Platinum alloys and iridium bottom electrodes for perovskite based capacitors in dram applications |
| |
Authors: | A. Grill M. J. Brady |
| |
Affiliation: | IBM Research Division , T. J. Watson Research Center , Yorktown Heights , N. Y. , 10598 , USA |
| |
Abstract: | Abstract Two types of potential bottom electrode structures for integration of ferroelectric materials in DRAM technology have been investigated: one based on iridium, the other based on platinum alloyed with oxygen gettering elements, such as B and Ti. The electrode structures, deposited on Si substrates, have been annealed in oxygen at 650°C for 30 min and characterized by RBS and AES. It was found that alloying the Pt with 3% of alloying elements had no beneficial effect and did not improve the properties of Pt as a barrier to oxygen diffusion. At the investigated annealing conditions, oxygen diffuses through Pt or its alloys and oxidizes the underlaying material. On the other hand, a thickness of 1100 Å of Ir was found to provide a barrier to oxygen diffusion under the same conditions. A layer of Ta in contact with Pt or Ir was found to deteriorate the barrier properties of both metals at the investigated annealing conditions. |
| |
Keywords: | electrodes iridium platinum alloys diffusion barriers |
|
|