Uniformity improvement of optical and electrical characteristics in integrated vertical-to-surface transmission electro-photonic device with a vertical cavity

We report an improvement in uniformity of both electrical and optical characteristics in an integrated vertical-to-surface transmission electro-photonic device with a vertical cavity. This improvement is due to both highly controlled reactive ion-beam etching and a self-alignment process. Reactive ion-beam etching highly controls etching depth, and leads to uniform electrical and optical characteristics. Self-alignment process makes it possible to fabricate a fine pattern with high accuracy. By using these fabrication processes, the deviations of both the electrical resistance and the optical light-output characteristics are reduced to less than half of those for the wet-etched devices. Furthermore, the remaining deviation in the light-output characteristics is reduced by suppressing light reflection on the surface. As a result, the standard deviation of the threshold current under the CW condition is 0.39 mA. This value is about half of that for the wet-etched devices.