1. A method of forming an etch barrier in the reactive ion etching of an aromatic polyamic acid/imide which comprises: coating a surface with a layer of an aromatic polyamic acid; at least partially curing the layer of aromatic polyamic acid to the corresponding aromatic polyimide; in situ converting the surface layer of the aromatic polyimide to a silicon containing alkyl polyamide/imide; applying, exposing, and developing a layer of photoresist over the silicon containing alkyl polyamide/imide to selectively expose a portion of the silicon containing alkyl polyamide/imide surface layer; reactive ion etching the exposed portion of the surface layer of the silicon containing alkyl polyamide/imide with carbon tetraflouride to remove the exposed portion of the silicon containing alkyl polyamide/imide surface layer; reactive ion etching the resultant structure with an oxygen agent to etch an interconnect in the aromatic polyimide while removing the photoresist down to the silicon containing alkyl polyamide/imide surface layer; and reacting the silicon containing alkyl polyamide/imide surface layer exposed upon removal of the photoresist by the oxygen reactive ion etching to thereby convert the same to a silicon dioxide etch barrier.