| 摘要 |
PURPOSE: A method for detecting an end point of a CMP(Chemical Mechanical Polishing) process is provided to be capable of obtaining a constant end point by using the reflectivity difference between a tungsten layer and an oxide layer. CONSTITUTION: A lamp(6) and a light detector(7) are located at the lower portion of a polishing pad(5). The polishing pad has a pad window(5a). After loading a wafer(10) at a wafer carrier, the wafer carrier is moved to the upper portion of the polishing pad. At this time, an oxide layer(3), a barrier(2), and a tungsten layer(1) are sequentially deposited at the upper portion of the wafer. Then, the light of the lamp is reflected at the tungsten layer toward the light detector through the pad window while carrying out a CMP process. As progressing the CMP process, the thickness of the wafer becomes thinner. In the end, the oxide layer(3) is exposed and the light reflectivity is changed. At this time, the CMP process is finished.
|
