CVD of fluorosilicate glass for ULSI applications

Moisture stability and structure relaxation processes in plasma-deposited SiOF films

“…The above conclusions are in good agreement with the numerous studies of SiOF films moisture stability versus F content. As it was reported elsewhere 1,8,14,26 the amount of silanols in SiOF films initially reduces with increasing the F content, but then starts to increase again demonstrating the existence of minimum at certain F content. which results in their structural relaxation towards the equilibrium ͗͘ during post-deposition period, as seen in Fig.…”

“…% Drastic increase of the silanol concentration when F content in the films reaches a critical concentration was reported in many studies. 1,3,26,29 Low-fluorinated SiOF films are characterized by relatively dense H-and OH-free network ͑see Fig. 1͒ built from low-order ring structural units.…”

The nature of fluorine in amorphous silica

“…Since fluorine is one of only two additives (the other being boron) that lowers the refractive index of silica, it is commonly used in controlling index profiles in optical fiber [1,2]. Fluorine also lowers the dielectric constant of silica, making Fdoped silica the preferred dielectric in microprocessors and logic devices [3]. This versatile material is also being considered as a photomask substrate for deep ultraviolet (157 nm) photolithography applications [4,5] and has been investigated for use in catalysis [6].…”

Structural role of fluorine in amorphous silica

“…This has resulted in widespread application of fluorine doping of silica to control the refractive index profile of optical fibers [2][3][4][5]. Fluorine also lowers the static dielectric constant of silica, from e s = 4.2 to values as low as 3.2 [6][7][8]. Therefore, F-doped silica is an extremely important material with low dielectric constant, used in microprocessors and logic devices [9].…”