An Effect of Filler-Induced-Stress to DRAM Sense Amplifier

As the higher integration of dymamic RAM (DRAM) causes the decrease of signal charge, the improvement on the sensitivity of sense amplifier circuits has become very important. The noise induced by peripheral circuits operation and the unbalance due to the variation of process parameters are dominant factors which reduce the sensitivity. Besides these factors, a new phenomenon has been found that the internal stress in the plastic molded package decreases the sensitivity of the sense amplifier. This paper will propose a new model describing the effect of the filler in plastics mold on the sensitivity of DRAM sense amplifier and investigate how to cope with the problem related to the plastic packaged VLSI DRAM.