公开(公告)号：US5576831A

公开(公告)日：1996-11-19

申请号：US263203

申请日：1994-06-20

申请人： Mehrdad Nikoonahad ,  James A. Tebelskis

发明人： Mehrdad Nikoonahad ,  James A. Tebelskis

IPC分类号： G01N21/95 ,  G01R31/28 ,  G01R31/308 ,  H01L21/66 ,  G01B11/00

CPC分类号： G01R31/308 ,  G01N21/9501 ,  G01R31/2831 ,  H01L22/12

摘要： A surface height detection and positioning device for use in a surface inspection system. An incident beam of light impinges obliquely upon the surface, and a position detector is disposed to receive light reflected from the surface. The position detector has a sensitivity characteristic graded along a direction transverse to the surface, so that the output of the position detector is used to determine a height of the surface. The device can be incorporated into a particle detection system that scans patterned wafers with obliquely incident light to search for particles with a particle detector positioned to receive scattered light. In one embodiment, the position detector can have a width that is graded along the direction transverse to the surface, so that a scan line on the surface that is focused upon the position detector crosses the width of that detector in a time that varies as a function of the height of the surface. This time can be measured as an electrical pulse from the position detector that can be used for various purposes, including adjusting the height of the surface during scanning. In another embodiment, the position detector can have a periodic variance in light sensitivity that is graded, so that varying a height of the surface varies a phase of the output from the position detector.

摘要翻译： 一种用于表面检测系统的表面高度检测和定位装置。 入射光束倾斜地撞击在表面上，并且设置位置检测器以接收从表面反射的光。 位置检测器具有沿横向于表面的方向分级的灵敏度特性，使得位置检测器的输出用于确定表面的高度。 该装置可以结合到使用倾斜入射光扫描图案化晶片的颗粒检测系统中，以用用于接收散射光的颗粒检测器搜索颗粒。 在一个实施例中，位置检测器可以具有沿着横向于表面的方向分级的宽度，使得聚焦在位置检测器上的表面上的扫描线在随时间变化的时间内穿过该检测器的宽度 表面高度的功能。 这个时间可以被测量为来自位置检测器的电脉冲，其可以用于各种目的，包括在扫描期间调整表面的高度。 在另一个实施例中，位置检测器可以具有渐变的光敏度的周期性变化，使得改变表面的高度改变来自位置检测器的输出的相位。