Model studies of dielectric thin film growth: Chemical vapor deposition of SiO2

Abstract

The reactive adsorption and decomposition of tetraethoxysilane is compared on Si(100) and SiO2 surfaces. The adsorption and decomposition behavior is compared to that observed for ethanol adsorption on both these surfaces. Tetraethoxysilane and ethanol both decompose to produce ethylene and hydrogen on Si(100). Ethylene desorption is also observed from decomposition of these molecules on SiO2. Ethanol adsorption on SiO2 is shown to model the chemistry of tetraethoxysilane on this surface. However, ethanol is significantly more reactive than tetraethoxysilane on the clean Si(100) surface. The decomposition is shown to be reaction limited, and distinct from that of adsorbed ethylene. The adsorbed species produced from adsorption of tetraethoxysilane on SiO2 at 450 K is shown to be a mixture of di- and triethoxysiloxanes.

Controlling Photoactivity in Ultrathin Hematite Films for Solar Water‐Splitting

“…[20,23] SiO 2 deposition from TEOS was found to be a self-limiting reaction in the absence of water or basic atmosphere. [20,28] Indeed, we also observed that the effect of the pretreatment did not vary with the amount of TEOS sprayed, even if large amounts of the TEOS/ ethanol mixture were used. This implies a film of SiO 2 is not grown under our conditions, but rather just a modification of the surface occurs.…”

The feasibility of inert colloidal processing of silicon nanoparticles

“…When comparing TEM results from cases 1, 2, and 3 as detailed in Table 1, amorphous silica is present in all three, indicating that the ethanol and silicon nanoparticle solution contains a reactant (although no TEOS was added to the reaction), either free in solution or bound to the surface of the nanoparticle that is able to form amorphous silica in a Stöber reaction. Indeed, Crowell contends that the chemistry of TEOS can be modeled by ethanol adsorption on SiO 2 surfaces [24]. From case 2, TEM illustrates the formation of ∼30 nm silica particles which are slightly agglomerated with small necks.…”

Chemical Vapor Deposition of Several Silicon-Based Dielectric Films

“…Because of the simplicity of the process and the superior film quality obtained, TEOS decomposition is the most frequently employed technique by the semiconductor industry for SiOz deposition (9)(10)(11)(12)(13)(14)(15). Moreover, this compound (TEOS) has less toxicity and is less hazardous to work with than conventional source gases, such as silane and chlorosilane (9).…”