For possible application to a gate dielectric in high-performance III-V transistors, nanolaminated HfO2-Al2O3 films with artificial compositional profiles were deposited on n-type InP substrates using atomic layer deposition. The films were vertically graded (HfO2 and Al2O3 at the surface and interface regions, respectively) and had a homogeneous composition. To compare their electrical properties, a similar physical thickness and capacitance-equivalent thickness (CET) were maintained, and the graded structure showed an increase in the Al2O3 content near the high-k and InP interface region without an increase in CET, which suppresses the In incorporation at the near-interface region and reduces the density of the interface trap. However, doing so results in a degradation of the leakage current characteristics under voltage stressing when compared to homogeneously-nanolaminated films.
Bibliographical noteFunding Information:
This work was supported by the Future Semiconductor Device Technology Development Program (Grant No. 10045216 ) funded by MOTIE (Ministry of Trade, Industry & Energy) and KSRC (Korea Semiconductor Research Consortium). In addition, it was partially supported by the Basic Science Research program (Grant No. 2014R1A4A1008474 ) through the National Research Foundation of Korea funded by the Ministry of Education and the Ministry of Science, ICT & Future Planning.
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All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physics and Astronomy(all)