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A high‐density inductively coupled plasma source has been used for the fabrication of nanostructures in GaAs and via holes in InP. High etch rates, smooth vertical sidewalls, and high selectivity to a Ni mask have been demonstrated with a pure Cl2 plasma at very low pressure, down to 0.10 mTorr. At a pressure of 0.12 mTorr, a GaAs etch rate of 582 nm/min, and a selectivity of 146 to a Ti/Ni mask were obtained. Higher stage powers or low pressures induced more damage in GaAs. Horizontal distributed Bragg reflector structures were fabricated in GaAs with mirror widths of 150 nm, spaces of 700 nm, and a depth of 2.3 μm. Etching at a pressure of 0.12 mTorr resulted in a higher normalized etch rate compared to etching at 1.30 mTorr in trench widths ranging from 95 nm to 2 μm. Via holes were etched in InP to depths <360 μm. Vertical sidewalls and high etch rates (4.0 μm/min) were achieved with selectivity of 302 to a Ti/Ni mask at a pressure of 0.5 mTorr. The effect of the aspect‐ratio‐dependent etching was investigated. It was found that the aspect ratio of the via hole, and not the hole diameter, is mostly responsible for the reduced etch rate in deep trenches. © 1999 The Electrochemical Society. All rights reserved.

A microcavity surface-emitting coherent electroluminescent device operating at room temperature under pulsed current injection is described. The microcavity is formed by a single defect in the center of a 2-D photonic crystal consisting of a GaAsbased heterostructure. The gain region consists of two 70-Å compressively strained In 0 15 Ga 0 85 As quantum wells, which exhibit a spontaneous emission peak at 940 nm. The maximum measured output power from a single device is 14.4 W. The near-field image of the output resembles the calculated TE mode distribution in a single defect microcavity. The measured far-field pattern indicates the predicted directionality of a microcavity light source. The lightcurrent characteristics of the device exhibit a gradual turn-on, or a soft threshold, typical of single-or few-mode microcavity devices. Analysis of the characteristics with the carrier and photon rate equations yields a spontaneous emission factor 0 06.

Articles you may be interested inEffects of rapid thermal annealing on the optical properties of In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As multiple quantum wells with InGaAs and dielectric capping layers Cl 2 plasma passivation of etch induced damage in GaAs and InGaAs with an inductively coupled plasma sourceThe effects of etch induced damage on the electrical and optical properties of AlGaAs/InGaAs quantum wells ͑QWs͒ were studied. From the variations in the photoluminescence ͑PL͒ intensity and the conductivity of etched gratings, the optical cutoff width was found to be 33 nm whereas the electrical cutoff width was 136 nm. The PL intensity of the gratings indicated that increased stage power during etching causes more damage. Comparisons were also made between the sheet resistivity ( s ) of transmission lines and the conductivity of wires after etching of AlGaAs/InGaAs and AlInAs/InGaAs QWs grown on GaAs and InP substrates, respectively. The AlGaAs/InGaAs QW transmission lines showed reduced s after etching with higher stage power, although the s was still higher than that of the unetched control sample. The AlInAs/InGaAs QW transmission lines had a higher s as the stage power was increased. The two material systems also showed different etch time and sidewall damage characteristics. The AlInAs/InGaAs QW structure degraded more severely at a shorter etch time and had a larger cutoff width as extracted from etched conducting wires.

Smooth sidewall in InP-based photonic crystal membrane etched by N 2 -based inductively coupled plasmaLow energy Cl species generated in an inductively coupled plasma source have been used to passivate etch induced damage in GaAs and InGaAs. Improved electrical and optical characteristics were measured after Cl 2 plasma passivation. The ideality factor and barrier height of etched GaAs Schottky diodes were improved back to the values of an unetched sample with a 10 min passivation. No etching occurred during passivation due to the presence of a surface oxide layer. The growth conditions of the oxide layer were found to have a large effect on the ability of the Cl 2 plasma to passivate the surface. It was found that native oxides allow more effective passivation by Cl species as compared to plasma grown oxides. The passivation techniques were used to passivate damage along an etched sidewall for improved electrical conductivity of GaAs wires and increased photoluminescence signal from etched gratings containing an InGaAs quantum well.