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Passivation kinetics at semiconductor interfaces Gheorghita, Ligia
Abstract
The interaction of atomic hydrogen with defects at a GaAs (100) surface was studied by continuously monitoring the photoluminescence of a GaAs wafer in a discharge-flow system at room temperature. It was found that there was an initial irreversible passivation of the surface in the presence of the hydrogen atoms, and this was followed by an improved (but reversible) passivation that occurred when the exposure to atomic hydrogen was discontinued. This reversible recovery of the passivation level was found to follow a non-exponential rate law. A kinetic study of the interaction of atomic hydrogen with the defects at a Si/Si0₂ interface was undertaken at temperatures between 23°C and 330°C. The concentration of defects at the interface was monitored continuously, in situ, with a remote radio frequency (RF) probe, which measured the steady-state photogenerated carrier concentration. The results were similar to those obtained with GaAs. The kinetics of the hydrogen atom loss from both semiconductors have been analyzed in terms of a distribution of trapping sites. A comparison of the GaAs and Si/Si02 systems leads us to conclude that hydrogen atoms can be trapped at interstitial sites near these interfaces. The reaction of molecular hydrogen with defects at the (111) Si/Si0₂ interface has been investigated in the 135°C to 300°C temperature range, using the RF-probe to continuously monitor the rate of removal of electrically active defects. The kinetic parameters calculated from these experiments are compared with earlier workers' electron paramagnetic resonance (EPR) studies of the so-called "P[sub b]" defect. Our results confirm the non-exponential nature of the reaction reported by one of these studies, and are consistent with the rate constants obtained earlier at high temperatures. This process has an activation energy of 1.5 eV. However, the new results indicate that there are other interfacial defects, which could not be detected by EPR, that react with H₂ in a process that has a much lower activation energy (0.5 eV). Similar experiments were conducted on intrinsic and p-type (100) Si/Si0₂ and the same non-exponential rate law was observed for the passivation of interfacial defects in the presence of H₂.
Item Metadata
Title |
Passivation kinetics at semiconductor interfaces
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1999
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Description |
The interaction of atomic hydrogen with defects at a GaAs (100) surface was studied by
continuously monitoring the photoluminescence of a GaAs wafer in a discharge-flow system at
room temperature. It was found that there was an initial irreversible passivation of the surface in
the presence of the hydrogen atoms, and this was followed by an improved (but reversible)
passivation that occurred when the exposure to atomic hydrogen was discontinued. This
reversible recovery of the passivation level was found to follow a non-exponential rate law.
A kinetic study of the interaction of atomic hydrogen with the defects at a Si/Si0₂
interface was undertaken at temperatures between 23°C and 330°C. The concentration of defects
at the interface was monitored continuously, in situ, with a remote radio frequency (RF) probe,
which measured the steady-state photogenerated carrier concentration. The results were similar
to those obtained with GaAs. The kinetics of the hydrogen atom loss from both semiconductors
have been analyzed in terms of a distribution of trapping sites. A comparison of the GaAs and
Si/Si02 systems leads us to conclude that hydrogen atoms can be trapped at interstitial sites near
these interfaces.
The reaction of molecular hydrogen with defects at the (111) Si/Si0₂ interface has been
investigated in the 135°C to 300°C temperature range, using the RF-probe to continuously
monitor the rate of removal of electrically active defects. The kinetic parameters calculated from
these experiments are compared with earlier workers' electron paramagnetic resonance (EPR)
studies of the so-called "P[sub b]" defect. Our results confirm the non-exponential nature of the
reaction reported by one of these studies, and are consistent with the rate constants obtained
earlier at high temperatures. This process has an activation energy of 1.5 eV. However, the new
results indicate that there are other interfacial defects, which could not be detected by EPR, that
react with H₂ in a process that has a much lower activation energy (0.5 eV). Similar experiments
were conducted on intrinsic and p-type (100) Si/Si0₂ and the same non-exponential rate law was
observed for the passivation of interfacial defects in the presence of H₂.
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Extent |
7067385 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-07-02
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0061535
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1999-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.