High Intensity Nitrogen Beam Source for Molecular Beam Epitaxy

该计划的目标是开发用于分子束外延(MBE)的高强度、大面积、定向原子氮束光源。氮束源将基于感应驱动的等离子体加速器，该加速器可以有效地将等离子体电离并加速到1至100 eV之间的能量。等离子体束的密度将在1015到1017厘米-3之间。在这些高等离子体密度下，分子离子如氮气或氨离子迅速分解，产生高强度、高能的原子等离子体束。在高脉冲率下工作时，平均束流密度可达1-10A/cm2。这种束流密度是现有RF或ECR等离子体源的100到1000倍。此外，氮源可以被配置为具有从0.1到1m2的束横截面，并且具有可缩放到数十千瓦或更高的平均束功率，从而允许GaN、AlN和其他氮化物的大范围、高速率生长。在第一阶段，将对这种无电极原子/等离子体束加速器作为分子束外延的高功率氮源的可行性进行实验分析。在第二阶段，将设计一个优化的氮原子束光源用于制造。第二阶段计划的结构是为了对用于分子束外延的氮束源进行实验表征和优化。

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.