Characterization of interfacial morphology of low temperature, low pressure Au–Au thermocompression bonding

Goorsky, Mark S.; Schjølberg-Henriksen, Kari; Beekley, Brett; Bai, Tingyu; Mani, Karthick; Ambhore, Pranav; Bajwa, Adeel; Malik, Nishant; Iyer, Subramanian S.

doi:10.7567/jjap.57.02bc03

Cited by 10 publications

(5 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…AlN was grown on quartered 2 inch 6H-SiC substrates (SiCrystal AG) by MOCVD as described elsewhere [81]. A one-step lapping process was used to thin the SiC substrates after bonding them to a carrier with high thermal conductivity (4.9 W cm −1 a-plane, 3.9 W cm −1 c-plane) with n-and pbonding pads using Au/Au thermocompression bonding [99,100]. The SiC based samples were mounted episidedown on a 2 inch stainless-steel chuck using a wax (that melts at 120 °C), which provides mechanical adhesion during lapping.…”

Section: Sic Substrate Thinning Characteristicsmentioning

confidence: 99%

Fabrication technology for high light-extraction ultraviolet thin-film flip-chip (UV TFFC) LEDs grown on SiC

SaifAddin¹,

Almogbel

Zollner³

et al. 2019

Semicond. Sci. Technol.

View full text Add to dashboard Cite

The light output of deep ultraviolet (UV-C) AlGaN light-emitting diodes (LEDs) is limited due to their poor light extraction efficiency (LEE). To improve the LEE of AlGaN LEDs, we developed a fabrication technology to process AlGaN LEDs grown on SiC into thinfilm flip-chip LEDs (TFFC LEDs) with high LEE. This process transfers the AlGaN LED epi onto a new substrate by wafer-to-wafer bonding, and by removing the absorbing SiC substrate with a highly selective SF6 plasma etch that stops at the AlN buffer layer. We optimized the inductively coupled plasma (ICP) SF6 etch parameters to develop a substrateremoval process with high reliability and precise epitaxial control, without creating micromasking defects or degrading the health of the plasma etching system. The SiC etch rate by SF6 plasma was ~46 µm/hr at a high RF bias (400 W), and ~7 µm/hr at a low RF bias (49 W) with very high etch selectivity between SiC and AlN. The high SF6 etch selectivity between SiC and AlN was essential for removing the SiC substrate and exposing a pristine, smooth AlN surface. We demonstrated the epi-transfer process by fabricating high light extraction TFFC LEDs from AlGaN LEDs grown on SiC. To further enhance the light extraction, the exposed N-face AlN was anisotropically etched in dilute KOH. The LEE of the AlGaN LED improved by ~3X after KOH roughening at room temperature. This AlGaN TFFC LED process establishes a viable path to high external quantum efficiency (EQE) and power conversion efficiency (PCE) UV-C LEDs.

show abstract

Section: Sic Substrate Thinning Characteristicsmentioning

confidence: 99%

Fabrication technology for high light-extraction ultraviolet thin-film flip-chip (UV TFFC) LEDs grown on SiC

SaifAddin¹,

Almogbel

Zollner³

et al. 2019

Semicond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Au is a relatively compliant metal and free of any native oxide. This allows intimate contact at the interface of the mating surfaces during thermal compression bonding [6].…”

Section: Mechanical Characterizationmentioning

confidence: 99%

Demonstration of a Heterogeneously Integrated System-on-Wafer (SoW) Assembly

Bajwa

Jangam

Pal

et al. 2018

2018 IEEE 68th Electronic Components and Technology Conference (ECTC)

Self Cite

View full text Add to dashboard Cite

This paper describes the integration of a System-on-Wafer (SoW) assembly using test dielets mounted on a Silicon Interconnect Fabric (Si-IF) with an inter-dielet spacing of 100 μm and using 10 μm interconnect pitch. The continuity within and across the dielet assembly is shown using daisy chains of Au-capped Cu-Cu thermal compression bonds. The daisy chains run not only through every dielet but also across all the adjacently mounted dielets on the Si-IF. The interconnections exhibited an effective contact resistivity of 0.8-0.9 Ω-μm 2 and an average shear strength of 125 MPa. Our investigations showed that Argon plasma pre-treatment improves the shear strength of the metal bonds by a factor of 5X. Thermal simulation of the SoW assembly showed superior heat spreading across the assembly in a checkerboard configuration of alternate hot (0.5 W/mm 2) and cold (0.1 W/mm 2) dielets with an average temperature of 82 °C & 78 °C respectively.

show abstract

“…In the present study, we fabricated SMRs by joining two separate Au-coated silicon-on-insulator (SOI) substrates with Au-Au thermal diffusion bonding, which is a welding technique to create a joint between materials [24], [25]. We investigated different bonding temperatures and Au film thicknesses to attain a robust bond between the Au films.…”

Section: Introductionmentioning

confidence: 99%

Silicon-Based Suspended Microchannel Resonator Developed Using Au Thermal Diffusion Bonding for Mass Sensing of Biomaterials

Funayama,

Miura,

Arai

et al. 2024

J. Microelectromech. Syst.

View full text Add to dashboard Cite

Suspended microchannels are of great interest in applications such as physical and chemical sensor systems. In this study, we developed a suspended microchannel resonator (SMR) by bonding two separate Au-coated silicon-insulatorsilicon substrates via thermal diffusion bonding. To obtain a secure bond between Au films, we investigated different bonding temperatures and Au film thicknesses. As a result, we successfully fabricated an SMR. We show that the developed resonator has a resonance frequency of 229.55 kHz and a quality factor of 171 for the empty channel. The response of the channel to absolute mass was 18.7 pg/Hz. The measurement results were in good agreement with the results of numerical simulations. In addition, we estimated the practical mass detectability of the developed SMR via statistical analysis. The developed SMR enabled mass detection with a resolution of 710.6 pg. Our SMR can be produced via typical semiconductor fabrication technology, which is advantageous in terms of mass production.[

show abstract

Characterization of interfacial morphology of low temperature, low pressure Au–Au thermocompression bonding

Cited by 10 publications

References 27 publications

Fabrication technology for high light-extraction ultraviolet thin-film flip-chip (UV TFFC) LEDs grown on SiC

Fabrication technology for high light-extraction ultraviolet thin-film flip-chip (UV TFFC) LEDs grown on SiC

Demonstration of a Heterogeneously Integrated System-on-Wafer (SoW) Assembly

Silicon-Based Suspended Microchannel Resonator Developed Using Au Thermal Diffusion Bonding for Mass Sensing of Biomaterials

Contact Info

Product

Resources

About