Microstructure and electrical properties of diborides modified by rapid thermal annealing

Zagozdzon‐Wosik, W.; Rusakova, Irene; Darne, Chinmay; Zhang, Z.-H.; Heide, Paul van der; Majhi, P.

doi:10.1111/j.1365-2818.2006.01626.x

Cited by 8 publications

(11 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This clearly indicates that there is no evidence of superconductivity in this compound. Of course, this conclusion matches to direct calculation of transition temperature according Formula (5).…”

Section: Discussionmentioning

confidence: 89%

See 1 more Smart Citation

Interaction between Electron and Phonon Subsystems in Hafnium Diboride

Sichkar¹

2016

Metallofiz. Noveishie Tekhnol.

View full text Add to dashboard Cite

Ab initio calculation of the electron-phonon coupling functions is carried out, using full potential LMTO method. Low value of the averaged electronphonon interaction constant for HfB 2   0.17 indicates that there is no evidence of superconductivity in this compound. Electrical resistivity and anisotropy factor  z / x  1.079 (T  300 K) are theoretically calculated. A good agreement with experimental data of electrical resistivity is achieved. Comparative analysis of ABINIT, SIESTA, VASP, and present LMTO method for phonon spectra calculating is performed.Ab initio розрахунок функцій електрон-фононного зв'язку виконано за методом ЛМТО з використанням повного потенціалу. Низьке значення усередненої константи електрон-фононної взаємодії для HfB 2   0,17 сві-дчить, що немає підстав для виникнення надпровідного стану в цій спо-луці. Вперше було розраховано електричний опір і коефіцієнт анізотропії  z / x  1,079 (Т  300 К) для дибориду гафнію. Було досягнуто добру узго-дженість з експериментальними даними для електричного опору. У робо-ті виконано порівняльний аналіз результатів розрахунків фононних спе-ктрів методами ABINIT, SIESTA, VASP та запропонованим методом ЛМТО з детальним обговоренням одержаних відмінностей.Ab initio расчёт функций электрон-фононной связи выполнен в рамках метода ЛМТО с использованием полного потенциала. Низкое значение усреднённой константы электрон-фононного взаимодействия для HfB 2   0,17 свидетельствует, что нет оснований для возникновения сверхпро-водящего состояния в этом соединении. Впервые были рассчитаны элек-трическое сопротивление и коэффициент анизотропии  z / x  1,079 (Т  300 К) для диборида гафния. Было достигнуто хорошее согласие с экспериментальными данными для электрического сопротивления. В ра-боте выполнен сравнительный анализ результатов расчётов фононных спектров методами ABINIT, Siesta, VASP и предложенным методом ЛМТО с детальным обсуждением полученных различий.

show abstract

Section: Discussionmentioning

confidence: 89%

“…Presently, a number of experimental studies exists dealing with the physical properties of HfB 2 , such as thermal and electrical properties [4][5][6][7], mechanical [8], and elastic properties [9].…”

Section: Introductionmentioning

confidence: 99%

Interaction between Electron and Phonon Subsystems in Hafnium Diboride

Sichkar¹

2016

Metallofiz. Noveishie Tekhnol.

View full text Add to dashboard Cite

show abstract

“…The stoichiometric diborides are thermally stable with very high melting temperatures, well in excess of those of both Ni and Pt. 21,22 They also exhibit good corrosion resistance but are susceptible to oxidation during thermal processing. 21,22 This may be countered by depositing an overlayer of a metal such as Au in the same deposition chamber.…”

Section: Introductionmentioning

confidence: 99%

“…18 Typical Schottky metallizations for AlGaN/GaN HEMTs are based on Pt/Au or Ni/Au, with Au included to reduce the sheet resistance of the contact and to prevent oxidation of the other metal. [20][21][22][23][24][25][26][27][28][29][30][31] Other potentially more thermally stable metallization schemes based on W or WSi x have been reported. [13][14][15][16]20 These exhibit low barrier heights around 0.4-0.5 eV.…”

Section: Introductionmentioning

confidence: 99%

Annealing temperature dependence of TiB2 schottky barrier contacts on n-GaN

Khanna

Pearton

Ren

et al. 2006

J. Electron. Mater.

View full text Add to dashboard Cite

The annealing temperature (25-700°C) dependence of Schottky contact characteristics on n-GaN using a TiB 2 /Ti/Au metallization scheme deposited by sputtering is reported. The Schottky barrier height increased from 0.65 to 0.68 eV as the anneal temperature was varied from 25°C to 350°C and decreased to 0.55 eV after annealing at 700°C. The barrier height showed no measurable dependence on measurement temperature up to 150°C. The elemental profile obtained from samples annealed at 350°C showed limited Ti diffusion from the elemental Ti layer into the gold layer. Annealing at 700°C produced significant out-diffusion of this layer, while the TiB 2 layer retained its stability. These contacts show promise for applications requiring good thermal stability, such as power amplifiers, but much more work is needed to establish their long-term reliability. In addition, TiB 2 has a strong propensity for oxidation, and it is imperative that overlayers such as Au be deposited in the same deposition chamber.

show abstract

“…It has been showed that annealing of amorphous ZrB2 films, deposited by e-beam evaporation, decreases their resistivity due to grain growth [65]. Annealing of sputtered epitaxial ZrB2 films should be investigated to see if the column width increases and the resistivity decreases.…”

Section: Future Outlookmentioning

confidence: 99%

ZrB2 Thin Films : Growth and Characterization

Tengdelius¹

2016

View full text Add to dashboard Cite

Zirconium diboride, ZrB2, is a ceramic material with bulk properties such as high melting point (3245 °C), high hardness (23 GPa), and low resistivity (~8 µΩcm). Thin film growth of ZrB2 using physical vapor deposition has suffered from problems with films deviating from stoichiometry and with high levels of contaminants, especially high oxygen content. The homogeneity range of ZrB2 is very narrow, and consequently it is vital to achieve the correct stoichiometry to grow films with high crystalline order.This thesis describes a direct current magnetron sputtering process to grow stoichiometric ZrB2 thin films with a low degree of impurities. Growth of epitaxial ZrB2 films was achieved on 4H-SiC(0001), Si(111) and Al2O3(0001) substrates. The effect of deposition temperature and power applied on the sputtering target was investigated and showed that high power density (8.77 Wcm -2 ) and high temperature (900 °C) resulted in films with the best composition and the highest crystal quality. ZrB2 films on GaN(0001) templates exhibit an amorphous layer at the film-substrate interface and the resulting films are either polycrystalline or textured.Resistivity measurements showed that the ZrB2 thin films exhibit typical resistivity values of ~100-250 µΩcm and that the resistivity decreased with increasing deposition temperature.Nanoindentation was applied to assess the mechanical properties of the films. The epitaxial ZrB2 films exhibit high elastic recovery and a hardness of ~45-50 GPa, twice as high as the literature bulk value. In addition, evaluation of the mechanical properties was performed at high temperatures of up to 600 °C and showed that the epitaxial films retained a higher hardness, compared to textured ZrB2 films and bulk, also at these temperatures. Forskningsfältet tunnfilmsfysik handlar om att utveckla och förstå nya och redan existerande tunnfilmsmaterial. En tunn film kan vara allt från bara ett atomlager tjockt till ~1 mikrometer tjock. III Populärvetenskaplig sammanfattningDe flesta filmer som jag gjort är ungefär 400 nanometer tjocka. Som jämförelse kan nämnas att ett hårstrås radie är ungefär hundra gånger större än tjockleken på mina filmer.En del av forskningen inom tunnfilmsfysik är riktad mot att lösa ett specifikt problem för en specifik tillämpning. Det kan t.ex. innebära utveckling av ett tunnfilmsmaterial för att förlänga livstiden för verktyg inom metallbearbetningsindustrin. Men en stor del av forskningen är även så kallad grundforskning där syftet med forskningen är att lära sig att förstå så mycket som möjligt om ett material för att i ett senare skede tillämpa den kunskapen för att lösa specifika problem. Min During the course of research underlying this thesis, I was enrolled in Agora Materiae, a multidisciplinary doctoral program at Linköping University, Sweden. IX Acknowledgments I would like to express my deepest thanks:To my supervisor Hans. Thank you for giving me this opportunity, for your support, for generously giving of your time, and for sharing your knowledge. We ha...

show abstract

Microstructure and electrical properties of diborides modified by rapid thermal annealing

Cited by 8 publications

References 13 publications

Interaction between Electron and Phonon Subsystems in Hafnium Diboride

Interaction between Electron and Phonon Subsystems in Hafnium Diboride

Annealing temperature dependence of TiB2 schottky barrier contacts on n-GaN

ZrB2 Thin Films : Growth and Characterization

Contact Info

Product

Resources

About