High dielectric LDD spacer technology for high performance MOSFET using gate-fringing field effects

A MOSFET with high-dielectric LDD (lightly doped drain) spacer material (HLDD) was investigated. As the dielectric constant of the LDD spacer becomes higher, the gate-fringing field increases, resulting in drain field reduction. Therefore, low impact ionization in HLDD can be achieved. Moreover, high transconductance can be realized in the HLDD due to small source parasitic resistance in the HLDD caused by the large gate-fringing field effects. It is also shown that gate-fringing field effects have a considerable influence on the LDD MOSFET performance in scaling down the transistor's dimensions. >