Impact of BTI on Random Logic Circuit Critical Timing
Kin P. Cheung, Jiwu Lu, Guangfan Jiao, Jason P. Campbell, Jason T. Ryan
Bias temperature instability (BTI) is known to be a serious reliability issue for state-of-the-art Silicon MOSFET technology [1-6]. It is well-known that in addition to a permanent degradation, there is a large recoverable degradation component  that gets larger as the delay between stress and measure is shorter. This recoverable component, when it is taken into account, is often treated as a source for lifetime extension [1-6, 8-12]. In other words, the recovery buys margin in measured lifetime. BTI degradations mostly manifest as threshold voltage (VTH) increase, leading to frequency degradation in ring-oscillator (RO) test circuits [8-12]. This RO degradation is the most circuit relevant BTI guidance for circuit designers even though RO patterns are poor representations of random digital logic. The fact that recovery is time sensitive leads one to ask, naturally, what will happen to the random pattern in a real logic circuit? To answer this question, existing experimental techniques are not adequate. We recently developed a single transistor eye-diagram technique to address this question and found a previously overlooked but serious BTI impact on critical timing of random logic circuits [13, 14].
2014 IEEE 12th International Conference on Solid-State and Integrated Circuit Technology
, Lu, J.
, Jiao, G.
, Campbell, J.
and Ryan, J.
Impact of BTI on Random Logic Circuit Critical Timing, 2014 IEEE 12th International Conference on Solid-State and Integrated Circuit Technology, Guilin, -1, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=917272
(Accessed August 8, 2022)