Ringing error prevention techniques in Lucy-Richardson deconvolution process for SRAM space-time margin variation effect screening designs

This paper proposes a ringing error avoidance technique in Lucy-Richardson-deconvolution (L-R-Dcnv) process, which is used for inversely analyzing the Random Telegraph Noise (RTN) effects on overall SRAM margin variations. The proposed ringing prevention technique successfully circumvents the ringing error by reducing the phase difference between the feedback-gain and deconvolution target distributions in L-R-Dcnv iteration cycles. This avoids any unwanted positive feedbacks, resulting in no error amplification. This effectiveness has been demonstrated with applying it to a real L-R-Dcnv analysis for the effects of the RTN on the overall SRAM margin variations, while exploiting a quicker convergence benefit of L-R-Dcnv algorithm. It has been shown that the proposed technique reduces its relative errors of the RTN deconvolution by 10²~10³ times compared with the conventional L-R-Dcnv. This enables to increase an accuracy of the fail-bit-count prediction based on the cumulative density function (cdf) of the convolution of the RTN with the Random Dopant Fluctuation (RDF) by over 2-orders of magnitude while accelerating its convergence speed by 7~30 times of the conventional one.