Plasma dicing of silicon wafers is beginning to move from pilot scale into mainstream production. Attention is now focusing on other market sectors which may benefit from a similar dicing approach. The fragility of GaAs wafers leads to issues (such as wafer breakages, damage to die edges) during conventional wafer saw dicing. Although LASER techniques have been developed, they also have their own drawbacks – specifically sidewall quality. A systematic investigation of the current capabilities of plasma dicing of GaAs substrates has been performed, developing technology which is both practical and economically viable. Preliminary results show smooth vertical sidewalls of trenches suitable for dicing thinned GaAs substrates at etch rates up to 23μm min-1.