Ultra thin TCS (SiCl4) cell nitride for DRAM capacitor with DCS (SiH2cl2) interface seeding layer

摘要

A method for forming silicon nitride films on semiconductor devices is provided. In one embodiment of the method, a silicon-comprising substrate is first exposed to a mixture of dichlorosilane (DCS) and a nitrogen-comprising gas to deposit a thin silicon nitride seeding layer on the surface, and then exposed to a mixture of silicon tetrachloride (TCS) and a nitrogen comprising gas to deposit a TCS silicon nitride layer on the DCS seeding layer. In another embodiment, the method involves first nitridizing the surface of the silicon-comprising substrate prior to forming the DCS nitride seeding layer and the TCS nitride layer. The method achieves a TCS nitride layer having a sufficient thickness to eliminate bubbling and punch-through problems and provide high electrical performance regardless of the substrate type. Also provided are methods of forming a capacitor, and the resulting capacitor structures.