Homogeneous bonding was successfully demonstrated on 150 mm Si wafers by face-to-face direct dielectric bonding of clean and smooth aluminum nitride (AlN) layers. Characterization result from XPS confirms the layer composition and reveals that approximately 5 nm of the layer surface was partially oxidized during processing. After activation, substoichiometric nitrogen bound to aluminum, Al-O and Al-OH bonds were found at the thin film surface. The as-bonded wafer pairs are nearly void and particle free with a high bonding strength of 1527.8 ± 272.2 mJ/m 2 , enabling them to withstand the subsequent process steps. In addition, experimental results have indicated that the AlN-AlN bonded wafers can achieve a 23 and 16% improvement respectively in terms of heat dissipation compared with those using SiO 2 and Al 2 O 3 as the bonding layer. It is concluded that this AlN-AlN bonded wafer pairs can exhibit a better heat dissipation capability than other bonded counterparts. Wafer bonding allows heterogeneous integration of two materials that have similar or very different lattice parameters and thermal properties, via an intermediate bonding layer or direct bonding. One of the most prominent applications of wafer bonding is silicon-oninsulator (SOI), [1][2][3][4][5] and it can also be extended to germanium-oninsulator (GOI) 6,7 or other III-V groups integration. 8,9 First direct bonded SOI was reported by Lasky et al. in 1986. Since then, SOI fabricated from wafer bonding has been gaining ground from the conventional Si substrate in ultra-large scale integrations (ULSI) and micro-electro-mechanical systems (MEMS) 10 as the starting substrate, which benefits from its on-insulator structure. The "on-insulator" advantages make it possible to attain mechanical stability close to Si substrate and excellent electrostatic control, such as attenuated shortchannel effects, 11 reduced parasitic capacitance and absence of latchup. 12 As the most common buried insulator material, SiO 2 has already shown extensive popularity in a couple of optical devices. [13][14][15] However, the low thermal conductivity of SiO 2 (1.46 Wm −1 K −1 ) limits the heat dissipation efficiency and degrades the advantages of SOI. Also, the degraded heat dissipation path deteriorates its heat transfer efficiency to the underlying bulk Si layer, leading to severe self-heating effect. This effect is further magnified by device scaling for performance improvement, which constrains the applicability of SOI in electronics, especially in the cases where high temperature and power dissipation are expected. In order to address this problem, numerous efforts have been dedicated to exploring for novel buried insulator materials with high thermal conductivity such as diamond and silicon carbide. 16 Liang et al. had demonstrated the outstanding heat dissipation advantage of silicon-on-diamond (SOD) comparing to the conventional SOI substrate.17 Furthermore, high-k dielectric materials with high thermal conductivity have drawn great attention in SOI fabrication. For ...

Nitride-based ultraviolet (UV) photosensors with a low-temperature (LT) AlGaN interlayer were fabricated and characterized. Material analysis results showed that dark pits corresponding to threading dislocation (TD) terminations were almost invisible after inserting the LT AlGaN interlayer. It was also found that we could significantly suppress the dark leakage current by using the LT AlGaN interlayer owing to TD annihilation and demultiplication processes. For photosensors with the LT AlGaN interlayer, the responsivity at 360 nm and UV-to-visible rejection ratio were found to be 0.12 A/W and 2.45 9 10 3 , respectively, under 5 V applied bias.