PLASMA IMMERSION ION-IMPLANTATION FOR SOI SYNTHESIS - SIMOX AND ION-CUT

We have demonstrated feasibility to form silicon-on-insulator (SOI) su bstrates using plasma immersion ion implantation (PIII) for both separ ation by implantation of oxygen and ion-cut. This high throughput tech nique can substantially lower the high cost of SOI Substrates due to t he simpler implanter design as well as ease of maintenance. For separa tion by plasma implantation of oxygen wafers, Secondary ion mass spect rometry analysis and cross-sectional transmission electron micrographs show continuous buried oxide formation under a single-crystal silicon overlayer with sharp Si/SiO2 interfaces after oxygen plasma implantat ion and high-temperature (1300 degrees C) annealing. Ion-cut SOI wafer fabrication technique is implemented for the first time using PIII. T he hydrogen plasma can be optimized so that only one ion species is do minant in concentration and there are minimal effects by other residua l ions on the ion-cut process. The physical mechanism of hydrogen indu ced silicon surface layer cleavage has been investigated. An ideal gas law model of the microcavity internal pressure combined with a two-di mensional finite element fracture mechanics model is used to approxima te the fracture driving force which is sufficient to overcome the sili con fracture resistance.