数字集成电路课件(英文版)：chapter4 The Wire

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Wires
Sheet Resistance
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Wires
Modern Interconnect
▪ reduce average wire-length
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Wires
Polycide Gate MOSFET
Silicide PolySilicon SiO2
n+
n+
p
Silicides: WSi 2, TiSi 2, PtSi 2 and TaSi Conductivity: 8-10 times better than Poly
M4 Vout2
Cdb1 Cw
Cg3
M1
M3
Interconnect
Vin Simplified
Model
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Fanout Vout CL
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Wires
Capacitance: The Parallel Plate Model
L
H tdi
consumption
Classes of parasitics
▪ Capacitive ▪ Resistive ▪ Inductive
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Wires
Nature of Interconnect
Local Interconnect SLocal = STechnology
transmitters
schematics
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receivers
physical
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Interconnect Impact on Chip
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Wires
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Wires
Fringing Capacitance
(a)
H
W - H/2
+
(b)
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Wires
Fringing versus Parallel Plate
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Pentium Pro (R) Pentium(R) II Pentium (MMX) Pentium (R) Pentium (R) II
Global Interconnect SGlobal = SDie
No of nets (Log Scale) Source: Intel
10
100
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Digital Integrated Circuits
A Design Perspective
Jan M. Rabaey Anantha Chandrakasan Borivoje Nikolic
The Wire
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Wires
The Wire
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Wires
Dealing with Resistance
Selective Technology Scaling Use Better Interconnect Materials
▪ reduce average wire-length ▪ e.g. copper, silicides
More Interconnect Layers
Wire Models
All-inclusive model © DEEig1i4ta1l Integrated Circuits2nd
Capacitance-only
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Wires
Impact of Interconnect Parasitics
Interconnect parasitics
▪ reduce reliability ▪ affect performance and power
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Wires
Wire Resistance
H W
R= L HW
L
Sheet Resistance
Ro
R1
R2
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Wires
Interconnect Resistance
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(from [Bakoglu89])
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Wires
Wiring Capacitances (0.25 mm CMOS)
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Wires
INTERCONNECT
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1,000 Length (u)
10,000
100,000
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Wires
INTERCONNECT
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Wires
Capacitance of Wire Interconnect
VDD
VDD
M2
Vin
Cgd12
Cdb2
Cg4
Vout
(from [Bakoglu89])
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Interwire Capacitance
fringing
parallel
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Impact of Interwire Capacitance
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cint
di
tdi
WL
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Current flow W
Electrical-field lines
Dielectric Su bstrat e
Βιβλιοθήκη Baidu
SCwire
S S SL
1 SL
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Wires
Permittivity
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