The major problem faced by the high power Group III elements and Nitride optical and electronic devices, such as LEDs, lasers and high-electron-mobility transistor (HEMTs), is to overcome self-heating in devices when they are biased at high voltage. For most of the time, substrates such as sapphire are used in the devices. But they have poor thermal conductivity and they are also an insulator. Along with high temperatures, they will affect the device performance and shorten the lifeline of the device as sapphire cannot absorb heat and provide pathway for conducting the heat generated during operation.
This technology provides a unique laser lift-off process to attach or fuse Group III elements and nitride-based structures, for optical and electronic devices, with multiwalled carbon nanotubes (MWCNT’s). Through the adoption of the laser lift-off process, devices made out of these structures are removed from sapphire substrate and held on a temporary support.
The laser lift-off process induces surface texturing at the removed interface. The attachment of GaN is a 2 step process. The CNT grown on SiO2/Si(100) is first attached to Si(100) using a benzocyclobutene (BCB) polymer. The virgin Si(100) substrate is removed by etching away the SiO2 layer. On the textured GaN surface, BCB is coated and the 2nd step of attachment is completed by merging it with CNT/Si(100) substrate. A similar process can be done with copper substrates.
Key features of the invention include:
- Fusion of grp III elements and nitride based structures
- Fusion of grp III elements with MWCNTs
- Laser lift off techniques
- Improved thermal properties
["CNT","gallium nitride","Group III elements","LED","nanotube","semiconductor","solid state lighting"]