A model for hydrogen-induced piezoelectric effect in InP HEMTs and GaAs PHEMTs

Abstract

This thesis would not have been possible without the help of many people. First, I would like to thank Prof. Jesus del Alamo for imparting me with an ethically sound approach to research. Throughout the past six years, he provided great answers and also posed the right questions. I would also like to thank my readers, Prof. Clifton Fonstad and Prof. Rajeev Ram, for their comments and suggestions to improve this thesis. Roxann Blanchard established a solid foundation upon which I based my research. I would like to thank her for her efforts and for her invaluable help during the past six years. I learned a lot about InP HEMTs through my discussions with Tetsuya Suemitsu and I would like to thank him and Takatomo Enoki for providing the advanced InP HEMTs which added an important experimental component to this research. This thesis would not have been possible without the tremendous support of the MTL and its expert staff and amazing students. The radius-of-curvature and Auger Electron Spectroscopy measurements were very successful thanks to the expert help of Tim

Impact of ⟨110⟩ uniaxial strain on n-channel In0.15Ga0.85As high electron mobility transistors

“…where BC stands for the back channel-barrier interface, z is the distance from a point in the heterostructure to the gate contact along ͓001͔ direction, and ͑z͒ is the dielectric constant along z. 13 From Eqs. ͑1͒ and ͑2͒, it can be seen that alternating uniaxial strain from ͓110͔ to ͓110͔ directions reverses the direction of P z and consequently the sign of ⌬V T .…”

Degradation Mechanisms for GaN and GaAs High Speed Transistors

“…The most commonly reported degradation mechanisms for both GaAs and InP-based HEMTs include contact problems (such as sinking gates in which the gate metal begins to react with the underlying semiconductor), creation of surface states (which can be manifested as what is commonly called gate lag), hot carrier-induced (impact ionization at gate edge), mechanical stress (the absorption of H into Ti-based Schottky gates can lead to compressive stress due to piezo effects in the semiconductor) [ 3 ], or avalanche breakdown in the semiconductor, fluorine contamination, and corrosion (mainly related to Al oxidation) [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. Metamorphic HEMT (MHEMT) technology has been developed using metamorphic buffer layers to grow InAlAs/InGaAs on larger diameter GaAs substrates to overcome the limitations of InP substrates: smaller wafer size, higher cost, and brittle nature.…”

“…Employment of GaN HEMTs for high power radar systems will require devices to be subjected to large-signal RF while being driven into saturation, resulting in devices experiencing high electric fields and high current densities. Impressive mean-time-to-failure values of greater than 10 7 h have been reported at operating temperatures below 200 °C, with activation energies ranging from 0.18 eV to 2 eV [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. However, these studies neglect the effect of high electric field and current on device lifetime.…”

Роль пьезоэффекта в аномальной зависимости проводимости гетероструктуры AlGaAs/GaAs с двумерным электронным газом от расстояния между контактами

“…Из других эффектов в [3] наблюдалась зависимость сопротивления от направления протекания тока в кристалле, что объяснялось анизотропией диффузии металла контакта, анизотропией роста кристаллов металла и пьезоэлектрическим эффектом в полупроводнике, вызванным наличием на его поверхности металла или диэлектрика. А аналогичный нашему эффект описан в [4] [7], где источником механических напряжений служил слой фоторезиста, рассчитывался созданный пьезозарядами потенциал в канале, а в [8,9] пьезоэффект влиял на дрейф характеристик вследствие химической реакции остаточного водорода с металлизацией затвора.…”