention and secondary-ion mass spectroscopy, is 3–9 orders of magnitude smaller than the previously accepted value measured by Van Wieringen and Warmoltz in 1956. Here we point out several items often overlooked in the analysis of profiling measurements. A limited flux model is proposed to explain the observed results. Predictions by the model are supported by further experiments.

Depth Profiles of Thermal Donors in Czochralski-Grown N-Type Silicon

1992 ◽  
Vol 262 ◽  
Author(s):  
Yutaka Tokuda ◽  
Toshihisa Shimokata ◽  
Masayuki Katayama ◽  
Tadashi Hattori
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Error Function ◽  
Schottky Diodes ◽  
Interstitial Oxygen ◽  
Depth Profiles ◽  
Oxygen Diffusivity ◽  
Type Silicon ◽  
Initial Oxygen ◽  
Secondary Ion ◽  
Absorption Measurements

ABSTRACTDepth profiles of thermal donors introduced by heat treatment at 450°C in Czochralski-grown n-type silicon have been studied through capacitance-voltage measurements of Au Schottky diodes in the oxygen concentration range 8.1×1017 to 15.3×1017 cm3 Thermal donor concentrations increase with depth and their depth profiles are fitted to the error function equation. The obtained diffusivity decreases with annealing time and is higher for samples with the lower initial oxygen concentrations. Combining with the infrared absorption measurements, it is found that the curves of the diffusivity as a function of loss of interstitial oxygen coincide with each other. The similar tendency is observed on the oxygen diffusivity evaluated with secondary ion mass spectrometry. These results indicate that the oxygen diffusivity at 450°C is related to both the outdiffusion and clustering of oxygen. Depth profiles of thermal donors formed at 650°C are also reported.

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