초록 ▼

A laser end point detector incorporating adjustable-focus, variable-orientation detection optics for monitoring different types of structures such as laser-transparent thin films, isolated trenches or holes and patterned arrays of trenches or holes is disclosed. A collector lens package comprising a

A laser end point detector incorporating adjustable-focus, variable-orientation detection optics for monitoring different types of structures such as laser-transparent thin films, isolated trenches or holes and patterned arrays of trenches or holes is disclosed. A collector lens package comprising a laser and a focusing lens are mounted in a hole in a collector lens which is pivotally mounted for selectively focusing zero, first and higher orders of diffractions reflected from the wafer onto an associated detector to monitor the etching of different types of structures. For example, zero order diffraction signals are used to monitor the etching of large target areas in transparent thin films or of non-patterned trenches or holes. First order (or higher) diffraction signals are used for monitoring the etching of patterned features which effect a two-dimensional diffraction grating, such as the capacitor holes in dynamic random access memories.

대표청구항 ▼

A laser interferometer system for monitoring the etching of a workpiece, comprising: a laser for providing laser light; and for positioning a workpiece such that laser light from said laser is reflected off of said workpiece; detecting means for detecting laser light reflected from a surface of the

A laser interferometer system for monitoring the etching of a workpiece, comprising: a laser for providing laser light; and for positioning a workpiece such that laser light from said laser is reflected off of said workpiece; detecting means for detecting laser light reflected from a surface of the workpiece; means for analyzing the detected light to monitor at least one of etch rate, etch depth and etch-through of a selected layer of the workpiece; and, a collector lens mounting the laser within said collector lens; means for mounting said collected lens in said interferometer system, such that said collector lens is pivotally movable relative to said workpiece surface to focus selected diffraction orders of light reflected from said workpiece surface into said detecting means.