High-k dielectrics on (100) and (110) n-InAs: Physical and electrical characterizations
Two high-k dielectric materials (Al2O3 and HfO2) were deposited on n-type (100) and (110) InAs surface orientations to investigate physical properties of the oxide/semiconductor interfaces and the interface trap density (Dit). X-ray photoelectron spectroscopy analyses (XPS) for native oxides of (100) and (110) as-grown n-InAs epi wafers show an increase in As-oxide on the (100) surface and an increase in InOx on the (110) surface. In addition, XPS analyses of high-k (Al2O3 and HfO2) on n-InAs epi show that the intrinsic native oxide difference between (100) and (110) epi surfaces were eliminated by applying conventional in-situ pre-treatment (TriMethyAluminium (TMA)) before the high-k deposition. The capacitance-voltage (C-V) characterization of HfO2 and Al2O3 MOSCAPs on both types of n-InAs surfaces shows very similar C-V curves. The interface trap density (Dit) profiles show Dit minima of 6.1 × 1012/6.5 × 1012 and 6.6 × 1012/7.3 × 1012 cm−2 eV−1 for Al2O3 and HfO2, respectively for (100) and (110) InAs surfaces. The similar interface trap density (Dit) on (100) and (110) surface orientation were observed, which is beneficial to future InAs FinFET device with both (100) and (110) surface channel orientations present. authors: C. H. Wang, G. Doornbos, G. Astromskas, G. Vellianitis, R. Oxland, M. C. Holland, M. L. Huang, C. H. Lin, C. H. Hsieh, Y. S. Chang, T. L. Lee, Y. Y. Chen, P. Ramvall, E. Lind, W. C. Hsu, L.-E. Wernersson, R. Droopad, M. Passlack, and C. H. Diaz
Logic
High Mobility Channel
Silicon has been the transistor channel material of choice throughout all CMOS technology generations up until our 7nm node. TSMC’s 5nm technology is the first advanced logic production technology featuring SiGe as the channel material for p-type FinFET.
TSMC is actively exploring alternative transistor channel materials as an additional degree of freedom in the design of high performance and low power devices. Silicon-germanium and germanium are examples of TSMC’s exploratory research work, which has been extensively published and in some cases recognized as highlights in international conferences.
