High Speed 0.18μm Ion-implanted GaAs MESFET Process with High Uniformity & Excellent Reproducibility

We successfully obtained an 0.18μm gate MESFET with a high breakdown voltage (Vbd) of 7V, high current gain cut off frequency (fT) of 100 GHz, and sufficient transconductance (Gm) larger than 500mS/mm for high-speed front end ICs of optical communications. In addition, excellent uniformity and reproducibility of device characteristics, such as the standard deviation (std.) of threshold Voltage (Vth) across a 4-inch wafer of smaller than 35mV and the variation of Vth from wafer to wafer of smaller than 45 mV, were achieved. These results are comparable to those of P-HEMT and demonstrated that our ion-implanted MESFETs are suitable for low cost and high performance IC applications. Fig. 1 Schematic diagram of MESFET