Study Of Inductively Coupled Plasma Etch Of InP And Fabrication Of 14xxnm Pump Laser Diodes

14xxnm pump laser diodes (LD's) are the core of Raman amplifiers (RA). They can be use in fiber communications with a great market. Phosphorus indium, a kind of Ⅲ-Ⅴ compound semiconductor, has high electron mobility and good performance in luminescence. It has been used in photon devices, quanta devices and high-speed electric devices broadly. In this work, inductively coupled plasma (ICP) etching of InP using Cl₂/Ar has been investigated. We have also discussed the damage in InP surface induced by ICP etching. Then, we carry out the ICP etch process into laser diodes' manufacture and successfully achieve 14xxnm InAsP/InGaAsP Multiple-Quantum-Well laser diodes. Following is the details:ICP etch of InP is performed in a native equipment with different DC bias, ICP power, total flow rates and Cl₂:Ar ratio. The effects of these parameters on etch rates, selectivity, surface morphology and etched facet have been discussed. The maximal etch rate of InP is as high as 1.65μm. The deepest depth of etch could be 7 urn with the selectivity to Si₃N_x > 15. When Cl₂ percentage is about 30%, the etch rate is close to peak value and the surface is the smoothest. The SEM photo showed smooth etched surface and vertical sidewall.Electrochemical capacitance-voltage profiling (ECV) is employed to measure the carrier concentration of the damaged layer caused by ICP etch. Photoluminescence spectroscopy (PL) is applied to determine the optical properties. We found high ICP power and DC bias will increase the n-type carriers' concentration. To avoid damage effectively, DC bias should less than -130V when ICP power is 300W and less than -170V when ICP power is 200W. Through PL spectroscopy, we consider the increasing of n-type carriers' concentration attributed to phosphorus vacancies.We perform the ICP etch into laser diodes' manufacture and achieve 14xxnm ridge wave guide laser diodes. The threshold voltage is 0.5V and the threshold current density isabout 1.5KA/cm2. The output power could be 25mW with 1.443um wavelength in room temperature.