Doping of SiC Using Seeded Supersonic Beams

Controlled doping of silicon carbide (SiC) during epitaxial growth remains a significant problem due to the amphoteric nature of many dopants and competition for active sites between the dopants, silicon and carbon atoms. Currently, the most promising avenue for controlled doping of SiC is a process called site competition epitaxy which is a technique based on adjusting the SitC ratio within the growth reactor to effectively control the amount of dopant incorporated into the substitution SiC crystal lattice sites. Although this technique is effective it involves changing flow conditions during growth to vary dopant levels which can lead to varying growth rates during deposition and make abrupt changes in doping levels during growth difficult to achieve and control. Systems & Processes Engineering Corporation (SPEC) proposes an alternative doping procedure that uses seeded supersonic beams as the dopant source. The seeded supersonic beam will allow the energy of the arriving doping atoms to be varied effecting the surface mobility of the dopant atoms' doping level to be varied without changing the silicon and carbon flow conditions. Development of a highly controllable SiC doping process will aid in the development of devices that require abrupt changes in doping level as well as high power SiC based devices that require very high doping levels. SiC devices are useful in the development of new radiation hardened, high temperature, high speed electronic devices.