Effect of substrate negative bias on GIDL current in LDD nMOSFET´s

The effect of substrate negative bias V_B on the gate-induced drain leakage (GIDL) current is studied. It is found that the negative V_B leads GIDL current curve shifts upwards. The shift of GIDL current ΔI_D/I_D increases with increasing |V_B|. The GIDL current at V_G=-0.2V (in the low field region) increases with increasing |V_B| more largely than that at V_G=-1.2V (in the high field region).This is because that the negative V_B results in the additional GIDL tunneling current in the lateral direction and it has the different effects on the low field region and high field region. It is also found that ΔI_D/I_D at V_D=0.8V is larger than that at V_D=0.4V under V_G=-1.2V and is smaller than that at V_D=0.4V under V_G= 0.2V. This ascribes the different roles of the GIDL vertical tunneling current and the GIDL lateral current induced by negative V_B on the whole GIDL current.