Isolation of junction devices in GaP using electron bombardment

High energy electron bombardment produces high resistivity layers in n- and p-type GaP and varies from an original orange colour of the crystal to black colour. This new technique is useful for electrically and optically isolating GaP junction diodes. A test pattern of an XY matrix of LED arrays (∼100µm square) was fabricated by scanning the beam spot (∼5µmφ) at 1 and 2 MeV by ultra-high voltage electron microscope. After bombardment, the resistance between the separated diodes increased to over 10⁷Ω.