DocumentCode :
174649
Title :
Improved signoff methodology with tightened BEOL corners
Author :
Tuck-Boon Chan ; Dobre, Sorin ; Kahng, Andrew
Author_Institution :
ECE Depts., UC San Diego, San Diego, CA, USA
fYear :
2014
fDate :
19-22 Oct. 2014
Firstpage :
311
Lastpage :
316
Abstract :
To ensure functional correctness, conventional chip implementation methodology signs off the SOC design at extreme process, voltage and temperature (PVT) conditions. At the 20nm node and beyond, the back end of line (BEOL) layers have become major sources of variation, which must be accounted for by signoff at various BEOL corners. Conventional signoff methodology uses extreme BEOL corners, in which all BEOL layers are skewed to the worst-case condition (e.g., all BEOL layers have the worst parasitic capacitance). However, such a BEOL condition is very pessimistic because the probability of having all BEOL layers skew towards the worst-case condition simultaneously is extremely small. Such pessimism results in longer chip implementation schedules and poorer design quality. In this paper, we propose a signoff methodology with tightened BEOL corners to recover the pessimism incurred by the conventional BEOL corners. This approach is based on the observation that most timing-critical paths use different BEOL layers. When the variations of BEOL layers are not fully correlated, the BEOL-induced timing variation is much smaller due to averaging of random variations. Our experimental results show that by using tightened BEOL corners, we can reduce timing-violation paths by up to 100% and improve the WNS and TNS by up to 101ps and 53ns, respectively.
Keywords :
integrated circuit design; system-on-chip; SOC design; back-end-of-line layers; functional correctness; process variation; sign-off methodology; size 20 nm; temperature variation; tightened BEOL corner; timing critical path; voltage variation; Capacitance; Delays; Metals; Resistance; Sensitivity; Wires;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Computer Design (ICCD), 2014 32nd IEEE International Conference on
Conference_Location :
Seoul
Type :
conf
DOI :
10.1109/ICCD.2014.6974699
Filename :
6974699
Link To Document :
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