PHYSICAL AND ELECTRICAL CHARACTERIZATION OF THIN ANODIC OXIDES ON SI(100)

Gate oxides 4 to 50 nm thick have been grown on Si(100) by anodic oxid ation at room temperature. Different concentrations of aqueous NH4OH w ere used, as the electrolyte. Growth of oxides on n-type substrates re quired light illumination; however, the uniformity of the oxide thickn ess was not critically dependent on the uniformity of the illumination as long as light saturation conditions were maintained. The oxides on n-type Si were slightly thicker than those on p-type Si under the sam e growth conditions; nevertheless the physical properties of the oxide s grown on the two types of substrates were similar. The growth mechan ism was determined by secondary ion mass spectrometry with O-18 labeli ng, and depends on the solution pH. The as-grown and annealed oxides w ere characterized by Fourier transform infrared and by HF etch rate ex periments. After appropriate annealing, simple metal-oxide-semiconduct or capacitors exhibited promising electrical properties.