Surface Reactions of Atomic Hydrogen with Ge(100) in Comparison with Si(100)

Abstract

The reactions of thermal hydrogen atoms H(g) with the Ge(100) surface were examined with temperatureprogrammed desorption (TPD) mass spectrometry. Concomitant H 2 and CH 4 TPD spectra taken from the H(g)irradiated Ge(100) surface were distinctly different for low and high H(g) doses/substrate temperatures. Reactions suggested by our data are: (1) adsorbed mono(β 1)-/di-hydride(β 2)-H(a) formation; (2) H(a)-by-H(g) abstraction; (3) GeH 3 (a)-by-H(g) abstraction (Ge etching); and (4) hydrogenated amorphous germanium a-Ge:H formation. While all these reactions occur, albeit at higher temperatures, also on Si(100), H(g) absorption by Ge(100) was not detected. This is in contrast to Si(100) which absorbed H(g) readily once the surface roughened on the atomic scale. While this result is rather against expectation from its weaker and longer Ge-Ge bond as well as a larger lattice constant, we attribute the absence of direct H(g) absorption to insufficient atomic-scale surface roughening and to highly efficient subsurface hydrogenation at moderate (>300 K) and low (≤300 K) temperatures, respectively.

Enhanced Performance of Ge Photodiodes via Monolithic Antireflection Texturing and α-Ge Self-Passivation by Inverse Metal-Assisted Chemical Etching

“…KMnO 4 generates MnO4 – ions in the aqueous solution, which reacts with H + to produce holes in the presence of the Au catalyst by eq : Holes are injected into the Ge surface, resulting in the formation of amorphous Ge or Ge oxide. Dissolution process of Ge may consist of the combination of direct dissolution of Ge via removal of amorphous Ge and formation of Ge oxide followed by dissolution of oxide, which can be described by eqs , and , respectively. The formation of amorphous film, composed mostly of Ge, is revealed by STEM as will be shown below.…”

Copper(I)‐Catalyzed Four‐Component Coupling Using Renewable Building Blocks of CO2 and Biomass‐Based Aldehydes

“…The peaks with the kinetic energy located at 918.5 and 916.0 eV were assigned to metallic copper and Cu + species, respectively, [75] thus suggesting the presence of both Cu 0 and Cu + species in the catalytic cycle as described in the Scheme 4. [76] The Cu + species can be assigned to copper-acetylide intermediate 8 (Scheme 4), while the Cu 0 species can presumably attributed to the Cu 0 complex or Cu 0 nanoparticles. [77,78] Notably, Cu 0 -nanoparticles were reported for propargylamine synthesis through three-component coupling of aldehyde, amine, and alkyne.…”

Mass spectrometry and in situ x-ray photoelectron spectroscopy investigations of organometallic species induced by the etching of germanium, antimony and selenium in a methane-based plasma

“…There are valid reasons why methane-based plasmas are not commonly used for Ge (or Si) etching. Firstly, the adsorption of hydrogen on germanium is influenced by the gas temperature, with hydrogen desorption from GeH 4 observed at lower temperatures (<300 K) [51]. Additionally, thermal dissociation of germanium hydride products can occur at higher gas temperatures (T gas > 300 K) [50].…”