Abstract: A method for chemical mechanical polishing (CMP) of a shallow trench isolation (STI) structure employs a sequence of slurry polishes. In the first step the substrate is polished with either silica-based slurry or diluted ceria-based slurry. The first polishing is at a higher removal rate than the second polishing step. The polishing proceeds with some planarization but does not expose the polish stop layer. After partial planarization, the high selectivity slurry was used to complete the process. Improved throughput, lower defects and good within wafer uniformity are achieved.

Abstract: An in-line hot-wire sensor for monitoring the mixing and the flow rate of slurry is disclosed. The hot-wire sensor may include a number of resistors organized into a Wheatstone bridge, as well as a frequency-domain transform mechanism. The resistors include a hot-wire resistor that is placed in-line with the slurry after substances have been mixed to become the slurry. The Wheatstone bridge thus yields a signal that is transformed to the frequency domain by the frequency-domain transform mechanism, such as by performing a Fast Fourier Transform (FFT) of the signal. The frequency-domain transform is used to monitor the mixing of the substances into the slurry, and the flow rate of the slurry. The signal may be amplified prior to transformation to the frequency domain.

Abstract: A method for chemical mechanical polishing (CMP) of a shallow trench isolation (STI) structure employs a sequence of slurry polishes. In the first step the substrate is polished with either silica-based slurry or diluted ceria-based slurry. The first polishing is at a higher removal rate than the second polishing step. The polishing proceeds with some planarization but does not expose the polish stop layer. After partial planarization, the high selectivity slurry was used to complete the process. Improved throughput, lower defects and good within wafer uniformity are achieved.

Abstract: An in-line hot-wire sensor for monitoring the mixing and the flow rate of slurry is disclosed. The hot-wire sensor may include a number of resistors organized into a Wheatstone bridge, as well as a frequency-domain transform mechanism. The resistors include a hot-wire resistor that is placed in-line with the slurry after substances have been mixed to become the slurry. The Wheatstone bridge thus yields a signal that is transformed to the frequency domain by the frequency-domain transform mechanism, such as by performing a Fast Fourier Transform (FFT) of the signal. The frequency-domain transform is used to monitor the mixing of the substances into the slurry, and the flow rate of the slurry. The signal may be amplified prior to transformation to the frequency domain.