Research On Material Growth And Device Fabrication Process Of Silicon-Based Gaas Lasers

In current age, the rapid development of information industry forced the network transportation to have higher speed and larger capacity. As large quantity of photoelectronic and electro-optical conversions existing in the optical communications network, people want to integrate the photonic devices and electronic devices into one chip (called photoelectronic integration) in order to greatly improve the efficiency of network transmission. Being a mature semiconductor material in microelectronic field, silicon is an indirect band material which limits the applications in luminescent devices. This thesis focus on fabricating an optical source on silicon by heteroepitaxy of III-V compound semiconductor on silicon under the background of optoelectronic integration.Aiming at the optoelectronic integration, we had systemically investigatied the growth of GaAs laser on silicon. Meanwhile, according to the characteristics of Si-based laser materials, we also studied the fabrication processes. The achievements are listed as follows.1. On the basis of previous studies, we made a further exploration of GaAs/Si heteroepitaxy by inserting QDs dislocation filter, adding amorphous silicon layer and using a mask-free nano-patterned substrate. Combined with thermal-cycle annealing, we have grown several1.8μm-thick Si-based GaAs wafers with the etch pit density at the oder of105cm-2. And we also explained the mechanism that the mask-free nano-patterned substrate improved the crystalline of GaAs epilayer.2. We have investigated the method improving the Si-based InGaAs/GaAs quantum well and the solution suppressing the high thermal stress of GaAs/Si wafer. Then we obtained Si-based GaAs laser materials with good carrier distribution and high quality InGaAs/GaAs quantum well. Transmission electron microscope observations revealed that most of the threading dislocations were trapped below the lower cladding layer and there was almost no dislocation crossing the quantum well region.3. We fabricated Si-based pulse laser diodes with a threshold current density of1000mA/cm2and a slope efficiency of1.03W/A at room temperature. When injected with a pulsed current of300mA, the laser has a peak light power of184mW.