What’s Changing In DRAM


Most of the attention in chip scaling has been focused on logic and on-chip memory, but off-chip memory is starting to encounter problems, as well. David Fried, vice president of computational products at Lam Research, looks at the impact of shrinking features and increasing density, including variation, thermal effects and aging, as well as effects such as micro-loading and DRAM stacking. » read more

A Study Of Wiggling AA Modeling And Its Impact On Device Performance In Advanced DRAM


In this paper, a wiggling active area (fin) in an advanced 1x DRAM process was analyzed and modeled using the pattern-dependent etch simulation capabilities of the SEMulator3D semiconductor modeling software. Nonuniformity in sidewall passivation caused by hard mask pattern density loading was identified as the root cause of the wiggling profile. The calibrated model mimicked these phenomena, g... » read more

Micro Loading And Its Impact On Device Performance


In a DRAM structure, the charging and discharging process of capacitor-based memory cells is directly controlled by the transistor [1]. With transistor sizes approaching the lower limits of physical achievability, manufacturing variability and micro loading effects are becoming increasingly critical DRAM performance (and yield) limiters. The transistor’s AA (active area) dimension and profile... » read more