초록 ▼

The present invention provides an infrared spectroscopic method of removing a first layer from a semiconductor wafer without overpolishing the underlying second layer. The first layer and the second layer of the semiconductor wafer is subjected to infrared (IR) spectroscopy and an absorbance curve i

The present invention provides an infrared spectroscopic method of removing a first layer from a semiconductor wafer without overpolishing the underlying second layer. The first layer and the second layer of the semiconductor wafer is subjected to infrared (IR) spectroscopy and an absorbance curve is produced, whereby each layer absorbs IR light at different wavenumbers to produce different absorbance peaks. Once the CMP process is performed, a change in the IR absorptivity and thus the absorbance peak of each layer is detected. The endpoint of the CMP process is determined at a point when significant change in the IR absorptivity of the first layer is no longer detected and change in the IR absorptivity of the second layer occurs.

대표청구항 ▼

1. A method of determining an endpoint of a chemical mechanical polishing (CMP) process applied to a semiconductor wafer to remove a first layer directly atop a second layer on a first side of the semiconductor wafer, the first and second layer each absorbing infrared (IR) light at different wavelen

1. A method of determining an endpoint of a chemical mechanical polishing (CMP) process applied to a semiconductor wafer to remove a first layer directly atop a second layer on a first side of the semiconductor wafer, the first and second layer each absorbing infrared (IR) light at different wavelengths, the method comprising:directing an IR light source onto the first side of the semiconductor wafer; detecting transmitted IR light received by an IR detector located on a second side of the semiconductor wafer; graphing IR absorptivity of the first layer and the second layer; performing the CMP process and using the IR absorptivity of the first layer and the second layer to produce an IR absorbance curve;and determining the endpoint of the CMP process, wherein the endpoint of the CMP process is determined at a point when a lack of significant change in the IR absorptivity of the first layer occurs in combination with a decrease in the IR absorptivity of the second layer.