A high voltage logic circuit for high voltage system application comprises a first device layer formed from a first semiconductor material and comprises a low voltage logic circuit; and a second device layer formed from a second different semiconductor material and comprising one or more components of an additional circuit for generating a high voltage logic output from a low voltage logic input from the low voltage logic circuit; wherein the first and second device layers are integrally formed. Also, a logic circuit comprising: a low voltage logic input; a high supply voltage input; a circuit ground voltage input; a high voltage output; a first tail device made from a first semiconductor material; and a second tail device made from a second different semiconductor material; wherein the first and second tail devices are coupled, in series, between the high voltage output and the circuit ground voltage input; and wherein respective gates of the first and second tail devices are coupled, in parallel, to the low voltage logic input.