Monolithic Integration of Long Wavelength Photodetectors and High Electron Mobility Transistors on Metamorphic Gallium Arsenide Substrates

Long wavelength In0.53Ga0.47As photodiodes as well as In0.52Al0.48As/In0.53Ga0.47 As high electron mobility transistors (HEMTs) have mainly been fabricated on InP based material systems because these ternary materials are lattice matched to InP substrates. However, the several practical shortcomings of InP substrates such as mechanical fragility, high substrate cost, and small wafer size motivated the development of metamorphic devices on GaAs substrates. In this dissertation, high speed metamorphic double heterojunction photodiodes were designed and fabricated on metamorphic GaAs substrates for long-wavelength optical fiber communication applications. The use of a novel double heterostructure employing an InGaAlAs optical impedance matching layer, a chirped InGaAs/InAlAs superlattice graded bandgap layer (SL-GBL), and a large bandgap I-InAlAs drift region enabled photodiodes to achieve a low dark current of 500 pA, a responsivity of 0.6 A/W, and a -3 dB bandwidth of 38 GHz at -5 V reverse bias for 1.55 mum light. The photodiode heterostructure optimized for higher bandwidth by scaling the thickness of undoped In0.53Ga0.47 As and In0.52Al0.48As layers has demonstrated over 60 GHz bandwidth at 1.55 mum wavelength. Long wavelength In0.53 Ga0.47As photodetectors and In0.52Al0.48 As/In0.53Ga0.47As high electron mobility transistors (HEMTs) were monolithically integrated on metamorphic GaAs substrates for optoelectronic receiver application. By stacking the photodiode layers on top of HEMT layers, the performance of both devices can be optimized separately. The measured performance of both devices opened the possibility of ultra-high speed monolithic optoelectronic receiver circuits operating at 1.55 mum on metamorphic GaAs substrates.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Jang, Jae-Hyung

Contributors dc:contributor

• Adesida, Ilesanmi

• Engineering, Electronics and Electrical

Language dc:language

eng

Identifier

(MiAaPQ)AAI3070336

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/80795