Search

Defects and traps in strained-Si n-type metal-oxide-semiconductor field effect transistors (MOSFETs) are studied in detail. The inelastic electron tunneling spectroscopy (IETS) technique is shown to be capable of probing traps in ultrathin gate dielectrics and obtain the energies and spatial locations of the traps. Detailed analyses of electrical stress-induced build-up of traps and electrically active bonding defects and identification of the trap-features including trap-assisted conduction and charge-trapping have been performed. The location and energies of the traps are estimated from the IETS spectra measured at both bias polarities. Identification of the acoustic and optical phonon modes (inelastic) as well as trap-features (elastic) helps in better understandings of the complex transport-mechanisms in gate dielectrics on strained layers. [ABSTRACT FROM AUTHOR]

Atomic layer deposited (ALD) (TiO2)x(Al2O3)1-x(TiAlO) alloy gate dielectrics on In0.47Ga0.53As/InP substrates are shown to produce high quality interfaces between TiAlO and InGaAs. The surface morphology and interfacial reaction of nanolaminate ALD TiAlO on In0.53Ga0.47As are studied using atomic force microscopy and x-ray photoelectron spectroscopy. Measured valence and conduction band offsets are found to be 2.85 ± 0.05 and 1.25 ± 0.05 eV, respectively. Capacitance-voltage characteristics show low frequency dispersion (∼11%), interface state density (∼4.2 × 1011 cm-2eV-1), and hysteresis voltage (∼90 mV). Ga-O and As-O bonding are found to get suppressed in the gate stacks after post deposition annealing. Our experimental results suggest that higher oxidation states of In and Ga at the In0.53Ga0.47As surface and As diffusion in the dielectric are effectively controlled by Ti incorporation in Al2O3. [ABSTRACT FROM AUTHOR]

Growth of ultrathin (<100 Å) nitrided SiO[sub 2] on strained Si using microwave O[sub 2]/N[sub 2]O/NH[sub 3] plasma is reported. X-ray photoelectron spectroscopy results indicate a nitrogen-rich layer at the strained Si/SiO[sub 2] interface. The electrical properties of the nitrided oxides have been characterized using a metal–insulator–semiconductor structure. N[sub 2]O plasma treatment of O[sub 2]/NH[sub 3] nitrided SiO[sub 2] results in a lower insulator charge density (1.2×10[sup 11] cm[sup -2]) and a higher breakdown voltage. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]