High Intensity Nitrogen Beam Source for Molecular Beam Epitaxy

本计划的目标是发展高强度，大面积，定向氮原子束源的分子束外延（MBE）。氮束源将基于感应驱动的等离子体加速器，该加速器可有效地将等离子体电离和加速到1至100 eV的能量。等离子体束将具有1015和1017 cm-3之间的密度。在这些高等离子体密度下，诸如N2或NH3的分子离子快速分解，产生高强度、高能量原子等离子体束。当在高脉冲速率下操作时，可以输送1-10 A/cm 2的平均束流密度。该射束电流密度比现有的rf或ECR等离子体源可实现的高100至1000倍。此外，氮源可以被配置为具有从0.1到1 m2的束横截面，并且具有可缩放到几十千瓦或更高的平均束功率，从而允许GaN、AlN和其他氮化物的宽面积、高速率生长。在第一阶段，这种无电极原子/等离子体束加速器技术的可行性将实验分析作为MBE的高功率氮源。一个优化的原子氮束源将在第二阶段的制造设计。第二阶段计划的结构，实验表征和优化这种氮束源分子束外延。

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.