公开(公告)号：US4844617A

公开(公告)日：1989-07-04

申请号：US146046

申请日：1988-01-20

申请人： Herman F. Kelderman ,  Michael E. Fein ,  Alan E. Loh ,  Arnold Adams ,  Armand P. Neukermans

发明人： Herman F. Kelderman ,  Michael E. Fein ,  Alan E. Loh ,  Arnold Adams ,  Armand P. Neukermans

IPC分类号： G01B9/04 ,  G01J3/02 ,  G01J3/18 ,  G01J3/28 ,  G02B21/00

CPC分类号： G01B9/04 ,  G01J3/02 ,  G01J3/0229 ,  G01J3/0243 ,  G01J3/0248 ,  G02B21/006 ,  G01J3/18 ,  G01J3/2803

摘要： A confocal measuring microscope including a spectrometer and autofocus system sharing common optical elements in which the intensity of light entering the spectrometer from a particular spot on a workpiece is used to determine a focus condition for the same spot. The microscope includes at least one light source, an illumination field stop, and a microscope objective that images the stop onto a workpiece supported by a movable platform. The objective also forms an image of the illuminated portion of the object. An aperture in a second stop and intersecting the image plane passes light from part of the image to the spectrometer, while viewing optics are used to view the image. In one embodiment, a detector is placed at the zero order position, while in another embodiment a laser is placed at the zero order position. In the later embodiment an integrator circuit connected to the detector array replaces the zero order detector for measuring the total intensity of light entering the spectrometer. A best focus condition occurs when the total intensity is a maximum for a positive confocal configuration, i.e. where source and detector are on opposite sides of their respective field stops from said workpiece, and a minimum for a negative confocal configuration, i.e. where the source and workpiece are on the same side of a reflective illumination field stop with aperture. The movable platform may be scanned axially to achieve and maintain object focus as the object is scanned transversely.

摘要翻译： 共焦测量显微镜包括分光光度计和自动聚焦系统，共享共同的光学元件，其中使用从工件上的特定光点进入光谱仪的光的强度来确定同一光斑的聚焦条件。 显微镜包括至少一个光源，照明场停止器和将停止点图像到由可移动平台支撑的工件上的显微镜物镜。 该目的也形成对象的被照亮部分的图像。 在第二个停止点和与图像平面相交的孔将光从图像的一部分传递到光谱仪，而观察光学元件用于观看图像。 在一个实施例中，检测器被放置在零级位置，而在另一个实施例中，激光被放置在零级位置。 在后面的实施例中，连接到检测器阵列的积分器电路取代了用于测量进入光谱仪的光的总强度的零级检测器。 当总强度为正共焦配置的最大值时，即源和检测器位于其与所述工件相应的场停止位置的相对侧上，并且对于共焦焦配置为最小，即源和 工件位于具有孔径的反射照明场停止的同一侧。 当物体被横向扫描时，可移动平台可被轴向地扫描以实现和维持物体焦点。

公开(公告)号：US4899055A

公开(公告)日：1990-02-06

申请号：US193902

申请日：1988-05-12

申请人： Arnold Adams

发明人： Arnold Adams

IPC分类号： G01B11/06

CPC分类号： G01B11/0633

摘要： A method of measuring thin film thickness, especially on semiconductor substrates, in which the substrate is illuminated with ultraviolet light of a fixed wavelength corresponding to a persistent spectral line and the amount of light reflected from the substrate is detected and measured. The ultraviolet light preferably has a wavelength in the range from 240 nm to 300 nm, and the 253.6 nm spectral line of mercury is considered best. Comparing the measured amount of light from the substrate to a known amount of light detected from a standard calibration substrate with known reflectivity, the reflectivity of the test substrate is computed. The thickness of a thin film on the substrate is determined from the computed reflectivity using Fresnel's equation or a lookup table derived from the same.

摘要翻译： 一种测量薄膜厚度的方法，特别是在半导体衬底上，其中用与持久光谱线对应的固定波长的紫外光照射衬底并检测并测量从衬底反射的光量。 紫外线的波长优选为240nm〜300nm，253.6nm的汞线被认为是最佳的。 将来自基板的测量光量与从具有已知反射率的标准校准基板检测到的已知量的光进行比较，计算测试基板的反射率。 使用菲涅耳方程或从其导出的查找表，根据计算出的反射率确定衬底上薄膜的厚度。