Method for measuring and analyzing surface roughness on semiconductor laser etched facets
US5460034A · kind A · utility
9Cited by
17References
3Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 21, 1992 |
| Grant date | Oct 24, 1995 |
| Priority date | — |
| Expiry date | Jul 21, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/24578
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A scanning electron microscope is used to scan the etched facet edge to produce digital data representative of its profile. A Fourier transform of the edge profile is produced and the resulting plurality of spatial frequency components can be used to generate a first low frequency waveform component indicative of lack of precise edge definition, a midrange frequency component indicative of poor liftoff samples, and a high frequency component indicative of metal grain size. A tilt adjustment feature of the electron microscope is optionally used to advantageously magnify the shape of the profile in the y direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.