Study of the atomic models of three donor-like traps on oxidized silicon with aluminum gate from their processing dependences

The effects of processing on the generation of three donor-like traps, i.e., the bulk compensating donor, the donor-like turn-around trap, and the peaked interface donor in boron doped p-Si aluminum-gate metal-oxide- semiconductor capacitors, are reported. After a possible initial delay, the generation of the bulk compensating donor follows first-order kinetics with a final density always approaching the initial boron concentration over the present experimental range 2.5×10¹⁶-1. 5×10¹⁷ boron/cm³. The initial delay and the generation cross section of the bulk compensating donor and the generation cross sections and the densities of the turn-around and peaked interface donors are process dependent. Experimental evidence indicates that the three traps are water related. The close correlation of their generation-annealing kinetics suggests that they may be from the same water-related mobile impurity species, such as atomic hydrogen, released by the avalanche injected hot electrons. The generation kinetics of the three donors could involve (i) bond breaking and release of some water-related species, such as atomic hydrogen, at the Al-SiO₂ interface or in the oxide, (ii) transport of the species through the oxide, (iii) modification of the peaked interface donor and the donor-like turn-around trap when the species reached the oxide-silicon interface, and (iv) formation of the bulk compensating donor when the species penetrate the silicon surface space charge layer.