Vertical p-MOSFETs with gate oxide deposition before selective epitaxial growth

A novel vertical MOSFET concept using selective epitaxial growth by low pre ssure chemical vapor deposition is proposed and the first p-channel device characteristics measured are described. In contrast to other MOS technologi es, the gate oxide is deposited before epitaxy, and therefore it exists bef ore the channel region is grown. Compared to planar layouts, the vertical l ayout increases the packing density without the use of advanced lithography ; the extent of the increase depends on application. Compared to other Vert ical transistors, this concept reduces overlap capacitance and offers the p ossibility of three-dimensional integration. Vertical p-channel MOSFETs wit h a channel length L-G down to 130 nm and a gate oxide thickness d(ox) down to 12 nm have been fabricated and yield a transconductance of 100 mS mm(-1 ). (C) 1999 Elsevier Science Ltd. AII rights reserved.