Effect of sample doping level during etching of silicon by fluorine atoms

Abstract

The rate of silicon etching by XeF2 is dependent on the type of dopant and the doping level.Soft-x-ray photoemission was used in an effort to elucidate the mechanism responsible for this phenomenon. Si(111)samples were subjected to sufficient XeF2 to reach the steady-state etching regime, and spectra were collected of the fluorosilyl reaction intermediate species that form on the surface. Samples that were lightly doped (10' cm ) showed virtually no difference between p and n doping, while heavily doped samples (10 cm ) showed a marked difference. The heavily doped n-type sample had a slightly thinner reaction layer than did the lightly doped samples, while the heavily doped p-type sample had a much thicker layer, in which the composition of the layer was also changed. These results are discussed in terms of possible reaction mechanisms.

Detection of chemisorbed methyl and methylene groups: surface chemistry of methyl iodide on platinum(111)

“…Finally, Figures [9][10][11] show reflection-absorption infrared (RAIRS) spectra for methyl iodide adsorbed on Pt(lll) as a function of both initial exposures and annealing temperatures. Frequency / cm'1 1100 800…”

Interaction of nanostructured metal overlayers with oxide surfaces

“…12. The etching rate has been found to be strongly influenced by Si-doping [125][126][127][128][129][130][131][132]. The following facts were well-established in those papers: (1) heavily doped n-Si (n + -Si) etches much faster than undoped Si and lightly n-or p-doped Si; (2) lightly doped p-type and n-type Si have similar etching rates; (3) heavily doped p-Si (p + -Si) exhibits the lowest etching rate.…”

Foundations of low-temperature plasma enhanced materials synthesis and etching

“…The etching of silicon also depends on its electronic properties, which is called the doping effect [143][144][145][146][147][148]. For this, a dopant concentration of about 10 20 cm −3 is required, and the observation is that highly doped n-type silicon etches more rapidly than un-doped or p-type silicon.…”