【摘要】 <正> 一、引言 GaAs集成电路的发展与在半绝缘衬底上进行外延的外延层或进行出子注入形成导电沟道的质量和接触区的常规工艺有关。由于在器件和电路制造过程中,存在外延材料成本高以及难以制成浅结等问题,所以,近年来,国际上广泛开展了离子注入高纯半绝缘GaAs来制造砷化镓场效应晶体管和进行GaAs单片集成电路的研究。离子注入具有掺杂浓度可控,均匀性和重复性好的特点,以及与其它工艺组合灵活等优点。但注入样品必须在高温（≥800℃）下退火,以消除注入损伤和电激活掺杂剂。在通常的炉子退火（850℃,30′）条件下,由于GaAs表面的As原子易挥发,使得GaAs的化学计量比失配,造成器件特性变坏。使用包封层,虽然解决了As原子的挥发问题,但由于包封层与样品之间的热膨胀系数不匹配,在高温下存在热应力,进而引起膜皱曲甚至脱落,样品表面层中该热应力引入缺陷杂质对材料特性产生影响。目前,国外研究较多的是快速热退火（RTA）。这种方法由于退火时间短,退火温度高,更有利于复杂缺陷的消除,激活层电特性好,注入杂质和衬底杂质的互扩散小,不需包封层,因此消除了包封层和衬底界面处的应力和组分互扩散,而且退火时不涉及AsH₃这样的有毒气体。更多还原

【Abstract】 In this paper, the electrical characteristics for Si-implanted GaAs layers annealed in a salf-designed system, SCRFA, are described and discussed. The temperature of samples is monitored by a thermocouple and controlled with PID controller, the wafers were annealed caplessly by using the face-to-face (F/F) method uader an N2 atmosphere to prevent surface degradation during RTA, and GaAs Wafers supported by a larye size Si wafer were first kept at 400℃ for 20s in order to improve the reproducibility of the annealing process. Hall effect was performed by the Van der Pauw method, to examine Hall mobility and the activation efficiency in the implanted active layers with the highest mobility of 3950 cm2/V·s for the two-step annealing.更多还原