A method of manufacturing an electronic device comprises: providing a layer of semiconductor material comprising a first portion, a second portion, and a third portion, the third portion connecting the first portion to the second portion and providing a semiconductive channel for electrical current flow between the first and second portions; providing a gate terminal arranged with respect to said third portion such that a voltage may be applied to the gate terminal to control an electrical conductivity of said channel; and processing at least one of the first and second portions so as to have an electrical conductivity greater than an electrical conductivity of the channel when no voltage is applied to the gate terminal. In certain embodiments, the processing comprises exposing at least one of the first and second portions to electromagnetic radiation. The first and second portions may be laser annealed to increase their conductivities.