Direct Homo/Heterogeneous Bonding of Silicon and Glass Using Vacuum Ultraviolet Irradiation in Air

Abstract

We develop a cost-effective vacuum ultraviolet (VUV) irradiation in air combined with an in situ bonding process. The whole bonding process does not require high vacuum environments. Strong bonding strengths for Si/Si, Si/glass, and glass/glass pairs were achieved with the assistance of annealing at 200 • C. There was no crack or defect at the bonding interfaces. The excellent optical transparency of the bonded glass/glass pairs was demonstrated in the UV-visible range. On the basis of the surface and bonding interface characterizations, the low-temperature bonding mechanism was investigated and discussed. Similar to the plasma activated bonding, the internal water stress corrosion plays a crucial role in the mechanical evolution of bonding interface between the VUV irradiated surfaces during annealing. This facile bonding method offers great potential for silicon-and glass-based homo/heterogeneous integrations in microelectronics, optoelectronics and microfluidics.

Mechanisms for low-temperature direct bonding of Si/Si and quartz/quartz via VUV/O3 activation

“…20 And a shorter-wavelength vacuum ultraviolet (VUV) has been found to be more benecial to bonding due to an ultrathin hydrate layer formed through VUV irradiation. 21,22 To date, VUV has been successfully applied to Au/Au direct bonding as well as the heterogeneous bonding of polyether ether ketone (PEEK) and Pt. 22,23 However, little research has focused on the VUV assisted bonding of Si/Si and quartz/ quartz, and the VUV/O 3 -activated bonding mechanism has never been explored.…”

Progress in wafer bonding technology towards MEMS, high-power electronics, optoelectronics, and optofluidics

“…Besides, due to the excellent biocompatibility and transparency of SiC/glass in the visible range, the SiC/glass platform has been used for the cell culture, as shown in Figure 3 Figure 3(g). [56][57][58]65,67,74,75] They use one-step VUV/O 3 activation to realize strength SiC/Si, SiC/SiO 2 , and SiC/glass bonding interfaces with nanometer-scale (<10 nm) amorphous transition layers. The SiC substrate adjacent to the bonding interface can still keep single-crystal, which can maximize the excellent optical and electrical properties.…”

Nanometer-Scale Heterogeneous Interfacial Sapphire Wafer Bonding for Enabling Plasmonic-Enhanced Nanofluidic Mid-Infrared Spectroscopy

“…g ., PDMS, PMMA, PS, etc. ) have excellent bonding abilities with different rigid materials, − they are not suitable for the nanochannel/chamber fabrication because of the collapse. , So far, fabrication of the nanofluidic device mainly uses fused silica (SiO 2 ) because of its mature low-temperature bonding technique, such as O 2 /CF 4 plasma activation, sequential plasma activation, and VUV/O 3 activation. , In the sensing applications, MIR beyond 3 μm is a vital wavelength range that covers the fingerprint of gas and biological molecules, such as N–H, O–H, C–H, CO, etc . Unfortunately, SiO 2 only has a high transmittance of <2.8 μm wavelength.…”