The Hall coefficient and electrical resistivity have been measured on single-crystal specimens of «-type Sn02 between 80 and 900°K. Data were obtained on samples in the "as grown" state, as well as on crystals which were thermally equilibrated in oxygen. A single-donor-level analysis on heat-treated crystals with donor concentrations (ND) between 1X10 16 and 5X10 17 cm" 3 resulted in values of the "density-of-states" effective mass m (JNr) =0.22m. Values of the donor ionization energy ED were found to decrease with increasing ND. At infinite dilution ED has an estimated value of 0.15 eV. Room-temperature thermoelectric-power measurements resulted in calculated values of m {N) between 0.12 and 0.18m. Antimony-doped crystals of Sn02 with ND>6X10 18 cm -8 appeared to be degenerate above 80°K. The low-temperature Hall mobility was found to decrease with decreasing donor concentration. A qualitative treatment of the data appears consistent with the hypothesis of impurity-level transport. Mobility above 300°K was analyzed by considering polar-optical modes of vibration as being the dominant lattice scattering mechanism. Both the perturbation and intermediate-coupling theories were in reasonable agreement with experimental values using a Debye temperature ®r^500°K.

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Injection of hot carriers from the channel region into the gate insulator of an IGFET imposes design constraints on the device dimensions and operating voltages. A fraction of the injected charge is trapped in the gate dielectric, and an undesirable shift in the operating characteristics results. The magnitude of the shift is related to the device dimensions, operating voltages, and gate dielectric.

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Under certain bias conditions, electrons flowing through the channel of an n-channel IGFET can be injected into the gate insulator. A fraction of the injected electrons is trapped in the dielectric, producing a shift in device operating characteristics. This phenomenon is minimized by proper device design. A model is described to predict long-term shifts from accelerated stress test data.