Fabrication of group III-V nitrides on mesas
US6163557A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 21, 1998 |
| Grant date | Dec 19, 2000 |
| Priority date | — |
| Expiry date | May 21, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/32341
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Group III-V nitride films are fabricated on mesas patterned either on substrates such as sapphire substrates, or on mesas patterned on group III-V nitride layers grown on substrates. The mesas provide reduced area surfaces for epitaxially growing group III-V nitride films, to reduce thermal film stresses in the films to reduce cracking. The surfaces of the mesas on which the films are grown are dimensioned and oriented to reduce the number of thin film crack planes that can grow on the mesas. Further cracking reduction in the films can be achieved by thinning the substrate to form membranes. The reduced substrate thickness at the membranes reduces the thermal expansion mismatch tensile stress in the films. The mesas can reduce or eliminate the occurrence of cracks in GaN or AlGaN epitaxial films grown on the mesas, for percentages of aluminum in the AlGaN films of up to about 18%. The improved group III-V nitride films can be used in optoelectronic devices including LEDs and edge and surface emitting laser diodes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.