Athermal Annealing of Ion-implanted Compound Semiconductors

该项目旨在探索一种新的非热退火方法，以消除离子注入产生的晶格损伤，并首次激活重要化合物半导体（如GaAs，SiC和GaN）中的注入掺杂剂。在这种方法中，持续时间为几纳秒的高功率（~10焦耳）激光脉冲被聚焦到半导体样品中心的1-2 mm大小的小光斑。预期激光脉冲将发射穿过晶片传播的冲击波，从而导致整个晶片上的注入退火，甚至在远离激光焦点的区域中。这种方法有望减少退火过程中的杂质扩散，并保持半导体表面的完整性。非热退火方法将用于退火Si和Be注入的GaAs，N和Al注入的SiC，和Si注入的GaN。退火将通过各种参数调整进行，例如激光强度、光斑大小和脉冲持续时间。将非热退火材料的电学、杂质再分布和晶格质量特性与传统的热退火材料进行比较，采用在早期工作中开发的最佳退火条件，通过新的非热退火方法对注入的p-n结二极管和场效应晶体管器件结构进行退火。这些器件将被彻底表征，以评估新的退火方法对器件应用的有用性。这一基础性研究工作所取得的成果将对化合物半导体器件加工技术产生深远的影响。这项工作将与联邦实验室合作进行。

This project is aimed at exploring a new, athermal annealing method for removing ion-implantation generated lattice damage and activating the implanted dopants in important compound semiconductors such as GaAs, SiC and GaN for the first time. In this method a high power (~10 Joules) laser pulse of a few nanoseconds duration is focused to a small spot of 1-2 mm size in the center of a semiconductor sample. The laser pulse is expected to launch a shock wave that propagates across the wafer, resulting in implant annealing all over the wafer, even in areas far from the laser focal spot. This method is expected to minimize impurity diffusion during annealing and preserve surface integrity of the semiconductor.The athermal annealing method will be used to anneal Si- and Be- implanted GaAs, N- and Al- implanted SiC, and Si-implanted GaN. Anneals will be performed with various parameter adjustments such as laser intensity, spot size, and pulse duration. Electrical, impurity redistribution, and lattice quality characteristics of the athermally annealed material will be compared with those of conventional, thermally annealed material.Implanted p-n junction diode and field-effect transistor device structures will be annealed by the new athermal annealing method using the optimum annealing conditions developed during the early part of the work. The devices will be thoroughly characterized to evaluate the usefulness of the new annealing method for device applications. Results obtained from this basic research work could have a profound effect on compound semiconductor device processing technology. This work will be performed in collaboration with federal laboratories.