▎ 摘　　要

NOVELTY - The method of producing an electronic device precursor (400) involves: providing a plasma-etchable layer structure on a plasma-resistant substrate, where the layer structure has an exposed upper surface; patterning a plasma-resistant dielectric by physical vapor deposition onto the exposed upper surface to form an intermediate having at least one covered region and at least one uncovered region of the layer structure; subjecting the intermediate to plasma etching, where the uncovered region of the layer structure is etched away to form at least one covered region of the layer structure having an exposed edge surface; forming an ohmic contact in direct contact with a portion of the exposed edge surface, where the plasma-etchable layer structure has graphene layers which extend across the covered regions of the layer structure to the exposed edge surface; and forming a coating layer to provide the covered region of the layer structure with a continuous air-resistant coating (425). USE - Method of producing an electronic device precursor for use in electronic devices such as oraganic LEDs and Hall-sensors. ADVANTAGE - The method avoids unnecessary and detrimental contamination and/or doping, thus providing precursor with long-term stability and/or improved temperature stability. DETAILED DESCRIPTION - aAn INDEPENDENT CLAIM is included for an electronic device precursor. DESCRIPTION OF DRAWING(S) - The drawing shows a plan view of electronic device precursor. Electronic device precursor (400) Silicon substrate (405) Patterned alumina layer (415) Titanium contacts (420a, 420b, 420c, 420d) Continuous air-resistant alumina coating (425)