Process for fabricating a device using an ellipsometric technique
US5494697A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1993 |
| Grant date | Feb 27, 1996 |
| Priority date | — |
| Expiry date | Nov 15, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/32972
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ellipsometric method for process control in the context of device fabrication is disclosed. An ellipsometric signal is used to provide information about the device during the fabrication process. The information is used to better control the process. An ellipsometric signal of a particular wavelength is selected. The signal is selected based on the composition and thickness of the films on the substrate through which the ellipsometric signal will pass before it is reflected from the substrate. Once the appropriate wavelength is determined, the ellipsometric signal is used to monitor the thickness of the films on the substrate over time, to assist in controlling the deposition and removal of films on the substrate, and to perform other process control functions in the context of device fabrication. The ellipsometric method is used to control the deposition and removal of films that underlie patterned masks with aspect ratios of 0.3 or more, that overlie topography on a substrate surface, or that both underlie a mask and overlie topography.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.