Atomic Layer Deposition and Properties of Silicon Oxide Thin Films Using Alternating Exposures to SiH₂Cl₂ and O₃

Abstract

We report the process for the atomic layer deposition (ALD) of silicon dioxide thin films on a silicon wafer by alternating exposures to SiH2Cl2 and O3. The growth kinetics of silicon oxide films was examined by varying reactant exposures at various deposition temperatures ranging from 250 to 450 °C. The deposition was governed by a self-limiting surface reaction, and the growth rate at 350 °C was saturated at 0.25 nm/cycle for SiH2Cl2 exposures of over 5×109 L (10-6 Torr·s). The chlorine content and the wet-etching rate in a diluted HF solution were reduced by increasing the deposition temperature. The films deposited at temperatures ranging from 350 to 450 °C exhibited excellent physical and electrical properties that were equivalent to those of silicon oxide films deposited at 760 °C by low-pressure chemical vapor deposition.

Modeling Mechanism and Growth Reactions for New Nanofabrication Processes by Atomic Layer Deposition

“…A wide variety of Si precursors exist and have been used for these ALD processes, including alkylamides such as bis -(ethylmethylamino)silane (BDEAS) [ 9 ] or tris -dimethylaminosilane (TDMAS), [ 60 ] alkoxides like tetraethoxysilane (TEOS) [ 61 ] and halides SiH 2 Cl 2 [ 62,63 ] and SiCl 4.…”

In Situ Reaction Mechanism Studies on Atomic Layer Deposition of AlxSiyOz from Trimethylaluminium, Hexakis(ethylamino)disilane, and Water

“…Instead, more reactive oxygen sources such as ozone and oxygen plasma have been necessary for ALD of SiO 2 , but strong oxidation of the substrate or any other underlying material has been the main drawback of these approaches. Several processes have already been developed for SiO 2 deposition by plasma enhanced atomic layer deposition (PEALD) − and thermal ALD, using a wide range of precursors: chlorosilanes such as Si 2 Cl 6 , SiH 2 Cl 2 , − alkoxysilanes such as SiOH(O t Bu) 3 , Si(OEt) 3 C 3 NH 8 , , and aminosilanes such as Si(NEt 2 ) 4…”

Review—Atomic Layer Deposition of Silicon Dioxide Thin Films

“…Silicon chlorides: SiCl 4 , SiH 2 Cl 2 and Si 2 Cl 6 .-Silicon tetrachloride, [17][18][19][20][21][22] dichlorosilane, 23,24 and hexachlorodisilane 25 were studied for SiO 2 TA-ALD, but the first precursor was studied in detail.…”