A Study on Ultrafine Doping by Focused Ion Beam Implantation

1.聚焦离子束（FIB）装置的研制为了延长离子源的使用寿命，研制了高真空液态金属离子源。证实可以通过ExB质量过滤器选择所需的离子种类，聚焦到0.1 μ m直径，并通过计算机控制精确偏转。2.瞬态退火采用瞬态退火技术激活GaAs中注入的Si离子。霍尔和光致发光测试表明，退火过程中产生的SiAs和GaAs受主影响了激活效率.聚焦Si和Be离子注入GaAs，获得最大效率分别为40%和90%。这些值与传统的校正值是一致的。然而，被发现的Be原子扩散后，更长的退火时间超过60秒。4。小区域离子束注入制造新型功能器件提出了用离子束注入制造横向和垂直结型场效应晶体管。这些器件是通过计算GaAs中注入离子的分布来设计的。小区域高剂量注入制备新材料聚焦Ga离子注入InP形成GaInP合金半导体。光学测量表明，部分形成了合金化的GaInP。然而，观察到注入层的多晶化和Ga聚集。

1. Development of Focused Ion Beam (FIB) ApparatusLiquid Metal Ion Source for various ions were developed in high vacuum chamber to prolong the lifetimes. It was confirmed that desired ion species could be selected by ExB mass-filter, focused into 0.1 um diameter and deflected precisely by computer control.2. Transient AnnealA transient anneal technique was developed to activate implanted Si ion in GaAs. Hall and photoluminescence measurements revealed that SiAs and GaAs acceptors, which were created during anneal, affected the activation efficiency.3. Characterization of FIB implanted regionsFocused Si and Be ions were implanted into GaAs and maximum efficiency of 40% and 90% were obtained, respectively. These values are compatible to those for conventional implantations. However, Be atoms were found to anomalously diffuse after longer annealing than 60 sec.4. Fabrication of new functional devices by FIB implantation into small regionsLateral- and vertical-JFETs, which can be fabricated by FIB implantation, were proposed. These devices were designed by calculating distributions of implanted ions in GaAs.5. Fabrication of new materials by high-dose implantation into small regionsFocused Ga ions were implanted into InP to form GaInP alloy semiconductors. It was revealed by optical measurements that the alloyed GaInP was partly formed. However, poly-crystallization of implanted layers and Ga-clustering were observed.