Situ stringer removal during polysilicon capacitor cell plate delineation

摘要

Capacitors such as storage cells for Dynamic Random Access Memories are formed in a process for etching a polycrystalline silicon layer to form a storage cell during the manufacture of a semiconductor device. The etch results in a cell having reduced undercutting of the poly cell, and eliminates the formation of poly stringers. The inventive etch comprises the use of NF3 and/or SF6 during a magnetically enhanced low pressure reactive ion etch using a carbon-free etch gas of Cl2.