Universities design multi-project GaAs wafers

A number of UK universities have recently completed their designs for a multi-project gallium-arsenide wafer. These have been fabricated in the UK by Plessey III/V Limited. The initiative, which was led by the Science and Engineering Research Council, was aimed at giving the universities some experience in designing monolithic microwave integrated circuits (MMICs) at low cost. The project involved seven design teams from UK universities and the Rutherford-Appleton Laboratory. Each designer was allocated a 2 mm×2 mm area within a die site. The final eight designs, plus a process monitoring drop-in, were arranged in a 3×3 array. This was then replicated all over the 2" wafer. The author discusses the chosen design vehicle-the travelling wave amplifier, the fabrication process used, simulation, layout and present programme status