| Autor: |
Fuoco, Erick R., Hanley, Luke |
| Předmět: |
|
| Zdroj: |
Journal of Applied Physics; 7/1/2002, Vol. 92 Issue 1, p37, 8p, 1 Chart, 8 Graphs |
| Abstrakt: |
The preferential etching of SiO[sub 2] over Si in fluorocarbon plasmas occurs in part through the growth of a fluorocarbon layer. Large C[sub χ]F[sup +,0,sub y] (χ> 1) ions and radicals have been observed in etching fluorocarbon plasmas, but their role in the etching processes has not been clearly identified. Here we use mass-selected 5-200 eV C[sub 3]F[sup +,sub 5] and C[sub 2]F[sup +,sub 4] ion beams to form nanometer thick fluorocarbon and Si[sub χ]C[sub y]F[sub z] films on H-Si(100). Monochromatic x-ray photoelectron spectroscopy (XPS) shows that the average elemental and chemical content of the deposited film is nearly independent of ion identity and kinetic energy. The chemical nature of the fluorocarbon film instead is controlled largely by surface chemical and diffusion processes. However, ion energy and structure do control the fluorocarbon film morphology. Atomic force microscopy shows that 200 eV C[sub 3]F[sup +,sub 5] ion impact forms large oblong pits in the Si substrate that are ∼30 nm deep and ∼200 nm across. No large pits are observed in the Si substrate for 25 eV C[sub 3]F[sup +,sub 5] bombardment. XPS depth profiles of the films depend strongly upon ion energy and structure where the spatial distribution of the F depth profile increases with incident ion energy for both C[sub 3]F[sup +,sub 5] and C[sub 2]F[sup +,sub 4]. Higher F content is found deeper in the surface and the Si[sub χ]C[sub y]F[sub z] buried interface is thickest at higher ion energies. These results are discussed in terms of the role of large ions and radicals in etching fluorocarbon plasmas. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
