A NOVEL PLANARIZATION OF TRENCH ISOLATION USING POLYSILICON REFILL AND ETCHBACK OF CHEMICAL-MECHANICAL POLISH

Abstract

The planarization of trench isolation refilled by deposition oi polysilicon was investigated. Results show that the planarization by RIE etching has poor surface planarity. On the other hand, an excellent surface planarity can be achieved by the CMP process resulting from the high etching selectivity of polysilicon to nitride. This simple process provides a very promising candidate for trench isolation.