Interstitial Interactions: Arsenic‐Aluminum, Phosphorus‐Aluminum Push Effect

Abstract

Quantum chemical calculations on a model silicon lattice where the interstitial n‐type dopants, arsenic and phosphorus, interact with the interstitial p‐type dopants, aluminum and boron, yield net system energies in the sequence: . This sequence indicates that the interstitial boron‐phosphorus pair will repulse each other while the boron‐arsenic pair will not. This is consistent with the emitter push effect. However, when aluminum replaces boron the predicted behavior is that a push effect should be observed when either interstitial arsenic or phosphorus is present. The effect should be more pronounced in the aluminum‐arsenic case. Experiments, where low doses of aluminum with arsenic or phosphorus were implanted and then annealed, exhibited a push effect for both arsenic and phosphorus and, consistent with theoretical prediction, the effect was found to be more pronounced for arsenic.