Ion Implantation and Anneal Characteristics of SiC

In the commercial semiconductor world of silicon (Si) devices, great importance is attached to diffusion and ion implantation. These processes play a key role in the local doping performance through windows in a thermally grown oxide film. Because the diffusion coefficients for most dopants in silicon carbide (SiC) are negligible, at temperatures below 1800°C, the development of ion implantation into SiC for microelectronic technology is of major importance. 

Many ion species implanted in SiC have been experimented with in the past two decades. However, there are a few species that have been studied in detail. The behaviour of these ions is now briefly reviewed. 

This ion has not been used extensively. There are only a few reports of Ga-implanted SiC. The experimental projection range was reported to be 0.08 - 0.2 pm for the implanted energy of 90-360keV [4,14]. Burdel et al [4] reported a critical dose of 1.8 x 10,4cm 2, at which the implanted layer could be recrystallized. For a dose higher than the critical value, the structural perfection of the layer increases with the amount of Ga evaporated from the layer during annealing. 

This is an alternative ion for forming an nMayer by implantation. This ion is, however, heavier than N hence, the diffusion coefficient is extremely small. Suzuki et al [6] reported that no change in the depth profile occurred after annealing, but the activation is much lower than that of N (approximately half that of N). Davis [1,18] reported the critical dose of 1015 cm 2 at which the implanted layer could be recrystallized. 

There are many articles regarding the use of ion implantation in SiC. However, most of these articles describe the use of ion implantation for device fabrication only. The author has summarized the data from some of these articles in TABLE 1. 

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