Physical and electrical characterization of thin anodic oxides on Si(100)

Abstract

Gate oxides 4 to 50 nm thick have been grown on Si(100) by anodic oxidation at room temperature. Different concentrationsof aqueous NH4OH were used as the electrolyte. Growth of oxides on n-type substrates required light illumination;however, the uniformity of the oxide thickness was not critically dependent on the uniformity of the illumination as longas light saturation conditions were maintained. The oxides on n-type Si were slightly thicker than those on p-type Si underthe same growth conditions; nevertheless the physical properties of the oxides grown on the two types of substrates weresimilar. The growth mechanism was determined by secondary ion mass spectrometry with 18O labeling, and depends on thesolution pH. The as-grown and annealed oxides were characterized by Fourier transform infrared and by HF etch rateexperiments. After appropriate annealing, simple metal-oxide-semiconductor capacitors exhibited promising electricalproperties.Peer reviewed: YesNRC publication: Ye