Silicon carbide wafer bonding by modified surface activated bonding method

Abstract

4H-SiC wafer bonding has been achieved by the modified surface activated bonding (SAB) method without any chemical-clean treatment and high temperature annealing. Strong bonding between the SiC wafers with tensile strength greater than 32 MPa was demonstrated at room temperature under 5 kN force for 300 s. Almost the entire wafer has been bonded very well except a small peripheral region and few voids. The interface structure was analyzed to verify the bonding mechanism. It was found an amorphous layer existed as an intermediate layer at the interface. After annealing at 1273 K in vacuum for 1 h, the bonding tensile strength was still higher than 32 MPa. The interface changes after annealing were also studied. The results show that the thickness of the amorphous layer was reduced to half after annealing.

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

“…[68] Therefore, Tadatomo Suga et al from The University of Tokyo have developed a modified SAB method with Fe-Si nanolayers. [73] The modified SAB has been considered to realize the SiC wafer bonding with any other substrates. Applying Si as proof of sample, the detailed bonding process is shown in Figure 3(a).…”

Non-Destructive Eddy Current Measurements for Silicon Carbide Heterostructure Analysis

“…It is discussed the surface activated SiC-SiC wafer bonding [11]. Owing to this method the DB of SiC-SiC wafers can be achieved at the room temperature in comparison with past DB methods operated in high temperatures and thermal stressed exposed to the wafers.…”

Residual Stress in Lithium Niobate Film Layer of LNOI/Si Hybrid Wafer Fabricated Using Low-Temperature Bonding Method

“…However, previous research has demonstrated via experiment that it is difficult to apply the conventional SAB method to the direct bonding of oxide materials, such as SiO 2 [ 18 ]. To overcome this limitation, a modified SAB method has been proposed [ 19 , 20 , 21 , 22 ]. During the SAB process, the deposition of the Fe adhesion layer on each wafer is deployed simultaneously.…”

“…Mismatch also causes a change to the refractive index, which is important in photonics applications such as the waveguide-type ring resonator. Although room temperature bonding using sputtered Si film as the adhesion layer was also demonstrated [ 22 , 25 , 26 , 27 ], the application to photonic devices, including thin-film LNOI waveguides, was limited because the Si film was transparent in only a section of the infrared region.…”