Particle Sizing Uncertainties in Laser Scanning of Silicon Wafers Calibration/Evaluation of the Aeronca Wafer Inspection System 150
Particle Sizing Uncertainties in Laser Scanning of Silicon Wafers Calibration/Evaluation of the Aeronca Wafer Inspection System 150
复制标题
硅晶圆激光扫描中的粒度不确定性 Aeronca 晶圆检测系统的校准/评估 150
DOI：
10.1149/1.2100754
复制
发表时间：
1987
影响因子：
3.9
通讯作者：
R. Donovan
中科院分区：
文献类型：
--
作者：
B. Locke;R. Donovan
除了颗粒的光学特性外，来自诸如硅片之类的反射面上的颗粒的光散射还取决于反射表面的光学特性。支持这一结论的数据是基于测量沉积在裸硅片上和热生长在其上的不同厚度的氧化硅的单分散聚苯乙烯胶乳(PSL)微球的散射光强度。一种特殊的激光扫描仪(Aeronca的WIS-150)探测到的散射光的强度随颗粒所在的衬底表面而变化。对于所研究的任何表面，散射光的强度与PSL球的大小之间的关系都不是单调的。在硅片加工中使用的各种表面上的颗粒污染的检测是持续提高所制造器件的成品率和可靠性的一个非常重要的方面。目前测量表面颗粒污染的方法大致分为三种：(1)用肉眼或显微镜对强烈白色光源照射下的散射光进行人工颗粒计数；(2)用商用仪器进行自动颗粒计数，这种仪器使用氦/霓虹灯或氦/镉激光；(3)用汞或汞-氙弧灯光源和摄像机显示器进行自动计数。手工方法不能准确测定颗粒大小；第二种方法具有快速计数能力，具有测定颗粒大小的潜力，是本报告的主要重点。评估中使用的特定商用激光扫描仪是Aeronca晶圆检测系统(WIS)150。成像系统(第三种方法)具有允许检查表面缺陷和颗粒的优点，但在此不再讨论。
Light scattering from particles resting on a reflecting plane, such as a silicon wafer, is shown to depend on the optical properties of the reflecting surface in addition to the optical properties of the particle. Data supporting this conclusion are based on measuring the intensity of the light scattered from monodisperse polystyrene latex (PSL) spheres deposited on both bare silicon wafers and on wafers having various thicknesses of silicon oxide thermally grown on them. The intensity of the scattered light detected by a specific laser scanner (Aeronca's WIS-150) varies with the substrate surface on which the particle rests. The relationship between the intensity of the scattered light and the size of the PSL sphere is not monotonic for any of the surfaces investigated.The detection of particulate contamination on various surfaces used in silicon wafer processing is a very important aspect in the continued improvement of the yield and reliability of manufactured devices. The current methods for measuring particulate contamination on surfaces fall into three general types:(i) manual particle countingl by unaided eye or with a microscope, of the light scattered under the illumination of an intense white light source;(ii) automatic particle counting with a commercially available instrument that uses a helium/neon or helium/cadmium laser; and (iii) automatic counting with a mercury or mercury-xenon arc lamp source and a vidicon display. The manual method does not allow for accurate particle sizing; the second method with its rapid counting capability and its potential for particle sizing is the primary focus of this report. The specific commercial laser scanner used in this evaluation is the Aeronca wafer inspection system (WIS) 150. Imaging systems (the third method) have the advantage of allowing examination of surface defects and particles but will not be discussed here.