| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016) | |
| Thin Films | Tuesday Sessions |
| Session TF-TuM |
| Session: | Nanostructured Surfaces & Thin Films II |
| Presenter: | Youngseo An, Sungkyunkwan University, Republic of Korea |
| Authors: | Y. An, Sungkyunkwan University, Republic of Korea C. Lee, Sungkyunkwan University, Republic of Korea S. Choi, Sungkyunkwan University, Republic of Korea J. Song, Sungkyunkwan University, Republic of Korea Y.-C. Byun, University of Texas at Dallas, USA J. Kim, University of Texas at Dallas, USA H.S. Kim, Sungkyunkwan University, Republic of Korea |
| Correspondent: | Click to Email |
GaSb is one of the possible candidates for a p-channel layer in the high-speed metal-oxide-semiconductor field-effect transistors (MOSFETs). However, its poor thermal stability and high reactivity with ambient air produce a poor interface with the high-k gate dielectrics, and there have been several attempts to resolve these problems [1-3].
In this presentation, the sample loading temperature was varied to find an optimal atomic layer deposition (ALD) condition of an Al2O3 film on p-type GaSb substrates. Then, we compared in situ substrate treatments of two metal precursors, trimethylaluminum (TMA) and tetrakis(dimethylamino)titanium (TDMAT), at the same loading temperature prior to the ALD-Al2O3 process. According to various electrical characterizations of the capacitors, lowering the loading temperature was beneficial in reducing the Fermi level pinning effect, and further suppression could be achieved by the subsequent TMA/TDMAT pretreatments. Although the TDMAT treatment showed more efficient relief of Fermi level pinning than the TMA treatment, it undermined the frequency dispersion characteristics in an accumulation region, as an adverse effect. The interface characterization results using X-ray photoelectron spectroscopy will also be discussed to understand the observed electrical properties.
[1] A. Nainani et al., J. Appl. Phys., 109, 114908 (2011).
[2] M. Yokoyama et al., Appl. Phys. Lett., 106, 122902 (2015).
[3] L. B. Ruppalt et al., Appl. Phys. Lett., 101, 231601 (2012)