The effect of hydrogen denudation on thin oxides, device performance, and epitaxial elimination

With the cost of each new technology generation increasing at an alarming rate, it has become imperative that technologies that provide for process simplification and material cost reduction be investigated. With the switch from diffused wells to implanted retrograde wells the potential for epitaxial material replacement exists. The impact of pre-process high temperature annealing in a hydrogen ambient has been demonstrated to provide for improved material performance as compared to conventional CZ material. Improvements in gate oxide quality and diode leakage have been observed through application of the H₂ anneal. Material analysis such as TEM, SIMS impurity profiling, denuded zone analysis, and surface studies suggest that the mechanism for the improved performance of the H₂ annealed wafer is due to improvements in oxygen denuded zone formation and silicon surface quality