Sensitivity of proton implanted VCSELs to electrostatic discharge pulses

The sensitivity of vertical cavity surface-emitting lasers to electrostatic discharge (ESD) pulses has been investigated under human body model test c onditions. Very similar degradation behavior has been found for vertical-ca vity surface-emitting lasers (VCSELs) from two different manufacturers, bot h with proton-implantation for lateral current confinement. For all investi gated devices we observed during forward bias stress that the optical degra dation precedes the electrical degradation and the forward bias damage thre shold pulse amplitudes were only slightly higher than the reverse bias valu es. At the initial stage of the VCSEL degradation, damage of the upper p-DB R mirror region has been observed without modification of the active layer. During the ESD tests we monitored the electrical and the optical parameter s of the VCSELs and measured during forward bias stress additionally the op tical emission transients. The optical transients during ESD pulsing enable a fast evaluation of the damage threshold and give also an indication of t he time scale of the junction heating during ESD pulses.