Patent ID: 7267996

Claim:
A method of etching an iridium layer for use in a ferroelectric device, comprising: preparing a substrate; depositing a barrier layer on and in contact with the substrate; depositing an iridium layer on the barrier layer; depositing a layer of TiN over the iridium layer as a replacement gate; etching a portion of the iridium/TiN stack; depositing a layer of TEOS over the remaining iridium/TiN stack; polishing to remove the TEOS layer to the level of the upper surface of the TIN layer; etching to remove the TiN layer; depositing a hard mask layer on and in contact with the iridium layer; depositing, patterning and developing a photoresist layer on the hard mask; etching the hard mask layer; etching the iridium layer using argon, oxygen and chlorine chemistry in a high-density plasma reactor; and depositing a layer of ferroelectric material in place of the removed TiN; completing the ferroelectric device.