Identification of Defect Levels in III-V Semiconductors Using Radioactive Isotopes

使用放射性同位素识别 III-V 半导体中的缺陷水平

• 批准号: 5257770
• 负责人: Privatdozent Dr. Manfred Deicher
• 金额: --
• 依托单位: Naturwissenschaftlich-Technische Fakultät
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2000
• 资助国家: 德国
• 起止时间: 1999-12-31 至 2002-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5257770?language=en
• 关键词: Identification; Defect; Levels; III; Semiconductors

Spectroscopic techniques used in semiconductor physics like photoluminescence (PL) and Hall-effect that are able to detect and to characterize band gap states do not reveal information about their microscopic origin. To overcome this chemical "blindness" of the electrical and optical methods the present approach is to use radioactive isotopes as a tracer. Because of the characteristic concentration change according to the nuclear decay law, their involvement in the formation of electronic band gap states can be confirmed or denied definitely. Doping semiconductors with a variety of radioactive isotopes isotopically clean in a quantitatively controlled way is only realizable by ion implantation. GaN and its alloys with AlN and InN are one of the most interesting classes of materials in actual semiconductor research due to their potential as optoelectronic devices. The electrical activation of implanted dopants into these systems is more complex compared to other III-V compounds since this materials have both strong inter-atomic bonding demanding high annealing temperatures, and a constituent, N, having a high vapor pressure. An imperative prerequisite for these implantation studies is therefore the unambiguous identification of the PL signals and electrical properties related to potential doping atoms in GaN using radioactive isotopes of these dopants. An important class of intrinsic defects in many compound semiconductor of type AB like GaAs are antisites where an A atom is placed on a B site (AB) or vice versa. It is still an open question what the electronic levels of the GaAs antisite in GaAs are. A unique way to create GaAs antisite defects in GaAs in a controlled way and to avoid the introduction of any other defects during the production process is the transmutation of radioactive 71As to stable 71Ga. This transmutation can be followed up by PL and possibly created states in the band gap due to antisites can be clearly identified.

半导体物理学中使用的光谱技术，如光致发光（PL）和霍尔效应，能够检测和表征带隙状态，但不能揭示其微观起源的信息。为了克服电学和光学方法的这种化学“盲目性”，本方法是使用放射性同位素作为示踪剂。由于特征浓度的变化符合核衰变规律，它们参与电子带隙态的形成可以被肯定或否定。用各种放射性同位素掺杂半导体，以定量控制的方式进行同位素清洁，只能通过离子注入实现。GaN及其与AlN和InN的合金是实际半导体研究中最有趣的一类材料之一，因为它们具有作为光电器件的潜力。与其他III-V族化合物相比，将注入的掺杂剂电激活到这些系统中更复杂，因为这种材料既具有要求高退火温度的强原子间键合，又具有具有高蒸气压的成分N。因此，这些注入研究的一个必要的先决条件是明确识别的PL信号和电气性能相关的潜在掺杂原子在GaN中使用这些掺杂剂的放射性同位素。在许多AB型化合物半导体（如GaAs）中的一类重要的本征缺陷是反位，其中A原子位于B位（AB）上，反之亦然。GaAs中GaAs反位的电子能级是多少，至今仍是一个悬而未决的问题。以受控方式在GaAs中产生GaAs反位缺陷并避免在生产过程中引入任何其他缺陷的独特方法是将放射性71 As嬗变为稳定的71 Ga。这种嬗变可以被PL跟踪，并且可以清楚地识别出由于反位而在带隙中可能产生的状态。