| With its unique structure, silicon-on-insulator (SOI) has been found great potential in integrated circuits, where lower power consumption and high speed are required, as well as in radiation hardened circuits and high temperature devices. In addition, more recently SOI has been recognized as a promising substrate material for integrated optical components. With a breakthrough of IBM in 1998, SOI has been shifted from mainly military usage to commercial applications. Nowadays, Separation by implantation of oxygen (SIMOX) and Smart-cut are two major methods to commercially supply SOI wafers, but these SOI wafers are much expensive than Si wafers due to the long time ion implantation required for the high dosage (1017-10l8cm-2) by conventional beam-line ion implanters, which, to some extent, embarrasses its widespread adoption in mainstream microelectronic products. Plasma immersion ion implantation (PHI) seems to be an alternative approach to reduce the manufacture cost of SOI wafers due to its large ion current and independence of implantation time to the wafer size.In the present work, water plasma ion implantation, instead of the conventional oxygen plasma ion implantation, has been employed to fabricate SOI materials. The masses of the three dominant ion species in the water vapor plasma, H2O+, HO+, and O+, are very close to each other, which overcome the problem of co-existence of O and 02 in oxygen plasma source. The oxygen depth profiles in the water plasma ion as-implanted silicon do not disperse much, which makes it possible for the formation of single buried oxide (BOX) layer by choosing appropriate implantation energy and dose. An ion implanter without ion mass analyzer was applied to simulate the PHI procedure to fabricate SOI materials by implantation of water plasma ions. Thin SOI structure was successfully fabricated by the implanter using 50~90keV water plasma ion implantation with the dose ranging from 2-6.5+017cm-2 and, subsequently, the high temperature annealing. The SOI is of crystal quality and the BOX is uniform in thickness, with the interfaces of Si/SiOa/Si smooth and sharp.We have systematically studied the dependence of the formed SOI structure on the process parameters, such as ion energy, implantation dosage, substrate temperature, aswell as the annealing temperature. With XTEM, SIMS, SRP, RBS, IR, Raman, AES, XPS and other characterization tools, it was found that a dose window at fixed energy for water plasma ion implantation to form high quality SOI structure similar to the conventional SIMOX process exists. With increasing implantation dose, the thickness of the BOX layer increases while that of the Si over-layer decreases. The thickness of the Si over-layer is dependent of the ion energy. In the current experimental parameter range, thin and/or ultra-thin SOI with thickness of 50-150nm and BOX of 70-180nm thick were obtained.Compared to the conventional SIMOX-SOI, the SOI materials manufactured by water plasma ion implantation at the same implantation dosage and ion energy have much thicker BOX layers. SIMS depth profile analysis on the as-implanted wafers showed that there are two hydrogen enrichment peaks around both sides of the projected range (Rp) of oxygen, which correspond to the two interfaces of the BOX layer of the annealed samples. Additional annealing experiments in nitrogen atmosphere revealed that the heavily damaged region with hydrogen-induced defects appears to be the adsorption center for the outside oxygen to diffuse into the silicon during the high-temperature annealing process, and consequently, broaden the thickness of the BOX layer. This important finding may provide a possible solution to reduce the cost of the conventional SIMOX-SOI wafers while maintaining a desirable BOX thickness.The substrate temperature during the plasma implantation has influence both on the quality of the Si over-layer and the thickness of the BOX layer. The latter effect is probably caused by the deviated position of the hydrogen concentration peak in the as-impl...
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