Surface and optical properties of silicon nitride deposited by inductively coupled plasma-chemical vapor deposition

The surface and optical properties of silicon nitride samples with different compositions were investigated. The samples were deposited on In P by inductively coupled plasma chemical vapor deposition using different NH3flow rates. Atomic force microscopy measurements show that the surface roughness is increased for the samples with both low and high NH3flow rates. By optimization, when the NH3flow rate is 6 sccm, a smooth surface with RMS roughness of 0.74 nm over a 5 × 5 μm2area has been achieved. X-ray photoelectron spectroscopy measurements reveal the Si/N ratio of the samples as a function of NH3flow rate. It is found that amorphous silicon is dominant in the samples with low NH3flow rates, which is also proved in Raman measurements. The bonding energies of the Si and N atoms have been extracted and analyzed. Results show that the bonding states of Si atoms transfer from Si0to Si+4as the NH3flow rate increases.

Si-based InGaAs photodetectors on heterogeneous integrated substrate

In this paper,InGaAs p-i-n photodetectors(PDs)on an InP/SiO2/Si(InPOI)substrate fabricated by ion-slicing technology are demonstrated and compared with the identical device on a commercial InP substrate.The quality of epitaxial layers on the InPOI substrate is similar to that on the InP substrate.The photo responsivities of both devices measured at 1.55μm are comparable,which are about 0.808-0.828 A W^(-1).Although the dark current of PD on the InPOI substrate is twice as high as that of PD on the InP substrate at 300 K,the peak detectivities of both PDs are comparable.In general,the overall performance of the InPOI-based PD is comparable to the InP-based PD,demonstrating that the ion-slicing technology is a promising route to enable the highquality Si-based InP platform for the full photonic integration on a Si substrate.