Transcript Signal Propagation Along Interconnects

Signal Propagation
Along Interconnects
interconnect
Signal propagation along wires
(interconnects) can’t keep up with the
devices
Time to propagate signal along
interconnect between devices is an RC
delay
R = electrical resistance of wire
Depends on metal resistivity
Depends on wire length & width
C = capacitance of wire relative to its
surroundings
Depends on insulator dielectric constant
Depends on wiring geometries
device
Interconnect wire with resistance R
and capacitance C to rest of circuit
device B receives trigger
to switch at t=RC
ENMA 465 Spring 2003
Copyright G. W. Rubloff 2003, all rights reserved
device A switches at t=0
Microelectronics
Silicon ULSI, and more
•
Amazing success
Market +15%/yr for >30 yrs
Productivity +25-30%/yr
Springboard for the IT revolution
•
But…
Factory costs escalating +20%/yr
Increasing technology challenges,
possible show-stoppers
Market diversifying, segmenting, and
reconfiguring
•
Key questions
Maintaining productivity growth
curve
New technologies for end of
roadmap
Semiconductor International Jan 1998
Research Review Day 5/11/00
G. W. Rubloff 
Advanced Interconnect
Technology
Cu seed +
Cu fill
Metal barrier
Low-K dielectric
Polish stops
Etch stops
drawing to scale
within  10%
ITRS Interconnect 1999, Fig. 28
W plug
BPSG dielectric
KA Monnig, Sematech 09/02/96
ENMA 465 Spring 2003
Copyright G. W. Rubloff 2003, all rights reserved
Advanced Si ULSI Technology
Cu seed +
Cu fill
Metal barrier
Low-K dielectric
Polish stops
Etch stops
drawing to scale
within  10%
W plug
BPSG dielectric
KA Monnig, Sematech 09/02/96
ENMA 465 Spring 2003
Copyright G. W. Rubloff 2003, all rights reserved