Using effective wet etching technology to improve deep trench shape

Abstract

This paper reports a wet etching technoloLy for mod5ing french shape of fhe DRAM capacifor to enhance effective capacitance surface area. The ammonium hydroxide-wafer bured wet etching solution was prefered over other etchants in our sfu& experiments. The testedsamples dipped in obout 0.57 wt. % NH4OH then rinsed by HZO in sequence showed that excellent shape mod+ation of the DRAM capacitor deep trench can be achieved