Arsenic desorption kinetics from Si(100)

Ott, Adina K.; Casey, Sean M.; Leone, Stephen R.

doi:10.1016/s0039-6028(98)00063-6

Cited by 17 publications

(20 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…44 However, past studies indicate that this approximation is not always valid for first-order desorption processes. [45][46][47] These data suggest that an experimental determination of the pre-exponential factors is required for the accurate analysis of the kinetics governing the desorption of molecules from surfaces. We present below two methods used to determine both and ⌬E des ‡ from the TPD spectra.…”

Section: B Measurement Of ⌬E Des ‡ and For N-alkanes From Graphitementioning

confidence: 99%

Effects of conformational isomerism on the desorption kinetics of n-alkanes from graphite

Paserba

Gellman

2001

The Journal of Chemical Physics

136

176

View full text Add to dashboard Cite

The dynamics of oligomer desorption from surfaces have been studied by measuring the desorption kinetics of a set of n-alkanes from the surface of single crystalline graphite. Desorption rates were measured using a set of 21 monodispersed n-alkanes (C N H 2Nϩ2 ,5рNр60) each adsorbed at coverages in the range Ͻ0.1 to Ͼ1 monolayers. Desorption is observed to be a first-order process with a desorption barrier (⌬E des ‡ ) that is independent of coverage. The pre-exponential of the desorption rate constant is independent of the oligomer chain length and has a value of ϭ10 19.6Ϯ0.5 s Ϫ1 . We also find that ⌬E des ‡ has a nonlinear dependence on chain length and takes the empirical form ⌬E des ‡ ϭaϩbN ␥ , with the exponent having a value of ␥ϭ0.50Ϯ0.01. More interestingly, we have proposed a mechanism for the desorption process and a model for the energetics and the entropy of the oligomers on the surface that provide an extremely good quantitative fit to the observed chain length dependence of ⌬E des ‡ . ⌬E des ‡ is given by the difference in energy between the gas phase n-alkane and the conformation of the adsorbed n-alkane with the minimum free energy at the desorption temperature. These results reveal that conformational isomerism plays a significant role in determining the desorption kinetics of oligomers from surfaces.

show abstract

Section: B Measurement Of ⌬E Des ‡ and For N-alkanes From Graphitementioning

confidence: 99%

Effects of conformational isomerism on the desorption kinetics of n-alkanes from graphite

Paserba

Gellman

2001

The Journal of Chemical Physics

136

176

View full text Add to dashboard Cite

show abstract

“…To our knowledge this is the first report of the desorbing gasphase species during the surfactant enhanced growth process. The differences between As 2 desorption from Si(100) observed previously 30 and that from Ge(100) are discussed.…”

Section: Introductionmentioning

confidence: 73%

“…These experiments confirm the results of previous experiments in our group on the As/Si(100) system. 30 Figure 5 shows the results of such an experiment with an incident arsenic flux of ∼2 ML/s of As atoms. Again, at very low surface temperatures, the only signal observed is As 4 and as the surface temperature is raised, As 2 begins to desorb from the surface as in the case of Ge(100).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Desorption of Arsenic Species during the Surfactant Enhanced Growth of Ge on Si(100)

Berrie

Leone

2002

J. Phys. Chem. B

View full text Add to dashboard Cite

The desorption and scattering of As 4 and As 2 species from the surface during the growth of germanium films on Si(100) with continuous As 4 deposition is monitored using laser ionization time-of-flight mass spectrometry. A significant increase in the flux of As 2 from the surface is observed when the Ge flux is admitted to the surface. Upon discontinuation of the germanium growth process, the As 4 and As 2 signal levels remain at this increased level. A comprehensive study of the desorption fluxes of As 4 , As 2 , and As species from both Ge (100) and Si(100) substrates was performed as a function of substrate temperature and incident As 4 flux to determine the kinetics of desorption of the different species from the substrates. The behavior of the As 2 desorbed fluxes as a function of surface temperature is qualitatively different on the Ge(100) and Si(100) substrates.The results indicate that the catalytic cracking of As 4 to As 2 is more effective on Ge(100) compared to Si(100) at substrate temperatures between 800 and 1000 K, most likely because of more rapid desorption of As 2 at a given temperature on Ge(100). A phenomenological activation energy for the desorption of As atoms from Ge(100) of 1.2 ( 0.4 eV is also obtained. The implications for the surfactant enhanced growth of Ge on Si(100) are discussed.

show abstract

“…Moreover, the desorption of the segregated atoms is enhanced by applying a high-temperature baking step prior to each new growth cycle. The desorption baking step has been characterized in several studies of situations where it is important to have precise control of the As covering the Si (100) surface [ 11 , 12 , 13 ]. Some of the results are shown in Figure 1 (a) where it can be seen that there is a strong temperature dependence of the desorption, while the effect saturates in time so that 20 min or 60 min at 850 °C give practically the same result.…”

Section: Fabricationmentioning

confidence: 99%

Arsenic-Doped High-Resistivity-Silicon Epitaxial Layers for Integrating Low-Capacitance Diodes

et al. 2011

View full text Add to dashboard Cite

An arsenic doping technique for depositing up to 40-μm-thick high-resistivity layers is presented for fabricating diodes with low RC constants that can be integrated in closely-packed configurations. The doping of the as-grown epi-layers is controlled down to 5 × 1011 cm−3, a value that is solely limited by the cleanness of the epitaxial reactor chamber. To ensure such a low doping concentration, first an As-doped Si seed layer is grown with a concentration of 1016 to 1017 cm−3, after which the dopant gas arsine is turned off and a thick lightly-doped epi-layer is deposited. The final doping in the thick epi-layer relies on the segregation and incorporation of As from the seed layer, and it also depends on the final thickness of the layer, and the exact growth cycles. The obtained epi-layers exhibit a low density of stacking faults, an over-the-wafer doping uniformity of 3.6%, and a lifetime of generated carriers of more than 2.5 ms. Furthermore, the implementation of a segmented photodiode electron detector is demonstrated, featuring a 30 pF capacitance and a 90 Ω series resistance for a 7.6 mm2 anode area.

show abstract

Arsenic desorption kinetics from Si(100)

Cited by 17 publications

References 20 publications

Effects of conformational isomerism on the desorption kinetics of n-alkanes from graphite

Effects of conformational isomerism on the desorption kinetics of n-alkanes from graphite

Desorption of Arsenic Species during the Surfactant Enhanced Growth of Ge on Si(100)

Arsenic-Doped High-Resistivity-Silicon Epitaxial Layers for Integrating Low-Capacitance Diodes

Contact Info

Product

Resources

About