A study on ILD process of simple and CMP skip using polysilazane-based SOG

Abstract

Unit process conditions including coating and baking were optimized to use polysilazane-based spin on glass(SZ-SOG) which has excellent gap filling and planarization ability in an inter layer dielectric (ILD) layer, and this material was successfully and simply integrated for the first time in an ILD layer of a logic device without an expensive chemical mechanical polishing (CMP) process. Device characteristics showed that breakdown voltage and transistor threshold voltage of devices with SZ-SOG in the ILD layer are comparable with those with the conventional borophosphosilicate glass (BPSG). Also, the yield results showed that SZ-SOG group without CMP is similar to BPSG group with CMP. SZ-SOG has no reliability problems even up to 1000 hr.