Compound tunneling field effect transistor integrated on silicon substrate and method for fabricating the same

摘要

Compound tunneling field effect transistors integrated on a silicon substrate are provided with increased tunneling efficiency and an abrupt band slope by forming a source region with a material having a bandgap at least 0.4 electron volts (eV) narrower than that of silicon to increase a driving current (ON current) by forming a channel region with a material having almost no difference in lattice constant from a source region and having a high electron mobility at least 5 times higher than silicon. ON/OFF current ratio simultaneously is increased by forming a drain region with a material having a bandgap at least as wide as a channel region material to restrain OFF current. Tunneling field effect transistors having various threshold voltages according to circuit designs are formed easily by adding a specific material with an electron affinity less than a source region material when forming a channel region.

主权项

1. A compound tunneling field effect transistor comprising:
a silicon substrate; a source region formed of a first semiconductor material having a lattice constant difference with silicon 5% or less, a bandgap at least 0.4 electron volts (eV) narrower than that of silicon and a first conductive type on the silicon substrate; a channel region formed of a second semiconductor material having a lattice constant difference with the first semiconductor material 2% or less, a bandgap wider than that of the first semiconductor material and electron mobility at least 5 times higher than that of silicon on the source region; a drain region formed of a third semiconductor material having a lattice constant difference with the second semiconductor material 1% or less, a bandgap wider than or equal to that of the second semiconductor material and a second conductive type opposite to the first conductive type on the channel region; a gate dielectric layer formed on a sidewall of the channel region; and a gate electrode formed on the gate dielectric layer, wherein a vertical channel is further included.