A 17.5-GHz 3-bit phase-shift receive MMIC-fabrication and test results

A high-yield, FET gate fabrication technology is described. The main advantage of this processing approach is that it permits fabrication of devices with gate lengths of less than 0.5 μm using standard optical photolithography without recourse to deep UV or electron-beam lithography. The process is simple and easy to implement in a manufacturing environment. Exceptionally good gate-length control, typically 10% for a 0.4-μm-long gate, is demonstrated. Yield of a 300-μm-wide FET, designed for use in a gain block and in a switch, is found to be 89% on average. Data on wafer-to-wafer and on-wafer variations in device DC and RF parameters and equivalent circuit values are presented. Typical standard deviations are in the 5-10% range. This process technology has been used to fabricate a 17.5-GHz, 3-b phase-shift receive monolithic microwave integrated circuit (MMIC) of moderately high complexity. Statistics of RF data on 704 such devices, fabricated over a period of two years, are presented. It is shown that such MMICs can be fabricated with yields sufficient for prototype active phased-array antenna applications