Gases with sufficient Lewis acidity or basicity form weak and reversible complexes with carefully selected ionic liquids. We have prepared ionic liquid complexes with PH3 and BF3 that provide large gas capacities in the liquid phase at low pressures.

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The energy landscape of a full atomic layer deposition cycle to grow a layer of SiO 2 on the hydroxylated SiO 2 (001) surface was systematically explored using density functional theory. A monoaminosilane-based compound, di(sec-butylamino)silane (DSBAS), was utilized as the silicon precursor with ozone acting as an oxidizing agent. The ALD cycle includes dissociative chemisorption of DSBAS, oxidation, and condensation for surface regeneration.Our results indicate that the dissociative chemisorption of DSBAS is kinetically facile. Upon oxidation by ozone, the layer grows with a SiO 2 crystalline morphology. The entire ALD cycle was found to be thermodynamically and kinetically favorable. This is important for growing dense and conformal SiO 2 thin films free of impurities and thus well-suited for low-temperature deposition of SiO 2 thin films.

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Conformal and continuous silicon oxide films produced by atomic layer deposition (ALD) are enabling novel processing schemes and integrated device structures. The increasing drive toward lower temperature processing requires new precursors with even higher reactivity. The aminosilane family of precursors has advantages due to their reactive nature and relative ease of use. In this paper, the authors present the experimental results that reveal the uniqueness of the monoaminosilane structure [(R2N)SiH3] in providing ultralow temperature silicon oxide depositions. Disubstituted aminosilanes with primary amines such as in bis(t-butylamino)silane and with secondary amines such as in bis(diethylamino)silane were compared with a representative monoaminosilane: di-sec-butylaminosilane (DSBAS). DSBAS showed the highest growth per cycle in both thermal and plasma enhanced ALD. These findings show the importance of the arrangement of the precursor's organic groups in an ALD silicon oxide process.