Spin-on carbon compositions for lithographic processing

A method of forming a microelectronic structure, said method comprising:

• providing a substrate having a surface;
• optionally forming one or more intermediate layers on said substrate surface, there being an uppermost intermediate layer on said substrate surface, if one or more intermediate layers are present;
• applying a composition to said uppermost intermediate layer, if present, or to said substrate surface, if no intermediate layers are present, said composition comprising a polyamic acid dissolved or dispersed in a solvent system, wherein said polyamic acid includes recurring monomers having the formulas
• where each of
• is individually selected from the group consisting of aliphatic and aryl groups;
• heating said composition to form a carbon-rich layer, said carbon-rich layer being developer soluble, and exhibiting a weight loss of less than about 10% at a temperature of about 400° C. for about 10 minutes.