Method of photo-reflectance characterization of strain and active dopant in semiconductor structures

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	Method of photo-reflectance characterization of strain and active dopant in semiconductor structures
其他题名	Method of photo-reflectance characterization of strain and active dopant in semiconductor structures
	CHISM, WILLIAM, W
	2008-08-06
专利权人	XITRONIX CORPORATION
公开日期	2008-08-06
授权国家	欧洲专利局
专利类型	发明申请
摘要	A new method of photo-reflectance characterization of strain and active dopant in semiconductor structures has been developed for characterization of physical properties of semiconductor structures. The underlying principle of the strain and active dopant characterization technique is to measure photo-reflectance signals occurring nearby to interband transitions in the semiconductor bandstructure and which are highly sensitive to strain and/or active dopant through the effect of the nanometer scale space charge fields induced at the semiconductor surface. To attain this, the present disclosure comprises an intensity modulated pump laser beam and a continuous wave probe laser beam, focused coincident on a semiconductor structure. The pump laser provides approximately 15 mW optical power in the NIR-VIS. The pump light is amplitude modulated by a signal generator operating in the range of 100kHz-50MHz. The probe beam is approximately 5 mW operating in the VIS-UV and is generally of wavelength nearby to strong optical absorptions in the semiconductor structure. The pump and probe are focused co-incident to a micrometer scale spot on the sample. Probe specular reflections are collected and the pump wavelength light is removed using a color filter. The remaining probe light is directed onto a photodiode and converted to an electrical signal. The probe AC signal then contains pump induced changes in the semiconductor material optical response. Phase sensitive measurement is performed on the photodiode output and the AC signal is divided by the DC reflectance signal. Thus photo-reflectance information is recorded as a function of probe wavelength, modulation frequency, pump intensity, and pump and probe polarizations.
其他摘要	已经开发了一种用于半导体结构中的应变和活性掺杂剂的光反射表征的新方法，用于表征半导体结构的物理性质。应变和主动掺杂剂表征技术的基本原理是测量在半导体带结构中的带间跃迁附近发生的光反射信号，并且通过纳米尺度空间电荷场的影响对应变和/或活性掺杂剂高度敏感。在半导体表面。为了实现这一点，本公开包括强度调制的泵浦激光束和连续波探测激光束，其重合在半导体结构上。泵浦激光器在NIR-VIS中提供大约15 mW的光功率。泵浦光由在100kHz-50MHz范围内工作的信号发生器进行幅度调制。探测光束在VIS-UV中工作约为5mW，通常为波长附近有半导体结构中的强光学吸收。泵和探针聚焦在样品上的微米级点上。收集探针镜面反射，并使用滤色器去除泵浦波长光。剩余的探测光被引导到光电二极管上并转换成电信号。然后，探针AC信号包含泵引起的半导体材料光学响应的变化。对光电二极管输出执行相敏测量，并且将AC信号除以DC反射信号。因此，光反射信息被记录为探针波长，调制频率，泵浦强度以及泵浦和探针极化的函数。
主权项	12. Apparatus for detecting physical properties of a semiconductor structure, comprising: a semiconductor structure with a reflecting surface; a pump laser system, providing an amplitude modulated laser beam with a modulation frequency in the range of lOOkHz to 50MHz, operating at optical powers of approximately 5 mW or greater, and containing at least one wavelength with energy greater than the smallest interband transition energy of a semiconductor material within the semiconductor structure; a probe laser system, providing a continuous wave laser beam, operating at optical powers of approximately 10 mW or less, and containing at least one wavelength nearby an interband transition energy of a semiconductor material within the semiconductor structure; an optical system effective to focus either laser beam onto a common focal spot on a surface of the semiconductor structure of diameter 50 microns or less, and to separate and direct probe light reflected from the sample into a photoreceiver; a photoreceiver configured to generate an electrical current proportional to the input intensity; a phase locked signal detection system connected to record the photoreceiver output; and a computer with measurement and system control software.
申请日期	2006-10-25
专利号	EP1952122A2
专利状态	失效
申请号	EP2006826534
公开（公告）号	EP1952122A2
IPC 分类号	G01N21/00 \| G01N21/17 \| H01L21/66
专利代理人	-
代理机构	PETERREINS, FRANK
文献类型	专利
条目标识符	http://ir.opt.ac.cn/handle/181661/62509
专题	半导体激光器专利数据库
作者单位	XITRONIX CORPORATION
推荐引用方式 GB/T 7714	CHISM, WILLIAM, W. Method of photo-reflectance characterization of strain and active dopant in semiconductor structures. EP1952122A2[P]. 2008-08-06.