High quality Al/sub 2/O/sub 3/ IPD with NH/sub 3/ surface nitridation

In this letter, the effect of surface NH/sub 3/ nitridation on the electrical properties and reliability characteristics of aluminum oxide (Al/sub 2/O/sub 3/) interpoly capacitors is studied. With NH/sub 3/ 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/sub bd/) of Al/sub 2/O/sub 3/ interpoly capacitors with surface NH/sub 3/ nitridation.