NSF Award
9461195
The objective of this program is to develop high intensity, large area, directed atomic nitrogen beam sources for molecular beam epitaxy (MBE). The nitrogen beam source will be based on an inductively-driven plasma accelerator that efficiently ionizes and accelerates plasma to energies between 1 and 100 eV. The plasma beam will have densities between 1015 and 1017 cm-3. At these high plasma densities, molecular ions such as N2 or NH3 decompose rapidly, generating a high intensity, high energy atomic plasma beam. When operated at high pulse rates, average beam current densities of 1-10 A/cm2 can be delivered. This beam current density is a factor of 100 to 1000 times higher than achievable with existing rf or ECR plasma sources. Moreover, the nitrogen source may be configured with beam cross sections from 0.1 to 1 m2 and with an average beam power scaleable to tens of kilowatts or higher, allowing for broad area, high rate growth of GaN, AlN and other nitrides. In Phase I, the feasibility of this electrodeless atomic/plasma beam accelerator technology will be experimentally analyzed as a high power nitrogen source for MBE. An optimized atomic nitrogen beam source will be designed for fabrication in Phase II. The Phase II program is structured to experimentally characterize and optimize this nitrogen beam source for MBE.
