In this paper, a new pre-alignment approach based on Four-Quadrant-Photo-Detector （FQPD） for IC mask is presented. The voltage outputs from FQPDs are the functions of alignment mark＇s position offsets with respect ...In this paper, a new pre-alignment approach based on Four-Quadrant-Photo-Detector （FQPD） for IC mask is presented. The voltage outputs from FQPDs are the functions of alignment mark＇s position offsets with respect to FQPDs. The functions are obtained with least squares error （LSE）-based polynomial fitting after the normalization of experimental data. As the acquired functions are not monotonic about their variables, the alignment mark＇s position offset cannot be given by direct inverse operation on the obtained functions. However, the piecewise polynomial fitting gives the inverse function, with which the alignment mark＇s position offset can be predicted according to the voltage outputs of FQPDs. On the basis of prediction, a pre-alignment control strategy is proposed. The feasibility and robustness of the pre-alignment approach is shown by experiments. Furthermore, the results demonstrate that the maximum error of mask＇s position offset in the X- and Y- directions is less than 15μm after coarse pre-alignment. Keywords： Four-Quadrant-Photo-Detector （FQPD）, pre-alignment, IC mask, polynomial fitting展开更多
A modeling method of the support vector machine combined with matrix optics is considered; a complete new measurement model for double-four quadrant photoelectric detector is built. According to the analysis of the re...A modeling method of the support vector machine combined with matrix optics is considered; a complete new measurement model for double-four quadrant photoelectric detector is built. According to the analysis of the received light spot size and its motion with the changes of the defocusing amount of detector photosensitive surface and the detector position attitude in the optical path, a mathematic expression of photoelectrical conversion is given, which can be applicable to random setting position of the detector at any time. Based on least square support vector machine (LS SVM), the mapping relationship among the output signal linear characteristic parameters (zero neighborhood gradient and intercept), the defocusing amount of the detector and the installation position attitude angle is established. Thus, the multiple dimensional high accuracy measuring and adjusting control system can be left out, and adaptive measurement of the detector parameters can be realized. Compared with existed measurement model and method, the presented model has the advantages of more clear physical meaning, closer to work mechanism of detector, acquiring more complete sample data and wiping out the dead spots or bad spots in measurement. And the accuracy of displacement measurement is increased to 3?μm. At the same time, this measurement mode provides a technical shortcut for three-dimensional small angle measurement.展开更多
空间科学仪器广泛使用基于四象限光电探测器的太阳导行镜指向跟踪系统来实现对日精确指向控制。为满足对日指向高精度高稳定性需求,提出面向空间应用的四象限光电探测器筛选方法,研制针对四象限光电探测器的筛选系统。通过对比筛选试验...空间科学仪器广泛使用基于四象限光电探测器的太阳导行镜指向跟踪系统来实现对日精确指向控制。为满足对日指向高精度高稳定性需求,提出面向空间应用的四象限光电探测器筛选方法,研制针对四象限光电探测器的筛选系统。通过对比筛选试验前后四象限探测器的暗电流、响应度及象限响应度均匀性等参数变化,依据判别准则分析探测器的空间环境适应性,剔除可能存在的早期失效或性能差异变化较大的探测器。试验结果表明:研制的筛选系统具有高准确度,系统前端等效输入电流噪声为0.58 f Arms,通过筛选试验后依据评估标准最终优选的四象限光电探测器各通道暗电流绝对值最大值为6.08 p A,各通道的响应度变化最大值为0.716%,各象限响应度非一致性筛选前后变化最大值为1.24%。最终将该四象限探测器应用至太阳导行镜指向跟踪系统上,满足航天环境条件的使用要求。该筛选装置及筛选方法可实现对面向空间应用的四象限光电探测器的筛选,且对其他光电器件筛选具有借鉴意义。展开更多
在空间光通信中,捕获、跟踪、对准(Acquistion,Tracking and Pointing-ATP)是实现空间光通信的关键技术,故而该技术日益成为研究的热点。在ATP技术中用来实现目标捕获、跟瞄的光电传感器件大致有三种,即PSD(Position Sensitive Devices)...在空间光通信中,捕获、跟踪、对准(Acquistion,Tracking and Pointing-ATP)是实现空间光通信的关键技术,故而该技术日益成为研究的热点。在ATP技术中用来实现目标捕获、跟瞄的光电传感器件大致有三种,即PSD(Position Sensitive Devices)、QD(Quadrant Detector)和CCD(Charge-CoupledDevice)。在这些传感器之中,最简单、最有效也最常用的便是QD。本文对QD在探测中的性能进行了具体的分析和研究。展开更多
基金This work was supported by National High Technology Research and Development Program of PRC (No. 2002AA420040)National 973 Program of PRC (No. 2002CB312200).
文摘In this paper, a new pre-alignment approach based on Four-Quadrant-Photo-Detector （FQPD） for IC mask is presented. The voltage outputs from FQPDs are the functions of alignment mark＇s position offsets with respect to FQPDs. The functions are obtained with least squares error （LSE）-based polynomial fitting after the normalization of experimental data. As the acquired functions are not monotonic about their variables, the alignment mark＇s position offset cannot be given by direct inverse operation on the obtained functions. However, the piecewise polynomial fitting gives the inverse function, with which the alignment mark＇s position offset can be predicted according to the voltage outputs of FQPDs. On the basis of prediction, a pre-alignment control strategy is proposed. The feasibility and robustness of the pre-alignment approach is shown by experiments. Furthermore, the results demonstrate that the maximum error of mask＇s position offset in the X- and Y- directions is less than 15μm after coarse pre-alignment. Keywords： Four-Quadrant-Photo-Detector （FQPD）, pre-alignment, IC mask, polynomial fitting
文摘A modeling method of the support vector machine combined with matrix optics is considered; a complete new measurement model for double-four quadrant photoelectric detector is built. According to the analysis of the received light spot size and its motion with the changes of the defocusing amount of detector photosensitive surface and the detector position attitude in the optical path, a mathematic expression of photoelectrical conversion is given, which can be applicable to random setting position of the detector at any time. Based on least square support vector machine (LS SVM), the mapping relationship among the output signal linear characteristic parameters (zero neighborhood gradient and intercept), the defocusing amount of the detector and the installation position attitude angle is established. Thus, the multiple dimensional high accuracy measuring and adjusting control system can be left out, and adaptive measurement of the detector parameters can be realized. Compared with existed measurement model and method, the presented model has the advantages of more clear physical meaning, closer to work mechanism of detector, acquiring more complete sample data and wiping out the dead spots or bad spots in measurement. And the accuracy of displacement measurement is increased to 3?μm. At the same time, this measurement mode provides a technical shortcut for three-dimensional small angle measurement.
文摘空间科学仪器广泛使用基于四象限光电探测器的太阳导行镜指向跟踪系统来实现对日精确指向控制。为满足对日指向高精度高稳定性需求,提出面向空间应用的四象限光电探测器筛选方法,研制针对四象限光电探测器的筛选系统。通过对比筛选试验前后四象限探测器的暗电流、响应度及象限响应度均匀性等参数变化,依据判别准则分析探测器的空间环境适应性,剔除可能存在的早期失效或性能差异变化较大的探测器。试验结果表明:研制的筛选系统具有高准确度,系统前端等效输入电流噪声为0.58 f Arms,通过筛选试验后依据评估标准最终优选的四象限光电探测器各通道暗电流绝对值最大值为6.08 p A,各通道的响应度变化最大值为0.716%,各象限响应度非一致性筛选前后变化最大值为1.24%。最终将该四象限探测器应用至太阳导行镜指向跟踪系统上,满足航天环境条件的使用要求。该筛选装置及筛选方法可实现对面向空间应用的四象限光电探测器的筛选,且对其他光电器件筛选具有借鉴意义。
