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Plasma immersion ion implantation (PIII) has recently been shown to be a viable method to fabricate silicon-oninsulator (SOI) materials using either the SPIMOX (separation by plasma implantation of oxygen) or the ion cut/wafer bonding method. We have recently modified and characterized a new generation plasma immersion ion implanter for SOI fabrication, and this paper will discuss some of the instrumental and processing issues, including the plasma source, mean free path consideration, and dc sheath characteristics. NOMENCLATURE Ion current density. Mass of the ion. Ion density. Electron charge. or Steady-state sheath thickness. Ion-matrix sheath thickness. Electron temperature. Bohm acoustic speed. Permittivity of free space. Ion-neutral mean free path of the charge transfer collision. Cross section of charge transfer collision. Electron plasma frequency. Ion plasma frequency. I. INTRODUCTION S ILICON-ON-INSULATOR (SOI) offers many inherent advantages over silicon substrates for low-power highspeed deep-submicrometer CMOS (complementary metal oxide semiconductor) integrated circuits [1]-[3]. The two commercial ways to fabricate SOI wafers, namely, SIMOX (separation by implantation of oxygen) and BESOI (bonded and etch-back) SOI, are quite expensive because of the long implantation time for the SIMOX process and the need to use two wafers to form a single SOI wafer in BESOI. Recently,

A Johnsen–Rahbek (J-R type) type electrostatic chuck (ESC) was found to be more sensitive to wafer conditions than classic ESC, including backside dielectric quality and thickness and doping level. The wafer backside dielectric may reduce the clamp force and increase the declamping time, depending on dielectric quality, dielectric thickness, and ESC configurations. These issues and their mechanisms are studied extensively and potential solutions are proposed.

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We present secondary electron yield and plasma enhancement factor data for silicon surfaces exposed to Ar, He, N2, O2, H2, and BF3 plasmas, for incident ion energies from 0.5–10 keV. A fiber-optic isolated Faraday cup was used to directly measure the ion current Jion, allowing a direct measurement of the secondary electron yield. This method automatically accounted for the effect of pulse-induced plasma density enhancement due to the ionization of neutral gas by accelerated secondary electrons, which we observed and measured quantitatively. The values of the secondary electron yields measured by this method were higher than published values measured by the conventional (ultraclean surface and ultrahigh vacuum) methods but lower than published values measured by previous plasma immersion ion implantation methods.