signal propagation along interconnects

ENMA 465 Spring 2003Copyright G. W. Rubloff 2003, all rights reserved

Signal PropagationAlong Interconnects

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 wireDepends on metal resistivityDepends on wire length & width

C = capacitance of wire relative to its surroundings

Depends on insulator dielectric constantDepends on wiring geometries

device

interconnect

device A switches at t=0device B receives triggerto switch at t=RC

Interconnect wire with resistance R and capacitance C to rest of circuit

Research Review Day 5/11/00G. W. Rubloff

Microelectronics Silicon ULSI, and more

• Amazing successMarket +15%/yr for >30 yrsProductivity +25-30%/yrSpringboard for the IT revolution

• But…Factory costs escalating +20%/yrIncreasing technology challenges,

possible show-stoppersMarket diversifying, segmenting, and

reconfiguring

Semiconductor International Jan 1998

• Key questionsMaintaining productivity growth

curveNew technologies for end of

roadmap

ENMA 465 Spring 2003Copyright G. W. Rubloff 2003, all rights reserved

Advanced Interconnect Technology

ITRS Interconnect 1999, Fig. 28

KA Monnig, Sematech 09/02/96

drawing to scalewithin 10%

Etch stops

Polish stops

Low-K dielectric

Metal barrier

Cu seed +Cu fill

BPSG dielectric

W plug

ENMA 465 Spring 2003Copyright G. W. Rubloff 2003, all rights reserved

Advanced Si ULSI Technology

KA Monnig, Sematech 09/02/96

drawing to scalewithin 10%

Etch stops

Polish stops

Low-K dielectric

Metal barrier

Cu seed +Cu fill

BPSG dielectric

W plug