Papers by Keyword: Silicon Surface Passivation

Abstract: The silicon surface passivation with diluted HF solutions is hereby explained. Without a very stable, correct Si-H surface passivation, a rough silicon surface can be obtained, leading to poor gate oxide integrity or bad epi film quality. Detailed mechanism are depicted and solutions to obtain best Si-H passivated surface are given

Abstract: “HF Last” process are widely used as pre epi cleans. They enable a Si-H surface to grow a perfect Si layer by epitaxy. Nonetheless, such hydrophobic wafers are extremely sensitive to watermarks formation during the wafer drying. A design of experiments has been used to determine which parameters impact their formation on a single wafer cleaning tool. Plus, the silicon surface stability has been compared between this tool and an immersion batch cleaning tool.

Abstract: Surface passivation in silicon wafers is investigated by contactless photoconductance measurements. It is shown that the deposition of a-Si:H layers on top of c-Si wafers leads to passivation of the c-Si surface. Passivation by Si3N4 of the p c-Si surface is at least partially due to the depletion layer at the interface. The separation of excess charge carriers by the depletion field is responsible for a relatively slowly decaying part of the signal not directly related to bulk recombination. An HF dip is not sufficient for an appropriate passivation of p c-Si but immersion in I2/ethanol solution is promising.