Impact of dopant segregation on fully depleted Schottky-barrier SOI-MOSFETs

The effect of silicidation induced dopant segregation (DS) on the electrical behavior of silicon-on-insulator Schottky-barrier MOSFETs (SB-MOSFETs) is investigated. We use ion implantation with arsenic and boron and subsequent nickel silicidation to create highly n- and p-doped layers at the contact-channel interfaces. Devices with dopant segregation exhibit an inverse subthreshold slope of ∼60 mV/dec and improved on-currents for n-type as well as p-type SB-MOSFETs due to a lowering of the effective Schottky-barrier height (SBH) compared to SB-MOSFETs without DS. In addition, our findings are supported by simulations. Temperature dependent measurements show that a reduced SBH as low as ∼0.1 eV for electrons has been achieved. As a result, the dopant segregation technique greatly relaxes the requirement for low SB silicides to realize high performance SB-MOSFET devices.