Analyzing the Inherent Reliability of Moderately Sized Magnetic and Electrostatic QCA Circuits Via Probabilistic Transfer Matrices

As computing technology delves deeper into the nanoscale regime, reliability is becoming a significant concern, and in response, Teramac-like systems will be the model for many early non-CMOS nanosystems. Engineering systems of this type requires understanding the inherent reliability of both the functional cells and the interconnect used to build the system, and which components are most critical. One particular nanodevice, quantum-dot cellular automata (QCA), offers unique challenges in understanding the reliability of its basic circuits since the device used for logic is also used for interconnect. In this paper, we analyze the reliability properties of two classes of QCA devices: molecular electrostatic-based and magnetic-domain-based. We use an analytic model, probabilistic transfer matrices (PTMs), to compute the inherent reliability of various nontrivial circuits. Additionally, linear regression is used to determine which components are most critical and estimated the reliability gains that may be achieved by improving the reliability of just a critical component. The results show the critical importance of different structures, especially interconnect, as used by the two classes of QCA.