Evaluation of openings in a dielectric layer
US7379185B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 2004 |
| Grant date | May 27, 2008 |
| Priority date | — |
| Expiry date | Oct 26, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A patterned dielectric layer is evaluated by measuring reflectance of a region which has openings. A heating beam may be chosen for having reflectance from an underlying conductive layer that is several times greater than absorptance, to provide a heightened sensitivity to presence of residue and/or changes in dimension of the openings. Reflectance may be measured by illuminating the region with a heating beam modulated at a preset frequency, and measuring power of a probe beam that reflects from the region at the preset frequency. Openings of many embodiments have sub-wavelength dimensions (i.e. smaller than the wavelength of the heating beam). The underlying conductive layer may be patterned into links of length smaller than the diameter of heating beam, so that the links float to a temperature higher than a corresponding temperature attained by a continuous trace that transfers heat away from the illuminated region by conduction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.