Scalable High Voltage Trenchgate Transistor for Flash

A trench-gate n-MOSFET suitable for high voltage operation as required for flash memories or LCD-Displays is studied. The transistor channel is folded into the substrate along the walls of a trench. This geometry offers area scalability while keeping minimum dimensions of channel length and ldd drift region needed to deal with the high voltages. The maximum drain voltage of 15V for the transistors examined is limited by breakdown of the reverse biased drainsubstrate junction. Short channel effects as DIBL or punchthrough are suppressed due to the concave corner effect for structures down to 0.6 m gate footprint.