IMPACT OF A VERTICAL PHI-SHAPE TRANSISTOR (V-PHI-T) CELL FOR 1 GBIT DRAM AND BEYOND

We propose a vertical Phi-shape transistor (V Phi T) cell for 1 Gbit D RAM and beyond, The V Phi T is a vertical MOSFET whose gate surrounds its channel region like a Greek-alphabetic letter Phi, fabricated thro ugh the penetration of the gate electrode (= word line) which has been formed beforehand, and the formation of the channel plug inside the p enetrating hole. The V Phi T provides the 4F(2) cell, The substantial simplicity of the V Phi T process contributes to the reduction in the number of process steps, The above two features result in the drastic reduction in total chip cost, Moreover, we demonstrate that the advant ages on electrical properties of the V Phi T become more prominent wit h proceeding of scaling down, We have indicated that the V Phi T is a promising candidate for the gigabit DRAM in terms of size, cost, and p erformance.