A 45nm Logic Technology with High-k + Metal Gate Transistors, Strained Silicon, 9 Cu Interconnect Layers, 193nm Dry Patterning, and 100% Pb-free Packaging K. Mistry, C. Allen, C. Auth, B. Beattie, D. Bergstrom, M. Bost, M. Brazier, M. Buehler, A. Cappellani, R. Chau *, C.-H. Choi, G. Ding, K. Fischer, T. Ghani, R. Grover, W. Han, D. Hanken, M. Hattendorf, J. He #, J. Hicks #, R. Heussner, D. Ingerly, P. Jain, R. James, L. Jong, S. Joshi, C. Kenyon, K. Kuhn, K. Lee, H. Liu, J. Maiz #, B. McIntyre, P. Moon, J. Neirynck, S. Pae #, C. Parker, D. Parsons, C. Prasad #, L. Pipes, M. Prince, P. Ranade, T. Reynolds, J. Sandford, L. Shifren %, J. Sebastian, J. Seiple, D. Simon, S. Sivakumar, P. Smith, C. Thomas, T. Troeger, P. Vandervoorn, S. Williams, K. Zawadzki Portland Technology Development, * CR, # QRE, % PTM Intel Corporation
Outline Introduction Process Features Transistors Interconnects Manufacturing Conclusions 2
Introduction SiON scaling running out of atoms Poly depletion limits inversion T OX scaling 10 Poly 1000 Electrical (Inv) Tox (nm) SiON Silicon 100 10 1 0.1 Gate Leakage (Rel.) 1 0.01 350nm 250nm 180nm 130nm 90nm 65nm 3
High-k + Metal Gate Benefits High-k gate dielectric Reduced gate leakage T OX scaling Metal gates Eliminate polysilicon depletion Resolves V T pinning and poor mobility for high-k dielectrics 4
High-k + Metal Gate Challenges High-k gate dielectric Poor mobility, V T pinning due to soft optical phonons Poor reliability Metal gates Dual bandedge workfunctions Thermal stability Integration scheme 5
Outline Introduction Process Features Transistors Interconnects Manufacturing Conclusions 6
Process Features 45 nm Groundrules 193 nm Dry Lithography High-K + Metal Gate Transistors 3 RD Generation Strained Silicon Trench Contacts with Local Routing 9 Cu Interconnect Layers 100% Lead-free Packaging 7
Process Features 45 nm Groundrules 193 nm Dry Lithography High-K + Metal Gate Transistors 3 RD Generation Strained Silicon Trench Contacts with Local Routing 9 Cu Interconnect Layers 100% Lead-free Packaging 8
45nm Design Rules Layer Pitch (nm) Thick (nm) Aspect Ratio Isolation 200 200 -- Contacted Gate 160 60 -- Metal 1 160 144 1.8 Metal 2 160 144 1.8 Metal 3 160 144 1.8 Metal 4 240 216 1.8 Metal 5 280 252 1.8 Metal 6 360 324 1.8 Metal 7 560 504 1.8 Metal 8 810 720 1.8 Metal 9 30.5μm 7μm 0.4 ~0.7x linear scaling from 65nm 9
Contacted Gate Pitch Transistor gate pitch of 160 nm continues 0.7x per generation scaling Contacted Gate Pitch (nm) 1000 100 Pitch 250nm 180nm 130nm 90nm 65nm 45nm Technology Node 0.7x every 2 years Tightest contacted gate pitch reported for 45 nm generation
SRAM Cells 0.346 μm 2 and 0.382 μm 2 SRAM cells Optimize density and power/performance 10 SRAM Cell Size ( μm 2 ) 1 0.5x every 2 years 0.1 250nm 180nm 130nm 90nm 65nm 45nm Technology Node Transistor density doubles every two years 11
SRAM Array Density SRAM array density achieves 1.9 Mb/mm 2 Includes row/column drivers and other circuitry SRAM Array Density (Mb/mm 2 ) 10.0 1.9 Mb/mm 2 1.0 0.1 90nm 65nm 45nm Array density scales at ~2X per generation 12
Outline Introduction Process Features Transistors Interconnects Manufacturing Conclusions 13
Transistor Process Flow Key considerations Integrate hafnium-based high-k dielectric, dual metal gate electrodes, strained silicon Thermal stability of metal gate electrodes High-k First, Metal Gate Last Metal gate deposition after high temperature anneals Integrated with strained silicon process Transistor mask count same as 65nm 14
Transistor Process Flow Dummy Polysilicon n-ext n-ext p-ext p-ext STI High-k High-k p-well N-well Standard process except for ALD high-k 15a
Transistor Process Flow ILD0 N+ N+ STI SiGe SiGe p-well N-well e-sige & S/D, Thermal anneal, ILD0 deposition 15b
Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well Poly Opening Polish 15c
Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well Dummy Poly removal 15d
Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well PMOS WF Metal deposition 15e
Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well PMOS WF Metal patterning 15f
Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well NMOS WF Metal deposition 15g
Transistor Process Flow Al fill N+ N+ STI SiGe SiGe p-well N-well Metal Gate trenches filled with low resistance Al 15h
Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well Metal Gate Polish 15i
Transistor Process Flow Low Resistance Al Fill NMOS WF PMOS WF N+ N+ STI SiGe SiGe High-k High-k p-well N-well High-k + Metal gate transistor formation complete 15j
Transistor Features 35 nm min. gate length 160 nm contacted gate pitch 1.0 nm EOT Hi-K Dual workfunction metal gate electrodes 3 RD generation of strained silicon 16
Gate Leakage Gate leakage is reduced >25X for NMOS and 1000X for PMOS Normalized Gate Leakage 100 10 1 0.1 0.01 SiON/Poly 65nm SiON/Poly 65nm 0.001 HiK+MG 45nm HiK+MG 45nm 0.0001 PMOS NMOS 0.00001-1.2-1 -0.8-0.6-0.4-0.2 0 0.2 0.4 0.6 0.8 1 1.2 65nm: Bai, 2004 IEDM VGS (V) 17
Optimal Workfunction Metals Excellent V T rolloff and DIBL Threshold Voltage (V) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 VDS = 0.05V VDS = 1.0V NMOS 30 35 40 45 50 55 60 LGATE (nm) Threshold Voltage (V) 0.00-0.05-0.10-0.15-0.20-0.25-0.30-0.35-0.40-0.45-0.50 VDS = 0.05V VDS = 1.0V PMOS 30 35 40 45 50 55 60 LGATE (nm) 18
3 RD Generation Strained Silicon Increased Ge fraction 90 nm: 17% Ge 65 nm: 23% Ge 45 nm: 30% Ge SiGe closer to channel 19
NMOS I DSAT vs. I OFF 1000 VDD = 1.0V 90nm: Mistry 2004 VLSI 65nm: Tyagi, 2005 IEDM IOFF (na/μm) 100 10 90 nm 65 nm 160 nm 1 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 IDSAT (ma/μm) 1.36 ma/μm at I OFF = 100 na/μm 12% better than 65 nm 20
PMOS I DSAT vs. I OFF 1000 VDD = 1.0V 90nm: Mistry 2004 VLSI 65nm: Tyagi, 2005 IEDM IOFF (na/μm) 100 10 90 nm 65 nm 160 nm 1 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 IDSAT (ma/μm) 1.07 ma/μm at I OFF = 100 na/μm 51% better than 65 nm 21
Transistor Performance vs. Gate Pitch IDSAT (ma/μm) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 1000 1.0V, 100 na/μm 90nm: Mistry, 2004 VLSI 65nm: Tyagi, 2005 IEDM Gate Pitch (Generation) NMOS PMOS 320nm (90nm) 220nm (65nm) Contacted Gate Pitch (nm) 160nm (45nm) Simultaneous performance and density improvement 100 22
Ring Oscillator Performance DELAY PER STAGE (ps) 9 8 7 6 5 4 Fanout = 2 65nm @ 1.2V 45nm @1.1V 3 10 100 1000 10000 IOFFN + IOFFP (na/um) FO=2 delay of 5.1 ps at I OFFN = I OFFP = 100 na/μm 23% better than 65 nm at the same leakage 23
Transistor Reliability Challenges Defect types in SiO 2 have been studied for decades New defect types for high-k need to be suppressed T INV scaled ~0.7X relative to 65 nm Need to support 30% higher E-field 24
Transistor Reliability - TDDB TDDB (sec) 1.E+09 1.E+08 1.E+07 1.E+06 1.E+05 1.E+04 1.E+03 1.E+02 SiON/Poly 65nm 65nm: Bai, 2004 IEDM 45nm HK+MG 4 6 8 10 12 14 16 Field (MV/cm) 45nm High-k + Metal Gate supports 30% higher E-field 25
Transistor Reliability: Bias Temperature PMOS NBTI 45 nm Hi-k + MG supports 50% higher E-field Vt increase (mv) 50 40 30 20 10 SiON/Poly 65nm PMOS NBTI 45nm HK+MG Vt increase (mv) 50 40 30 20 10 0 SiON/Poly 65nm 5 7 9 11 13 SiO 2 equivalent E Field (MV/cm) 0 5 7 9 11 13 SiO 2 equivalent E Field (MV/cm) NMOS PBTI 45nm HK+MG NMOS PBTI 45 nm Hi-k + MG supports 15% higher E-field 65nm: Bai, 2004 IEDM 26
Outline Introduction Process Features Transistors Interconnects Manufacturing Conclusions 27
Interconnects Metal 1-3 pitches match transistor pitch Graduated upper level pitches optimize density & performance Lower layer SiCN etch stop layer thinned 50% relative to 65 nm Extensive use of low-k ILD CDO CDO CDO CDO CDO CDO CDO SiO 2 MT8 MT7 MT6 MT5 MT4 MT3 MT2 MT1 28
Metal 9: ReDistribution Layer (RDL) Metal 9 RDL: 7um thick with polymer ILD Improved on-die power distribution Cu Bump Polymer ILD Metal 9 7 μm MT8 MT7 29
100% Lead Free Packaging Environmental benefit, lower SER Cu Pad Pb/Sn Solder Pb Bump 90 nm Cu Pad Pb/Sn Solder Cu Bump Cu Pad Sn/Ag/Cu Solder 65 nm Cu Bump 45 nm 30
Outline Introduction Process Features Transistors Interconnects Manufacturing Conclusions 31
153Mb SRAM Test Vehicle Process learning vehicle demonstrates High yield High performance Stable low voltage operation 1.3V *****************************. 1.2V **************************. 3.8GHz 1.1V *************************. 4.7GHz 0.346 μm2 SRAM Cell >1 billion transistors Fully functional Jan 06 1.0V **********************. 0.9V ****************.. 2GHz 0.8V ******... +---------+---------+---------+ 1.8GHz 2.3GHz 3.2GHz 5.3GHz 32
Multiple Microprocessors Single Core Quad Core Dual Core 33
Defect Reduction Trend Mature yield demonstrated 2 years after 65 nm 130 nm 90 nm 65 nm 45 nm Defect Density (log scale) 2000 2001 2002 2003 2004 2005 2006 2007 2008
Defect Reduction Trend Mature yield demonstrated 2 years after 65 nm Matched yield in 2 ND Fab Copy Exactly! 130 nm 90 nm 65 nm 45 nm Defect Density (log scale) F32 2000 2001 2002 2003 2004 2005 2006 2007 2008
Conclusions A 45 nm technology is described with Design rules supporting ~2X improvement in transistor density 193nm dry lithography at critical layers for low cost Trench contacts supporting local routing 8 standard Cu interconnect layers with extensive use of low-k Thick Metal 9 Cu RDL with polymer ILD High-k + Metal gate transistors implemented for the first time in a high volume manufacturing process Integrated with 3 RD generation strained silicon Achieve record drive currents at low I OFF and tight gate pitch The technology is already in high volume manufacturing High yields demonstrated on SRAM and 3 microprocessors High yields demonstrated in two 300mm fabs 35
Acknowledgements The authors gratefully acknowledge the many people in the following organizations at Intel who contributed to this work: Portland Technology Development Quality and Reliability Engineering Process & Technology Modeling Assembly & Test Technology Development 36
For further information on Intel's silicon technology, please visit our Technology & Research page at www.intel.com/technology 37