Method for lithographic patterning of organic layers

A method for photolithographic patterning of an organic layer deposited on a substrate, the method comprising:

• providing a shielding layer on the organic layer;
• providing a photoresist layer comprising a negative tone photoresist on the shielding layer;
• illuminating the photoresist layer through a shadow mask;
• developing the photoresist layer, thereby forming a patterned photoresist layer;
• performing a first dry etching which uses the patterned photoresist layer as a mask, thereby completely removing the shielding layer at locations not covered by the photoresist layer, thus forming a patterned shielding layer;
• performing a second dry etching which uses the patterned shielding layer as a mask, thereby completely removing the organic semiconductor layer at locations not covered by the shielding layer;
• and
• completely removing the shielding layer,
• wherein:
• the performing of a first dry etching further comprises removing at least an upper portion of the photoresist layer;
• the performing of a second dry etching further comprises removing a remaining portion of the photoresist layer;
• the performing of a second dry etching further comprises removing an upper portion of the shielding layer;
• the upper portion of the photoresist layer which is not developed and removed in the first dry etching step and the upper portion of the shielding layer in which the region is covered by the photoresist layer are removed in the second dry etching step;
• the photoresist layer is completely removed, resulting in a thinned shielding layer in the second dry etching;
• and
• the step of completely removing the shielding layer comprises exposing the shielding layer to water, and the shielding layer comprises a water-based polymer material that is not cross-linkable.