Bottom gate tft with multilayer passivation

A transistor comprising:

• a substrate;
• a gate in contact with the substrate;
• a gate insulating layer in contact with at least the gate;
• an inorganic semiconductor layer in contact with the gate insulating layer;
• a source electrode in contact with a first portion of the inorganic semiconductor layer;
• a drain electrode in contact with a second portion of the inorganic semiconductor layer, the source electrode and the drain electrode separated by a gap;
• and
• a multilayer insulating structure in contact with at least the inorganic semiconductor layer in the gap, the multilayer structure including:
• an inorganic dielectric layer having a first pattern defining a first area;
• and
• a multilayer polymer structure comprising:
• a first polymeric layer having a second pattern defining second area located within the first area;
• and
• a second polymeric layer in contact with the first polymeric layer and with the semiconductor layer in the gap, the second polymeric layer having a third pattern defining a third area located within the second area, wherein the first area extends beyond the second area to define a reentrant profile under the inorganic dielectric layer, the transistor further comprising another inorganic dielectric layer that is conformal and extends beyond the first area.