Planar thin film transistor structures

A semiconductor transistor device formed on a semiconductor substrate, comprising:

• a transistor gate having a top surface;
• a transistor gate sidewall spacer against the transistor gate;
• a discrete conductor having a top surface which is substantially coplanar with the transistor gate top surface;
• a discrete conductor sidewall spacer against the discrete conductor;
• an insulating filler provided over the semiconductor substrate and against both the transistor gate sidewall spacer and the discrete conductor sidewall spacer, the insulating filler having generally planar upper insulating surfaces which are substantially coplanar with the top surfaces of the transistor gate and the discrete conductor, the insulating filler comprising a silicate;
• and
• a generally planar semiconductor thin film provided over the transistor gate, over the adjacent generally planar insulating surfaces, and at least partially over the discrete conductor, the generally planar semiconductor thin film being doped to form source and drain regions of a thin film transistor which is bottom gated by the transistor gate.