@article{alptekin_ozturk_2010, title={NixPt1-xSi/n-Si contacts with sub-0.1 eV effective Schottky barrier heights obtained by sulfur segregation}, volume={87}, ISSN={["1873-5568"]}, DOI={10.1016/j.mee.2010.04.008}, abstractNote={We demonstrate tuning of the Schottky barrier height, @fB of nickel-platinum alloy silicide (NixPt1-xSi) contacts on n-type silicon by segregating sulfur at the silicide/Si interface. It is shown that while there is negligible effect of sulfur on the thermal stability and silicide resistance, extremely small barrier height values of 0.05-0.07eV at the silicide/Si interface can be achieved by sulfur segregation.}, number={11}, journal={MICROELECTRONIC ENGINEERING}, author={Alptekin, Emre and Ozturk, Mehmet C.}, year={2010}, month={Nov}, pages={2358–2360} }
@article{alptekin_ozturk_2010, title={Ultrahigh Vacuum Chemical Vapor Deposition of Doped and Intrinsic Si1-xCx Epitaxy from Disilane, Trimethylsilane, and Phosphine}, volume={157}, ISSN={["1945-7111"]}, DOI={10.1149/1.3414167}, abstractNote={Epitaxial Si 1―x C x alloys grown in recessed source/drain junctions of n-channel MOSFETs are of interest to induce uniaxial tensile strain in the channel for electron mobility enhancement. In this work, we have studied chemical vapor deposition of intrinsic and heavily phosphorus-doped Si 1―x C x epitaxial layers on silicon using disilane, trimethylsilane, phosphine, and hydrogen as the gaseous precursors. The results show that phosphorus segregation to the growth surface can be fully suppressed by growing the layers at or below 550°C. The best films were obtained at this temperature yielding a growth rate of 4 nm/min. A maximum phosphorus concentration of 1.3 × 10 21 cm ―3 was obtained with a minimum resistivity of 0.67 mΩ cm and a substitutional carbon concentration of 1.0%.}, number={6}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Alptekin, Emre and Ozturk, Mehmet C.}, year={2010}, pages={H699–H704} }
@article{alptekin_ozturk_misra_cho_kim_chopra_2009, title={Erbium Silicide Formation on Si1-xCx Epitaxial Layers}, volume={156}, ISSN={["1945-7111"]}, DOI={10.1149/1.3097189}, abstractNote={Erbium silicide formation was investigated on epitaxial layers grown on Si substrates. Substitutional carbon incorporation in the epitaxial layers was in the range of 0.6–1.6%. The silicide films were formed by rapid thermal annealing of sputter-deposited erbium layers in the temperature range of . The sheet resistance of the silicide films formed on epitaxial layers was found to be equal to or less than the sheet resistance of the films formed on Si epitaxial layers. At , an average resistivity of was obtained. The silicide grains were found to be epitaxially aligned to the substrate along the (100) orientation, regardless of the carbon concentration in the underlying epitaxial layer. Compositional analysis of the films indicated carbon accumulation at the interface with no carbon incorporation in the silicide. The films formed on epitaxial layers exhibited a smooth interface/surface morphology free of pinholes, contrary to the silicides formed on Si. The root-mean-square surface roughness was found to be less than , which was found to be the case with both substitutional and interstitial incorporation of carbon atoms in the epitaxial layer.}, number={5}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Alptekin, Emre and Ozturk, Mehmet C. and Misra, Veena and Cho, Yonah and Kim, Yihwan and Chopra, Saurabh}, year={2009}, pages={H378–H383} }
@article{alptekin_kirkpatrick_misra_ozturk_2009, title={Platinum Germanosilicide Contacts Formed on Strained and Relaxed Si1-xGex Layers}, volume={56}, ISSN={["1557-9646"]}, DOI={10.1109/TED.2009.2018159}, abstractNote={Contact resistivity is a key contributor to the parasitic series resistance of nanoscale MOSFETs. Since the contact resistivity is an exponential function of the Schottky barrier height, new contact materials that can provide smaller barrier heights to source-drain junctions are needed. Platinum germanosilicide (PtSi 1-x Ge x ) is of interest as a contact material to the recessed Si 1-x Ge x junctions of p-channel MOSFETs due to the large work function of platinum silicide (PtSi). In this paper, we explore the impact of in-plane biaxial compressive strain in Si 1-x Ge x layers on PtSi 1-x Ge x formation and the impact of the PtSi 1-x Ge x on the strain in Si 1-x Ge x . The parameters considered in this paper include the Ge content, the thickness of the Si 1-x Ge x epitaxial layer, and the PtSi 1-x Ge x thickness. The results show that the resistance, surface morphology, and the crystalline structure of the PtSi 1-x Ge x films are independent of the strain in the original Si 1-x Ge x layer. The results also indicate that PtSi 1-x Ge x does not influence the strain in the Si 1-x Ge x layer. The barrier-height measurements suggest the presence of Fermi-level pinning, and the pinning position is independent of the strain in the alloy, and it is primarily determined by the Ge concentration. As a result of Fermi-level pinning, hole Schottky barrier height of PtSi 1-x Ge x -Si 1-x Ge x contacts is 0.1-0.2 eV higher than that of the PtSi-Si contacts.}, number={6}, journal={IEEE TRANSACTIONS ON ELECTRON DEVICES}, author={Alptekin, Emre and Kirkpatrick, Casey Joe and Misra, Veena and Ozturk, Mehmet C.}, year={2009}, month={Jun}, pages={1220–1227} }
@article{alptekin_ozturk_misra_2009, title={Schottky Barrier Height of Erbium Silicide on Si1-xCx}, volume={30}, ISSN={["1558-0563"]}, DOI={10.1109/LED.2009.2026297}, abstractNote={In this letter, the Schottky barrier height of erbium silicide contacts formed on Si 1-x C x alloys was measured. The alloys were pseudomorphically grown on Si wafers with 0% to 1.2% C occupying the substitutional sites. Schottky barrier diodes were fabricated with an ideality factor of 1.13 or less. The hole barrier height was found to be 0.73 eV independent of the C concentration. This suggests that the electron barrier height should decrease with increasing C concentration due to the reduction in the semiconductor bandgap. For 1.2% C, the electron barrier is estimated to be 0.29 eV.}, number={9}, journal={IEEE ELECTRON DEVICE LETTERS}, author={Alptekin, Emre and Ozturk, Mehmet C. and Misra, Veena}, year={2009}, month={Sep}, pages={949–951} }
@article{alptekin_ozturk_2009, title={Schottky Barrier Height of Nickel Silicide Contacts Formed on Si1-xCx Epitaxial Layers}, volume={30}, ISSN={["1558-0563"]}, DOI={10.1109/LED.2009.2034114}, abstractNote={Embedded Si 1 - x C x source/drain junctions are currently considered to achieve electron mobility enhancement in nMOSFETs by inducing uniaxial tensile strain in the channel region. To utilize the mobility advantage of this technology, it is imperative to form low-resistivity contacts to Si 1 - x C x alloys. In this letter, the electron and hole barrier heights at the NiSi/Si 1 - x C x interface were measured up to a carbon concentration of 1.2%. The results indicate that the NiSi Fermi level moves away from the valence-band edge with increasing carbon concentration such that the hole barrier height increases by 68 meV in spite of the upward movement of the valence band. Within the same carbon concentration range, the electron barrier height decreases by as much as 170 meV, which is significant considering the exponential dependence of contact resistivity on barrier height.}, number={12}, journal={IEEE ELECTRON DEVICE LETTERS}, author={Alptekin, Emre and Ozturk, Mehmet C.}, year={2009}, month={Dec}, pages={1320–1322} }
@article{alptekin_ozturk_2009, title={Tuning of the Nickel Silicide Schottky Barrier Height on p-Type Silicon by Indium Implantation}, volume={30}, ISSN={["1558-0563"]}, DOI={10.1109/LED.2009.2033451}, abstractNote={In this letter, indium (In) implantation is introduced as a method to tune the Schottky barrier height of nickel silicide (NiSi) contacts formed on p-type silicon. Indium implantation is performed prior to NiSi formation and the implant conditions are chosen such that the implanted region is entirely consumed by the silicide. During silicide formation, some of the indium segregates at the NiSi-Si interface and can have a significant impact on the Schottky barrier height. It is shown that the barrier height decreases almost linearly with the In dose from 0.37 eV on p-type Si to 0.16 eV with an In dose of 1 times 10 14 cm -2 on p-type Si.}, number={12}, journal={IEEE ELECTRON DEVICE LETTERS}, author={Alptekin, Emre and Ozturk, Mehmet C.}, year={2009}, month={Dec}, pages={1272–1274} }
@article{alptekin_ozturk_misra_2009, title={Tuning of the Platinum Silicide Schottky Barrier Height on n-Type Silicon by Sulfur Segregation}, volume={30}, ISSN={["1558-0563"]}, DOI={10.1109/LED.2009.2014182}, abstractNote={The Schottky barrier height PhiB of platinum silicide (PtSi) contacts on n-type silicon was tuned by sulfur segregation at the PtSi/Si interface. Sulfur was implanted prior to Pt deposition and segregated at the interface during PtSi formation. It was observed that the barrier height could be tuned by changing the sulfur dose. A minimum barrier height of 0.12 eV was obtained on n-type (100) Si substrates. Since PtSi naturally provides a small PhiB of 0.2 eV on p-type Si, it carries the potential to serve as the single metal source/drain contact metal in a CMOS integrated circuit with PhiB tuning on n-channel transistors.}, number={4}, journal={IEEE ELECTRON DEVICE LETTERS}, author={Alptekin, Emire and Ozturk, Mehmet C. and Misra, Veena}, year={2009}, month={Apr}, pages={331–333} }