Title :
50 nm vertical replacement-gate (VRG) nMOSFETs with ALD HfO/sub 2/ and Al/sub 2/O/sub 3/ gate dielectrics
Author :
Hergenrother, J.M. ; Wilk, G.D. ; Nigam, T. ; Klemens, F.P. ; Monroe, D. ; Silverman, P.J. ; Sorsch, T.W. ; Busch, B. ; Green, M.L. ; Baker, M.R. ; Baker, M.R. ; Boone, T. ; Bude, M.K. ; Ciampa, N.A. ; Ferry, E.J. ; Fiory, A.T. ; Hillenius, S.J. ; Jacobso
Author_Institution :
Agere Syst., Murray Hill, NJ, USA
Abstract :
We have integrated HfO/sub 2/ and Al/sub 2/O/sub 3/ gate dielectrics grown by atomic layer chemical vapor deposition (ALD) with poly-Si gate electrodes in the vertical replacement-gate (VRG) MOSFET geometry. These transistors are among the first reported with ALD HfO/sub 2/ gate dielectrics, and have HfO/sub 2/ target equivalent oxide thicknesses (tEOT´s) down to 13 /spl Aring/. The poly-crystalline HfO/sub 2/ films in these VRG nMOSFETs exhibit extremely low gate leakage (GL) current densities of J/sub G/ /spl sim/ 10/sup -7/ A/cm/sup 2/ at V/sub G/-V/sub T,Long/ = 0.6 V for 15 /spl Aring/ tEOT devices. This indicates that amorphous gate dielectrics may not be necessary to meet GL requirements. HfO/sub 2/ devices with 50 nm gate length L/sub G/ exhibit drive currents [normalized by the coded width W/sub C/] of 490 /spl mu/A//spl mu/m for 1 V operation (overdrive V/sub GS/-V/sub T/ = 0.6 V) with good short-channel performance. These results demonstrate that ALD is compatible with the demanding VRG geometry, thereby illustrating that it should be well-suited to essentially any novel device structure built with Si-compatible materials.
Keywords :
CVD coatings; MOSFET; alumina; dielectric thin films; hafnium compounds; leakage currents; 1 V; 50 nm; atomic layer chemical vapor deposition; drive current; equivalent oxide thickness; gate dielectric; gate leakage current density; polycrystalline film; polysilicon gate electrode; short channel effect; vertical replacement-gate nMOSFET; Atomic layer deposition; Chemical vapor deposition; Dielectrics; Electrodes; Gate leakage; Geometry; Hafnium oxide; Leakage current; MOSFET circuits; Reluctance generators;
Conference_Titel :
Electron Devices Meeting, 2001. IEDM '01. Technical Digest. International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-7050-3
DOI :
10.1109/IEDM.2001.979400
