Akihito Yamamoto

23.5 A 4Gb LPDDR2 STT-MRAM with compact 9F2 1T1MTJ cell and hierarchical bitline architecture

Spin-transfer torque magnetic RAM (STT-MRAM) is one of the most promising nonvolatile memories with guaranteed high-speed read and write operations. Along with performance improvements in the tunnel magnetoresistance (TMR) and the magnetic tunnel junctions (MTJ) required switching current, there have also been reports on high-capacity (up to tens of Mb) STT-MRAM [1–4]. In [2] a perpendicular-TMR (pMTJ) device is used to reduce the switching current and a high-speed current sense amplifier is proposed. In [3] a 54nm 2T-1MTJ 14F2-cell is proposed that uses a high-density DRAM process: self-aligned contact and plug process. However, the unit cell area of STT-MRAM is still much larger than that of DRAM, making STT-MRAM not cost-competitive to contemporary DRAM.

Gas cleaning technique for batch furnace at Agile-fab concept manufacturing

To satisfy both the quick turn around time and the process compatibility with the current product line at LPCVD process, the mini-batch furnace is one of the reasonable options. For the high tool utility and the capital scalability at small manufacturing line, the minibatch furnaces are required short time and high frequency tool cleaning for the low machine down time and process commonality for different kind of films LPCVD. In this paper, the short time and high frequency tool cleaning is proposed not only for productivity but also for particle controls.