@article{suh_heuss_misra_2004, title={Characteristics of TaSixNy thin films as gate electrodes for dual gate Si-complementary metal-oxide-semiconductor devices}, volume={22}, ISSN={["2166-2746"]}, DOI={10.1116/1.1640398}, abstractNote={Reactively sputtered TaSixNy films have been investigated as gate electrodes for dual gate Si-complementary metal-oxide-semiconductor devices. The as-deposited TaSixNy films were amorphous over a wide range of compositions. After annealing at 1000 °C, Ta30Si33N37 film became crystalline, however Ta26Si28N52 film remained amorphous. The x-ray photoelectron spectroscopy shows a significant increase of Si–N bonding in the TaSixNy films with increasing N content. The presence of Si–N bonds is attributed to cause the amorphous nature of the high N containing TaSixNy films. The work functions of TaSixNy films were extracted by capacitance–voltage analysis. The work function values for TaSixNy films with varying N contents range from 4.26 to 4.35 eV after forming gas annealing at 400 °C for 30 min, suggesting that TaSixNy films have work functions appropriate for n-type metal-oxide-semiconductor devices. However, it was observed, after 1000 °C anneals, that the work function of TaSixNy films increased to ∼4.8 eV. We believe that the mechanism that causes the work function to increase is the formation of a Ta-disilicide layer at the interface of the electrode and the dielectric. Current–voltage characteristics of the TaSixNy gates showed lower gate leakage compared to the TaSix gates, due to the retarding formation of an interface layer in the TaSixNy/SiO2/p-Si structures.}, number={1}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Suh, YS and Heuss, G and Misra, V}, year={2004}, pages={175–179} }
 @article{suh_heuss_lee_misra_2003, title={Effect of the composition on the electrical properties of TaSixNy metal gate electrodes}, volume={24}, ISSN={["1558-0563"]}, DOI={10.1109/LED.2003.814009}, abstractNote={In this letter, the effect of silicon and nitrogen on the electrical properties of TaSi/sub x/N/sub y/ gate electrode were investigated. The TaSi/sub x/N/sub y/ films were deposited on SiO/sub 2/ using reactive cosputtering of Ta and Si target in Ar and N/sub 2/ ambient. The thermal stability of TaSi/sub x/N/sub y//SiO/sub 2//p-type Si stacks was evaluated by measuring the flatband voltage and equivalent oxide thickness at 400/spl deg/C and 900/spl deg/C in Ar. It was found that under high temperature anneals, Si-rich TaSi/sub x/N/sub y/ films increased and this was attributed to the formation of a reaction layer at the electrode-dielectric interface. Reducing the Si content alone did not prevent the formation of this reaction layer while removing Si completely by utilizing TaN resulted in work functions that were too high. The presence of both Si and N was deemed necessary and their content was critical in obtaining optimized TaSi/sub x/N/sub y/ gates that are suitable for NMOS devices.}, number={7}, journal={IEEE ELECTRON DEVICE LETTERS}, author={Suh, YS and Heuss, GP and Lee, JH and Misra, V}, year={2003}, month={Jul}, pages={439–441} }
 @article{suh_heuss_misra_park_limb_2003, title={Thermal stability of TaSixNy films deposited by reactive sputtering on SiO2}, volume={150}, ISSN={["1945-7111"]}, DOI={10.1149/1.1562599}, abstractNote={The thermal stability of /p-type Si metal-insulator-semiconductor structure has been evaluated by measuring equivalent oxide thickness (EOT) from capacitance-voltage curves and gate leakage current as a function of annealing temperatures. films were deposited using reactive sputtering from a target, varying the nitrogen/argon flow ratio. A reaction between and was observed after a 1000°C anneal, resulting in the increase of interfacial roughness and oxide thickness in the structures. Cross-sectional transmission electron microscopy shows no indication of an interfacial reaction or crystallization in on up to 1000°C as manifested by the negligible change in EOT and the stable leakage currents density A/cm2 at V). The presence of Si-N bonds is attributed to cause the amorphous nature of the high N-containing films. This may retard the formation of an interface layer and improve the chemical-thermal stability of the gate electrode/dielectric interface and oxygen diffusion barrier properties under high-temperature annealing. © 2003 The Electrochemical Society. All rights reserved.}, number={5}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Suh, YS and Heuss, GP and Misra, V and Park, DG and Limb, KY}, year={2003}, month={May}, pages={F79–F82} }
 @article{suh_heuss_misra_2002, title={Electrical characteristics of TaSixNy/SO2/Si structures by Fowler-Nordheim current analysis}, volume={80}, ISSN={["0003-6951"]}, DOI={10.1063/1.1453478}, abstractNote={In this letter, the Fowler–Nordheim tunneling in TaSixNy/SiO2/p-Si structures has been analyzed. The effective barrier height at the metal–oxide interface was extracted by Fowler–Nordheim current analysis. The barrier height was found to increase with increased annealing temperature. The barrier height was correlated with the extracted work function from capacitance–voltage analysis. This indicated that the work function of TaSixNy films changes under high temperature annealing from 4.2∼4.3 eV after 400 °C anneals to ∼4.8 eV after 900 °C anneals. We believe that the mechanism that causes the work function to increase is the formation of a Ta-disilicide layer at the interface between the electrode and the dielectric.}, number={8}, journal={APPLIED PHYSICS LETTERS}, author={Suh, YS and Heuss, GP and Misra, V}, year={2002}, month={Feb}, pages={1403–1405} }
 @article{zhong_heuss_misra_luan_lee_kwong_2001, title={Characterization of RuO2 electrodes on Zr silicate and ZrO2 dielectrics}, volume={78}, ISSN={["1077-3118"]}, DOI={10.1063/1.1347402}, abstractNote={The rutile stoichiometric phase of RuO2, deposited via reactive sputtering, was evaluated as a gate electrode on chemical vapor deposited ZrO2 and Zr silicate for Si–p-type metal–oxide–semiconductor (PMOS) devices. Thermal and chemical stability of the electrodes was studied at annealing temperatures of 400, 600, and 800 °C in N2. X-ray diffraction was measured to study grain structure and interface reactions. The resistivity of RuO2 films was 65.0 μΩ cm after 800 °C annealing. Electrical properties were evaluated on MOS capacitors, which indicated that the work function of RuO2 was ∼5.1 eV, compatible with PMOS devices. Post-RuO2 gate annealing up to 800 °C, resulted in only a 1.4 Å equivalent oxide thickness (Tox-eq) change and 0.2 V flatband voltage change for Zr silicate and a 4 Å Tox-eq change for ZrO2 dielectrics. Tantalum electrodes were also studied on ZrO2 as a comparison of the stability of RuO2 electrodes.}, number={8}, journal={APPLIED PHYSICS LETTERS}, author={Zhong, HC and Heuss, G and Misra, V and Luan, HF and Lee, CH and Kwong, DL}, year={2001}, month={Feb}, pages={1134–1136} }
 @article{zhong_heuss_suh_misra_hong_2001, title={Electrical properties of Ru and RuO2 gate electrodes for Si-PMOSFET with ZrO2 and Zr-silicate dielectrics}, volume={30}, ISSN={["1543-186X"]}, DOI={10.1007/s11664-001-0164-2}, number={12}, journal={JOURNAL OF ELECTRONIC MATERIALS}, author={Zhong, HC and Heuss, G and Suh, YS and Misra, V and Hong, SN}, year={2001}, month={Dec}, pages={1493–1498} }
 @article{misra_heuss_zhong_2001, title={Use of metal-oxide-semiconductor capacitors to detect interactions of Hf and Zr gate electrodes with SiO2 and ZrO2}, volume={78}, DOI={10.1063/1.1380240}, abstractNote={Metal–oxide–semiconductor capacitors were used to study the interaction of Hf and Zr gate electrodes on SiO2, ZrSixOy, and ZrO2. A large reduction in the SiO2 equivalent oxide thickness accompanied by an increase in the leakage current was observed with Hf and Zr electrodes when subjected to anneal temperatures as low as 400 °C. The reduction in electrical thickness as observed from the capacitance–voltage measurements was attributed to the combination of (a) physical thinning of the SiO2 and (b) formation of a high-K layer. A severe instability of Zr and Hf electrodes was also observed on ZrSixOy and ZrO2 dielectrics. This behavior of Zr and Hf gates was attributed to high negative enthalpy of oxide formation and high oxygen solubility resulting in the reduction of the gate dielectric and subsequent oxygen diffusion to the gate electrode.}, number={26}, journal={Applied Physics Letters}, author={Misra, Veena and Heuss, G. P. and Zhong, H.}, year={2001}, pages={4166–4168} }
 @article{zhong_heuss_misra_2000, title={Electrical properties of RuO2 gate electrodes for dual metal gate Si-CMOS}, volume={21}, ISSN={["0741-3106"]}, DOI={10.1109/55.887476}, abstractNote={The rutile stoichiometric phase of RuO/sub 2/, deposited via reactive sputtering, was evaluated as a gate electrode for Si-PMOS devices. Thermal and chemical stability of the electrodes was studied at annealing temperatures of 400/spl deg/C and 600/spl deg/C in N/sub 2/. X-ray diffraction patterns were measured to study grain structure and interface reactions. Very low resistivity values were observed and were found to be a strong function of temperature. Electrical properties were evaluated on MOS capacitors, which indicated that the workfunction of RuO/sub 2/ was compatible with PMOS devices. Excellent stability of oxide thickness, flatband voltage and gate current as a function of temperature was also found. Breakdown fields were also measured for the samples before and after annealing.}, number={12}, journal={IEEE ELECTRON DEVICE LETTERS}, author={Zhong, HC and Heuss, G and Misra, V}, year={2000}, month={Dec}, pages={593–595} }