(VCSEL) chips on silicon (Si) substrates with Au microbumps was demonstrated by Au–Au
surface-activated bonding. The diameter at the top, the height, and the pitch of Au
microbumps measured approximately 5, 2, and 10 µm, respectively. Following activation of
the Au surfaces with argon radio-frequency plasma, Au–Au bonding was carried out using
contact at RT in ambient air. The measured results of light–current–voltage (L–I–V) …