T. Fink

Long wavelength MSM-HEMT and PIN-HEMT photoreceivers grown on GaAs

1.3 - 1.55μm wavelength 20 Gbit/s MSM-HEMT and 10 Gbit/s PIN-HEMT photoreceivers have been monolithically integrated on GaAs substrates using a 0.3 μm gate length AlGaAs/GaAs HEMT process. The In/sub 0.53/Ga/sub 0.47/As MSM and PIN photodiodes grown on GaAs have nearly identical characteristics to photodiodes grown on InP.

10 Gbit/s long wavelength monolithic integrated optoelectronic receiver grown on GaAs

The first 10 Gbit/s 1.3-1.55 /spl mu/m wavelength monolithic integrated photoreceiver grown on GaAs substrate has been fabricated using a 0.3 /spl mu/m gate length AlGaAs-GaAs HEMT process. At a wavelength of 1.3 /spl mu/m the integrated InGaAs MSM photodiode has a DC responsivity of 0.34 A/W. The photoreceiver bandwidth is 7.1 GHz and its sensitivity is better than -14.7 dBm (BER=10/sup -9/).

Monolithic integrated optoelectronic circuits

Monolithic integration of lasers and photodetectors with electronic circuits promises higher bandwidth, improved manufacturability, smaller size, lower power and hence lower costs. This paper reviews the activities of the Fraunhofer IAF on optoelectronic integrated circuits (OEICs) for serial and parallel optical links.

Monolithic integration of 1.3-μm InGaAs photodetectors and high-electron-mobility transistor (HEMT) electronic circuits on GaAs

For the first time, monolithic optoelectronic receivers for a wavelength of 1.3 micrometers have been fabricated successfully on GaAs substrates using InGaAs metal-semiconductor-metal (MSM) photodiodes and AlGaAs/GaAs/AlGaAs high-electron-mobility transistors (HEMTs). Using molecular beam epitaxy (MBE), the photodetector layers were grown on top of a double (delta) -doped AlGaAs/GaAs/AlGaAs HEMT structure which allows the fabrication of enhancement and depletion field effect transistors. The photoabsorbing InGaAs layer was grown at 500 degree(s)C. To fabricate the optoelectronic receivers, first, an etch process using a combination of non-selective wet etching and selective reactive ion etching was applied to produce mesas for the photoconductors and to uncover the HEMT structure in all other areas. For the electronic circuits, our well-established HEMT process for 0.3-micrometers transistor gates was used which includes electron-beam lithography for gate definition and optical lithography for NiCr thin films resistors, capacitors, and inductors. The interdigitated MSM photodiode fingers were also fabricated using electron-beam lithography. For interconnecting the electronic circuits and the photodetectors, air bridges were employed. The entire process was performed on 2-inch wafers with more than 90% yield of functional receivers. The finished receiver--basically an MSM photodetector linked to a transimpedance amplifier--is operational at an incident wavelength of 1.3 micrometers at data rates up to 1.2 Gbit/s. The sensitivity of the detectors is 0.16 A/W at a 10 V bias.

1.3 /spl mu/m monolithic integrated optoelectronic receiver using InGaAs MSM photodiode and AlGaAs/GaAs HEMTs grown on GaAs

The first 1.3 /spl mu/m monolithic integrated optoelectronic receiver using an InGaAs MSM photodiode and AlGaAs/GaAs HEMTs grown on a GaAs substrate has been fabricated. At each differential output the transimpedance is 26.8 k/spl Omega/. The bandwidth of 430 MHz implies suitability for transmission rates up to 622 Mbit/s.<<ETX>>

Technology for monolithic integration of GaInAs MSM photodetectors and AlGaAs/GaAs/AlGaAs-HEMT electronics

A process suitable for the monolithic integration of 1.3 /spl mu/m MSM photodiodes and HEMT electronics is presented A new MBE growth concept has been implemented to improve the performance of GaInAs photodetectors grown on GaAs. Photodetectors fabricated on linear and step graded buffer layers as well as those grown on InP substrates have been compared. The measured responsivities at the wavelength of 1.3 /spl mu/m were 0.34 A/W and 0.33 A/W for detectors on linear graded buffers and on InP, respectively. A -3 dB bandwidth of more than 8 GHz was obtained from high frequency measurements, The spectral response of the photodetectors show nearly the same responsivity for a wavelength of 1.3 /spl mu/m as for 1.55 /spl mu/m. Taking into account the high yield and reliability of our HEMT process the presented integration concept together with the new detector structure is suitable for large scale production of high performance long wavelength photoreceivers.