Two types of micron-diamond films were prepared on YG6 substrate by hot filament chemical vapor deposition(HFCVD) method. Morphology and orientation of crystalline growth were evaluated by SEM and XRD. Diamond film coated tools and sapphire wafer’ surface before and after lapping experiment  were contrasted. The results indicated that a significant change in Raman spectrum of two types of micro...

In this work [1], the influence of sapphire mis-orientation on the quality of coalesced (11 2̄2 ) GaN layers grown on r-plane prestructured sapphire substrates (r-PSS) is investigated. It was found that the angle of the GaN (11 2̄ 2 ) plane towards the surface plane of the sapphire wafer can be adjusted by the mis-orientation of the substrate. Furthermore, we discovered that the c-direction of Ga...

Light-emitting diodes (LEDs) become an attractive alternative to conventional light sources due to high efficiency and long lifetime. However, different material properties between GaN and sapphire cause several problems such as high defect density in GaN, serious wafer bowing, particularly in large-area wafers, and poor light extraction of GaN-based LEDs. Here, we suggest a new growth strategy...

Billions of LEDs are used today in traffic control, automotive headlights, flat panel display technology, mobile devices, back lighting, projection and general illumination applications. With the dramatic growth in LEDs, manufacturers are looking for technologies to increase production yield and decrease cost. Sapphire wafer singulation into miniature dies is one of the critical steps used in b...

Three-inch (100) gallium arsenide wafers were bonded to (1102) sapphire in a micro-cleanroom at room temperature under hydrophilic or hydrophobic surface conditions. Subsequent heating up to 500 ◦C increased the bond energy of the GaAs-on-sapphire (GOS) wafer pair close to the fracture energy of the bulk material. The bond energy was measured as a function of the temperature. Since the thermal ...

Vertical thin-GaN LED was successfully fabricated on the GaN LED epi-layers grown on the patternedsapphire substrate with the pyramidal pattern by low-temperature Cu/Sn/Ag wafer bonding at 150 C. An inverted pyramidal pattern formed on the n-GaN surface after the GaN epi-layer was transferred onto Si wafer, which resulted from the pyramidal pattern on the patterned-sapphire substrate. The inver...

We prepared 2”-GaN wafers as templates for a self separation process which is happening during cooldown after growing thick layers of GaN in our hydride vapor phase epitaxy (HVPE) reactor. Our templates process starts with GaN grown by metalorganic vapor phase epitaxy (MOVPE) directly on sapphire. These GaN layers are getting masked with 200nm of SiN that is structured by means of optical litho...

This study reports on the use of a substrate-reclamation technology for a gallium nitride (GaN)-based lighting-emitting diode (LED) wafer. There are many ways to reclaim sapphire substrates of scrap LED wafers. Compared with a common substrate-reclamation method based on chemical mechanical polishing, this research technology exhibits simple process procedures, without impairing the surface mor...