High quality Al2O3IPD with NH3 surface nitridation

Abstract

In this letter, the effect of surface NH3 nitridation on the electrical properties and reliability characteristics of aluminum oxide (Al2O3) interpoly capacitors is studied. With NH3 surface nitridation, the formation of an additional layer with lower dielectric constant during post-annealing process can be significantly suppressed, compared to that without nitridation treatment. Furthermore, the presence of a thin Si-N layer can make post-deposition annealing more effective in eliminating traps existing in the as-deposited films. As a result, a smoother interface and smaller electron trapping rate can contribute to the drastically reduced leakage current, enhanced breakdown field and charge to breakdown (Q(bd)) of Al2O3 interpoly capacitors with surface NH3 nitridation.