This work investigates the role of interstitial oxygen content in the starting Czochralski bonding wafers, and the effects of buried layered implants and thermal processing on the formation of crystalline defects in the surface of bonded silicon on insulator ͑SOI͒ material. We found that unimplanted SOI material originating from Si with high oxygen levels (Ͼ7.0 ϫ 10 17 /cm 3), were populated with heavy oxygen precipitation and related crystal defects, and were also characterized by low minority carrier lifetime values. However, a dramatic improvement was observed in the behavior of SOI with low oxygen levels (6 ϫ 10 17 /cm 3), where the development of oxygen precipitation in the SOI layer was inhibited. Incorporation of a buried As ion implanted layer in high oxygen level SOI increased the lifetime of the material and suppressed the formation of oxygen precipitates through an oxygen gettering effect. The gettering efficiency of the buried defect layer was found to be related to the dose of the As ion implantation, the annealing temperature, and type of starting silicon material. A dose of (1-5) ϫ 10 15 cm Ϫ2 was sufficient for effective gettering.

We have investigated the influence of the material properties of the silicon device layer on the generation of defects, and in particular slip dislocations, in trenched and refilled fusion-bonded silicon-on-insulator structures. A strong dependence of the ease of slip generation on the type of dopant species was observed, with the samples falling into three basic categories; heavily boron-doped silicon showed ready slip generation, arsenic and antimony-doped material was fairly resistant to slip, while silicon moderately or lightly doped with phosphorous or boron gave intermediate behavior. The observed behavior appears to be controlled by differences in the dislocation generation mechanism rather than by dislocation mobility. The introduction of an implanted buried layer at the bonding interface was found to result in an increase in slip generation in the silicon, again with a variation according to the dopant species. Here, the greatest slip occurred for both boron and antimony-implanted samples. The weakening of the implanted material may be related to the presence of a band of precipitates observed in the silicon near the bonding interface.

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