Gas-phase selective etching of native oxide

Gas-phase selective etching of native oxide film formed on a silicon surface is an essential requirement for ULSI process technologies. Ultraclear anhydrous hydrogen fluoride (AHF) gas and a corrosion-free system were developed for this etching process. The reaction mechanism of silicon oxide film with moistureless HF was investigated, and selective etching conditions were developed. The gas-phase selective etching of native oxide in an environment of strictly controlled AHF concentration in N/sub 2/ is described.<
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