Vertical tft with multilayer passivation

A vertical transistor comprising:

• a substrate;
• an electrically conductive gate structure having a reentrant profile, the electrically conductive gate structure in contact with the substrate;
• a conformal gate insulating layer in contact with the gate structure in the reentrant profile;
• a conformal semiconductor layer in contact with the conformal gate insulating layer, the conformal semiconductor layer having a channel portion;
• a first electrode in contact with a first portion of the conformal semiconductor layer over the electrically conductive gate structure;
• a second electrode that is in contact with a second portion of the conformal semiconductor layer and separated vertically from the first electrode, the first and second electrodes defining the channel portion of the conformal semiconductor layer that is between the first and second portions of the conformal semiconductor layer;
• and
• a multilayer insulating structure in contact with at least the channel portion of the conformal semiconductor layer in the reentrant profile, the multilayer insulating structure including an inorganic dielectric layer and a polymer structure, the polymer structure in contact with the channel portion of the conformal semiconductor layer in the reentrant profile.