Title :
The performance of high permitivity TiO/sub 2/ dielectric MOSFETs
Author :
Campbell, S.A. ; Gilmer, D.C. ; Wang, X. ; Hsiehl, M.T. ; Kim, H.S. ; Gladfelter, W.L. ; Yan, J.H.
Author_Institution :
Dept. of Electr. Eng., Minnesota Univ., Minneapolis, MN, USA
Abstract :
Tunnelling leakage currents limit the scaling of SiO/sub 2/ based dielectrics to approximately 30 /spl Aring/, which will be used for 0.25 /spl mu/m devices. We have investigated the use of the lattice polarizable material TiO/sub 2/ as a possible SiO/sub 2/ replacement for smaller devices. Layers of polycrystalline anatase, which has a bandgap of approximately 3.2 eV, were deposited through the thermal decomposition of titanium tetrakis-isopropoxide. Rutherford backscattering spectrometry showed a [Ti]/[O] stoichiometric ratio of 1:2, within the sensitivity of the analysis. Atomic force microscopy indicated that the surface morphology was a sensitive function of deposition and post deposition annealing conditions. Optimum films, which were annealed in oxygen at 750/spl deg/C after deposition, had average roughnesses of about 6% of the film thickness.
Keywords :
MOSFET; Rutherford backscattering; annealing; atomic force microscopy; dielectric thin films; permittivity; semiconductor technology; titanium compounds; MOSFET; Rutherford backscattering spectrometry; TiO/sub 2/; annealing; atomic force microscopy; bandgap; deposition; dielectric film; lattice polarizable material; permitivity; polycrystalline anatase; roughness; stoichiometry; surface morphology; thermal decomposition; titanium tetrakis-isopropoxide; tunnelling leakage current; Annealing; Atomic force microscopy; Dielectric devices; Dielectric materials; Lattices; Leakage current; Photonic band gap; Polarization; Thermal decomposition; Tunneling;
Conference_Titel :
Device Research Conference, 1996. Digest. 54th Annual
Conference_Location :
Santa Barbara, CA, USA
Print_ISBN :
0-7803-3358-6
DOI :
10.1109/DRC.1996.546332
