(Invited, Digital Presentation) Low-Temperature Direct Bonding of Wide-Bandgap Semiconductor Substrates

Abstract

For the next-generation semiconductor devices, our research group has developed direct bonding techniques of wide-bandgap materials, including SiC, Ga2O3, and diamond. It is known that the semiconductor substrates activated by oxygen plasma can form atomic bonds at low temperatures. In this case, a thick oxide layer, which may become a thermal and electrical barrier, is formed at the bonding interface. Meanwhile, our research group demonstrated that the OH-terminated Ga2O3 and diamond substrates were directly bonded without an oxide intermediate layer. In addition, the SiC substrate dipped into the HF acid can be bonded with the Ga2O3 substrate with an ~1-nm-thick amorphous layer. The dissimilar substrates bonded through the ultra-thin intermediate layer would contribute to efficient heat dissipation and future heterojunction devices.

Insight into Interfacial Heat Transfer of β-Ga2O3/Diamond Heterostructures via the Machine Learning Potential

“…The thermal conductivity of the β-Ga 2 O 3 /diamond van der Waals heterogeneous interface has been analyzed in the experiment, which could confirm that the heat dissipation performance of Ga 2 O 3 devices could be significantly improved via the integration of diamond heat sink . It is noteworthy that Matsumae et al achieved the β-Ga 2 O 3 /diamond heterostructure by low-temperature direct bonding of β-Ga 2 O 3 and diamond substrate under atmospheric conditions. , Sittimart et al reported that the electrical performance of diamond/β-Ga 2 O 3 p-n heterojunction diodes fabricated by the interfacial bonding was better than that prepared by van der Waals . In addition, Graham et al reported that the thermal boundary resistance of β-Ga 2 O 3 /diamond heterostructure adhered by van der Waals interactions is 10 times larger than that of interfacial bonding .…”

Sn-58Bi/Cu porous joint formation under air condition without pressure

“…However, in addition to self-heating issues, high-temperature working environments can reduce product performance, reliability, and lifespan. Therefore, the reliability of soldering interconnection in SMD packaging of WBG devices has become a focus in the packaging field [1,2] . Recently, TLP has broad application prospects in many fields, and its significant advantages allow it to solve the problem of soldering interconnection [3] .…”