公开(公告)号：GB2516841A

公开(公告)日：2015-02-11

申请号：GB201313718

申请日：2013-07-31

Applicant: IBM

Inventor： ELEFTHERIOU EVANGELOS STAVROS ,  MARCHIORI CHIARA ,  SANTINI CLAUDIA ,  SEBASTIAN ABU ,  DELLMANN LAURENT A

IPC: G11C13/00 ,  C23C16/26 ,  G11C11/56 ,  H01L45/00

Abstract: A resistive memory element preferably a resistive read only memory element (RRAM), comprising a resistively switchable material 14 coupled to two conductive electrodes 12, 16, wherein the resistively switchable material 14 is an amorphous compound comprising 5 carbon and oxygen, the C:O stoichiometric ratio being a range of 1:0.30 to 1:0.80 and preferably in the range 1:0.4 to 0:0.6. The properties of the switching material are determined by the presence of the sp2 bonds which are conducting and the sp3 bonds which are insulating. Preferably the ratio of C-C sp2 bonds to C-C sp3 bonds in the resistively switching material is less than 0.4 preferably less than 0.2 or 0.1 . The resistively switching material may be doped with silicon, hydrogen of nitrogen and may be of thickness 2nm to 30nm. The electrodes may consist of differing materials in contact with the resistively switching material and made from Tungsten, Platinum, graphite, graphene and aluminium. The resistive memory element may comprise a patterned SiO2 insulating layer over an electrode (12, figure 3) to form a cavity enabling a conformal layer of restively switching material to be formed (14, figure 3). Programming of storage information is achieved by a method of applying a voltage pulse between the conductive electrodes and can be unipolar or bipolar. The fabrication process includes a method whereby reactive sputtering in a chamber comprising a graphite target in the presence of oxygen O2 and Argon Ar gases in a plasma state such that oxygenated amorphous material (a-C:O ) is deposited on the conductive electrode 12 (see figure 4).