Ultra-violet band-systems of GeCl and GeBr

Jevons, W.; Bashford, L A; Briscoe, H. V. A.

doi:10.1088/0959-5309/49/5/309

“…= -b(' A II)BuUp(14) Since the potential energy curves of the d 'A and D 'A states are very similar, the vibrational overlap integral (v3A 1 vlA ) can be approximated to unity. Making use of the single configuration where (v;v,) is the vibrational overlap integral and B,,, is given by approximation the CA parameter can be estimated from(15) r a(n) + a(n') 1 \ ,Both integrals can be calculated from the RKR potentials.…”

mentioning

confidence: 99%

The Low Lying Electronic States of GeO

Lagerqvist

¹

,

Renhorn

²

1982

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The A 1Π-X 1Σ+ band system in 74Ge16O and 74Ge18O is analyzed and the local perturbations of the A 1Π state are assigned. Four new electronic states are reported, namely the d 3Δ, e 3Σ-, C 1Σ- and D 1Δ states. Vibrational numbering is determined from the isotopic shifts. The vibrational variations of the perturbation matrix elements are shown to be in agreement with single configuration arguments. The electronic spin-orbit parameter a + and the Coriolis parameter b are determined. The molecular constants for the eight lowest electronic states are reported. Semi-empirical and isovalent relationships between spin-orbit and spin-spin constants are also discussed. The equilibrium constants for the A 1Π state and the four perturbing states are in cm-1: State Te ω e Be A 1Π 37 763.1 648.8 0.414 32 D 1Δ 32 715 591 0.362 2 C 1Σ- 32 475 591 0.362 2 e 3Σ- 32 214 600 0.362 2 d 3Δ1 30 492 597 0.362 2

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“…The 308 nm laser induces resonant excitation in both GeCl B 2 ⌺←X 2 ⌸ r subsystems, [13][14][15][16] specifically, vЈϭ1, 2←vЉϭ3, 4 in the first subsystem (rϭ3/2) and vЈϭ0, 1←vЉϭ4, 5 in the second subsystem (rϭ1/2). This same laser both heated the sample, to induce thermal desorption of surfaceadsorbed species, and excited laser-induced fluorescence in those desorbed species that absorb at 308 nm.…”

Section: Experimental Methodsmentioning

confidence: 99%

Laser-induced thermal desorption analysis of the surface during Ge etching in a Cl2 inductively coupled plasma

Choe¹,

Herman²,

Donnelly³

1998

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

10

0

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Articles you may be interested inTransition between two states of surface coverage and etch rate during Si etching in inductively coupled Cl 2 -Ar plasmas with changing mixtures Laser desorption laser-induced fluorescence ͑LD-LIF͒ detection of GeCl was used to determine in situ the surface coverage of chlorine during the etching of germanium by Cl 2 in an inductively coupled plasma ͑ICP͒ reactor. The ICP operated in the dim mode for radio frequency ͑rf͒ power Շ350 W and in the bright mode for higher powers. The etch rate was 3.5 m/min with 540 W rf power and Ϫ40 V substrate bias. The chlorine surface coverage was about 2ϫ that with chlorine flow only and the plasma off, both with dim-and bright-mode operation, and was independent of rf power within each mode for laser repetition rates of 0.2, 5, and 15 Hz. Similarly, the chlorination of the adlayer did not change when the ion energy was increased from 16 to 116 eV by increasing the substrate bias voltage, both with dim-and bright-mode operation. This was confirmed by x-ray photoelectron spectroscopy measurements in a similar high density reactor, where it was found that the surface density of chlorine was ϳ2.6ϫ10 15 Cl/cm 2 . As the ion energy increases from 16 to 116 eV, the etch yield of ions increases from 1 to 3 atoms/ion. ''Wait and probe'' measurements show that the GeCl x adlayer is quite stable. Since the same adlayer chlorine content was measured by LD-LIF under high ion current/fast etch conditions ͑bright mode͒ and low ion current/slow etch conditions ͑dim mode͒, both the adlayer chlorine content and the etch rate seem to be controlled by the ion current to the wafer. Previously reported work in Si etching in this ICP ͓J. Vac. Sci. Technol. A 15, 3024 ͑1997͔͒ showed a similar independence of adlayer chlorination with rf power, but much slower chlorination and an increasing chlorination of the adlayer with increasing ion energy.

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“…The electronic spectrum of GeCl has been observed by several authors in the ultraviolet [6][7][8][9][10][11][12] and visible regions [13][14][15]. The resonance enhanced multiphoton ionization (REMPI) spectroscopy was also reported [16].…”

Section: Introductionmentioning

confidence: 99%