A Subthreshold Adaptive-Reference Leakage- Compensation Sensing Scheme for 3D PCM With Enhanced Sensing Margin and Endurance

3D phase-change memory (3D PCM) is one of the primary candidates for next-generation memory technologies. To enhance its endurance, a subthreshold read operation has been proposed. However, this operation exhibits extremely low read currents, which are further compromised by a considerable amount of leakage currents, thereby deteriorating the sensing margin. To address this challenge, this paper proposes a subthreshold adaptive-reference leakage-compensation sensing scheme for 3D PCM. The reference current is address-adaptive, and the leakage current is sampled and compensated accurately. Evaluation results demonstrate significant improvements in the proposed circuit. The sensing margin is increased by up to 46.7% and 34.7% across different half-selected cell statuses and addresses, respectively, compared to the conventional leakage-compensation sensing scheme. Moreover, the read endurance is increased by
$51\times $
, compared to the conventional read operation.