P-type SiGe transistors with low gate leakage using SiN gate dielectric

Using high-quality jet-vapor-deposited (JVD) SIN as gate dielectric, p-type SiGe transistors are fabricated on SiGe heterostructures grown by ultra-hi gh-vacuum chemical vapor deposition (UHVCVD), For an 0.25-mu m gate-length device, the gate leakage current is as small as 2.4 nA/mm at V-ds = -1.0 V and V-gs = 0.4 V. A maximum extrinsic transconductance of 167 mS/mm is meas ured, A unity current gain cutoff frequency of 27 GHz and a maximum oscilla tion frequency of 45 GHz are obtained.