Title :
Low-Temperature Bonding of Laser Diode Chips on Silicon Substrates Using Plasma Activation of Au Films
Author :
Higurashi, Eiji ; Imamura, Teppei ; Suga, Tadatomo ; Sawada, Renshi
Author_Institution :
Tokyo Univ., Tokyo
Abstract :
A low-temperature bonding of vertical-cavity surface-emitting laser (VCSEL) chips on Si substrates was achieved by using plasma activation of Au films. After the surfaces of Au films were cleaned using an Ar radio frequency plasma, bonding was carried out by contact in ambient air with applied static pressure. The experimental results showed that surface morphological change (the reduction of asperity width) as well as removal of adsorbed organic contaminants by plasma treatment significantly improved the quality of joints. At a bonding temperature of 100degC, the die-shear strength exceeded the failure criteria of MIL-STD-883.
Keywords :
failure (mechanical); flip-chip devices; gold; integrated circuit bonding; integrated optics; laser cavity resonators; metallic thin films; plasma materials processing; semiconductor lasers; shear strength; surface emitting lasers; surface morphology; Ar radiofrequency plasma; Au; Au films; MIL-STD-883 failure criteria; Si; adsorbed organic contaminants; die-shear strength; flip-chip bonding; laser diode chips; low-temperature bonding; plasma activation; plasma treatment; silicon substrates; surface morphological change; temperature 100 degC; vertical-cavity surface-emitting laser; Bonding; Diode lasers; Gold; Plasma temperature; Semiconductor films; Silicon; Surface contamination; Surface morphology; Surface treatment; Vertical cavity surface emitting lasers; Flip-chip bonding; hybrid integration; low-temperature bonding;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2007.908642
