Author :
Heyns, M. ; Beckx, S. ; Bender, H. ; Blomme, P. ; Boullart, W. ; Brijs, B. ; Carter, R. ; Caymax, M. ; Claes, M. ; Conard, T. ; Gendt, S. De ; Degraeve, R. ; Delabie, A. ; Deweerdt, W. ; Groeseneken, G. ; Henson, K. ; Kauerauf, T. ; Kubicek, S. ; Lucci, L
Abstract :
High-k dielectric layers are deposited using ALD or MOCVD. Most of the work focused on Hf-based high-k dielectrics, either as pure HfO2, as silicate or mixed with Al2O3. In some cases nitrogen is added to improve the high-temperature stability. Various surface preparation methods and deposition conditions are tested. Compatibility of the high-k stacks with poly-Si and metal electrodes is investigated. Significant improvements in yield and thermal stability are obtained by optimized modifications of the high-k stack. Scaling of the equivalent oxide thickness (EOT) is accomplished by implementing novel ideas in interface engineering and high-k materials processing. High-k stacks are tested in transistor structures with small gate lengths. The origin of the electrical instabilities and the observed drive current degradation of high-k transistors as compared to the SiO2 reference transistors are studied in detail.
Keywords :
MISFET; MOCVD coatings; alumina; dielectric materials; dielectric thin films; silicon compounds; thermal stability; 1 nm; Al2O3; HfO2-SiO2; Si; SiO2 reference transistors; SiO4; electrical instability; equivalent oxide thickness; high temperature stability.; high-k dielectric layers scaling; high-k materials processing; high-k stacks; high-k transistors; interface engineering; metal electrodes; metal-organic chemical vapour deposition; poly-Si electrodes; surface preparation methods; thermal stability; transistor structures; yield stability; Degradation; Electrodes; Hafnium oxide; High K dielectric materials; High-K gate dielectrics; MOCVD; Materials processing; Nitrogen; Testing; Thermal stability;
Conference_Titel :
VLSI Technology, Systems, and Applications, 2003 International Symposium on
