Combined Surface-Activated Bonding Technique for Low-Temperature Cu/SiO₂ Hybrid Bonding

Abstract

The commercial introduction of three dimensional integrated circuits (3D-ICs) has been hindered by reliability challenges, such as stress related failures, resistivity changes, and unexplained early failures. In this paper, we discuss a new RF-based metrology, based on dielectric spectroscopy, for detecting and characterizing electrically active defects in fully integrated 3D devices. These defects are traceable to the chemistry of the insolation dielectrics used in the through silicon via (TSV) construction. We show that these defects may be responsible for some of the unexplained early reliability failures observed in TSV enabled 3D devices.

Recent progress on bumpless Cu/SiO2 hybrid bonding for 3D heterogeneous integration

“…To bond SiO 2 -SiO 2 and Cu-Cu simultaneously, He et al (2015He et al ( ,2016aHe et al ( , 2016bHe et al ( , 2016c) developed a combined SAB method, and the process diagram is illustrated in Figure 2(e). A schematic diagram of the SiO 2 surface and copper surface is shown in Figure 3(a) and 3(b).…”

“…Combined SAB schematic diagram of: (a) the SiO 2 surface (He et al , 2016a) and (b) the copper surface (He et al , 2016a); (c) the surface treatment principle diagram of SiO 2 and Cu (He et al , 2016a); (d) schematic diagram of hybrid bonding by the combined SAB method (He et al , 2016a); (e) the fractured interfaces after the tensile test (He et al , 2015)…”

Combined Surface Activated Bonding Technique for Low-Temperature Cu/Dielectric Hybrid Bonding

“…20,23,[27][28][29] Recently, we proposed a combined surface activated bonding (SAB) technique to improve the SiO 2 -SiO 2 bonding strength. 30,31 The combined SAB method involves a combination of surface irradiation using a Si-containing Ar beam and prebonding attach-detach process prior to bonding in vacuum. The Si atoms added in the Ar beam are expected to increase the number of reactive Si sites on SiO 2 surface, while the prebonding attach-detach process is used to enhance the OH adsorption and to remove excess H 2 O prior to bonding.…”