Advantages of vapor-plated phosphosilicate films in large-scale integrated circuit arrays

The use of low temperature phosphosilicate glass (PSG) films which are compatible with aluminum-metallized integrated circuits, has been found to possess significant merits in LSI applications. PSG used on integrated circuits fabricated in production has resulted in improvements in fabrication yields and device performance and reliability. The properties and effects of PSG which contribute to these benefits have been determined and studied. They include hardness, ability to getter alkali ions, effect on immobile charge density, ability to quench fast states, low stress, resistance to cracking, low pinhole density, and effect on electromigration. The deposition system used to deposit the PSG films and the phosphorus content of the films are also discussed.