Title :
A New Fabrication Procedure for Reproducibly Observing Leakage Current Reduction of SiO2 due to Enhanced Phonon-Energy Coupling
Author :
Ong, Pang-Leen ; Chen, Zhi
Author_Institution :
Dept. of Electr. & Comput. Eng., Kentucky Univ., Lexington, KY
Abstract :
We analyzed the problems in observation of large leakage-current reduction of ultrathin SiO2 due to enhanced phonon-energy coupling. A lithographic method for fabrication of MOS capacitors with post-metal anneal is needed to have reproducible and reliable results. We developed a bilayer resist lithographic method based on all-organic resist and developer to fabricate Ni-gate MOS capacitors. The bilayer resist lift-off procedure uses SU-8 with Shipley S1813 as the intermediate layer. After development, an undercut profile of the bi-layer resist is clearly demonstrated. The Ni-gate MOS capacitors are fabricated successfully, which can withstand post-metal anneal. Experimental I-V and C-V curves, together with the C-V curves simulated using the Berkeley Quantum (QM) simulator, demonstrate that large leakage-current reduction (~1000 x) can be reliably and reproducibly achieved on ultra thin SiO2 (~24 A) after proper RTP processing.
Keywords :
MOS capacitors; annealing; dielectric materials; dielectric thin films; elemental semiconductors; leakage currents; lithography; nickel; rapid thermal processing; semiconductor device models; silicon; silicon compounds; Berkeley Quantum simulator; C-V curves; I-V curves; Ni-SiO2-Si; Ni-gate MOS capacitor; RTP processing; SU-8; Shipley S1813; all-organic resist; bilayer resist lithographic fabrication; intermediate layer; leakage current; lift-off method; phonon-energy coupling; post-metal anneal; ultrathin silicon dioxide dielectric film; undercut profile; Annealing; Capacitance-voltage characteristics; Chemicals; Fabrication; Leakage current; MOS capacitors; Phonons; Power engineering and energy; Resists; Tunneling;
Conference_Titel :
University/Government/Industry Micro/Nano Symposium, 2008. UGIM 2008. 17th Biennial
Conference_Location :
Louisville, KY
Print_ISBN :
978-1-4244-2484-9
Electronic_ISBN :
978-1-4244-2485-6
DOI :
10.1109/UGIM.2008.21
