Portland Technology Development, * CR, # QRE, % PTM Intel Corporation

Transcription

1 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

2 Outline Introduction Process Features Transistors Interconnects Manufacturing Conclusions 2

3 Introduction SiON scaling running out of atoms Poly depletion limits inversion T OX scaling 10 Poly 1000 Electrical (Inv) Tox (nm) SiON Silicon Gate Leakage (Rel.) nm 250nm 180nm 130nm 90nm 65nm 3

4 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

5 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

6 Outline Introduction Process Features Transistors Interconnects Manufacturing Conclusions 6

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 7

8 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

9 45nm Design Rules Layer Pitch (nm) Thick (nm) Aspect Ratio Isolation Contacted Gate Metal Metal Metal Metal Metal Metal Metal Metal Metal μm 7μm 0.4 ~0.7x linear scaling from 65nm 9

10 Contacted Gate Pitch Transistor gate pitch of 160 nm continues 0.7x per generation scaling Contacted Gate Pitch (nm) Pitch 250nm 180nm 130nm 90nm 65nm 45nm Technology Node 0.7x every 2 years Tightest contacted gate pitch reported for 45 nm generation

11 SRAM Cells μm 2 and μm 2 SRAM cells Optimize density and power/performance 10 SRAM Cell Size ( μm 2 ) 1 0.5x every 2 years nm 180nm 130nm 90nm 65nm 45nm Technology Node Transistor density doubles every two years 11

12 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 ) Mb/mm nm 65nm 45nm Array density scales at ~2X per generation 12

13 Outline Introduction Process Features Transistors Interconnects Manufacturing Conclusions 13

14 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

15 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

16 Transistor Process Flow ILD0 N+ N+ STI SiGe SiGe p-well N-well e-sige & S/D, Thermal anneal, ILD0 deposition 15b

17 Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well Poly Opening Polish 15c

18 Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well Dummy Poly removal 15d

19 Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well PMOS WF Metal deposition 15e

20 Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well PMOS WF Metal patterning 15f

21 Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well NMOS WF Metal deposition 15g

22 Transistor Process Flow Al fill N+ N+ STI SiGe SiGe p-well N-well Metal Gate trenches filled with low resistance Al 15h

23 Transistor Process Flow N+ N+ STI SiGe SiGe p-well N-well Metal Gate Polish 15i

24 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

25 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

26 Gate Leakage Gate leakage is reduced >25X for NMOS and 1000X for PMOS Normalized Gate Leakage SiON/Poly 65nm SiON/Poly 65nm HiK+MG 45nm HiK+MG 45nm PMOS NMOS nm: Bai, 2004 IEDM VGS (V) 17

27 Optimal Workfunction Metals Excellent V T rolloff and DIBL Threshold Voltage (V) VDS = 0.05V VDS = 1.0V NMOS LGATE (nm) Threshold Voltage (V) VDS = 0.05V VDS = 1.0V PMOS LGATE (nm) 18

28 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

29 NMOS I DSAT vs. I OFF 1000 VDD = 1.0V 90nm: Mistry 2004 VLSI 65nm: Tyagi, 2005 IEDM IOFF (na/μm) nm 65 nm 160 nm IDSAT (ma/μm) 1.36 ma/μm at I OFF = 100 na/μm 12% better than 65 nm 20

30 PMOS I DSAT vs. I OFF 1000 VDD = 1.0V 90nm: Mistry 2004 VLSI 65nm: Tyagi, 2005 IEDM IOFF (na/μm) nm 65 nm 160 nm IDSAT (ma/μm) 1.07 ma/μm at I OFF = 100 na/μm 51% better than 65 nm 21

31 Transistor Performance vs. Gate Pitch IDSAT (ma/μm) V, 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

32 Ring Oscillator Performance DELAY PER STAGE (ps) Fanout = 2 1.2V 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

33 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

34 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 Field (MV/cm) 45nm High-k + Metal Gate supports 30% higher E-field 25

35 Transistor Reliability: Bias Temperature PMOS NBTI 45 nm Hi-k + MG supports 50% higher E-field Vt increase (mv) SiON/Poly 65nm PMOS NBTI 45nm HK+MG Vt increase (mv) SiON/Poly 65nm SiO 2 equivalent E Field (MV/cm) 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

36 Outline Introduction Process Features Transistors Interconnects Manufacturing Conclusions 27

37 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

38 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

39 100% 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

40 Outline Introduction Process Features Transistors Interconnects Manufacturing Conclusions 31

41 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 μm2 SRAM Cell >1 billion transistors Fully functional Jan V **********************. 0.9V ****************.. 2GHz 0.8V ****** GHz 2.3GHz 3.2GHz 5.3GHz 32

42 Multiple Microprocessors Single Core Quad Core Dual Core 33

43 Defect Reduction Trend Mature yield demonstrated 2 years after 65 nm 130 nm 90 nm 65 nm 45 nm Defect Density (log scale)

44 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) F

45 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

46 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

47 For further information on Intel's silicon technology, please visit our Technology & Research page at 37