A device quality of selective epitaxy growth of InGaAsP/InP multiple quantum well (MQW) structure using low-pressure metalorganic vapor phase epitaxy (MOVPE) technique is described. The technique is applied to a monolithically integrated electroabsorption modulator with distributed feedback (DFB) and distributed Bragg reflector (DBR) lasers. Superior device characteristics such as efficient modulation, low threshold current and high efficiency operation of the integrated devices are obtained.

Addition of HCl generated by pyrolysis of 1,1,1 trichloroethane (TCA) during both low pressure and atmospheric pressure MOCVD (metalorganic chemical vapor deposition) of InP has been used to improve the performance of the MOCVD selective area regrowth process. The addition of TCA provides good planar growth on unmasked areas without polycrystalline deposition on the mask or growth over the mask edges. Growth protrusions in the (111) direction for conventional MOCVD regrowth around re-entrant mesas are eliminated when TCA is added. TCA does not effect dopant incorporation or the ability to grow semi-insulating InP:Fe, but does cause a reduction in the growth rate proportional to the TCA partial pressure. Planarization of etched features without masks is also improved. Improved morphology is shown by demonstrating reproducible selective area InP regrowth around SiO2 capped etched mesas of various shapes, including reactive ion etched (RIE) mesas.

Heterostructures of InGaAs/InP and InGaAs/InGaAsP were grown by low pressure metalorganic chemical vapor deposition (LP-MOCVD) in an EMCORE GS3200 system. Highly abrupt interfaces were attained with PL line widths for the InGaAs/InP system comparable to the best values reported in the literature for any crystal growth technique, MOCVD, MBE or CBE. These structures were characterized with low temperature (10K) photoluminescence (PL), transmission electron microscopy (TEM) and high resolution X-ray diffraction (HRXD).

We have investigated the doping incorporation and activation of InP growth using metalorganic chemical vapor deposition on <100≳, <311≳B, and <110≳ InP substrates. Effects of orientation, growth temperature, and V/III fluxes were studied. The dopants used were Zn from dimethylzinc [(CH3)2Zn] and diethylzinc [(C2H5)2Zn], S from hydrogen sulfide [H2S], Si from silane [SiH4], and Sn from tetraethyltin [(C2H5)4Sn]. The incorporation and activation of the p-type dopant Zn are elevated on the <311≳B and <110≳ planes, while the incorporation is suppressed for the n-type dopants (S, Si, and Sn). The n-type dopant Sn has similar incorporation and activation on the various substrate orientations studied. Anomalous Zn doping on the higher order planes <311≳B and <110≳ lead to the Zn incorporation exceeding the solubility limit in InP. Incorporated Zn levels as high as 1.0×1019 cm−3 were measured, and the corresponding activated Zn level was as high as 5.4×1018 cm−3 on a <110≳ InP substrate. Interdiffusion of the p-type dopant Zn into the S-doped n-type InP substrate is inhibited by a high S-doping level and segregates at the substrate–epilayer interface. If the S-doping level is lower than the Zn concentration, then Zn diffuses deep into the substrate at a uniform level.

A mature optoelectronic integrated circuit (OEIC) technology is expected to offer benefits in the areas of increased functionality, improved reliability, size reduction, higher performance, and, finally, reduced cost. Although significant progress has been made in OEICs, the problem of interconnection between photonic device (e.g., laser diode, LD) and an electronic device (e.g., field-effect transistor, FET) still exists because of nonplanar topography. In this paper we will present a fabrication technology for which the above problem is eliminated.