Improving threshold-voltage uniformity of 0.1 /spl mu/m InP-based MODFETs with different gate layouts
It is shown that the threshold-voltage uniformity of 0.1 µm InAlAs/InGaAs-based modulation-doped field-effect transistors with different numbers of gate fingers and different gate widths can be improved when a thin cap-layer structure is employed. This improvement is based on the reduction of the recess time. This reduction suppresses the difference in etching that results from the different etching rates caused by the different electrochemical effects that occur because of the varied gate layouts.