Boron segregation and electrical properties in polycrystalline Si1ÀxÀyGexCy and Si1ÀyCy alloys
نویسندگان
چکیده
In this article, we report strong boron segregation to polycrystalline Si12x2yGexCy from polysilicon during thermal anneals in the temperature range of 800–900 °C. This effect is larger than previous reports of segregation to single-crystal Si12xGex and increases with carbon concentration. Segregation also occurs in polycrystalline Si12yCy , revealing that carbon by itself can drive the segregation ~without germanium present!. This segregation is used to model the enhanced threshold voltage stability of p-channel metal oxide semiconductor field effect transistors with boron-doped polycrystalline Si12x2yGexCy gates. We also study the electrical properties of polycrystalline Si12x2yGexCy . For low carbon concentrations ~0.4%!, polycrystalline Si12x2yGexCy has a similar level of dopant activation and mobility as polycrystalline Si12xGex ; increasing the concentration to 1.6% results in significant losses in both. Annealing the films for time scales similar to those needed for segregation causes no degradation of the electrical properties, indicating that electrically inactive defects are not driving the segregation. © 2004 American Institute of Physics. @DOI: 10.1063/1.1649452#
منابع مشابه
Segregation of boron to polycrystalline and single-crystal
Strong boron segregation to polycrystalline Si1 x yGexCy alloys from Si has previously been reported [MRS Symp. Proc. 669 (2001) J6.9]. In this study, we investigate potential mechanisms for this effect. We find that comparable segregation also occurs in both polycrystalline Si1 yCy and single-crystal Si1 x yGexCy, indicating neither Ge nor grain boundary effects are needed for it to occur. In ...
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