Properties of SiO2 Grown in the Presence of HCl or Cl2

Effects associated with the incorporation of chlorine during the thermal growth of (500–1400Å) on <100> Si are investigated as a function of additive species ( , ), additive concentration, and oxidation temperature (900°–1150°C). Chlorine profiles are measured mainly by nuclear backscattering spectroscopy, and oxide thicknesses and refractive index changes by ellipsometry. The highest chlorine concentrations in unannealed oxides always occur at the interface. Under otherwise similar conditions, the use of results in higher, more evenly distributed chlorine levels (up to ). The incorporated chlorine is gradually removed by annealing at temperatures in excess of 1100°C, as well as under conditions where further oxide growth takes place without the presence of or . Additional oxide formation in steam effectively removes all the incorporated chlorine. MOS capacitors made from oxides grown in or show fixed charge levels lower than 10 11 cm −2 and mobile charge levels less than 10 10 cm −2 . When biased at high fields (>6 MV/cm) significant shifts in the flatband potential of Si were observed. Chlorine‐grown oxides exhibit positive and negative shifts attributed to a mobile species; the smaller negative shifts in oxides are attributed to interface states. Other electrical data of intentionally Na‐contaminated oxides suggest that only a constant fraction of the Na is trapped.