半导体的CO_2激光退火和合金化

本文主要研究连续CO_2激光对半导体的照射效应。实验结果与理论分析说明,用连续CO_2激光照射可将半导体样片加热到所需的温度。与其它短波长的激光不同,波长为10.6μm的连续CO_2激光照射半导体有如下特点:CO_2激光是借助于自由载流子吸收与半导体耦合;样片在深度方向被均匀加热;激光背面照射可以增强退火效果。连续CO_2激光照射可以固相外延再生长的方式使As离子注入Si的损伤层退火恢复。在再生长的过程中注入的As离子进入替位,电激活率很高,而且不发生杂质再分布。将连续CO_2激光背面照射成功地应用于GaAsFET制备欧姆接触,既可避免激光正面照射对器件结构的破坏,又能得到比热退火为好的电学性能。     

磷分子离子(P2+)注入硅的损伤行为

本文研究了不同能量(5—600keV)和不同剂量(10¹⁴-10¹⁶atom/cm²)下的P₂⁺和P⁺注入〈100〉单晶硅后的损伤及退火行为。实验结果表明,P₂⁺注入所产生的损伤总是大于P⁺注入所产生的损伤。由移位效率之比N_D^*(mol)/2N_D^*(atom)所表征的分子效应随入射能量的改变而变化并在100keV(P₂⁺),50keV(P⁺)处达到极大值。P₂⁺与P⁺注入的样品,退火后的载流子分布也有某些区别。我们认为,产生这些分子效应的基本原因是位移尖峰效应,但当入射离子的能量较高时,还应该考虑离子、靶原子之间的多体碰撞效应的贡献。 关键词：     

激光在半导体电子学中的应用

激光在半导体电子工业生产中已得到日益广泛的应用,这是激光微加工最集中、最重要的应用领域.所谓激光微加工,系指激光与被加工材料互作用区大小在亚毫米至亚微米并且互作用激光能量在毫焦耳范围内的加工.激光微加工的许多技术如激光微调、激光划片、激光标记、激光焊接等等已用于生产线,取得了明显的经济效果.有不少技术还正在深入研究,具有重要的应用前景,如激光再结晶、激光化学气相沉积、激光诱导化学光刻与掺杂等等.特别是半导体集成电路已跨入超大规模集成电路(VLSI)的八十年代,微米乃至亚微米级的微细加工技术已成为电路制造的核心…     

FORMATION OF A BURIED LAYER OF ALUMINIUM NITRIDE BY HIGH DOSE N2+ IMPLANTATION INTO ALUMINIUM

Aluminium films with various thickness between 700 nm and 1μm were deposited on Si (100) substrates, and 400 keV N₂⁺ ions with doses ranging from 4.3×10¹⁷ to 1.8×10¹⁸ N/cm² were implanted into the alu-minium films on silicon, Rutherford Backscattering (RBS) and channeling, secondary ion mass spectroscopy (SIMS), Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and spreading resistance probes (SRP) were used to characterize the synthesized aluminium nitride. The experiments showed that when the implantation dose was higher than a critical dose N_c, a buried stoichiometric AlN layer with high resistance was formed, while no apparent AlN XRD peaks in the as-implanted samples were observed; however, there was a strong AlN(100) diffraction peak appearing after annealing at 500 ℃ for 1h. The computer program, Implantation of Reactive Ions into Silicon (IRIS), has been modified and used to simulate the formation of the buried AlN layer as N₂⁺ is implanted into aluminium. We find a good agreement between experimental measurements and IRIS simulation.