An improved process for self-aligned contact window formation in an integrated circuit leaves a "Stick" of etch stop on vertical sidewall surfaces to be protected. The technique includes, in the preferred embodiment, a layer of oxide over active areas and on top of the gate electrode of a transistor....http://www.google.es/patents/US4686000?utm_source=gb-gplus-sharePatente US4686000 - Self-aligned contact process
