METHOD FOR PRODUCING A SEMICONDUCTOR MEMORY ELEMENT

摘要

The invention relates to a method for producing a semiconductor memory element, in particular a DRAM or FRAM. Said memory element comprises a silicon substrate, an intermediate oxide layer (1) applied to the latter, upon which an upper layer (3) consisting of a ferroelectric material or a material with higher dielectric constants is provided. A contact cavity (8) which extends up to the border between the silicon substrate and the upper layer is etched, from the starting point of an opening (5) in a cavity mask which has been configured in a previous stage. A material resistant to high temperatures is used for the cavity mask. Such a material must withstand high temperatures so that the subsequent deposition of O>3<-TEOS-SiO>2< onto this layer (for example polyimide) can take place, without causing any degradation of said layer. The cavity mask is used for etching into the intermediate oxide layer (1), causing the formation of a recess (8'). A layer consisting of O>3<-TEOS-SiO>2< is then deposited onto the resultant structure. In order to create the contact cavity, the O>3<-TEOS-SiO>2< layer is removed from the base of the recess (8') by etching and said recess (8') is then sunk to the border with the silicon substrate by etching, thus exposing the substrate.