Characterization of the bonding strength and interface current of p-Si/n-InP wafers bonded by surface activated bonding method at room temperature

Abstract

Bonding between p-Si and n-InP was performed through the surface activated bonding method at room temperature. Tensile results show that the samples were visibly separated from the bonded interface, indicating a weak bonding strength. The cause of the weak bonding strength was intensively investigated. Consistent results between x-ray photoelectron spectroscopy and atomic force microscope investigations show that a weak phase of indium is terminated on the InP due to the depletion of phosphorus in the sputtered surface. Existence of indium layers on the debonded Si surface indicate that the samples were separated from the interface of In/InP, but not across the bonded interface of Si and indium. Typical pn junction current-voltage behavior indicates no high resistance interface layer that can withstand the flow of current through the interface. Remarkably, sputtering time as well as energy dependence on the interface current is found to be due to the accumulation of sputtering induced defects.

Strain analysis of InP/InGaAsP wafer bonded on Si by X-ray double crystalline diffraction

“…3. When the temperature of the thermal treatment is high enough (above 350 • C), the indium in the InP surface will separated out to the bonding interface [24]. The indium atoms first form islets in the InP/Si interface, as the islets grow up, the combination strength between the indium islets and the InP and Si basal body is strengthened, the movement of these atoms are restricted by the basal body.…”

Transparent and electrically conductive GaSb/Si direct wafer bonding at low temperatures by argon-beam surface activation

“…III-V layers on silicon allow combining favorable material characteristics of compound semiconductors with the low-cost, the mechanical stability and the advantages in the processing of silicon. Hence, direct wafer bonding between GaAs/Si [4,5] and InP/Si [5,6] was investigated extensively in the past years. Likewise, GaSb offers a wide choice of promising and unique characteristics such as small effective masses, high electron and hole mobilities and a band gap suitable for long-wavelength optical devices [7,8].…”

Low-Temperature Bonding for Silicon-Based Micro-Optical Systems

“…This approach has also been used to bond Cu-filled through-Si vias and Au stud bumps [99]. Using the first SAB approach, material combinations such as Si-InP [20], Si-GaAs [21], Si-GaP, and GaP-GaAs [100] with high bond strength and smooth material interfaces, suitable for optical applications have been reported. There is also demand to bond dissimilar crystalline materials directly for optical isolation in optical systems.…”

“…The sequential plasma activation provides highly hydrophilic and reactive surfaces. It also generates nanopores and oxides on surfaces that remove and absorb water from the interface to the bulk material, resulting in strong covalent bonding [13][14][15][16][17][18][19][20][21][22][23]27,28,99,100,102,[104][105][106][107].…”

“…Surface activated bonding (SAB) is an example of the direct wafer bonding [13]. The SAB technologies do not require high temperature, high pressure, and extra additives to provide bonding interface with high bond strength, high electrical conductivity and low optical loss [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”